| 1. |
- Abreha, Kibrom Berhe, et al.
(författare)
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Phosphite protects against potato and tomato late blight in tropical climates and has varying toxicity depending on the Phytophthora infestans isolate
- 2019
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Ingår i: Crop Protection. - : Elsevier BV. - 0261-2194 .- 1873-6904. ; 121, s. 139-146
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Tidskriftsartikel (refereegranskat)abstract
- Late blight caused by the oomycete Phytophthora infestans is one of the most severe diseases of potato (Solarium tuberosum L.) and tomato (Solarium lycopersicum L.). In this study, field trials were conducted in a cool tropical highland of Ethiopia for three consecutive years to investigate the efficacy of phosphite alone and in combination with conventional fungicide against late blight in two potato cultivars and one tomato cultivar. Phosphite alone and in combination with reduced dosages of the fungicide Ridomil (mancozeb 64% and metalaxyl-M 4% (w/w)) led to effective suppression of late blight in research plots and in farmers' fields under light-to-normal late blight pressure. However, phosphite was not as effective as the fungicide under high disease pressure. Notably, phosphite was more effective against tomato late blight than against potato late blight, and gave the same protection as the fungicide in tomato. In vitro assays showed small differences in sensitivity to phosphite among five European and two Ethiopian isolates of P. infestans in terms of radial growth, sporangium production and sporangium germination, which could affect the population structure. Since phosphite can be provided at a lower price than conventional fungicides, it can reduce expenses for Ethiopian farmers with preserved late blight control.
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| 2. |
- Aqueveque, Pedro, et al.
(författare)
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Antifungal activities of extracts produced by liquid fermentations of Chilean Stereum species against Botrytis cinerea (grey mould agent)
- 2016
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Ingår i: Crop Protection. - : Elsevier BV. - 0261-2194. ; 89, s. 95-100
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Tidskriftsartikel (refereegranskat)abstract
- Extracts obtained from liquid mycelial fermentations of Chilean species of the Stereum genus showed antifungal activity against Botrytis cinerea. Thirty-six strains were evaluated in vivo and in vitro assays, 25 belonging to Stereum hirsutum (Sh) and 11 to Stereum rameale (Sr). Two types of extracts were obtained: EtOAc-extract (liquid phase) and MeOH-extract (mycelial phase). Plate diffusion assay showed that EtOAc-extracts were more active than MeOH-extracts. S. hirsutum included 4 strains with the highest antifungal activity (Sh134-11, Sh144-11, Sh152-11, Sh155-11) and S. rameale highlighted with two strains (Sr25-11, Sr27-11). Effects on the mycelial growth of B. cinerea showed that EtOAc-extracts produced by S. hirsutum (Sh134-11, Sh152-11) inhibited from 1000 μg mL−1, reaching 67 and 49%, respectively. At 2000 μg mL−1, these strains inhibited nearly 80% of mycelial growth. EtOAc-extract of Sh134-11 was more effective to control the sporogenesis, inhibiting in 100% the sporulation at 500 μg mL−1. Assays showed that Sh134-11 and Sh152-11 exhibited a minimal fungicidal concentration (MFC) of 50 and 100 μg mL−1 respectively and minimal inhibitory concentration (MIC) at 20 μg mL−1. EtOAc-extracts of Sr25-11 and Sr27-11 showed MFC value at 100 μg mL−1 and MIC at 20 and 50 μg mL−1, respectively. Strawberries treated with 1000 μg mL−1of Sh134-11 and Sr25-11 reached 82 and 72% of decay inhibition, respectively. Treatments with 2000 μg mL−1 showed a decay inhibition of 90% approximately. In vivo tests are in accordance with the results obtained in vitro assays, confirming the efficacy of Sh134-11 and Sr25-11 to control B. cinerea. Differences in antifungal activities observed in the different strains suggested that the ability to produce bioactive compounds is not homogenously distributed among S. hirsutum and S. rameale. Our study would suggest that submerged fermentations of Chilean S. hirsutum strain Sh134-11 produce extracts, which could be used as possible biofungicides and an alternative to synthetic fungicides.
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| 3. |
- Baroffio, C. A., et al.
(författare)
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Combining plant volatiles and pheromones to catch two insect pests in the same trap : Examples from two berry crops
- 2018
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Ingår i: Crop Protection. - : ELSEVIER SCI LTD. - 0261-2194 .- 1873-6904. ; 109, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- Most horticultural crops are attacked by more than one insect pest. As broad-spectrum chemical control options are becoming increasingly restricted, there is a need to develop novel control methods. Semiochemical attractants are available for three important horticultural pests, strawberry blossom weevil, Anthonomus rubi Herbst (Coleoptera: Curculionidae), European tarnished plant bug, Lygus rugulipennis Poppius (Hemiptera: Miridae) and raspberry beetle, Byturus tomentostts deGeer (Coleoptera: Byturidae). Traps targeting more than one pest species would be more practical and economical for both monitoring and mass trapping than traps for single-species. In this study we aimed to (1) improve the effectiveness of existing traps for insect pests in strawberry and raspberry crops by increasing catches of each species, and (2) test if attractants for two unrelated pest species could be combined to capture both in the same trap without decreasing the total catches. Field tests were carried out in four European countries and different combinations of semiochemicals were compared. A volatile from strawberry flowers, 1,4 dimethoxybenzene (DMB), increased the attractiveness of the aggregation pheromone to both sexes of A. rubi. The host-plant volatile, phenylacetaldehyde (PAA), increased the attraction of female L. rugulipennis to the sex pheromone, and, in strawberry, there was some evidence that adding DMB increased catches further. Traps baited with the aggregation pheromone of A. rubi, DMB, the sex pheromone of L rugulipennis and PAA attracted both target species to the same trap with no significant difference in catches compared to those single-species traps. In raspberry, catches in traps baited with a combination of A. rubi aggregation pheromone, DMB and the commercially available lure for B. tomentosus, based on raspberry flower volatiles, were similar to those in single-species traps. In both crops the efficiency of the traps still needs improvement, but the multi species traps are adequate for monitoring and should not lead to confusion for the user as the target species are easy to distinguish from each other.
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| 4. |
- Cotes Ramal, Belén, et al.
(författare)
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A first approach to pest management strategies using trap crops in organic carrot fields
- 2018
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Ingår i: Crop Protection. - : Elsevier BV. - 0261-2194 .- 1873-6904. ; 112, s. 141-148
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Tidskriftsartikel (refereegranskat)abstract
- Cultural control methods in integrated pest management (IPM) refer to practices that modify the agricultural environment in ways that favour crop protection to the detriment of pest performance. Trap cropping is one of these practices and involves luring insect pests away from the main crop to a more attractive host plant growing beside or around the crop. The trap crop can then be destroyed, and the pest killed. The carrot psyllid, Trioza apicalis Forster (Homoptera: Triozidae), is one of the most important carrot pests in Scandinavia, and cultural control of this pest could be achieved through the introduction of more attractive cultivars of carrots in the trap crop at different sowing times than used for the main crop. In a multichoice bioassay and a field experiment, T. apicalis females oviposited the highest numbers of eggs on the most developed carrot plants in the trap crop, while different carrot cultivars did not play any role in females' choice, In the field experiment, probability of damage was highly correlated with number of eggs counted on the plants, which was highest on the most developed plants. The cultivar Bolero was used as trap crop in subsequent trials in three commercial carrot fields in different regions of Sweden. The trap crop concentrated the egg laying to the field edges and it decreased with increasing distance within the main crop from the first row of carrots, while this pattern could not be observed in control plots. These first results are promising, but further trials to better quantify efficacy and to evaluate the spatial design of the trap crop in field, at different sites and population pressure, are needed before trap cropping can be a reliable strategy for carrot psyllid control.
