Progress 09/01/18 to 08/19/21
Outputs
Target Audience:Primary audience of the project is the watermelonstakeholders in Georgia and Florida. This includes watermelon producers, packers, shippers, agronomists, crop consultants, farm managers, field workers, seed companies, and dealers; and owatermelon storage and shipping/transport personnel and companies. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Two graduate students were trained in UGA and one graduate student was trained in UFL. Extension agents and consultants were also trained on the symptoms and management of Fusarium wilt of watermelon. PI Dutta and Co-PIs Grey, Hajihassani, Coolong, Freeman and Paret provided training for graduate students in both field- and laboratory-based agricultural scientific techniques. Field-based techniques include establishing and evaluating field fumigation and fungicide efficacy trials, field plot design, field plot maintenance, fungicide application, disease diagnostics, disease evaluation, and yield assessments. Laboratory-based techniques included the isolation and morphological identification of disease-causing organisms, data analysis, statistics, and the preparation of presentations, technical reports, and manuscripts. How have the results been disseminated to communities of interest?Findings of the reserach were presented by PI Dutta, Co-PIs Freeman, Coolong and Hajihassani in various extension trainings and county extension meetings in Georgia and Florida. Extension publications and peer-reviewed articles were helpful in disseminating infomration to both scientific community and stakeholders. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Impact of bed architecture (standard vs. compact) and plastic mulch-type [low density polyethylene film (LDPE) vs. totally impermeable film (TIF)] on fumigation efficacy in Fusarium wilt management were evaluated in GA and FL in 2021. In both locations, six treatments were utilized; standard bed with LDPE plastic mulch (non-fumigated), standard bed with LDPE plastic mulch (fumigated with Pic-clor 60 at 300 lb/A), standard bed with TIF plastic mulch (fumigated with Pic-clor 60 at 300 lb/A), compact bed with LDPE plastic mulch (non-fumigated), compact bed with LDPE plastic mulch (fumigated with Pic-clor 60 at 300 lb/A), and compact bed with TIF plastic mulch (fumigated with Pic-clor 60 at 300 lb/A). Based on our results, bed architecture did not increase the efficacy of fumigation (Pic clor 60) as Fusarium wilt incidence was not significantly different between compact vs. standard beds. In contrast, the type of plastic-mulch affected the efficacy of fumigation. Irrespective of the bed architecture, plots with TIF-plastic mulch had significantly lower Fusarium wilt incidence compared with the plots with LDPE-plastic mulch. Overall, field trials were conducted over three years in FL and GA to examine bed architecture and plastic type of Fusarium wilt incidence. Bed architecture did not provide any benefit for Fusarium wilt management. The use of TIF improved Fusarium wilt management compared to standard LDPE. The use of TIF also significantly improved fumigant efficacy on nutsedge species compared to LDPE. Bed architecture did not have a significant effect on nutsedge control. Though the use of soil fumigation and TIF improved Fusarium wilt management compared to LDPE, disease incidence was above acceptable levels for commercial producers. Two independent trails were conducted in GA and FL in 2021. In GA, the field trial was conducted at the Crisp County Vegetable Park, Cordele, GA. In GA, an integrated trial was conducted where fumigant (Pic-clor 60 at 300 lb/A), non-fumigant nematicide (Nimitz; 5 pt/A) and post-transplant fungicide (Proline; 4.8 fl oz/A) were integrated in different combinations to constitute high-input and medium-input treatments. These treatments were compared with the grower's standard practice for Fusarium wilt control in watermelon. High input treatment comprised of fumigation with Pic-clor 60 (300 lb/A), a pre-transplant treatment with Nimitz via. drip-irrigation system (a week before transplanting) and a post-transplant treatment with Proline (a day after transplanting) as a soil-drench. Medium-input treatment comprised of fumigation with Pic-clor 60 (300 lb/A), and a post-transplant treatment with Proline (a day after transplanting) as a soil-drench whereas grower's standard treatment comprised of only Proline application as a soil-drench (a day after transplanting).A split-plot experimental design was adopted with four replications for each treatment. Plots were 100-ft long and 6-ft wide. An alley space of 10-ft was provided