Location: Crop Production and Protection
Project Number: 0500-00102-001-027-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: May 17, 2023
End Date: Jun 4, 2025
Objective:
Objective 1. Management PLOTS with active and passive sampling of air borne spores to build and validate pathogen models- This task will include the following subtasks:
a. In Alabama, two management plots will be established in Brewton and in Tallassee.
b. Capture weather data using subscription to Cooperator and/or on-site weather stations.
c. Collect crop information like planting date, planting rate, management data, crop phenology, and yield.
d. Capture disease incidence and severity. Visit plot weekly to collect disease symptoms (target spot, areolate mildew, and leaf spot complex ratings), and replace and ship passive and active air cartridges.
Objective 2. COMMERICIAL FIELD with active and passive sampling of air borne spores near management plots to validate models and demonstrate the utility of pathogen sampling- This task will include the following subtasks:
a. In Alabama, three commercial fields in Escambia and Lee counties will be monitored in this study. Active and passive air samplers will be installed at two opposite ends of the commercial cotton fields located near the management plots. Air sampling will be conducted for 4 months (mid-June to mid-October) for Alternaria, areolate mildew, and target Spot.
b. Capture weather data using subscription to Cooperator and/or on-site weather stations.
c. Collect disease symptoms. Bi-weekly visit and record limited crop phenology and to replace passive air sampler from mid-June to mid-October.
Objective 3. SEED TREATMENT TRIALS to relate soil-borne pathogens, environmental conditions, and seed treatment pesticides to cotton stand establishment – This task will include the following subtasks:
a. In Alabama, one seed treatment trial will be established at the E.V. Smith Research Center in Tallassee as part of the NCST program.
b. Capture weather data using subscription to Cooperator and/or on-site weather stations.
c. Collect crop information like planting date, planting rate, management data, and yield.
d. Capture disease data. Stand data will be collected and soil and plant tissue samples will be collected for disease prevalence of Pythium spp., Fusarium spp., Rhizoctonia solani, and Thielaviopsis basicola. DNA detection tools will be used from soil and cotton seedling root tissue to identify the pathogens present in samples.
Approach:
Foliar Disease Investigation – Thirteen 'management plots' will be established across the cotton belt with two varieties per plot to create a range of maturities or microclimates. In Alabama, two management plots will be established in Brewton and in Tallassee and will include a tolerant target spot variety (Deltapine 1646 B2XF) and a susceptible variety (Phytogen 500 W3FE). Weather will be captured daily with onsite weather stations. Plots will be visited weekly to 1) conduct incidence and disease severity ratings for target spot, areolate mildew, and leaf spot complex , 2) record limited crop phenology (height, canopy closure, 1st flower, 1st open boll), and 3) replace and ship passive and active air cartridges. Plot dimensions, fungicide, defoliant application dates, planting and harvest dates, and yield data will also be collected. Air will be sampled for four months (mid-June to mid-October) at two heights for Alternaria, areolate mildew, Stemphylium and target spot. In-canopy air sampling at four heights was conducted at least once during full canopy for the same pathogens. Commercial fields with an active and passive sampling of airborne spores near management plots will validate models and demonstrate the utility of pathogen sampling. Air samplers will be installed at all four corners of commercial cotton fields near the management plots. Air sampling will be conducted for four months (mid-June to mid-October) for Alternaria, areolate mildew, and target spot. We will identify and map the adjacent crops and native vegetation within one mile of the field. We will visit the plots biweekly to collect disease symptoms and limited crop phenology and to replace the passive air sampler from mid-June to mid-October.
Seedling Disease Investigation – We will leverage the existing National Cotton Seed Treatment Trial, for which specific details about the trial can be found in previous publications at http://www.cotton.org/beltwide/proceedings/2005-2020/index.htm. Using these data and new data in 2023, we will investigate the relationship between soil-borne pathogen populations, environmental conditions, soil edaphic factors, and seed treatment pesticides for cotton stand establishment. Cotton of the cultivar Deltapine 1646 B2XF will be treated with fungicide treatments and planted in a randomized complete block design, with between 3 and 5 seeds per foot. The stand will be evaluated 30 days after planting. Plots will be established at nine field sites. In Alabama, seed treatment trials will be established in Tallassee. Environmental data and soil and plant tissue samples will be collected for disease prevalence. Soil samples and cotton seedlings will be collected at 30 days (approximately 10 cores, 0-6") from the nontreated plots. Samples should be taken randomly from each nontreated plot at 30 days (100 seedlings total). The 100 seedlings will be sent to a Cooperator for laboratory pathogen isolation. Fifty of the 100 seedlings will be sent to a Cooperator.