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| 5. |
- Cuc, Nguyen Thi Thu, et al.
(författare)
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Hot water treatment prevents Aphelenchoides besseyi damage to Polianthes tuberosa crops in the Mekong Delta of Vietnam
- 2010
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Ingår i: Crop Protection. - 0261-2194. ; 29:6, s. 599-602
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Tidskriftsartikel (refereegranskat)abstract
- Polianthes tuberosa is a commercially valuable flower crop in the Mekong Delta of Vietnam that is propagated by the harvesting and planting of bulbs. The cultivation of P. tuberosa is infected by an endemic Aphelenchoides besseyi nematode that damages a high proportion of plants and persists within the bulbs. Here we report on the comparison of hot water and pesticide treatments as control methods to protect P. tuberosa from A. besseyi damage, and conclude that a hot water treatment consisting of soaking bulbs in water for 30 minutes at 57 °C is the most efficacious method to produce healthy flowers in a cost-effective manner.
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| 6. |
- Djurle, Annika
(författare)
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An outlook on wheat health in Europe from a network of field experiments
- 2021
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Ingår i: Crop Protection. - : Elsevier BV. - 0261-2194 .- 1873-6904. ; 139
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Tidskriftsartikel (refereegranskat)abstract
- Wheat disease management in Europe is mainly based on the use of fungicides and the cultivation of resistant cultivars. Improving disease management implies the formal comparison of disease management methods in terms of both crop health and yield levels (attainable yield, actual yield), thus enabling an assessment of yield losses and yield gains. Such an assessment is not available for wheat in Europe. The objective of the analysis reported here is to provide an overview of wheat health and yield performance in field experiments in Europe. Data from field experiments in six European countries (Belgium, France, Germany, Italy, Norway, and Sweden) conducted between 2013 and 2017 were analysed to that aim. Relationships between multiple disease levels, yield, level of cultivar resistance, level of fungicide protection, and weather patterns were assessed. The analyses included 73 field experiments, corresponding to a total of 447 [fungicide protection level x cultivar] combinations. Analyses across the six countries led to ranking the importance of foliar wheat diseases as follows, in decreasing order: leaf blotch (septoria tritici blotch, septoria nodorum blotch, and tan spot), leaf rust, yellow rust, and powdery mildew. Fusarium head blight was observed in France and Italy, and stem rust was sporadically observed in Italy. Disease patterns, crop inputs (fertiliser, fungicides), and yields widely varied within and across countries. Disease levels were affected by the level of fungicide use, by cultivar resistance, as well as by weather patterns. While this analysis enables a better documentation of the status of wheat health in Europe, it also highlights the critical need for policies in Europe enabling a more judicious use of pesticides. First, common standards for field experiments are needed (experimental designs and protocols; disease assessment procedures and scales; references, including reference-susceptible cultivars); second, assessments in farmers' fields - and not in research stations - are necessary; and third, there is a need to use available process-based crop models to estimate attainable yields, and so, yield losses.
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| 7. |
- Edin, Eva
(författare)
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Species specific primers for identification of Alternaria solani, in combination with analysis of the F129L substitution associates with loss of sensitivity toward strobilurins
- 2012
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Ingår i: Crop Protection. - : Elsevier BV. - 0261-2194 .- 1873-6904. ; 38, s. 72-73
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Tidskriftsartikel (refereegranskat)abstract
- A species specific forward primer was designed in order to identify the phytopathogenic fungus Alternaria solani, which causes early blight on potato. The reverse primer came from another survey of the American population of A. solani. The combination of these two primers can be used both as molecular identification of A. solani as well as sending the PCR product for sequencing in search for the F129L substitution associated with loss of sensitivity toward fungicides based on strobilurins. The diagnostic method has been successfully used when identifying the causal agent of lesions on potato leaflets during large field assays. (C) 2012 Elsevier Ltd. All rights reserved.
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| 8. |
- Ekbom, Barbara
(författare)
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Flea beetle (Phyllotreta undulata Kutschera) sensitivity to insecticides used in seed dressings and foliar sprays
- 2011
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Ingår i: Crop Protection. - : Elsevier BV. - 0261-2194 .- 1873-6904. ; 30, s. 1376-1379
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Tidskriftsartikel (refereegranskat)abstract
- Flea beetles of the genus Phyllotreta (Coleoptera: Chrysomelidae), which are severe pests in spring oilseed rape, have become increasingly difficult to control in some areas in Sweden. The current practice for plant protection is to use seed treatments followed by foliar applications of insecticide. Seed treatment with the single, currently registered neonicotinoid insecticide (active ingredient: imidacloprid) was compared to untreated controls and seed treatment with clothianidin using Phyllotreta undulata Kutschera beetles from 10 locations. Beetles from the overwintered generation and the new generation from the same 10 locations were used in bioassays to detect possible reduced sensitivity to the pyrethroid lambda-cyhalothrin. Seed treatment with clothianidin provided better protection for seedlings than imidacloprid. Highly variable results were obtained from the pyrethroid bioassays, but tests performed on beetles collected in August indicated that most sampled beetle populations are still susceptible to lambda-cyhalothrin. It is, however, important that the need for foliar applications is minimized to avoid insecticide resistance selection pressure. This requires seed treatments with adequate efficacy against flea beetles together with cultural control measures that can reduce flea beetle damage. (C) 2011 Elsevier Ltd. All rights reserved.
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| 9. |
- Fountain, M. T., et al.
(författare)
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Design and deployment of semiochemical traps for capturing Anthonomus rubi Herbst (Coleoptera : Curculionidae) and Lygus rugulipennis Poppius (Hetereoptera: Miridae) in soft fruit crops
- 2017
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Ingår i: Crop Protection. - : Elsevier. - 0261-2194 .- 1873-6904. ; 99, s. 1-9
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Tidskriftsartikel (refereegranskat)abstract
- Strawberry blossom weevil (SBW), Anthonomus rubi Herbst (Coleoptera: Curculionidae) and European tarnished plant bug (ETB), Lygus rugulipennis Poppius (Hetereoptera: Miridae), cause significant damage to strawberry and raspberry crops. Using the SBW aggregation pheromone and ETB sex pheromone we optimized and tested a single trap for both species. A series of field experiments in crops and semi-natural habitats in five European countries tested capture of the target pests and the ability to avoid captures of beneficial arthropods. A Unitrap containing a trapping agent of water and detergent and with a cross vane was more efficient at capturing both species compared to traps which incorporated glue as a trapping agent. Adding a green cross vane deterred attraction of non-pest species such as bees, but did not compromise catches of the target pests. The trap caught higher numbers of ETB and SBW if deployed at ground level and although a cross vane was not important for catches of ETB it was needed for significant captures of SBW. The potential for mass trapping SBW and ETB simultaneously in soft fruit crops is discussed including potential improvements to make this more effective and economic to deploy.
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| 10. |
- Hagnell, J, et al.