between each plot along the row. Disease incidence rating was assessed as percentage of plants with visible Fusarium wilt symptoms. Apart from the visual Fusarium wilt incidence, percent vascular discoloration for each plant per plot per treatment was recorded after the final visual rating in 2020. Yield data was collected for one harvest by harvesting and weighing all marketable fruit in each plot for the research-farm trials. Data were analyzed using analysis of variance (ANOVA) and the Fischer LSD test to separate means. Disease incidence based on both visual rating as well as vascular discoloration, Fusarium wilt incidence was significantly lower for the high- and medium input integrated treatments compared with the grower's standard treatment. Yield response did not follow the trend as observed with the Fusarium wilt incidence. The total marketable yield for the high- and medium-input treatments were 16,250 and 19,190 lb/A, respectively whereas marketable yield for the grower's standard control was 15,380 lb/A. These observations indicate that medium-input integrated treatment with Pic-clor 60 and post-transplant application of Proline (as soil-drench) will be effective in reducing Fusarium wilt incidence, which can potentially be translated into higher marketable yield and quality. Field trials were conducted in FL (2020 and 2021) to investigate the use of drip applied fungicides (Proline) with soil fumigation (Pic clor 60). Results indicated that drip applied Proline did not provide sufficient control of Fusarium wilt. When the same treatment was added to soil fumigation with a Pic-clor 60, it did not significantly improve Fusarium wilt management. An additional trial was conducted to evaluate the method of Miravis Prime application for the control of Fusarium wilt of watermelon in Georgia. Watermelon seedlings (Mickey Lee) were transplanted (10 April) on to black-plastic mulch. Plots were 40-ft long and 6-ft wide. An alley space of 10-ft was provided between each plot along the row. For treatment 1: Proline at 5.7 fl oz/A was applied as soil-drench application at planting (10 April) followed by two applications of Miravis Prime (11.7 fl oz /A) as a foliar spray in 40 gallons per acre of water on 20 April and 30 April. For treatment 2: Miravis Prime (11.4 fl oz/A) was applied as a 10-inch band prior to transplanting on 9 April. Treatment 3 represented grower's standard where Proline (5.7 fl oz/A) was applied as a soil-drench at planting on 10 April. Plots not treated with fungicides served as a non-treated check. Based on the final disease rating taken on 18 May (at harvest), all treatments significantly reduced Fusarium wilt incidence compared with the non-treated check (P < 0.05). Significant differences among treatments and grower's standard were not observed; however, treatment 1 had numerically lowest final disease incidence compared to others. These results indicate that Proline and Miravis Prime can be utilized in a fungicide program to manage Fusarium wilt incidence. A study was conducted to evaluate the impact of herbicide (Halsoulfuron) and non-fumigant nematicide (Nimitz) to control yellow and purple nutsedge and root-knot nematode (Meloidogyne spp.). Halosulfuron was applied pre-emergence to formed soil beds but before soil beds were covered with a plastic mulch (totally impermeable film [TIF]) at 16 g ai/A. Nimitz was applied at a rate of 5 pt/A via. drip irrigation system a week before transplanting. Yellow and purple nutsedge plants were counted multiple days after treatment and were continuously evaluated every two to three weeks throughout the growing season. Additionally, if multiple weed species are present visual estimates of weed control were also evaluated using a 0 to 100 scale, with 0 representing no weed control and 100 representing complete weed control. Our results indicate an increased amount of nutsedge in plots that did not receive a Halosulfuron application compared with plots that received it. Also, single application of Nimitz did not significantly reduce the number of adult Meloidogyne spp., which indicates that a fumigant (nematicide) in a program with Nimitz could provide better control. We conducted demonstration trials in FL and GA where fumigant, and fungicides were integrated to evaluate the efficacy of Fusarium wilt management. In both trials, although some effect of treatments could be observed in terms of decreased disease incidence but the level of control was above the acceptable levels for profitable watermelon production. Economic analysis was conducted to evaluate the economic feasibility of proposed integrated management option.
