Progress 08/07/14 to 05/14/19
Outputs
Target Audience:Cotton producers and those involved in the cotton industry in TX, AZ, NM, and CA. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Undergraduate and graduate students gained hands-on training and experience in data collection, laboratory procedures, written and verbal communication skills, and overall management efforts. How have the results been disseminated to communities of interest?I have given presentations at grower meetings (total audience about 920) throughout Texas addressing the research: - Cotton diseases and their management. New Mexico Crop Production Association, Ruidoso, NM. Jan. 22, 2019 -Cotton diseases and management options. 57th Blackland Income Growth Conference, Waco, TX. Jan. 15, 2019. - Cotton root rot control and phytotoxicity. 2018 Texas State Support Review, Lubbock, TX Nov. 28, 2018. - Site specific management of cotton root rot. 56th Blackland Income Growth Conference, Waco, TX. Jan. 10, 2018. - Management of cotton root rot. Consultants Conference. Beltwide Cotton Conferences, San Antonio, TX. Jan. 3, 2018. - Cotton root rot control and phytotoxicity. 2017 Texas State Support Review, Lubbock, TX Nov. 29, 2017. - Cotton root rot update. Concho Valley Cotton Conference, San Angelo, TX March 7, 2017. - Disease management in cotton. Cotton Management in Northeast Blacklands, Paris, TX Feb. 23, 2017. - Cotton root rot update. 2017 Texas/Oklahoma Cotton Physiology Meeting, College Station, TX Jan. 31, 2017. - Cotton Root Rot Disease Update. 55th Blackland Income Growth Conference, Waco, TX, Dec. 13, 2016. - Cotton root rot control and phytotoxicity, Texas State Support Committee, Lubbock, TX, Dec. 1, 2016. - Cotton Root Rot and Integrated Pest Management. Medina County Cotton Field Day. Castroville, TX, Sept. 16, 2016. - Cotton Disease Update. Tom Green County Turn Row Meeting, Wall, TX, Aug. 18, 2016. - Cotton Diseases and Management. South Texas County Agent Cotton Training, Corpus Christi, TX, May 4, 2016. - Situation and research update. Site-specific Management of Cotton Root Rot Meeting, San Angelo, TX, Jan. 26, 2016. - Topguard application strategies and other disease management issues for cotton and sorghum, Field Crop Symposium, Corpus Christi, TX, Jan. 30, 2015. - Cotton Root Rot. Blackland Income Growth Conference, Waco, TX, Feb. 3, 2015. - Phytotoxicity of flutriafol and new application methods for cotton root rot control, 2015 Texas/Oklahoma/Louisiana Cotton Physiology Meeting, Austin, TX, Feb. 9, 2015. - Phytotoxicity of flutriafol and new application methods for control of cotton root rot, Concho Valley Cotton Conference, San Angelo, TX, Mar. 24, 2015. - Management of cotton root rot with Topguard - prevention of phytotoxicity and evaluation of new fungicides in the field, Texas State Support Committee, Lubbock, TX Dec. 3, 2015. - Control of Cotton Root Rot, Cotton Production Meeting, Birome, TX Aug. 19, 2014 - Cotton Root Rot Report, Texas State Support Committee, Lubbock, TX Dec. 3, 2014 What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
1. Evaluate factors contributing to phytotoxicity of Topguard Terra to cotton. Research was focused on development of a greenhouse assay system for studying Topguard Terra phytotoxicity, which is seen as delayed or reduced emergence. It occurs as a result of heavy rain or irrigation to treated soil, prior to the emergence of the seedlings. If the moisture is applied to the soil after seedling emergence, there is no phytotoxicity.Evaluate factors contributing to the phytotoxicity of Topguard Terra to cotton. The in vitro experiments done in 2015 and in subsequent years provided no useful guidance for reducing or preventing phytotoxicity. 2. Evaluate new methods of application of Topguard Terra for PRR control. The data from the 2016 study show that surface treatments with Topguard Terra after planting can reduce the level of root rot to the same extent as the currently-labeled at-planting treatments. This confirms previous studies. The novel finding is that these post-plant, surface treatments were still effective, even though more than a month had elapsed between the application and the first rain, which is needed to "activate" the fungicide. If this retained effectiveness following a long, dry period occurs consistently, then growers would have additional options for applying Topguard Terra. Growers may opt to apply Topguard Terra only after planting, with complete immunity from phytotoxicity. Growers have also stated that they would prefer to add the cost of a Topguard Terra application to their inputs if they were sure that they had a good cotton stand to start the season. Alternatively, growers could split applications. Instead of applying a high rate at planting and risking greater phytotoxicity than with a lower rate that may play out later in the season, they could apply a safer, lower rate at planting and then boost the fungicide level around the plant with a later application.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2015
Citation:
Isakeit, T. 2015. Interaction of flutriafol with germinating cotton. In Proc. Beltwide Cotton Conferences (abstract), page 231. National Cotton Council of America, Memphis, TN
- Type:
Journal Articles
Status:
Published
Year Published:
2016
Citation:
Yang, C., Odvody, G.N., Thomasson, J.A., Isakeit, T., and Nichols, R.L. 2016. Change detection of cotton root rot infection over 10-year intervals using airborne multispectral imagery. Computers and Electronics in Agriculture 123:154-162. DOI:10.1016/j.compag.2016.02.026
- Type:
Journal Articles
Status:
Published
Year Published:
2018
Citation:
