Cotton farmers should focus on soil temperature rather than the calendar for optimal planting time, according to Dan Fromme, LSU AgCenter cotton specialist.
Cotton is usually planted between mid-April and mid-May in Louisiana.
However, recent cooler temperatures may have slowed seasonal spring soil warming and could significantly affect the critical germination period required for cotton.
“If planted too early, survival of cotton seedlings will be reduced, and the remaining plants are less vigorous, which can cause reduced yield potential,” said Fromme.
“Warmer temperatures are needed the first four to five days after planting when the seed begins to germinate and imbibe water followed by the tiny roots, or radicles, beginning to emerge from the seed. This will lead to a more rapid emergence and less energy used trying to emerge from the soil.”
A cumulative effect from cool temperatures during the germination period can result in stand loss and yield reduction. “If emerging seedlings are injured, they will lose the capacity to manufacture vital carbohydrates and proteins needed to remain vigorous and healthy during the early vegetative stage of development,” Fromme said.
Malformed seedlings, loss of the taproot, reduced vigor, undesirable stand and increased likelihood of seedling disease problems can occur from chilling injury.
“The longer the seeds are exposed to the cold, the severity of injury increases, causing delayed maturity and reduced yields,” Fromme said.
“Delayed planting of up to four weeks until optimal conditions exist may only result in a one- to two-week difference in flowering.
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