Publications
- Type:
Journal Articles
Status:
Under Review
Year Published:
2021
Citation:
Karki, K., Grant, J., da Silvac, A.B.H.R., Petkar, A., Hajihassani, A., Coolong, T., and Dutta. B. 2021. Evaluation of efficacy of Pic-clor 60 [choloropicrin pre-mixed with 1,3 dicholoropropene] and soil-applied fungicides to manage Fusarium wilt in watermelon. Crop Protection (accepted with revisions).
- Type:
Journal Articles
Status:
Published
Year Published:
2021
Citation:
Karki, K., Coolong, T., Kousik, C., Petkar, A., Myers, B., Hajihassani, A., Mandal, M., and Dutta, B. 2021. The transcriptome profile of watermelon is affected by Zn in the presence of Fusarium oxysporum f. sp. niveum and Meloidogyne incognita. Pathogens 10:796 https://doi.org/10.3390/pathogens10070796.
- Type:
Journal Articles
Status:
Published
Year Published:
2021
Citation:
Dutta, B., Karki, K., Foster, M.J., Donahoo, Grant, J., McCallister, S., Murdoch, M., and Starr, B. 2021. Evaluation of Pic-Clor 60 and fungicides for the control of Fusarium wilt of watermelon in Georgia 2020. PDMR 15:V018.
- Type:
Journal Articles
Status:
Published
Year Published:
2021
Citation:
Dutta, B., Karki, K., Foster, M.J., Donahoo, Grant, J., and Starr, B. 2020. Evaluation of Pic-Clor 60 and fungicides for the control of Fusarium wilt of watermelon in Georgia 2019. PDMR 14:V130.
- Type:
Other
Status:
Published
Year Published:
2020
Citation:
Fusarium wit of watermelon: Disease cycle. Plant Management Network, American Phytopathological Society
- Type:
Other
Status:
Published
Year Published:
2021
Citation:
Thompson, C. 2021. Fusarium wilt on rise in watermelon. Vegetable and Specialty Crop News, May 2021.
- Type:
Other
Status:
Published
Year Published:
2020
Citation:
Thompson, C. 2020. Managing Fusarium wilt disease in watermelon. Vegetable and Specialty Crop News, March 2020. (edits provided by B. Dutta)
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Progress 09/01/19 to 08/31/20
Outputs
Target Audience:Stakeholders involved in the southeastern US watermelon industry are the primary audience for this project. This includes watermelon producers (farmers), shippers, and associated stakeholders engaged in various capacities in watermelon production, distribution, and marketing, personnel associated with agricultural supply companies (pesticide dealers, fumigation and irrigation supply companies, etc.), cucurbit seed companies, and dealers,watermelonbreeders (public and private),andcounty extension agents. Changes/Problems:Evaluation of bed architecture and plastic mulch in GA could not be conducted due to COVID-19 related restrictions at UGA. Evaluationinteraction of nematicide and herbicide could not be conducted due to COVID-19 related restrictions at UGA. What opportunities for training and professional development has the project provided?Data generated during the 2018 and 2019 research season was presented to a scientific audience at the International Conference on Methyl Bromide Alternatives and Emissions Reductions in San Diego, CA during November 2019. Data was also presented to watermelon grower clientele at a producer meeting in Fanning Springs, FL during January 2020. How have the results been disseminated to communities of interest?Extension and outreach efforts were made using several regional and local stakeholder meetings. Research outcomes were communicated to the growers, county extension agents and consultants in several county extension meetings. A field demonstration trial was done in Cordele, GA where stakeholders were invited and local news channel covered the story. Four county extension trainings and six local county extnsion meetings were conducted to disseminate the information. The outcomes were also disseminated at the Southeast Fruit and Vegetable Conference at Savannah, GA (Jan, 2020). What do you plan to do during the next reporting period to accomplish the goals?We will conduct objective 3 where integration of best approaches identified in objective 1 and 2 will be conducted in GA and FL. We will also conduct economic analysis and extension in 2021. We will conduct a demonstration trial in a watermelon grower's field in GA and FL.