(författare)
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How to trap a slug: Commercial versus homemade slug traps
- 2006
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Ingår i: Crop Protection. - : Elsevier BV. - 1873-6904 .- 0261-2194. ; 25:3, s. 212-215
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Tidskriftsartikel (refereegranskat)abstract
- The Iberian Slug, Arion lusitanicus Mabille (Stylomatophora: Arionidae), has developed into a destructive pest in Swedish gardens and orchards over the past 10-20 years. Many attempts to eradicate this pest have been made using a variety of different methods. The aim of this study was to investigate the effectiveness of two different types of homemade traps made from simple, inexpensive materials (plastic PET bottle or an ice-cream box) compared to one type of commercially sold trap (Slugtrap((R)) IT-PAC A B, Sweden) used with bait and beer as attractants. Experiments were carried out on a private property outside Lund, Sweden, over a period of 7 days. The results showed that a homemade trap, i.e. a box trap, can be as efficient as a commercial trap, particularly due to their similar design. In contrast, the homemade bottle trap was not very successful. Additionally, it was discovered that the bait used in the commercial traps did not increase the number of slugs trapped. It was concluded that the beer was the main slug attractant. Ultimately this study suggests a low-cost alternative for small scale to the rather expensive commercially sold traps.
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| 11. |
- Hultberg, Malin, et al.
(författare)
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Strategies for administration of biosurfactant-producing pseudomonads for biocontrol in closed hydroponic systems
- 2011
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Ingår i: Crop Protection. - : Elsevier BV. - 0261-2194 .- 1873-6904. ; 30, s. 995-999
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Tidskriftsartikel (refereegranskat)abstract
- Zoospore-producing oomycetes are major plant pathogens of particular concern in hydroponic systems. Compared with pesticides, biocontrol using antagonistic microorganisms is a sustainable approach to control oomycetes. Previous research has demonstrated that biosurfactants and biosurfactant-producing microorganisms are potentially useful components of a sustainable biocontrol strategy.In this study three ways of supplying a biosurfactant-producing strain to a recirculating hydroponic cultivation system infected with a zoospore-producing plant pathogen were evaluated. The strain Pseudomonas koreensis 2.74 was added as washed cells, in its spent KB broth or in a minimal medium adapted from the nutrient solution, and compared with control treatments. A significant reduction in disease with up to 50% was achieved when a high concentration of washed cells was added weekly to the plant cultivation system. The disease suppression obtained through addition of washed cells equalled the effect achieved when the purified biosurfactant was used. Phytotoxicity was observed when the spent broth was included in the treatment. (C) 2011 Elsevier Ltd. All rights reserved.
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| 12. |
- Hysing, Shu-Chin, et al.
(författare)
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Agronomic and economic effects of host resistance vs. fungicide control of barley powdery mildew in southern Sweden
- 2012
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Ingår i: Crop Protection. - : Elsevier BV. - 0261-2194 .- 1873-6904. ; 41, s. 122-127
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Tidskriftsartikel (refereegranskat)abstract
- Agronomic and economic effects of powdery mildew host resistance and a fungicide treatment were investigated in nine ‘Pallas' near-isogenic barley lines. Four years of field trials and virulence surveys detected virulence against all fourteen mildew resistance genes present in the lines. In the field trials, with the exception of gene Mlra, the resistance genes were found to significantly reduce disease severity by 38e99%. The gene mlo5 had a significant negative effect on agronomic characters, while the other resistance genes were neutral. Fungicide treatment reduced powdery mildew by 50e97% and increased grain yield 11e17%, thousand grain weight 6e10%, grain volume weight 2e3% and water content 8e13%, while there was no significant effect on straw strength. From an agronomic perspective, the benefit of the fungicide treatment was greater than that of the selected host resistance. Profitability was directly related to the grain price and cost of fungicide. Net return was negative when using fungicides in years with the lowest grain price, while a higher grain price resulted in a positive net return. It thus seems unprofitable to use fungicides in years with low grain prices, especially when cultivars with effective host resistance are available.
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| 13. |
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| 14. |
- Larsson Herrera, Sebastian, et al.
(författare)
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Assessing allelochemicals as species-specific attractants for the cherry bark tortrix, Enarmonia formosana (Lepidoptera: Tortricidae)
- 2020
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Ingår i: Crop Protection. - : Elsevier BV. - 0261-2194 .- 1873-6904. ; 138
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Tidskriftsartikel (refereegranskat)abstract
- Field trapping experiments were carried out in Norway to measure attraction of the cherry bark tortrix (CBT) Enarmonia formosana to volatile blends of candidate compounds including acetic acid (AA), linalool oxide pyranoid (LOXP), 2-phenylethanol (PET), pear ester (E,Z)2,4-ethyl decadienoate (PE) and (E)-beta-farnesene (BF). The binary blend of AA and LOXP caught the highest number of CBT adults. While addition of PET along with PE did not significantly change the attraction, a sex-dependent decrease of female captures was found when LOXP was replaced by PET/PE. Male attraction to AA/LOXP did not differ when PET/PE were added to the blend or when LOXP was substituted by the same two compounds. A similar attraction to blank traps was recorded for the ternary blend of LOXP/PET/PE, for the binary blend of PET/PE and for LOXP alone, supporting AA as a possible fundamental component of CBT kaimmone. In addition, a lower number of bycatches of Hedya nubiferana, Anthophila fabriciana, Synanthedon myopaeformis, Pammene spp. and Pandemis spp. were scored in the AA/LOXP than in any blend including AA/PET/PE. BF was not behaviourally active on CBT in our field experiments. The high attraction of both sexes of CBT to the binary blend of AA/LOXP represents a first step towards the identification of a multicomponent kairomone for this pest. A continuous flight activity of both sexes of CBT was recorded from the end of May until the beginning of August, supporting the hypothesis that CBT is univoltine in Norway. Because larval infestation on tree trunks varies substantially with apple varieties, we encourage the collection of additional data to attempt a correlation between adult catch by AA/LOXP traps and the following larval population.
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| 15. |
- Larsson Herrera, Sebastian, et al.
(författare)
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Monitoring and discrimination of Pandemis moths in apple orchards using semiochemicals, wing pattern morphology and DNA barcoding
- 2020
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Ingår i: Crop Protection. - : Elsevier BV. - 0261-2194 .- 1873-6904. ; 132
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Tidskriftsartikel (refereegranskat)abstract
- Non-phemmonal insect attractants of plant and microbial origin are often classified as kairomones. They differ from moth pheromones in that they can attract both sexes of several insect species. Kairomones are nowadays the object of several studies, due to their promising properties for monitoring and selective control of agricultural pests. Here we report on field trapping experiments carried out in apple orchards to quantify the response of the two leafroller species Pandemis heparana (Denis & Schiffermuller) and Pandemis cerasana (Hubner) to potential kairomones (acetic acid (AA), 2-phenyl ethanol (2-PET), pear ester (PE) and benzyl cyanide (BC)) in apple orchards. Specimens of the two species were sexed and classified to the species level using a morphological key based on wing traits. DNA barcoding was used to validate the discrimination between the two species through the morphological key. A two-component blend of AA and 2-PET was effective in catching significant numbers of females of P. heparana and P. cerasana. The addition of PE increased male but not female catches of only P. heparana. For P. heparana blends containing AA and BC with or without PE caught significantly fewer males and females than blends with PET and the AA/BC combination was as effective as PET releasing blends in trapping P. cerasana females. Morphological identification of Pandemis by wing pattern was in agreement with the DNA barcoding in the majority of cases. Additional studies are now required to establish an economic threshold to correlate moth catches with fruit damage and to the possibility that attract and kill based on the identified kairomones can be used to reduce damage.
