Use a soil probe or look at the roots of this year's crop to evaluate hardpans. Fertilizer applications of P and K are appropriate in the fall or early spring. Applications of N should be delayed until stand establishment. Contact your local county Extension agent for assistance in obtaining this information if access to the internet is not available. However, environmental influences such as temperature, water, and potassium availability can modify the genetic potential for length.
Extreme heat can limit fiber length.
This may lower overall length if the plant is under drought stress or if nighttime temperatures are abnormally high. Although daytime temperatures were high, we did not have an extended period of time that nighttime temperatures were 80 o or higher as we have seen in previous years. Strength, too, is primarily determined by variety. Longer strands of cellulose molecules with more cross linkages between strands create stronger fibers. Avoiding severe potassium deficiencies and excessive field weathering will help maintain strength.