Impacts
What was accomplished under these goals?
For objective 1, a trial was conducted at the North Florida Research and Education Center in Quincy, FL during spring 2020 to investigate the effect of bed architecture and film type on Fusarium wilt incidence. This experiment investigated compact and standard bed architecture in combination with low density or totally impermeable film. Experiments have been concluded recently but data is awaiting analysis. For objective 2, two independent trails were conducted in GA and FL in 2020. In GA, the field trial was conducted at the Crisp County Vegetable Park, Cordele, GA. A mixture of chloropicrin and 1,3-dichloropropene (Pic-Clor 60) at 250 lb/A and 300 lb/A were applied at a depth of 12 in. using fumigation rig and subsequently raised beds were covered with a black plastic mulch using Rain-flo plastic layer. The soil type is sandy loam (sand: 55%, silt: 38%, clay: 7%). This field has a history of Fusarium oxysporum f. sp. niveum (race 2 and 3), hence, natural inoculum was relied upon. A split-plot experimental design was adopted with four replications for each treatment. Fumigated plots served as a main effect whereas fungicide-treated plots served as the sub-effect. Watermelon seedlings were transplanted onto single row beds. Plots were 100-ft long and 6-ft wide. An alley space of 10-ft was provided between each plot along the row. Fungicides; Proline (5.7 fl oz/A) and Miravis (11.3 fl oz/A) were applied through drip-irrigation line at a two week interval for a total of three applications. First application was made after a day of transplanting. Plots neither fumigated nor applied with fungicides served as negative control. For irrigation, plots were overhead-irrigated weekly as necessary. Fertility and insecticide treatments were applied according to University of Georgia Extension recommendations. Disease incidence rating was assessed as percentage of plants with visible Fusarium wilt symptoms. Data were analyzed using analysis of variance (ANOVA) and the Fischer LSD test to separate means. Mid-season Fusarium wilt incidence was not taken as symptomatic plants were not observed during this period. However, as the air and soil temperature increased in late June, Fusarium wilt incidence was observed. Disease incidence was taken a day before harvesting. Fusarium wilt incidence was significantly higher for the non-fumigated non-fungicide plots compared with other treatments. Plots treated with 300 lb/A (27.5%) of Pic-clor 60 significantly reduced disease incidence compared with plots fumigated with only 250 lb/A (50%). Although disease incidence for the plots treated with either Proline only (15%) or Miravis only (20%) were not significantly different from each other but they did significantly reduce Fusarium wilt incidence compared with non-fumigated non-fungicide plots. Interestingly, when plots were fumigated with Pic-clor 60 at 300 lb/A rate followed by a fungicide program with either Proline (2.5%) or Miravis (5%), disease incidence was significantly reduced compared with other treatments. Plots fumigated with Pic-clor 60 at 250 lb/A rate along with a fungicide program with Proline (35%) or Miravis (27.5%) had disease incidence not significantly different from Proline only (15%) or Miravis only (20%) treated plots. These observations indicate that Pic-clor 60 at 300 lb/A rate is optimum for reducing Fusarium wilt incidence; however, additional benefit can be achieved if a fungicide program comprised of either Proline or Miravis or both is used. Although significant reductions were achieved with Pic-clor 60 at a rate of 250 lb/A along with Proline or Miravis compared with only Pic-clor 60 treatments (250 lb/A), the response was more pronounced when the same fumigant was used at a rate of 300 lb/A along with either Proline or Miravis. One research trial was conducted at the North Florida Research and Education Center in Quincy, FL during spring 2020 to investigate the effect of Pic Clor 60 use rate on Fusarium wilt incidence. This experiment investigated standard bed architecture combined with a low and high rate of Pic Clor 60, both under totally impermeable film. Experiments have been concluded recently and but data is awaiting analysis. Extension and outreach efforts were made using several regional and local stakeholder meetings. Research outcomes were communicated to the growers, county extension agents and consultants in several county extension meetings.
