Progress 07/01/10 to 09/30/14

Outputs
Target Audience: Thetarget audiencewho directly benefitted from this project include leafy vegetable growers, PCAs, and local Agro-chemical Industry representatives. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Due to the analytical nature of this project I was exposed to the use of HPLC and the sample preparation required to use this technology. How have the results been disseminated to communities of interest? This project was designed to further enhance the ability of vegetable growers to properly employ a new insecticide technology by designing studies that specifically defined Coragen/Durivo residual soil activity by correlating worm efficacy with known levels of clorantraniliprole concentrations in leaf tissue collected from treated plants. We believe that all Arizona vegetable growers have benefitted from this information while this new technology becomes integrated into their standard management programs for worm control. We anticipated that one of the outcomes of this would be a significant increase in growers awareness and technical knowledge of this new chemical and the diagnostic tools that are developed. We proposed that the project would significantly increase their awareness of chlorantraniliprole. We feel confident that this occurred. Although difficult to measure, we have presented the results of this project several times to PCAs and growers at extension meetings including: 2010-2013 Desert Ag Conference, Casa Grande AZ;2010-2013 Pre-season Vegetable Workshops, Yuma AZ;2010-2013 Desert Crops Workshop, El Centro CA; and at the 2010 and 2011 DuPont Fieldman Seminars, San Diego CA. In addition, information on this project has been provided to most AZ PCAs through our bi-weekly Veg IPM updates. We further proposed to measure this outcome by surveying of PCAs and growers following the 2010-2011 season to determining whether they had increased their implementation of this new technology for insect control. Results from our annual Lettuce Insect Losses Workshops held each April which formally survey PCAs/Growers on their insecticide usage has shown that Coragen use on lettuce in 2008 was applied to 0% of the acreage, increased to 3.1 % in 2009, and was used on 10.3% of the lettuce acreage in 2010. Surevey in 2012 showed that usage has inreasd to over 25%. An additional expected outcome we anticipated was to develop a diagnostic tool for evaluating the residual activity and persistence of this new soil applied insecticide technology in leafy vegetables (i.e, concentrations of clorantraniliprole within the plant relative to worm control). Prior to this project no such tools (or baseline data) existed. We have accomplished this goal and now have baseline data on the range of chlorantraniliprole concentrations (ppm) that should be measureable in lettuce and broccoli plant tissue at 20 and 30 DAP. This diagnostic index allowed us to assist growers in 2010 by showing that application errors/environmental factors were responsible for the poor field performance of Coragen in their fields, rather than insecticide resistance by worms. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? The project was initiated in August 2010 with research plots being planted on the Yuma Agricultural Center (YAC), and with cooperating vegetable growers in the Yuma area during August and September. A total of 4 field trials were established at YAC where Coragen was applied as at-planting, soil treatment at 5 oz /ac in replicated lettuce and broccoli plots. Plants were sampled for the presence of live worms (beet armyworm and cabbage looper) at weekly intervals from untreated and Coragen treated plots using standard protocols for a 6 week period to determine chlorantraniliprole efficacy. Plant leaf tissue samples were collected at 20, 30 and 40 days after planting for chlorantraniliprole chemical analysis. A total of 7 field plots were established in commercial lettuce growers where a similar sampling protocol was followed. Analytical quantification of chlorantraniliprole was conducted by using a protocol originally derived from DuPont Crop Protection and adapted by previous work conducted at YAC. Plant sample consisted of collecting leaves from the 3rd and 5th nodes of plants at each sampling interval. Plant leaf tissue samples were stored in a freezer prior to preparation for analytical quantification of clorantraniliprole in the laboratory that utilized an extraction and analysis methods