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| 16. |
- Liljeroth, Erland, et al.
(författare)
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Potassium phosphite combined with reduced doses of fungicides provides efficient protection against potato late blight in large-scale field trials
- 2016
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Ingår i: Crop Protection. - : Elsevier BV. - 0261-2194 .- 1873-6904. ; 86, s. 42-55
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Tidskriftsartikel (refereegranskat)abstract
- Potato late blight caused by the oomycete Phytophthora infestans is a devastating disease of potato worldwide. Most of the potato cultivars grown in conventional agriculture are susceptible, or at best moderately resistant, and require frequent applications of fungicides to avoid heavy yield losses.In field trials spanning four years, we have investigated the effect of potassium phosphite, an inorganic salt on potato late blight. Potassium phosphite is known to induce defence responses in potato and to also have direct toxic effects on oomycetes, which in turn counteract late blight and tuber blight development. However, the use of this salt is not yet implemented and approved in European potato cultivation. We compared the effect of phosphite alone with fungicides currently used in Swedish potato cultivation. We also investigated the combined use of potassium phosphite and reduced doses of fungicides. Table potato cultivars and starch potato cultivars with different levels of resistance were used.We found that potassium phosphite in combination with reduced doses of fungicides results in the same level of protection as treatments with the recommended full dose of fungicides. These combined treatments reduce the need of traditional fungicides and may also decrease the selection pressure for fungicide resistance development in the pathogen. In relatively resistant starch potato cultivars using phosphite alone gave sufficient protection against late blight. Furthermore, in starch potato a combination of phosphite and fungicides at two-week intervals provided similar protection to weekly applications of fungicide at the recommended dose. Foliar treatment with phosphite also gave protection against tuber blight at similar levels to that of the best-performing fungicide. Our data suggests that potassium phosphite could be used in potato cultivation in temperate regions such as in Sweden, at least in combinations with reduced rates of fungicides. The implementation of the use of phosphite in practical potato crop protection as part of an IPM strategy is discussed. Doses, intervals and combinations could be adjusted to the level of cultivar resistance. (C) 2016 The Authors. Published by Elsevier Ltd.
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| 17. |
- Lundin, Ola, et al.
(författare)
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Pest management and yield in spring oilseed rape without neonicotinoid seed treatments
- 2020
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Ingår i: Crop Protection. - : Elsevier BV. - 0261-2194 .- 1873-6904. ; 137
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Tidskriftsartikel (refereegranskat)abstract
- Use of neonicotinoid insecticides as seed treatments has been prohibited in the EU. As a consequence, concerns of lost production have been raised among producers. It remains, however, unclear to what extent the ban has increased pest attacks and crop damage, and reduced yield and farm profit. It is also unclear to what extent alternative, non-chemical options can protect crops. Flea beetles (Chrysomelidae: Alticini) are the main pests targeted by insecticide seed treatments in spring oilseed rape (Brassica napus L.). Over three years, we conducted 23 field experiments in which we compared seeds treated with neonicotinoids with untreated seeds, grown at normal or doubled sowing rates. The experiments were established during a range of sowing times at the same time as the hosting farmer sowed, which also allowed us to assess the impact of sowing date. We measured flea beetle activity density, crop plant density, cotyledon damage, crop yield and relative economic performance. Flea beetle activity density was eight times higher in 2014 than in 2016, with intermediate activity in 2015. Neonicotinoid seed treatment, increased sowing rate and an earlier sowing date all reduced crop damage. Seed treatment decreased crop yield loss by 521 kg ha(-1) and relative profit loss by 144 Euro ha(-1) in 2014, but had no effect on yield or profit in 2015-2016. Increased sowing rate did not affect yield, but decreased profit in 2015 (-138 Eum ha(-1)) and 2016 (-114 Euro ha(-1)), mainly due to higher costs for seed. Earlier sowing date was consistently associated with higher yield and profit. Our results put prophylactic seed treatments in question, as they gave lower yield losses in only one year out of three. Earlier sowing and somewhat higher sowing rate emerge as viable alternative pest management practices. Because management outcomes depended on pest pressure, which varied from year to year, crop damage prognosis tools are needed based on improved understanding of the population ecology of crop pests, to support the growers' decisions and avoid unnecessary use of insecticides.
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| 18. |
- Lundin, Ola, et al.
(författare)
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The effects of reduced tillage and earlier seeding on flea beetle (Phyllotreta spp.) crop damage in spring oilseed rape (Brassica napus L.)
- 2018
-
Ingår i: Crop Protection. - : Elsevier BV. - 0261-2194 .- 1873-6904. ; 107, s. 104-107
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Tidskriftsartikel (refereegranskat)abstract
- The restriction on seed treatments containing neonicotinoid insecticides in the European Union has brought crop protection into focus for oilseed rape (Brassica napus L.). In spring sown oilseed rape, neonicotinoid seed treatments have mainly been used for protection against flea beetles (Phyllotreta spp.), and there is now a need to evaluate alternative control methods. We investigated the effect of reduced tillage and altered seeding date on flea beetle crop damage in spring oilseed rape in eight field experiments over three years in south central Sweden. The average proportion of cotyledon area damaged by flea beetles was not affected by the tillage treatment. Proportion of crop damage was, however, lower in early seeded compared to late seeded plots (0.21 compared to 0.28). We conclude that earlier seeding holds promise to be incorporated into an integrated pest management program for flea beetles in spring oilseed rape, whereas further research on reduced or zero tillage strategies for flea beetle control is warranted.
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| 19. |
- Mahbuba Kaniz, Hasna, et al.
(författare)
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Management of corky root disease of tomato in participation with organic tomato growers
- 2009
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Ingår i: Crop Protection. - : Elsevier BV. - 0261-2194 .- 1873-6904. ; 28, s. 155-161
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Tidskriftsartikel (refereegranskat)abstract
- Corky root disease of tomato, caused by the soil-borne fungus Pyrenochaeta lycopersici, is a common and serious problem for organic tomato production. This paper addresses the possibility of developing a management strategy for corky root disease in participation with organic tomato growers in Sweden. The participatory research group consisted of nine organic tomato growers from central Sweden, two extension workers and two researchers. Regular meetings were held so that growers, extension workers and researchers could exchange knowledge on corky root disease management. A number of research issues were identified during group discussions: use of mulch, break crop, grafted tomato plants, composts, composted Pyrenochaeta-infested soil, fungivorous nematodes and commercially available bio-control agents based on Trichoderma, Streptomyces and Gliocladium in corky root disease control. The issues were investigated in on-farm experiments and experiments at a research station. The outcomes of the research work were presented in the group in subsequent meetings and assessed in joint discussions. The results from the study showed that a compost with low NH(4)-N concentration and high Ca concentration reduced corky root disease severity in greenhouse experiments at the research station. However, although the potential of other measures such as use of fungivorous nematodes and commercially available bio-control agents was demonstrated, these measures need further improvement to be adopted in commercial growing conditions. (c) 2008 Elsevier Ltd. All rights reserved.
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| 20. |
- Malacrino, Antonino, et al.