Yang, C., Odvody, G.N., Thomasson, J.A., Isakeit, T., Minzenmayer, R.R., Drake, D.R., and Nichols, R.l. 2018. Site-specific Management of Cotton Root Rot Using Airborne and High-resolution Satellite Imagery and Variable-rate Technology. Transactions of the ASABE 61:849-858. doi.org/10.13031/trans.12563
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Progress 10/01/14 to 09/30/15
Outputs
Target Audience:Cotton producers and those involved in the cotton industry in TX, AZ, NM, and CA. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?The project gave three undergraduate students the opportunity to learn about field and lab experiment design and execution. How have the results been disseminated to communities of interest?The data from 2015 was presented to a group of about 40 people in the cotton industry (growers, scientists and university administrators) on December 3, 2015 at a meeting in Lubbock, TX. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Until recently, there has been no effective control for cotton root rot (PRR), a disease caused by a soilborne fungus that is widespread in Texas as well as Arizona. My research, done under a previous Hatch project, identified Topguard (flutriafol) as an effective fungicide and also determined that it could be applied at planting to control this disease, which occurs later in the growing season, about when cotton starts flowering. This fungicide is now on the market and is increasing cotton income in the order of tens of millions of dollars annually. As a more specific documentation, in December, 2015, a west Texas cotton farmer who has 1200 acres told me that Topguard is increasing his productivity by 800 bales annually, or about $230,000. However, if there is more than about one inch of rain within three or four days of planting, before the cotton has emerged, there is a high risk for phytotoxicity from the fungicide that reduces stand. My research is devoted to determining why this is happening and evaluate safer or more efficient methods for applying the fungicide. 1. Evaluate factors contributing to phytotoxicity of Topguard to cotton. I did an in vitro experiment to determine if a commercial potassium fertilizer that is applied at planting could prevent phytotoxicity. It did not. I also continued experiments to evaluate Topguard phytotoxicity in a soil system where soil moisture could be control. In a previous in vitro experiment, I screened many commercial cotton varieties for reaction to Topguard. From this information, I chose two large-seeded varieties, one much more sensitive to Topguard than the other, and also, two small-seeded varieties that differed in the same way. When these varieties were planted in the soil system, the growth inhibition did not correlate with inhibition observed in the in vitro experiment. These results suggest that I need to continue development of a better lab system to study phytotoxicity. 2. Evaluate new methods of application of Topguard for PRR control. In 2014, I found that shanking Topguard into the planting row about a month before planting could control the disease without risk of phytotoxicity. I also obtained data that supports a post-plant or post-emergence application that year. In 2015, I repeated these field experiments, and also, to see whether there was any carry-over of fungicide applied in 2014 and whether this carry-over could control disease in 2015. However, there was very little rain during the growing season and consequently, little disease development, so I was unable to obtain any useful data.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2015
Citation:
Isakeit, T. 2015. Interaction of flutriafol with germinating cotton. In Proc. Beltwide Cotton Conferences (abstract), page 231. National Cotton Council of America, Memphis, TN
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Progress 08/07/14 to 09/30/14
Outputs
Target Audience: Cotton producers and those involved in the cotton industry in TX, AZ, NM, and CA. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? The project gave four undergraduate students the opportunity to learn about field and lab experiment design and execution. How have the results been disseminated to communities of interest? The data from 2014 was presented to a group of about 40 people in the cotton industry (growers, scientists and university administrators) on December 3, 2014 at a meeting in Lubbock, TX. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
1. Evaluate factors contributing to phytotoxicity of Topguard to cotton: A. Experiments with germination of cototn on paper: Thirteen varieties of different seed sizes (ranging from 7.689 to 10.898 g/ 100 seed) were evaluated. Fifty seeds per replicate were placed on a sheet of germination paper (Anchor Paper, St. Paul, MN), saturated either with water or with a flutriafol suspension (1.56 mg /ml), rolled up, and incubated for five days, at either 22°C or 20°C. Germination was then counted, roots were excised, pooled, dried over-night in an oven at 45°C, and weighed. There were four replicates per treatment. Exposure to flutriafol had no effect on seed germination but the exposure significantly (P=0.05) reduced root weight as compared with the control. With the 13 varieties, seed size was positively correlated with root growth at both 22°C and 20°C . The degree of inhibition of root growth of the varieties by flutriafol at both temperatures was proportional to growth in the controls, i.e. there was no apparent interaction between seed size and flutriafol treatment. With seeds that were treated with flutriafol two days after the start of the experiment, there was no