similar to that used for the neonicotinoid insecticide quantification with HPLC. The study was expanded into the 2011-2012 growing seasons. A total of 4 research plots were established at YAC where insect samples were collected from treated plots at weekly intervals for 5 weeks post emergence to determine chlorantraniliprole efficacy. At the request of several growers, tissue samples were collected in 16 commercial lettuce fields using the sampling and analytical protocol developed in 2009. Plant leaf tissue samples were collected for chlorantraniliprole chemical analysis at 20 and 30 days after planting. Results of the efficacy trials conducted at the Yuma Ag Center clearly showed that Coragen applied at a precise placement and at proper rates provided significant residual control of both cabbage loopers and beet armyworms. Data combined over both years, along with data from previous studies, showed that average residual control of cabbage loopers varied from 27-36 days after planting and control of beet armyworms for 26-38 days in lettuce plots. On broccoli, average residual control of cabbage loopers varied from 32-39 days after planting and control of beet armyworms for 24-30 days. These values are based on the earliest presence of 2nd and 3rd instar larvae. In addition, control of both cabbage looper and beet armyworm (based on cooperating PCAs evaluation) varied from 24-32 days after planting in Coragen -treated lettuce and broccoli fields. Tissue samples from the previous studies, and the 4 trials at YAC in 2009, showed that chlorantraniliprole concentrations in lettuce plant tissue averaged ~850 ppm at 20 days after planting and ~290 ppm at 30 DAP using the sampling protocol and analytical technique developed in this project. Furthermore, tissue samples from the 7 commercial fields in 2009 indicated that chlorantraniliprole concentrations averaged 824 ppm at 20 DAP and 190 ppm at 30 days. Residual control of both cabbage looper and beet armyworm (based on cooperating PCAs evaluation) varied from 24-32 days after planting. Based on these results we concluded that lettuce growers should expect about 4 weeks of residual control following soil applications of Coragen/Durivo with chlorantraniliprole concentrations in plant tissue averaging at or above 800 ppm at 20 DAP, and decreasing significantly thereafter. However, in 2011 we decided to continue the study because of unusual events occurring in commercial lettuce fields. Beginning in mid-September, four separate growers complained that soil applications of Coragen (similar to those they applied in 2009) were not providing acceptable control of worms (mainly beet armyworm) under commercial growing conditions. Inspection of 16 individual fields in 2011 revealed unacceptable numbers of large larvae (2nd -3rd instars) found throughout the fields with obvious damage occurring to seedling lettuce plants at anywhere from 14-18 days following planting. Consequently, each of the fields were treated with foliar sprays, unlike the previous year. This level of pest occurrence and damage was not observed this early in the crop in our 2009 commercial lettuce trials. Collections of larvae were taken from 2 fields and bioassayed for resistance to Coragen. Neither was considered a resistant population based on baseline data developed previously at our laboratory at the YAC. Subsequently, we collected tissue samples from each of the 16 fields at 20 and 30 DAP and an analysis for chlorantraniliprole concentrations was conducted using the protocol we developed in 2009. Results showed that chlorantraniliprole levels in all of the commercial lettuce fields were significantly lower than what our baseline data suggested they should be. Concentrations ranged from 41.8-115 ppm among the fields, significantly lower than expected index levels in lettuce plants at 20 DAP. Since insecticide resistance was ruled out, we could only speculate that the lack of performance was likely due to a combination of environmental (high temperatures, excessive worm pressure) and operational (light soil/water stress and misapplication) factors. Results from trials conducted at the YAC in 2010, showed less residual control and lower chlorantranilprole concentrations than 2009, but not at the same levels as were experienced in the commercial lettuce fields. These reduced levels were likely due to high temperatures and excessive worm pressure experienced in these plots for the first 20 days of the crop season.