(författare)
-
Integrated pest management for yard-long bean (Vigna unguiculata subsp. Sesquipedalis) in Cambodia
- 2020
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Ingår i: Crop Protection. - : ELSEVIER SCI LTD. - 0261-2194 .- 1873-6904. ; 135
-
Tidskriftsartikel (refereegranskat)abstract
- Pesticides are widely used to protect crops against insect pests and diseases. However, current conventional pest management strategies can severely impact environmental and human health. Therefore, it is timely to find an alternative to conventional chemical control in order to counteract the negative effects of pesticides. Integrated Pest Management (IPM) represents a promising alternative in vegetable production to reduce pesticide use while also maintaining acceptable yields. In this study, we compared an IPM strategy with conventional management and a no-spray control for managing arthropod pests and pathogens in yard-long bean (Vigna unguiculata subsp. Sesquipedalis), an important crop in Southeast Asia. We conducted the study during two crop cycles (rainy and dry season) on 24 farms (12 per season) spread across the Soutr Nikum district of Siem Reap, Cambodia. In both seasons, our IPM strategy controlled overall pest levels better than conventional pest management, which exhibited better pest control than the no-spray control. This pattern was not reflected by yields, however, since dry season yields were similar across all three treatments (conventional = 1.68, IPM = 1.73, control = 1.52 kg m(-2)), and rainy season yields were similar between conventional and IPM treatments, which were higher than yields in the no-spray control treatment (conventional = 1.74, IPM = 1.71, no-spray control = 1.33 kg m(-2)). The costs of IPM were higher than conventional management, which contributed to lower profits in the IPM treatments in both seasons despite yields being as high as in conventional production. Therefore, future efforts should focus on increasing the profitability of IPM production.
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| 21. |
- Meheretu, Yonas
(författare)
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From problem to progress: Rodent management in agricultural settings of sub-Saharan Africa and calling for an urban perspective
- 2024
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Ingår i: Crop Protection. - 0261-2194 .- 1873-6904. ; 181
-
Tidskriftsartikel (refereegranskat)abstract
- In sub-Saharan Africa, agricultural intensification and urbanization have increased the risk of proliferation of rodents in rural and urban habitats. Management of rodent populations is a challenge in terms of food security and public health. However, conventional efforts to manage rodents are currently reactive and based on the inadequate use of synthetic chemical rodenticides, including first- and second-generation anticoagulants and acute rodenticides. This approach carries substantial environmental and health risks and has yielded limited success in terms of reduction of rodent populations sustainably. In this paper, which is the second part of a diptych, we advocate for a shift towards more sustainable and environmentally friendly approaches, such as Ecologically-Based Rodent Management (EBRM), as a realistic alternative to synthetic rodenticides. This method is based on a good knowledge of habitat use, species diversity and population dynamics of major rodent pests, and involves community-based interventions aimed at reducing rodent abundance to economically and hygienically acceptable levels in the long term. We present for the first time a comprehensive compilation of published and unpublished information derived from observational field studies conducted in Ethiopia, Niger, Nigeria, Benin, Mali, Mauritania and Senegal with the aim to provide an overview of EBRM case studies in these countries of sub-Saharan Africa. This paper intends to serve as a catalyst for change, encouraging the transformation of rodent management practices towards sustainable methods. We aim at stimulating further research and interventions that promote EBRM in Africa, ultimately fostering more environmentally conscious and effective solutions.
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| 22. |
- Mendesil, Esayas, et al.
(författare)
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Smallholder farmers' knowledge, perceptions and management of pea weevil in north and north-western Ethiopia
- 2016
-
Ingår i: Crop Protection. - : Elsevier BV. - 0261-2194 .- 1873-6904. ; 81, s. 30-37
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Tidskriftsartikel (refereegranskat)abstract
- Pea weevil (Bruchus pisorum L.) is one of the most serious insect pests of field pea (Pisum sativum L) in Ethiopia. A survey of 400 farmers was conducted in four main pea-growing districts in north and northwestern Ethiopia. The objectives were to assess farmers' knowledge and perceptions of pea weevil, to examine their current pest management practices and to identify challenges to pea weevil control, so that participatory integrated pest management for smallholder farmers in Ethiopia can be developed. The results revealed that most (71%) of the farmers surveyed had knowledge about pea weevil and were able to identify damaged seeds based on common visible symptoms of weevil infestation. However, most farmers did not know that pea weevil attacks plants in the field, but rather considered it a storage pest. The results also showed that farmers' cultural practices influence the incidence and spread of pea weevil and that most farmers did not check seed for pea weevil symptoms before planting. Only a minority of farmers (19%) harvested peas early and some harvested late, unintentionally promoting infestation and carryover of weevils. In addition, most farmers (74%) were not aware of the source and means of weevil spread on their farm and some did not clean up fallen and shattered peas during harvesting and threshing. The majority (63%) of the farmers surveyed relied on chemical insecticides, namely actellic dust and phostoxin, to treat harvested peas in storage. However, the results revealed a knowledge gap in that farmers were well aware of the problem of pea weevil, but lacked knowledge of cultural practices affecting pea weevil and of problems in the use of pesticides. This highlights the need for farmer training and for development of participatory integrated pest management methods for pea weevil. (C) 2015 Elsevier Ltd. All rights reserved.
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| 23. |
- Månsson, Johan
(författare)
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Lethal scaring - Behavioral and short-term numerical response of greylag goose Anser anser
- 2017
-
Ingår i: Crop Protection. - : Elsevier BV. - 0261-2194 .- 1873-6904. ; 96, s. 258-264
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Tidskriftsartikel (refereegranskat)abstract
- Lethal scaring is one method used to alleviate crop damage by grazing geese. During lethal scaring, a few geese foraging on growing crops are shot to achieve a deterrent effect on other flock members. An additional aim is to reinforce the effects of non-lethal scaring measures. As the populations of geese increase in large parts of the world, an increased need for tools within the multifaceted area of goose management has been highlighted. Lethal scaring can potentially be one method, but currently little evidence exists about the effectiveness of the method.In this study, I tested whether grazing greylag geese Anser anser show short-term numeric and behavioral responses due to lethal scaring in targeted fields, using a Before-After-Control-Impact (BACI) study design. The study includes 26 fields with lethal scaring and 43 controls (geese were left undisturbed), where the number of birds was counted and the distance between an approaching person and the geese when all individuals have raised their heads and when they escaped were measured - before and after lethal scaring was performed.On average, 33 geese were shot per trial, which corresponds to 8.9% of the counted geese on the lethal scaring fields before the shooting occurred. The number of geese significantly decreased in the lethal scaring fields after the shooting (63% less) but were also reduced in numbers on the control fields (17% less). This result may be due to the same goose individuals using both control and lethal scaring fields, and when affected at scaring fields they choose another area or habitat for foraging; for example, in wetlands. However, the difference in the number of geese on control fields, both before and after lethal scaring, did not relate to the distance to lethal scaring fields. Moreover, birds did not seem to become more afraid of an approaching person (i.e., a non-lethal scaring tool) after the lethal scaring had been conducted (flight distance before 134 m (+/- 15.3 S.E.) and after 149 m (+/- 14.1 S.E.) in lethal scaring fields).In conclusion, this study shows that lethal scaring can substantially decrease the number of greylag geese in damage prone fields for at least three consecutive days, hence this method may also work as a tool to reduce crop losses. Practical experience from tools for alleviating crop damage is available from both Europe and North America, but very little has been published. It is therefore important to evaluate the effectiveness of the available tools under controlled conditions to increase our understanding of appropriate preventive tools and provide guidelines for stakeholders involved in the multifaceted area of goose management and crop protection. (C) 2017 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
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| 24. |
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| 25. |
- Ringselle, Björn, et al.