Publications
- Type:
Other
Status:
Published
Year Published:
2019
Citation:
Dutta, B., Foster, M.J., Donahoo, W.M., Coolong, T., Gay, W and Grant, J. 2019. Evaluation of a pre-plant fumigant and a post-plant fungicide on the control of Fusarium wilt of watermelon in Crisp County, Georgia 2018. PDMR13:V060.
- Type:
Other
Status:
Awaiting Publication
Year Published:
2020
Citation:
Dutta, B., Foster, M.J., Donahoo, Karki, K., McCallister, S., Murdoch, M., Starr, W., and Grant, J. 2020. Evaluation of a pre-plant fumigant and a post-plant fungicide on the control of Fusarium wilt of watermelon in Crisp County, Georgia 2019. PDMR13:V130.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2019
Citation:
Freeman, J.H., M.L. Paret, and B. Dutta. 2019. Managing Fusarium wilt of watermelon with pre-plant fumigation. Proceeding of the International Conference on Methyl Bromide Alternatives and Emissions Reductions, Sand Diego, CA. https://www.mbao.org/static/docs/confs/2019-sandiego/papers/21freeman__joshua_h._.pdf
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Progress 09/01/18 to 08/31/19
Outputs
Target Audience:A field day was organized on July 2, 2019 (UGA)to demonstrate the efficay of fumigant (Pic-clor-60) and soil-applied fungicides (Proline and Miravis) in managing Fusarium wilt of watermelon.The field day was well attended by watermelon growers, industry cooperators (Syngenta, Valent, TriEST Ag.) and county extension agents. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Two graduate students (one at UGA and one at UFL) have been trained on Fusarium wilt symptomatology, administration of treatments, data collection and data analysis. A field day was organized to train county agents in Georgia and showcased the effect of treatments on Fusarium wilt. In Florida, county extension agents were trained on Fusarium wilt symptomology and disease progression. They have aided in data collection for field research that was held locally. How have the results been disseminated to communities of interest?Results were disseminated through county meetings in Georgia and also through a field day where county agents, watermelon growers and industry cooperators participated. What do you plan to do during the next reporting period to accomplish the goals?We will repeat our field study to evaluate effects of bed architecture, plastic mulch and fungicides on Fusarium wilt incidence. We will also repeat our field trials on interaction of Pic-clor-60 with two non-fumigant nematicides (Vydate and Nimitz) and halosulfuron on M. incognita nutsedge control. Results will be disseminated through county meetings, national and regional meetings and also through extension and peer-reviewed publications.
Impacts
What was accomplished under these goals?
