Progress 09/01/09 to 08/31/13
Outputs
Target Audience: Vegetable growers; Chemical industry personnel; County and state extension agents; Scientists in weed science, plant pathology, nematology, and other agricultural sciences. Changes/Problems: None. What opportunities for training and professional development has the project provided? Graduate students, undergraduate students, postdoctoral students, county extension agents, and vegetable growers were educated and trained in the project for management of weeds and vegetable diseases. How have the results been disseminated to communities of interest? Results have been disseminated to stakeholders through local, regional, national and international meetings, publications, and frequent visits of growers, industry representatives, extension agents, and other end users. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
A series of field studies were conducted in 2009-2010 in Tifton, GA, to evaluate several herbicides for purple nutsedge control, pepper and cucumber tolerance to herbicides, nematicides and fungicides for root-knot nematode and soilborne disease control, as compared to methyl bromide (MeBr) and the Georgia 3-way combination of Telone II, chloropicrin, and Vapam. Herbicides were applied simultaneously with polyethylene mulch laying and included single and combination treatments of s-metolachlor, clomazone, fomesafen, halosulfuron, and sulfentrazone. A combination of clomazone, s-metolachlor, and fomesafen or sulfentrazone were required to provide acceptable control (>80%) of purple nutsedge, but no single herbicide application provided acceptable purple nutsedge control as compared to methyl bromide or the GA 3-way mixture. Cucumber was tolerant to combinations of clomazone, s-metolachlor with fomesafen, but not sulfentrazone that reduced cucumber yields. Bell pepper early season injury also occurred with sulfentrazone alone and when used in combination with other herbicides. A number of nematicides and fungicides were evaluated for control of root-knot nematodes and soilborne diseases. A nematicide fluensulfone (thiazosulfene) when applied at 3.56 lb /acre caused phytotoxicity in both pepper and cucumber although nematode control was generally best with fluensulfone. A reduced rate of fluensulfone (1.58 lb /acre) was used in further experiments and compared with methyl bromide, GA 3-Way and Vydate. On cucumber, fluensulfone provided nematode control comparable to fumigant treatments which was significantly better than the non-treated control. Pepper plots treated with fluensulfone yielded significantly better than those receiving the Georgia 3-way and MeBr/chloropicrin (MeBrC) while maintaining nematode control. Fluopicolide and mandipropamid significantly reduced incidence of Phytophthora blight compared with the non-treated control. The efficacy of these products in disease suppression was similar or numerically superior compared with mefenoxam and not significantly different from MeBrC. In 2011-2013, combinations of herbicides, nematicides, and fungicides were evaluated for control of weeds and diseases on cucumber and pepper in repeated field studies and demonstrations. For cucumber, the combinations of halosulfuron plus clomozone plus S-metholachlor provided 50-85% reduction of purple nutsedge as compared to the non-treated control though this reduction was not as effective as MBrC. However, herbicide injury to cucumber was a concern and vine lengths up to 8 weeks after transplanting were reduced in some field studies. For pepper, S-metholachlor plus clomoazone plus fomesafen provided significant purple nutsedge control, and no treatments involving the herbicides affected growth of pepper up to 8 weeks after transplanting. Fluensulfone and the non-fumigant fungicides provided significant root-knot nematode and Phytophthora blight reductions that were comparable to the application of MBrC. Analysis showed that application of the nonfumigants was economically feasible compared to the fumigants. Studies in the project indicated that non-fumigant nematicide and fungicides provided similar root-knot and disease control efficacy as MBrC. While purple nutsedge did reestablish in the herbicide treated areas and herbicide injury was a concern for cucumber, both pepper and cucumber could be successfully produced without methyl bromide for a single crop. Results of the studies were presented at local, national and international meetings and frequent visits of growers, industry representatives, extension agents, and other end users.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Ji, P. and Csinos, A. S. 2013. Biology and management of Phytophthora blight on pepper and squash. Abstracts of 4th International Phytophthora capsici meeting. Duck Key, FL.
Blanchett, B. H., Grey, T. L., and Webster, T. M. 2012. Non-fumigant methyl bromide alternatives for vegetable production. In Proc. Southern Weed Sci. Soc. 65: online at http://www.swss.ws/NewWebDesign/Proceedings/Archives/2012%20Proceedings-SWSS.pdf
Jackson, K. L., Yin, J., and Ji, P. 2012. Sensitivity of Phytophthora capsici from vegetable crops in Georgia to mandipropamid, dimethomorph, and cyazofamid. Plant Dis. 96:1337-1342.
Yin, J., Jackson, K. L., Candole, B. L., Csinos. A. S., Langston, D. B., and Ji, P. 2012. Aggressiveness and diversity of Phytophthora capsici on vegetable crops in Georgia. Ann. Appl. Biol. 160:191-200.