difference in the inhibition by flutriafol, in comparison with seeds continuously exposed to flutriafol. In other experiments, root growth was inversely proportional to flutriafol concentration. B. Experiments with germination of cotton in soil: Soil matric potential was controlled using a Haines’ apparatus. The apparatus consisted of a 97 mm diameter buchner funnel with fritted glass plates of fine porosity as tension plates. Each funnel was evenly filled with 100 g of a Mereta clay loam and 50 seed of either a “small seed” variety (8.144 g/100 seeds) or a “large seed” variety (10.672 g/100 seed) were placed evenly on the surface. Flutriafol (0.3 g in a volume of 2.4 ml) was then sprayed onto the exposed seed and soil using a hand sprayer. The seeds were then covered with 50 g soil and the soil matric potential was adjusted to -3.7 kPa. There were three replicates per treatment. Using the Haines’ apparatus to control soil moisture, root growth inhibition with flutriafol did not consistently occur. With four varieties, there were differences in root growth in soil that were proportional to seed size, but there was no interaction with flutriafol treatment, nor was there an interaction with soil type. The soil moisture levels in the experiments were continuously high and did not fluctuate. The data suggests that root growth inhibition by flutriafol is not variety-specific, but growth inhibition may have a greater impact in varieties with small seed. In a commercial field, the concentration of flutriafol in the vicinity of the seed in soil is probably lower than concentration used in these experiments, so at this time, the paper germination data can not be used to predict varietal response in the field. To date, results with soil have been inconsistent and the duplication of flutriafol inhibition of germination was not seen with very wet soils. Current experiments are evaluating the effect of fluctuating soil moistures on root growth. 2. Evaluate new methods of application of Topguard for PRR control. Experiments were established on two commercial farms (Nueces and Hill counties) and the Stiles Farm (Texas AgriLife Extension Station in Williamson county). The Nueces county experiment was abandoned because of drought. The treatments at the Hill county field comprised 1 or 2 pints Topguard per acre, applied as a band on the soil surface at planting (April 17), at the cotyledon stage (April 26), and at four true leaves (May 25). There was no T-band or in-furrow treatment at planting. Treatments were four rows, 100 feet long, with four replicates per treatment and two non-treated rows between treatments. On August 16, plots were rated for root rot in 40, 10-ft segments using the following scale: 0= no symptoms; 1= one or two symptomatic plants; 2= symptoms visible in less than 50% of plants in the segment; 3= symptoms in greater than 50% of plants; 4= all plants in segment dead. The ratings provided information on the distribution of the disease within the experimental area and allowed for a comparison with non-treated rows next to treated segments of plots. The first rainfall that saturated the soil was on May 8. There were two other rain events that saturated the soil, including one on May 27, two days after the application at four true leaves. There were 6 other soil-saturating rain events in June and July. Disease within the field became apparent in mid-July. There was less disease in all the fungicide treatments at the Hill county site overall, as compared with the non-treated plots, based on the sum of ratings of 40 segments within each plot. There was substantial variability in all plots because of the lack of uniform disease development, but in segments adjacent to non-treated rows, the fungicide treatments tended to have lower disease ratings. The percent rating differences between adjacent fungicide-treated and non-treated segments tended to be greater, with less variability. There was a trend of less disease with the 2 pint/A rate, in comparison with 1 pint/A. In September, following defoliation, we decided that there was not a great contrast between treated and non-treated plots which would be reflected in yield, so we did not take this experiment to yield. There were two experiments at the Stiles Farm. One experiment compared surface band applications at three times after planting with a T-band application at planting. Another experiment compared incorporation (knifing) in the center of the row at three depths one month prior to planting, with a T-band application at planting (May 19). The rates were equivalent to 2 pints/A. At this location, there were soil-saturating rains on May 27, June 9, July 3, July 18 and August 29. The May 27 rain was 8 days after planting and two days after the first surface band spray (cotyledon stage). There was also rain two days after the second band spray ( 2-3 true leaf stage) and seven days after the third band spray (8 true leaf stage). With the post-plant application experiment, all treatments reduced root rot and increased yield. Of the fungicide treatments, the T-band application had the lowest root rot and the highest yield, while the surface band applied at the cotyledon stage gave the least effective response. With the pre-plant knifing experiment, all treatments reduced root rot and increased yield. The lowest disease and the highest yield was with the equivalent of a 6 pint/A T-band application. Although the 2 pint/A T-band application had the second lowest level of disease, it also had the lowest yield. The best pre-plant application was the two- inch depth.
Publications
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