Publications

• Type: Journal Articles Status: Published Year Published: 2010 Citation: Evaluation Of New Insecticides For Control Of Lepidopterous Larvae On Head Lettuce, 2010. Peer-reviewed. Palumbo, J.C. 2011. Arthropod Management Tests, Online. Vol 36, Section E_, 2 pp. Published. (100%). Ghidiu, G., T. Kuhar, J. Palumbo, and D. Schuster. 2012. Drip Chemigation of Insecticides as a Pest Management Tool in Vegetable Production. J. Integ. Pest Mngmt. 3(3): 2012; DOI: http://dx.doi.org/10.1603/IPM10022 Palumbo, J. C. 2008. Systemic efficacy of Coragen applied through drip irrigation on romaine lettuce, fall 2007. Arthropod Management Tests 33: E24.

Progress 01/01/12 to 09/30/12

Outputs
Target Audience: Thetarget audiencewho directly benefit from this project include leafy vegetable growers, PCAs, and local Agro-chemical Industry representatives. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest? The goal of this project was to further enhance the ability of vegetable growers to properly employ a new insecticide technology by designing studies that specifically defined Coragen/Durivo residual soil activity by correlating worm efficacy with known levels of clorantraniliprole concentrations in leaf tissue collected from treated plants. We believe that all Arizona vegetable growers have benefitted from this information while this new technology becomes integrated into their standard management programs for worm control. The first project goal was to increase the awareness and technical knowledge of these chemical alternatives and the diagnostic indices developed in this project. We anticipated that one of the outcomes of this would be a significant increase in growers awareness and technical knowledge of this new chemical and the diagnostic tools that are developed. We proposed that the project would significantly increase their awareness of chlorantraniliprole. We feel confident that this occurred. Although difficult to measure, we have presented the results of this project several times to PCAs and growers at extension meetings including: 2009-2013 Desert Ag Conference, Casa Grande AZ; 2009-2013 Pre-season Vegetable Workshops, Yuma AZ; 2012 Desert Crops Workshop, El Centro CA; and at the 2013 DuPont Fieldman Seminars, San Diego CA. In addition, information on this project has been provided to most AZ PCAs through our bi-weekly Veg IPM updates. We further proposed to measure this outcome by surveying of PCAs and growers following the 2009 and 2010 season to determine whether they had increased their implementation of this new technology for insect control. Results from our annual Lettuce Insect Losses Workshops held each April which formally survey PCAs/Growers on their insecticide usage has shown that Coragen use on lettuce in 2008 was applied to 0% of the acreage, increased to 3.1 % in 2009, and was used on 10.3% of the lettuce acreage in 2010. We feel strongly that this project has had an influence on this sharp increase in usage in 2010. An additional expected outcome we anticipated was to develop a diagnostic tool for evaluating the residual activity and persistence of this new soil applied insecticide technology in leafy vegetables (i.e, concentrations of clorantraniliprole within the plant relative to worm control). Prior to this project no such tools (or baseline data) existed. We have accomplished this goal and now have baseline data on the range of chlorantraniliprole concentrations (ppm) that should be measurable in lettuce and broccoli plant tissue at 20 and 30 DAP. This diagnostic index allowed us to assist growers in 2010 by showing that application errors/environmental factors were responsible for the poor field performance of Coragen in their fields, rather than insecticide resistance by worms. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Results of the efficacy trials conducted at the Yuma Ag Center clearly showed that Coragen applied at a precise placement and at proper rates provided significant residual control of both cabbage loopers and beet armyworms. Data combined over both years, along with data from previous studies, showed that average residual control of cabbage loopers varied from 27-36 days after planting and control of beet armyworms for 26-38 days in lettuce plots. On broccoli, average residual control of cabbage loopers varied from 32-39 days after planting and control of beet armyworms for 24-30 days. These values are based on the earliest presence of 2nd and 3rd instar larvae. In addition, control of both cabbage looper and beet armyworm (based on cooperating PCAs evaluation) varied from 24-32 days after planting in Coragen -treated lettuce and broccoli fields. Tissue samples from the previous studies, and the 4 trials at YAC in 2009, showed that chlorantraniliprole concentrations in lettuce plant tissue averaged ~850 ppm at 20 days after planting and ~290 ppm at 30 DAP using the sampling protocol and analytical technique developed in this project. Furthermore, tissue samples from the 7 commercial fields in 2009 indicated that chlorantraniliprole concentrations averaged 824 ppm at 20 DAP and 190 ppm at 30 days. Residual control of both cabbage looper and beet armyworm (based on cooperating PCAs evaluation) varied from 24-32 days after planting. Based on these results we concluded that lettuce growers should expect about 4 weeks of residual control following soil applications of Coragen/Durivo with chlorantraniliprole concentrations in plant tissue averaging at or above 800 ppm at 20 DAP, and decreasing significantly thereafter. Beginning in mid-September, four separate growers complained that soil applications of Coragen (similar to those they applied in 2009) were not providing acceptable control of worms (mainly beet armyworm) under commercial growing conditions. Inspection of 16 individual fields in 2012 revealed unacceptable numbers of large larvae (2nd -3rd instars) found throughout the fields with obvious damage occurring to seedling lettuce plants at anywhere from 14-18 days following planting. Consequently, each of the fields were treated with foliar sprays, unlike the previous year. This level of pest occurrence and damage was not observed this early in the crop in our 2009 commercial lettuce trials. Collections of larvae were taken from 2 fields and bioassayed for resistance to Coragen. Neither was considered a resistant population based on baseline data developed previously at our laboratory at the YAC. Subsequently, we collected tissue samples from each of the 16 fields at 20 and 30 DAP and an analysis for chlorantraniliprole concentrations was conducted using the protocol we developed in 2011. Results showed that chlorantraniliprole levels in all of the commercial lettuce fields were significantly lower than what our baseline data suggested they should be. Concentrations ranged from 41.8-115 ppm among the fields, significantly lower than expected index levels in lettuce plants at 20 DAP. Since insecticide resistance was ruled out, we could only speculate that the lack of performance was likely due to a combination of environmental (high temperatures, excessive worm pressure) and operational (light soil/water stress and misapplication) factors. Results from trials conducted at the YAC in 2010, showed less residual control and lower chlorantranilprole concentrations than 2009, but not at the same levels as were experienced in the commercial lettuce fields. These reduced levels were likely due to high temperatures and excessive worm pressure experienced in these plots for the first 20 days of the crop season.

