Project Number: 6066-21000-001-011-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Jun 1, 2021
End Date: May 30, 2023
1. To evaluate the effect of cultivar and environment on seasonal trends in nectar production and soluble carbohydrate concentration in cotton. 2. To quantify photosynthetic activity of the subtending leaf in relation to bract nectar secretion and boll mass for modern and obsolete cultivars. 3. To determine if associations exist between intra-boll yield components and nectar production.
This study will be conducted over two years at field sites in three locations across the cotton belt. Specifically, field studies will be established in Tifton, GA, Stoneville, MS, and Lubbock, TX. In order to isolate environmental effects on nectar secretion and yield component responses, it will be important to utilize the same cultivars at all locations. To this end, a minimum of 6 common cultivars will be grown at all sites. The cultivars selected will represent modern cultivars and cultivars released over a nearly four decade period by public breeding programs. Plots will be arranged as a randomized complete block design with a minimum of four replicate plots per variety at each location. Planting dates, harvest dates and management practices will be recorded for each site and will be conducted according to local extension service recommendations. In-season measurements of nectar production will begin at approximately five weeks after planting (the onset of squaring) and will be conducted every two weeks throughout the season until defoliation.