Cotton Consultant's Corner:
BS degree in Agronomy – University of Arkansas, Fayetteville
There are several potential problems associated with lateplanted cotton, including greater vulnerability to worm and plant bug pressure. Once other crops besides cotton, such as corn, start to shut down, insects move from those fields into cotton. And those insects – mainly corn earworm or cotton bollworm moths – like to seek out cotton that isn’t as far along in growth. The moths will gravitate toward the younger, greener, more succulent cotton versus seeking out more mature cotton fields. These bollworms are more likely to show up later and in greater numbers.
Even in Bollgard® or Bollgard II® cotton, heavy egg lays from the bollworm can translate into young worms feeding in blooms. This situation also applies to fall armyworms, which tend to show up later in the season anyway. Growers and their consultants need to be extra vigilant when scouting late-planted cotton and be prepared to apply insecticides when economic thresholds are reached.
One way growers can compensate for late-planted cotton is to be more aggressive with their use of plant growth regulators (PGRs), such as Pix®. By using PGRs earlier and at higher rates, it is possible to “push” the cotton plant and re-channel its energy from making stalks to making bolls.
Late-emerging grasses can also be a problem in late-planted cotton, especially if the cotton is not Roundup Ready® Flex. You just can’t come back into the field with a sprayer as late in the season as you can with Roundup Ready Flex cotton, and late-emerging grass can be difficult to control.
Cotton planted after May 25, according to university studies, loses an average of one to two percent of its yield potential for every day after that date before the seed goes in the ground. A late, open fall can compensate somewhat for yield loss, but we all know that a late fall can’t be counted on. When planting cotton late, avoid late-maturing varieties in favor of early- and mid-maturing varieties.