(författare)
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Vertical rhizome disking to reduce Elymus repens (quackgrass) abundance in grass-clover leys
- 2023
-
Ingår i: Crop Protection. - 0261-2194 .- 1873-6904. ; 172
-
Tidskriftsartikel (refereegranskat)abstract
- Elymus repens is a problematic perennial weed in annual crops, grasslands and leys. Rhizome fragmentation by vertical disking can potentially reduce E. repens abundance with minimal tillage, but data are lacking on its efficiency in forage production. In a two-year study (2017–2018, 2018–2019) conducted in two forage grass-clover leys that were mostly weed-free except for large E. repens populations, this study examined effects on forage yield, botanical composition, and E. repens rhizome biomass of rhizome fragmentation at significant growth initiation in spring (early rhizome fragmentation, ERF) and/or when conditions allowed after the first forage cut (late rhizome fragmentation, LRF). Cold, wet springs and hard, dry soil in summer delayed treatment in both treatment years, to late spring (ERF) and late summer/early autumn (LRF). In the treatment year, ERF reduced first-cut forage yield by 44% compared with no rhizome fragmentation, while LRF decreased second- and third-cut yield by 24% and 53%, respectively. In the year after treatment, ERF increased total forage yield by on average 10%, while LRF had no effect. Over both years, combined forage yield was reduced by 11% by ERF and 4% by LRF. Both treatments reduced E. repens rhizome biomass, but inconsistently (ERF by 25% in one year only, LRF by 24% at one of two sites). ERF reduced E. repens incidence in forage by 10% in the treatment year, but had no effect in the following year. Thus, rhizome fragmentation by vertical disking can reduce E. repens abundance in grass-clover leys, but the effect is inconsistent and forage yield can be impaired, especially in swards with much E. repens. Moreover, disking is hampered by hard, dry soil conditions.
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| 26. |
- Robai, Christine I., et al.
(författare)
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Reducing the number of grazing geese on agricultural fields : Effectiveness of different scaring techniques
- 2023
-
Ingår i: Crop Protection. - : Elsevier BV. - 0261-2194 .- 1873-6904. ; 177, s. 7
-
Tidskriftsartikel (refereegranskat)abstract
- Scaring is a widely used damage mitigation tool to make agricultural fields less attractive to wildlife and by that reduce crop damage. However, few experimental studies exist where the numerical response of different scaring devices has been compared. We tested experimentally the effect of three different scaring devices (kite, scarecrow, inflatable man) on the number of geese in fields with cereals, ley, rapeseed, potatoes, and carrots in Sweden. Geese were counted by camera traps and two approaches were used; in a first (model 1) only geese within 50–150m of the scaring devices were counted, and in a second (model 2) all geese in the field were included. A total of 42,281 geese were counted: Greylag goose Anser anser was the most common species (87%), followed by bean goose Anser fabalis (6%), greater white-fronted goose Anser albifrons (3%), barnacle goose Branta leucopsis (2%), and Canada goose Branta canadensis (2%). During scaring the number of geese significantly decreased for all three devices in model 2. The inflatable man decreased goose numbers by 90.0 %, scarecrow 64.6%, and kite 60.5%. A similar pattern was found in model 1, but the decrease was not significant. Our study shows that the scaring devices studied can reduce goose grazing pressure for some time and locally. However, since geese continue to graze during scaring, we conclude that scaring alone is not a final solution to mitigate crop damage. Future work to develop more effective control measures should address the efficiency of other management tools and scaring techniques in combination.
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| 27. |
- Rodriguez-Saona, C.R., et al.
(författare)
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Color preference, seasonality, spatial distribution and species composition of thrips (Thysanoptera: Thripidae) in northern highbush blueberries
- 2010
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Ingår i: Crop Protection. - : Elsevier BV. - 0261-2194. ; 29:11, s. 1331-1340
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Tidskriftsartikel (refereegranskat)abstract
- We investigated color preference, seasonal abundance, spatial distribution and species composition of thrips in northern highbush blueberries, Vaccinium corymbosum L, in New jersey (USA). White sticky traps were more attractive to thrips compared with yellow or blue traps. Thrips captures using white sticky traps showed that their flight activity begins 20-30 d after the onset of flowering, with 10, 50 and 90% of trap captures observed at 383, 647 and 1231 degree-day accumulations, respectively (10 degrees C base temperature). Two methods were used to study thrips distribution within a blueberry bush. First, white sticky traps were placed within the bush canopy at three different heights. The highest numbers of thrips were caught on traps in the middle and top one-third of the canopy while the lowest numbers were caught in the bottom one-third. A second method determined the distribution of thrips on the blueberry plant at different heights and phenological stages. The highest numbers of thrips were found on young leaves at lower parts of the canopy, whereas flowers and fruit had fewer thrips and none were found on buds; these thrips were identified as, Scirtothrips ruthveni (88% of adults) and Frankliniella tritici (12%). The distribution of thrips within a blueberry planting was investigated using an evenly-spaced grid of white sticky traps in combination with on bush beating-tray samples. Thrips counts from traps correlated with direct counts on the bush across the entire blueberry field (macro-scale level); however, within the field (micro-scale level), there was no correlation between the number of thrips on traps and on individual bushes near traps. Early in the season, trap counts were higher on bushes closer to the forest, indicative of movement of thrips from wild hosts into blueberry fields. However, this was not the case for direct on bush counts or trap counts for the later part of the season, where there was no clear forest "edge" effect. Percent fruit injury due to thrips feeding was low, and it correlated with thrips counts on bushes but not from counts on traps. Overall, our data show that thrips counts on sticky traps need to be interpreted with care because these numbers weakly correlated with the numbers of thrips on bushes at the micro-scale level and percent fruit injury; however, they can be useful predictors of thrips activity across entire blueberry fields (macro-scale).
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| 28. |
- Sylla, Justine, et al.
(författare)
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In vitro compatibility of microbial agents for simultaneous application to control strawberry powdery mildew (Podosphaera aphanis)
- 2013
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Ingår i: Crop Protection. - : Elsevier BV. - 0261-2194 .- 1873-6904. ; 51, s. 40-47
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Tidskriftsartikel (refereegranskat)abstract
- Biological control of plant pathogens on strawberries may be improved by the simultaneous application of different biological control agents (BCAs). Therefore, the compatibility of various BCAs which had previously shown to be effective against powdery mildew (Podosphaera aphanis (Wallr.) U. Braun & S. Takam) under laboratory conditions was examined in vitro. Inhibitory effects between fungal and bacterial BCAs were demonstrated in dual culture tests on two solid nutrient media. Leaf disc assays with single and multiple strain treatments demonstrated either unaffected or significantly improved control of P. aphanis for many multiple strain treatments, even if antagonistic interactions previously occurred in dual culture tests. Highest inhibition of powdery mildew conidiation (80.7% reduction) was achieved with multiple strain treatments with Bacillus subtilis FZB24 and Metarhizium anisopliae (p < 0.001). In this combination, conidiation was 3.7 times lower than in single treatments with B. subtilis indicating synergistic interactions between these BCAs. Combinations of Trichoderma harzianum T58 and B. subtilis FZB24 showed antagonistic interactions in dual culture tests as well as in leaf disc assays. In this combination, powdery mildew conidiation on leaf discs was four times higher compared to single treatments with T. harzianum T58.