Ji, P., Langston, D. B., and Grey, T. L. 2011. Non-fumigants as methyl bromide alternatives for managing vegetable diseases and weeds. Pages 4-1, 4-2, in: Proceedings of 2011 Annual International Research Conference on Methyl Bromide Alternatives and Emissions Reductions. San Diego, CA.
Langston, D. B. and Sanders, F.H. 2011. Reducing damage to root-knot nematode with fluensulfone (formerly thiazosulfene) in cucumbers and peppers. Phytopathology 101:S97.
Langston, D. B., and Sanders, F.H. 2011. Methyl bromide replacement systems for controlling root-knot nematode in bell pepper in Georgia, 2010. Plant Disease Management Report No. 5:N013.
Kuhn, P., Babadoost, M., Thomas, D., Ji, P., Mclean, H., Hert, A., Tory, D., Tally, A. 2011. Evaluation of drip applications of Revus in fungicide programs for management of Phytophthora blight (Phytophthora capsici) on bell pepper and squash. Phytopathology 101:S94.
Ji, P., Jackson, K. L., Yin, J., Langston, D. B., and Csinos, A. S. 2011. Developing biological and chemical management programs for Phytophthora blight on pepper and cucurbits. Page 18, in: Abstracts of 3rd International Phytophthora capsici Conference. Duck Key, FL.
Ji, P., Csinos, A. S., and Langston, D. B. 2010. Integrated management of Phytophthora blight on vegetables update. Page 17, in: Proceedings of the Southeast Regional Vegetable Conference. Savannah, GA.
Langston, D. B. and Sanders, F.H. 2010. Fungicide and plant disease update. Page 18, in: Proceedings of the Southeast Regional Vegetable Conference. Savannah, GA.
Langston, D. B., Sanders, F.H., Culpepper, A.S. and Foster, M.J. 2010. Methods of controlling soil-borne pests of vegetables utilizing non-fumigant pesticides. Page 32, in: Proceedings of the Southeast Regional Vegetable Conference. Savannah, GA.
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Progress 09/01/11 to 08/31/12
Outputs
OUTPUTS: Combinations of herbicides, nematicide, and fungicides were evaluated for cucumber and pepper crop response and purple nutsedge control in autumn 2011. Methyl bromide/chloropicrin 50/50 (MBrC) was included along with a nontreated control for comparisons. For pepper, MCW2 plus fluopicolide or mefenoxam were applied in conjunction with herbicide applications of clomazone plus fomesafen, S-metholachlor plus fomesafen, or colomazone plus fomesafen plus S-metolachlor (8 total treatments). For cucumber, the same nematicide and fungicides were combined with halosulfuron, S-metolachlor plus clomozone plus fomesafen, or halosulfuron plus S-metolachlor. No combination of herbicides plus nematicide plus fungicide affected stand or growth of pepper (height). However, cucumber (length) up to 8 weeks after transplanting was reduced by all herbicide treatments. Control of purple nutsedge was variable by crop. For cucumber, the combinations of halosulfuron plus clomozone plus S-metholachlor provided control equal to the other treatments. None was as effective as MBrC. However, by the end of the harvest, this herbicide combination provided 85% control of purple nutsedge as compared to the nontreated control. Injury to cucumber was a major concern and was reflected in the reduced vine lengths. Fluopicolide and mefenoxam significantly reduced incidence of Phytophthora blight compared with the non-treated control. Root-knot galling on cucumber and pepper was low in all treatments and there was no significant difference among the treatments when incidence or severity of galling was evaluated. Plots treated with MBrC produced the highest yield of cucumber which was significantly higher than other treatments. All fumigants and non-fumigants increased pepper yield significantly compared with the nontreated control, and there was no significant difference between the non-fumigants and MBrC. Field experiments to evaluate selected combinations of herbicides, nematicide, and fungicide are being conducted in 2012. These data indicate that non-fumigant nematicide and fungicides provide similar root-knot and disease control efficacy as MBrC. While purple nutsedge did reestablish in the herbicide treated areas, both pepper and cucumber could be successfully produced without methyl bromide for a single crop, but injury was a concern for cucumber. PARTICIPANTS: Pingsheng Ji, Assistant Professor, University of Georgia; David Langston, Professor, University of Georgia; Tim Grey, Associate Professor, University of Georgia. TARGET AUDIENCES: Vegetable growers; Industry personnel; County and state extension agents; Scientists in plant pathology, weed science, and other agricultural sciences. PROJECT MODIFICATIONS: None.