Publications

• Type: Journal Articles Status: Published Year Published: 2012 Citation: Ghidiu, G., T. Kuhar, J. Palumbo, and D. Schuster. 2012. Drip Chemigation of Insecticides as a Pest Management Tool in Vegetable Production. J. Integ. Pest Mngmt. 3(3): 2012; DOI: http://dx.doi.org/10.1603/IPM10022 Published. CROSS-SPECTRUM INSECT CONTROL WITH VERIMARK IN HEAD LETTUCE, 2011. Peer-reviewed. Palumbo, J.C. 2012. Arthropod Management Tests, Online. Vol 37, Section E29, 2 pp., doi: 10.4182/amt.2012.E29 Published. (100%). SOIL-SURFACE APPLIED SYSTEMIC INSECTICIDES FOR CONTROL OF WHITEFLY IN BROCCOLI. Peer-reviewed. Palumbo, J.C. 2012. Arthropod Management Tests, Online. Vol 37, Section E12, 2 pp., doi: 10.4182/amt.2012.E12 Published. (100%).

Progress 01/01/11 to 12/31/11

Outputs
OUTPUTS: The objectives of this study were to evaluate foliar and soil applied insecticide approaches using novel insecticide technologies for cost-effective management of lepidopterous larvae under a conventional head lettuce production system. Two separate large-block, field trials where rynaxypyr were conducted in 2008 and 2009 that evaluated at-planting, in-furrow soil treatments of rynaxypyr compared to a conventional, foliar management program. The soil treatments effectively controlled lepidopterous larvae for up to 30 days after planting in each trial. After that point, the rynaxypyr soil treatments only required 2 additional foliar sprays (with spinetoram and emamectin benzoate) to protect lettuce plants until harvest. In contrast, a conventional spray program required 5 foliar insecticide in both years sprays to provide comparable levels of insect control and yield/quality at harvest. Additionally, the economic and residual effectiveness of Rynaxypyr soil treatments were evaluated when applied to romaine lettuce under diverse production and irrigation systems. In a separate study, rynaxypyr soil treatments was applied to romaine lettuce plots through in-furrow applications at planting or through drip irrigation as a post emergence treatment. Three irrigation systems were compared: drip, sprinkler and furrow on both narrow beds (42 inch centers) and wide bed (84 inch centers). Application to narrow beds provided the longest residual efficacy of lepidopterous larvae regardless of delivery system. In both experiments, a protocol for analyzing lettuce tissue for rynaxypyr concentrations was developed using HPLC. Data was collected that defined the concentration (ppm) of rynaxypyr for each soil application method at discrete intervals throughout the growing season. Tissue samples from the 4 trials conducted in 2008 and 2009, showed that rynaxypyr concentrations in lettuce plant tissue averaged ~850 ppm at 20 days after planting and ~290 ppm at 30 DAP using the sampling protocol and analytical technique developed in this project. Furthermore, tissue samples from the 7 commercial fields in 2009 indicated that chlorantraniliprole concentrations averaged 824 ppm at 20 DAP and 190 ppm at 30 days. Residual control of both cabbage looper and beet armyworm (based on cooperating PCAs evaluation) varied from 24-32 days after planting. Based on these results we concluded that lettuce growers should expect about 4 weeks of residual control following soil applications of Coragen/Durivo with chlorantraniliprole concentrations in plant tissue averaging at or above 800 ppm at 20 DAP, and decreasing significantly thereafter. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Based on our results the impact of these studies are several fold. First by identifying that this compound can be effectively uses as a soil systemic insecticide against lepidopterous larvae, we have already observed a reduction in the growers reliance on organophosphate, carbamate and pyrethroid insecticides. We will be able to quantify this impact following the completion of this project through our outreach efforts. Secondly, demonstration that this new safe, and reduced-risk insecticide technology can cost-effectively control insect in lettuce should allow growers to significantly reduce total number of insecticide sprays in lettuce. Finally, based on field efficacy and measurements concentrations in plant tissue, growers have become aware of the long residual activity of this product when applied to the soil and the heightened risks for insecticide resistance using this management approach. An as outcome of this project we anticipated that a diagnostic tool could be developed for evaluating the residual activity and persistence of this new soil applied insecticide technology in leafy vegetables (i.e, concentrations of rynaxypyr within the plant relative to worm control). Prior to this project no such tools (or baseline data) existed. We have accomplished this goal and now have baseline data on the range of rynaxypyr concentrations (ppm) that should be measureable in lettuce and broccoli plant tissue at 20 and 30 DAP. This diagnostic index allowed us to assist growers in 2010 by showing that application errors/environmental factors were responsible for the poor field performance of Coragen in their fields, rather than insecticide resistance by worms.

Publications

• Palumbo, J.C. 2011. Evaluation Of New Insecticides For Control Of Lepidopterous Larvae On Head Lettuce. Arthropod Management Tests, Online. Vol 36, Section E43, 2 pp., doi: 10.4182/amt.2011.E43
• Palumbo, J.C. 2011. Foliar and Soil Applied Insecticides for conrol of Beet armyworm On Head Lettuce. Arthropod Management Tests, Online. Vol 36, Section E45, 2 pp., doi: 10.4182/amt.2011.E45