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| 29. |
- Taab, Alireza, et al.
(författare)
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Ecological intensification using Persian clover to support weed management in winter wheat under semiarid conditions
- 2023
-
Ingår i: Crop Protection. - : Elsevier BV. - 0261-2194 .- 1873-6904. ; 164
-
Tidskriftsartikel (refereegranskat)abstract
- There is a need for non-chemical weed control due to evolution of herbicide resistance in weeds and environ-mental issues that arise due to prolonged use of herbicides. In three field experiments conducted during 2016-2018 in the Nahavand region of Iran, the effects of under-sown Persian clover on weed suppression and yield of winter wheat were evaluated. Persian clover was under-sown in wheat at four seed rates (12.5, 25.0, 37.5 and 50.0 kg ha -1, called InW-C1, InW-C2, InW-C3 and InW-C4, respectively). Pure wheat in weedy and weed -free conditions were included as control treatments (Wh-We and PW, respectively). Persian clover biomass increased from 59 to 184 g m- 2 from the lowest to the highest seed rate and the weed biomass decreased from 272 g m- 2 with no Persian clover (Wh.We) to 20 g m- 2 (InW-C4) with the highest seed rate. As expected, grain yield was highest (4604 kg ha -1) for wheat grown in weed-free conditions (PW), while wheat yield was inter-mediate (mean 2764 kg ha -1) at the three highest Persian clover seed rates (InW-C1, InW-C2, InW-C3) and lowest (1932 kg ha -1) in the weed-infested control (Wh-We). We conclude that the ecological intensification with Persian clover under-sown in wheat can reduce weed biomass without further negatively affecting yield. However, it might represent a feasible tool to manage weeds and for agriculture to become less dependent on herbicides. This approach could become economically viable if other values added by Persian clover, such as feed for livestock, green manure, or lower pesticide costs, exceed the cost of the grain yield reduction compared to a weed free situation.
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| 30. |
- Twengström, Eva, et al.
(författare)
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Fungicide treatments in winter wheat: The probability of profitability
- 2018
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Ingår i: Crop Protection. - : Elsevier BV. - 0261-2194 .- 1873-6904. ; 106, s. 182-189
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Tidskriftsartikel (refereegranskat)abstract
- The marginal return of fungicide applications against leaf blotch diseases in winter wheat fields were analysed based on data from field trials performed in 1996-2011 in Sweden. Yield increases from fungicide treatments were compared with data on growing conditions (precipitation, previous crop, nitrogen fertilization, soil type, and disease severity) using logistic regression. After identification and quantification of single factors with good predictive ability, multiple factor models were analysed. A model with five factors; rain days in April/May and three weeks before ear emergence, disease severity at ear emergence, soil type and previous crop, identified situations when a fungicide treatment gave a positive marginal return. The sensitivity and specificity of the model was evaluated by using receiver operating characteristic (ROC) curves.
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| 31. |
- Watz, Johan, 1977-, et al.
(författare)
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Artificial barriers against arionid slug movement
- 2021
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Ingår i: Crop Protection. - Amsterdam : Elsevier. - 0261-2194 .- 1873-6904. ; 142, s. 1-5
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Tidskriftsartikel (refereegranskat)abstract
- Arionid slugs can be serious pests on horticultural and agricultural crops. Using slug movement barriers is a potentially effective method to control slug damage. We evaluated the performance of waterglass (sodium silicate) and copper foil as barriers against Arion vulgaris movement both in a controlled experiment and in a semi-field validation under natural conditions. We used strawberry fruits as baits behind the barriers and monitored slug movement and damage to the strawberries. In the controlled experiment, copper foil barriers delayed but did not prevent passage, whereas waterglass barriers completely hindered slugs from passing. Barrier width (3, 4 or 6 cm) did not affect the passability of the barriers. In the semi-field validation, there was no difference in slug damage events between pots with and without copper foil barriers. Waterglass barriers applied to the pots reduced slug damage events by 50 % compared with pots without a barrier. Using waterglass to hinder slug movement may prove to be a cost-effective method to control slug damage in horticulture without any adverse side effects on non-targeted organisms.
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| 32. |
- Weiss, Jana
(författare)
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Import, disposal, and health impacts of pesticides in the East Africa Rift (EAR) zone: A review on management and policy analysis
- 2018
-
Ingår i: Crop Protection. - : Elsevier BV. - 0261-2194 .- 1873-6904. ; 112, s. 322-331
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Forskningsöversikt (refereegranskat)abstract
- East Africa Rift (EAR) zone countries, such as Ethiopia, Tanzania, Kenya, and Uganda are among the least developed countries in the world. Agricultural activities are the main source of their economy and huge amounts of pesticides have been imported for decades to protect crops from damage by pests and diseases. Some of these pesticides expired in storage before they were used and their disposal became a major problem. Further, these countries declare different policies related to pesticide management. This study reviews the relevant literature about import, disposal and health impacts of pesticides together with different related policies. Web of Science, Google Scholar, and Google were used as the main sources of information. Records show the increases in the import of pesticides in Ethiopia from 2013 to 2016, in Tanzania from 2006 to 2011, in Kenya from 2008 to 2015, and in Uganda from 1980 to 2004. Disposing of obsolete pesticides is very costly and needs proper facilities. Therefore, EAR countries transport these pesticides to European countries for incineration. For example, Ethiopia disposed of 1574.5 and 926 tonnes of obsolete pesticides in collaboration with the FAO. Acute and passive pesticide poisoning occurrences are also discussed in the review. The paper also highlights the policies so far stated. However, these policies lack proper implementation. Therefore, this study suggests EAR countries should use alternative methods to protect crops from the damage caused by pests and diseases, which could reduce the excessive import of pesticides. Similarly, training should also be given to all stakeholders to ensure implementation of all policies.
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| 33. |
- Wibe, Atle, et al.
(författare)
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Combining 1,4-dimethoxybenzene, the major flower volatile of wild strawberry Fragaria vesca, with the aggregation pheromone of the strawberry blossom weevil Anthonomus rubi improves attraction
- 2014
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Ingår i: Crop Protection. - : Elsevier BV. - 0261-2194 .- 1873-6904. ; 64, s. 122-128
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Tidskriftsartikel (refereegranskat)abstract
- The aggregation pheromone of strawberry blossom weevil [Anthonomus rubi Herbst (Col.: Curculionidae)1, a 1:4:1 blend of Grandlure I, II and racemic lavadulol, has been available for pest monitoring for several years but shows low attractancy. Attempts to control A. rubi using the pheromone alone were also unsuccessful. This paper reports the finding that addition of the major flower volatile from wild strawberry flowers [Fragaria vesca L. (Rosaceae)], 1,4-dimethoxybenzene (comprising 98% of the volatiles emitted from wild strawberry flowers), to the aggregation pheromone increased trap catches by over two fold compared to the pheromone alone. There was no significant difference between the response of overwintered or summer emerged adults. Field trials in 2007-2008 in central and southern Norway, Denmark and southern England used green funnel traps with white cross vanes for the evaluations. (-)-Germacrene D, previously shown to be emitted by plants in increased amounts in the presence of pheromone producing weevils, did not improve trap catches. Thus, the combined use of the aggregation pheromone and 1,4-dimethoxybenzene is promising for improved monitoring and possibly control of this important pest of strawberry.