Impacts
The loss of methyl bromide requires alternative methods for control of weeds, nematodes, and soilborne diseases. Studies in this project indicated that purple nutsedge could be effectively controlled by combinations of non-fumigant herbicides. In addition, non-fumigant nematicide and fungicides provided similar root-knot and disease control as methyl bromide. Combinations of non-fumigant nematicide, fungicides, and herbicides could be viable alternatives to fumigants for control of soilborne pests and weeds.
Publications
- Jackson, K. L., Yin, J., and Ji, P. 2012. Sensitivity of Phytophthora capsici from vegetable crops in Georgia to mandipropamid, dimethomorph, and cyazofamid. Plant Dis. 96:1337-1342.
- Ji, P., Yin, J., and D. Kone. 2011. Application of acibenzolar-S-methyl and standard fungicides for control of Phytophthora blight on squash. Crop Prot. 30:1601-1605.
- Blanchett, B. H., Grey, T. L., and Webster, T. M. 2012. Non-fumigant methyl bromide alternatives for vegetable production. In Proc. Southern Weed Sci. Soc. 65: online at http://www.swss.ws/NewWebDesign/Proceedings/Archives/2012%20Proceedin gs-SWSS.pdf
- Kuhn, P., Babadoost, M., Thomas, D., Ji, P., Mclean, H., Hert, A., Tory, D., Tally, A. 2011. Evaluation of drip applications of Revus in fungicide programs for management of Phytophthora blight (Phytophthora capsici) on bell pepper and squash. Phytopathology 101:S94.
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Progress 09/01/10 to 08/31/11
Outputs
OUTPUTS: Field studies were conducted in fall 2010 in Tifton, GA, to evaluate several herbicides for purple nutsedge control and pepper and cucumber tolerance as compared to methyl bromide and the Georgia 3-way combination of Telone II, chloropicrin, and Vapam. A number of nematicides and fungicides were evaluated for control of root-knot nematodes and soilborne diseases. No single herbicide application provided acceptable purple nutsedge control as compared to methyl bromide or the GA 3-way mixture. A combination of clomazone, S-metolachlor, and fomesafen or sulfentrazone were required to provide acceptable control (>80%). Cucumber was tolerant to combinations of clomazone, S-metolachlor with fomesafen, but not sulfentrazone. Bell pepper early season injury also occurred with sulfentrazone alone and when used in combination with other herbicides. Thiazosulfene (1.58 lb /acre) was used in the fall experiments and compared with methyl bromide, GA 3-Way and Vydate. Pepper plots treated with thiazosulfene yielded significantly better than those receiving the Georgia 3-way and MBrC while maintaining nematode control. This was attributed to the fumigants causing phytotoxicity in the fall crop and a reduced rate of thiazosulfene applied. Yields in the fall cucumber trial were not different and thiazosulfene provided nematode control comparable to fumigant treatments but significantly better than the control. Fluopicolide and mefenoxam significantly reduced incidence of Phytophthora blight compared with the non-treated control. The efficacy of these products in disease suppression was not significantly different from MBrC. In spring 2011, combinations of herbicides, nematicides, and fungicides were evaluated for control of weeds and diseases for cucumber and pepper. Methyl bromide/chloropicrin 50/50 (MBrC) was included along with a non-treated control for comparisons. No combination of herbicides plus nematicide plus fungicide affected stand or growth of pepper or cucumber up to 8 weeks after transplanting. Control of purple nutsedge was variable by crop. For cucumber, only those treatments that had a combination of halosulfuron plus clomozone plus S-metholachlor provided control equal to MBrC. However, by the end of the harvest, this herbicide combination provided 53% control of purple nutsedge as compared to 75% for MBrC. For pepper, the purple nutsedge control was 60% for S-metholachlor plus clomoazone plus fomesafen as compared to 95% for MBrC. Thiazosulfene and the fungicides provided significant root-knot nematode and Phytophthora blight reduction that was comparable to the application of MBrC. PARTICIPANTS: Pingsheng Ji, Assistant Professor, University of Georgia; David B. Langston, Professor, University of Georgia; Tim Grey, Associate Professor, University of Georgia. TARGET AUDIENCES: Vegetable growers; Industry personnel; County and state extension agents; Scientists in plant pathology, weed science, and other agricultural sciences. PROJECT MODIFICATIONS: None
Impacts
With the phaseout of methyl bromide from use, the search for methyl bromide alternatives is desperately needed to control troublesome pests on vegetables. Intensive efforts have been made to develop methyl bromide alternatives and the majority of studies have focused on other soil-applied fumigants. However, buffer restrictions, rising costs, and efficacy of the fumigants limit their use. Studies in this project indicated that combinations of clomazone, S-metolachlor, and halosulfuron provided acceptable weed control and did not cause season long pepper injury. The results also indicated that certain non-fumigant nematicide and fungicides had the promise to be used as an alternative to methyl bromide for control of root-knot nematodes and important soilborne diseases such as Phytophthora blight.
