ABSTRACT
Trends in cotton variety improvement continues to focus on yield, earliness and fiber quality. Smaller plant size, lower leaf index, and high harvest index are some specific traits being developed for future varieties. Such variety traits make more effective use of high nitrogen-water inputs to achieve maximum yields in 30-inch row width. Variety recommendations to producers are primarily based on yield performance, degree of earliness, fiber properties and method of harvest. Sound, vigorous seed are essential to insure a uniform stand of healthy seedlings. Quality recommendations for cotton planting seed include a standard germination percentage of 80 or more and a cool germination percentage of 50 or higher. Planting date recommendations are generally based on soil temperature or a combination of soil and air temperature readings. Time and soil depth for determining temperatures will vary across the Cotton Belt. In California, a 5-day heat unit accumulation forecast can be used to determine planting dates. Chilling injury (50° or below) during early hydration period can slow early seedling growth and cause greater sensitivity to pathogens. Important up front decisions also include row-spacing and plant population. Primary decisions concerning row spacing must take into account yield advantage, earliness, grade improvement and harvesting consideration. Planting rate recommendations suggest 4 to 6 seed per foot (38 to 40-inch row width) to achieve a final plant population of 30 to 40 thousand plants per acre. Planter metering systems should be in good repair to ensure uniform spacing of plants and maximum yields.
|