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| 34. |
- Wiik, Lars, et al.
(författare)
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Impact of temperature and precipitation on yield and plant diseases of winter wheat in southern Sweden 1983-2007
- 2009
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Ingår i: Crop Protection. - : Elsevier BV. - 0261-2194 .- 1873-6904. ; 28, s. 952-962
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Tidskriftsartikel (refereegranskat)abstract
- Weather factors are driving forces in plant disease development and differ between years and locations. Results from long-term fungicide field trials 1983-2007 and disease surveys 1988-2007 in winter wheat in southern Sweden were used to evaluate relationships between yield, the yield increase obtained by fungicide treatment, thousand grain weight (TGW), disease severity and disease incidence, and the independent variables air temperature and precipitation as monthly means. These two weather variables explained more than 50% of the variation between years regarding yield increase, TGW, LBDs (Leaf Blotch Diseases, including Septoria tritici blotch, Stagonospora nodorum blotch and tan spot), brown rust, yellow rust and eyespot, but less than 50% of the variation in yield and powdery mildew. Precipitation in May was the factor most consistently related to LBD disease intensity, and adding another two weather factors further improved the degree of explanation. Weather factors in the preceding growing season influenced growth stage, powdery mildew and brown rust. Mild winters and springs favoured the biotrophs such as powdery mildew, brown rust and yellow rust. Statistically significant correlations between incidence and severity were found for LBDs, brown rust and eyespot, but not for yellow rust and powdery mildew. Regression models with disease incidence as dependent variable generally had a higher degree of explanation and lower P-value than models with disease severity as dependent variable. Our results confirm that weather data can be successfully used in wheat disease prediction models. (C) 2009 Elsevier Ltd. All rights reserved.
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| 35. |
- Wiik, Lars, et al.
(författare)
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The economics of fungicide use in winter wheat in southern Sweden
- 2010
-
Ingår i: Crop Protection. - : Elsevier BV. - 0261-2194 .- 1873-6904. ; 29, s. 11-19
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Tidskriftsartikel (refereegranskat)abstract
- In southern Sweden, fungicide treatment of winter wheat is prevalent and recommended almost routinely against leaf blotch diseases. However, yield increases and hence the resulting net returns from fungicide use are highly variable within and between years. These variations raise questions about whether, when and how fungicides should be used. To help answer these questions, a thorough economic evaluation of fungicide use was carried out, based on results from untreated plots and fungicide-treated plots in trials in farmers' fields, 1983-2007. Scenarios with varying grain prices and costs of fungicide treatment were evaluated and examined. Doubling and tripling the grain price led to the largest impact on the net return from fungicide treatment, followed by increasing cost of the fungicide. Other costs were of minor importance. The mean net return from fungicide use was no more than 12 (sic) ha(-1) over the 25 years (2008 grain prices and costs used in calculations). Furthermore, the mean net return was negative in 10 years and less than 50% of the entries were profitable to treat in 11 years. Changes over time and changes in controllable factors (e.g. fungicide and cultivar choice, crop rotation, techniques) and uncontrollable factors (e.g. emerging and new diseases. price relations) influenced the profitability of fungicide use. Fungicide use was in fact more profitable (mean net return 21 compared with 3 (sic) ha(-1)) during the latter part of the period (1995-2007) than in the earlier part (1983-1994). Improved decision support systems in a holistic framework based on sound economics are urgently needed. (C) 2009 Elsevier Ltd. All rights reserved.
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| 36. |
- Wiik, Lars
(författare)
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Yield and disease control in winter wheat in southern Sweden 1977-2005
- 2009
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Ingår i: Crop Protection. - : Elsevier BV. - 0261-2194 .- 1873-6904. ; 28, s. 82-89
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Tidskriftsartikel (refereegranskat)abstract
- Fungicides are routinely used to prevent yield losses in winter wheat in southern Sweden. Yield and 1000 grain weight (TGW) data from 432 trials in farmers’ fields were evaluated to review long-term yields (1977-2005) and control of eyespot and Leaf Blotch Diseases (LBDs, including Septoria tritici blotch, Stagonospora nodorum blotch and tan spot), powdery mildew, brown rust and yellow rust. Regression analyses revealed that control of LBDs explained 74% of the yield increase achieved by fungicide treatment at GS 45-61, followed by powdery mildew (20%), brown rust (5%) and yellow rust (1%). Yield of both untreated and fungicide-treated plots increased from approx. 6000 to 12000 kg ha-1 over the period 1983-2005. Single eyespot treatment improved yield by ~320 kg ha-1 yr-1 during the period 1977-2002, mainly due to occasional years with severe eyespot. Single leaf disease treatment at GS 45-61 increased mean yield by 10.3% or 810 kg ha-1 yr-1 ( 9.9% or 660 kg ha-1 yr-1 for 1983-1994 and 10.7% or 970 kg ha-1 yr-1 for 1995-2005) due to increased TGW and grain numbers, especially in high yielding stands. Additional extra early treatment at GS 30-40 against LBDs increased yield by ~250 kg ha-1 yr-1. Estimated variance in yield and TGW was higher between years than within years, while that in yield increase and plant diseases was lower between years than within. The results confirm potential and limits of fungicides and the need for supervised control strategies including factors affecting disease, yield and interactions
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| 37. |
- Åkerblom Espeby, Liv, et al.
(författare)
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Susceptibility variation to new and established herbicides: Examples of inter-population sensitivity of grass weeds
- 2011
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Ingår i: CROP PROTECTION. - : Elsevier Science B.V., Amsterdam.. - 0261-2194 .- 1873-6904. ; 30:4, s. 429-435
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Tidskriftsartikel (refereegranskat)abstract
- The objectives of this study were to describe the intra-specific variation in herbicide response of weed populations when subjected to new vs. well-established herbicides, and to assess distributions of logLD(50)- and logGR(50)-estimates as a potential indicator for early resistance detection. Seeds of two grass weeds (Alopecurus myosuroides, Apera spica-venti) were collected in southern Sweden, mainly in 2002. In line with the objectives of the study, the collections sites were not chosen for noted herbicide failures nor for detected herbicide resistance, but solely for the presence of the target species. For each species, seedlings were subjected to two herbicides in dose-response experiments in a greenhouse. One herbicide per species was recently introduced and the other had been on the market for control of the species for a decade, with several reports of resistance in the literature. Fresh weight of plants and a visual vigour score were used to estimate GR(50) and LD50, respectively. Resistance to fenoxaprop-P-ethyl in A. myosuroides was indicated by the LD50-estimates to be present in frequencies sufficient to affect the population-level response in 9 of 29 samples, and was correlated to response to flupyrsulfuron, while low susceptibility to isoproturon in A. spica-venti populations was not linked to the response to sulfosulfuron. In the study as a whole, the magnitude of the estimated herbicide susceptibility ranges differed irrespective of previous exposure. No consistent differences were found in the distribution of LD50-estimates for new and "old" herbicides, and normality in the distribution of estimates could not be assumed for a non-exposed sample, even in the absence of an indication of cross-resistance.
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