Publications
- Langston, D. B. and Sanders, F.H. 2011. Reducing damage to root-knot nematode with fluensulfone (formerly thiazosulfene) in cucumbers and peppers. Phytopathology 101:S97.
- Langston, D. B., and Sanders, F.H. 2011. Methyl bromide replacement systems for controlling root-knot nematode in bell pepper in Georgia, 2010. Plant Disease Management Report No. 5:N013.
- Ji, P., Langston, D. B., and Grey, T. L. 2011. Non-fumigants as methyl bromide alternatives for managing vegetable diseases and weeds. Pages 4-1, 4-2, in: Proceedings of 2011 Annual International Research Conference on Methyl Bromide Alternatives and Emissions Reductions. San Diego, CA.
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Progress 09/01/09 to 08/31/10
Outputs
OUTPUTS: Field studies were conducted in 2010 in Tifton, GA, to evaluate several herbicides for purple nutsedge control and pepper and cucumber tolerance as compared to methyl bromide and the Georgia 3-way combination of Telone II, chloropicrin, and Vapam. Herbicides were applied simultaneously with polyethylene mulch laying and included single and combination treatments of s-metolachlor, clomazone, fomesafen, halosulfuron, and sulfentrazone. No single herbicide application provided acceptable purple nutsedge control as compared to methyl bromide or the GA 3-way mixture. A combination of clomazone, s-metolachlor, and fomesafen or sulfentrazone were required to provide acceptable control (>80%). Cucumber was tolerant to combinations of clomazone, s-metolachlor with fomesafen, but not sulfentrazone. Sulfentrazone reduced cucumber yields in all treatments. Bell pepper early season injury also occurred with sulfentrazone alone and when used in combination with other herbicides. This translated into reduced yields in fruit number and mass throughout the season. Experiments for control of root-knot nematodes were conducted in spring 2010. The experimental product thiazosulfene significantly reduced vigor yields in both pepper and cucumber in the spring compared to plots receiving soil fumigants, although nematode control was generally best with thiazosulfene in the spring. The rate of soil-incorporated thiazosulfene used in the spring was 3.56 lb /acre which caused phytotoxicity. Treatments receiving Vydate as the sole nematicide demonstrated significantly more nematode galling than fumigant treatments but generally outperformed the non-treated plots for both crops. A reduced rate of thiazosulfene (1.58 lb /acre) is being used in the fall experiments and compared with methyl bromide, GA 3-Way and Vydate. Several fungicides were evaluated for control of soilborne diseases in the fall of 2009 and spring of 2010. Fluopicolide and mandipropamid significantly reduced incidence of Phytophthora blight compared with the non-treated control. The efficacy of these products in disease suppression was similar or numerically superior compared with mefenoxam and not significantly different from methyl bromide. Additional studies are being conducted in the fall of 2010. PARTICIPANTS: Pingsheng Ji, Assistant Professor, University of Georgia; David B. Langston, Professor, University of Georgia; Tim Grey, Associate Professor, University of Georgia. TARGET AUDIENCES: Vegetable growers; Industry personnel; County and state extension agents; Scientists in plant pathology, weed science, and other agricultural sciences. PROJECT MODIFICATIONS: None
Impacts
The loss of methyl bromide requires alternative methods for control of weeds, nematodes, and soilborne diseases. Weed control is generally with herbicides but crop injury is a concern due to a lack of efficacy information. While sulfentrazone provided good residual purple nutsedge control, cucumber and pepper tolerance to sulfentrazone varied and can be a major concern. Studies in this project indicated that combinations of clomazone, s-metolachlor, and halosulfuron provided acceptable weed control and did not cause season long pepper injury. The results also indicated that certain newer nematicide and fungicides had the promise to be used as an alternative to methyl bromide for control of root-knot nematodes and important soilborne diseases such as Phytophthora blight.
Publications
- Ji, P., Csinos, A. S., and Langston, D. B. 2010. Integrated management of Phytophthora blight on vegetables update. Page 17, in: Proceedings of the Southeast Regional Vegetable Conference. Savannah, GA.
- Langston, D. B. and Sanders, F.H. 2010. Fungicide and plant disease update. Page 18, in: Proceedings of the Southeast Regional Vegetable Conference. Savannah, GA.
- Langston, D. B., Sanders, F.H., Culpepper, A.S. and Foster, M.J. 2010. Methods of controlling soil-borne pests of vegetables utilizing non-fumigant pesticides. Page 32, in: Proceedings of the Southeast Regional Vegetable Conference. Savannah, GA.
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