2024 UF/IFAS Cotton Variety Test Summary

Sudeep Sidhu, Agronomy Specialist, UF/IFAS North Florida Research and Education Center, Quincy.

Gabrielle Alves Comitre, Graduate Research Assistant, UF/IFAS North Florida Research and Education Center, Quincy.

Shivendra Kumar, Regional Specialized Agent, UF/IFAS North Florida Research and Education Center, Live-Oak.

Ethan Carter, Regional Crop IPM Agent, UF/IFAS Extension, Jackson County.

Lydia Bolton, Ag/Food Scientist, UF/IFAS North Florida Research and Education Center, Quincy.

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Purpose and Scope

In 2024, a total of 27 cotton varieties and testing lines from four companies were planted under irrigated and dryland conditions. Most of the cotton grown in Florida is in the Panhandle, particularly in Jackson, Santa Rosa and Escambia Counties where the majority of cotton production is non-irrigated, however, significant irrigated acreage also exists. Due to the distinct agroclimatic characteristics of the Panhandle and Suwannee Valley, cotton variety trials under irrigated and dryland conditions are needed to better understand the agronomic performance of cotton varieties. Cotton seed is one of the major costs associated with cotton production for Florida growers. Therefore, crop variety trials ensure that new crop varieties confer tangible agronomic benefits, thereby enhancing agricultural efficiency, sustainability, and economic viability. These trials enable the identification of varieties best suited to diverse environmental conditions. Two replicated small plot trial sites were established as a Randomized Complete Block Design (RCBD) with four replications, one site at North Florida Research and Education Center (NFREC)-Quincy, FL and another site at North Florida Research and Education Center-Suwannee Valley (NFREC-SV), Live-Oak, FL.

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Management

The treatments consisted of 27 varieties/experimental lines that were evaluated in small plot replicated trials at both locations planted on 36-inch rows, 20 feet long. In Quincy, the irrigated cotton trial was planted on April 30th and non-irrigated trial was planted on May 1st. Due to weather conditions, cotton planting was behind in our region, last season we finished planting small plot replicated cotton variety trial in Live-Oak on May 30^th (irrigated) and May 31st (non-irrigated). The irrigated cotton in Quincy was harvested on October 16th and the non-irrigated cotton was harvested on November 13th . For cotton harvest in Quincy a cotton picker was used and the two central lines of each plot were harvested to get yield data and fiber evaluation.  The irrigated cotton in Live-Oak was harvested on October 30th and the non-irrigated cotton was harvested on November 4th. For cotton harvest in Live-Oak, cotton bolls were hand-picked from the two center rows of each plot, and it was equal to 40 feet, and after harvest the total weight was measured to obtain yield data.

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Fertility

Due to the difference in soil type and climate, cotton management was site specific. Total fertilization use for irrigated cotton in Quincy was 120 lbs/ac of nitrogen (N), 182.5 lbs/ac of potassium (K) and for non-irrigated cotton 90 lbs/ac of N was applied. N and K were applied in two split applications, the first application was made before planting, using the fertilizer 5-0-30 at a rate of 275 lbs/ac.

In Live-Oak, the total fertilization use for irrigated cotton was 115 lbs/ac of N, 81 lbs/ac of K, 20 lbs/ac of phosphorus (P), 5.4lbs/ac of magnesium (Mg) and 11 lbs/ac of sulfur (S). N was applied in three split applications, the first application at 15 days after planting was 200lbs/ac of 14-4-14, the second application at 45 days after planting was 300lbs/ac of 14-4-14 plus 50lbs/ac of Kmag to provide K, sulfur (S) and magnesium (Mg), and the third application at 60 days after planting was 15gal/ac of 28-0-5 applied by pivot. For the non-irrigated cotton in Live-Oak, fertilizer was applied at a rate of 98 lbs/ac of N, 109 lbs/ac of K, 28 lbs/ac of P, 11 lbs/ac of S, and 5.4 lbs/ac of Mg. N, P and K were applied in three applications, at 15, 45 and 70 days after planting.

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Data Collection

The data was collected throughout the season to evaluate several agronomic traits to understand how different cotton varieties behave in each location. The data measured consisted of plant emergence rate, plant height, number of nodes, number of nodes above white flower, yield and lint quality. In Quincy, the irrigated cotton emergence rate was evaluated three times 5, 8 and 22 Days After Planting (DAP), and the non-irrigated cotton emergence was evaluated with 6, 11 and 22 DAP. This evaluation was performed randomly in 20 feet from each plot. Plant height and number of nodes data were measured twice, in June and July, for these measurements five randomized plants from each plot were used.  Due to the two hurricanes, Debby and Helene, that hit Florida last year, our on-farm cotton trails in Jefferson County were completely compromised and unable to be harvested, therefore these plots were lost.

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Table 2: Fiber Evaluation

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Table 3 Quincy Irrigated Cotton Variety Test Summary

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Table 4 Quincy Dryland Cotton Variety Test Summary

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Table 5 Live Oak Irrigated Cotton Variety Test Summary

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Table 6 Live Oak Dryland Cotton Variety Test Summary