Two field experiments were conducted during the first year of the project, one at the Crisp County UGA Extension field site at Cordele, GA and other in the watermelon grower's field in Levy County, Florida. These two field sites are heavily infested with FON These two field sites had low infestation of nutsedge. We evaluated the efficacy of chloropicrin containing (Pic-clor 60) product for the control of Fusarium wilt in two different plasticulture bed types: standard bed and compact high bed. The standard bed configuration was 8 inches (in.) high and 30 in. wide, and the compact high bed was 10 in. high and 15 in. wide. Prior to fumigation, the area were harrowed, roto-tilled and plots of 100-ft in length were prepared with 10-ft alley space between each plots. All bed configurations received similar fumigant use of 250 lb/A of Pic-clor 60. In Georgia, we observed that bed architecture did not significantly influence the efficacy of Pic-clor 60 (P =0.721). The final Fusarium wilt incidence for the compact and standard bed architecture was 23.2% and 28.2%, respectively. However, the mulch-type significantly affected Fusarium wilt incidence (P=0.045). Fusarium wilt incidence was significantly lower in total impermeable film (TIF) (18.2%) compared to low density polyethylene (LDPE) (23.4%) mulch, irrespective of bed architecture. Interaction between bed architecture and mulch-type was not observed. In Florida, similar trend was observed. Bed architecture did not significantly affect Fusarium wilt incidence. Although mulch type (TIF vs. LDPE) did not significantly affect disease incidence but numerical trends indicated higher incidence of Fusarium wilt with TIF compared with LDPE mulch. We conducted field trial in Georgia to evaluate the interaction of Pic-clor-60 and soil-applied fungicides (Proline and Miravis) on Fusarium wilt. A split plot, field experiment was conducted at the Crisp County UGA Extension field site at Cordele, GA, evaluating the interaction of fumigation and fungicide program on Fusarium wilt incidence/severity. This field site has a history of only FON infestation and has been under continuous watermelon production since 2010. Nematode populations (including M. incognita) are below action thresholds. We also identified three different races of FON from this site; race 1, 2 and 3. Fumigant (Pic-clor 60) was used as the main plot and the fungicide program as the first split. Prior to fumigation, the area was harrowed, roto-tilled and plots (100 ft long and 6 ft) wide were prepared. An alley space of 10 ft were kept between plot ends. Plots were fumigated with Pic-clor-60 (250 lb/A) as described in objective 1. A totally impermeable film (TIF) was used as a plastic mulch. After 24 days of fumigant application, two-week old watermelon seedlings (cv. Troubadour) were planted in each plot at a 2 ft spacing. Foliar and soilborne diseases other than Fusarium, insects and weeds were controlled using University of Georgia Extension recommendations. All treatments were arranged in a random complete block design with four replicates per treatment. We observed that application of Pic-clor 60 significantly affected final Fusarium wilt incidence with 10.2% incidence in fumigated plots compared with 18.1% in non-fumigated plots. Although interaction between Pic-clor 60 and soil applied fungicides were not observed but trends suggest that disease incidence was considerably lower in fumigated and fungicide treated plots compared with only fumigated or only fungicide treated plots. Watermelon fruit were harvested at 89 days after transplanting. Each fruit was weighed and graded into 60-count (9?13.5 lb), 45-count (13.6?17.5 lb), 36-count (17.6?21.4 lb.), and 30-count (21.5 lb. or more) classes according to the National Watermelon Research and Development. Three random fruit per plot were sampled and utilized for the internal quality parameters such as firmness, brix, and hollow heart disorder. Significant interactions between fungicide and fumigation treatments for the yield parameters evaluated were not observed. A fourth field trial is underway where we are currently evaluating a potential interaction of Pic-clor-60 with two non-fumigant nematicides (Vydate and Nimitz) on M. incognita control. In addition, we are also evaluating a pre-emergence herbicide (halosulfuron) for yellow nutsedge (YNS) (Cyperus esculentus) and purple nutsedge (PNS) (Cyperus rotundus) control and assess if managing these weed species aid in nematode management. A split plot design with one fumigant (main effect), and two non-fumigant nematicides with one pre-emergence herbicide for PNS and YNS control (sub effects) is being utilized. Nimitz and Vydare were applied as pre-plant band treatments and were thoroughly incorporated in the soil as per the label. In addition, two-post-plant drip applications of Nimitz was applied at 3- and 6-weeks after transplanting and two-foliar application of Vydate was applied during the same period. Halosulfuron was applied as a split plot. Currently, the preliminary data shows an increased amount of YNS and PNS in plots that did not receive a halosulfuron and nematicide treatments. Treatments with halosulfuron have <2 nutsedge plants/ft2.
Publications
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