Bill Pettigrew, USDA-ARS agronomist in Stoneville, Miss., has spent more than a decade studying cotton’s optimum planting date.
“A consistent yield advantage could be gained from planting in the first half of April instead of in the traditional planting time of late April to early May,” Pettigrew says. “The idea of this approach is to shift bloom closer to the first day of summer, the day with the longest period of sunlight, which synchronizes peak bloom with the availability of more sunlight to achieve maximum photosynthesis.”
However, all of these studies were conducted with the use of irrigation. Interested in what effect the absence of irrigation would have, Pettigrew conducted a four-year study on the yield performance of irrigated versus dryland cotton planted early compared to normal planting time.
Six different varieties were planted either the first week of April or the first week of May. Half of the plots were irrigated, the other half dryland. Except for the first year of the study, which was affected by hurricanes, irrigation always increased lint yield regardless of the planting date.
Normal Timing For Dryland
“Irrigation increased lint yield by 55 percent in three of the four years,” he says. “Under early planted conditions, in 2006 and 2007, yield was increased by 13 percent under irrigated conditions, but not dryland.”
Pettigrew found that under dryland conditions early planting decreased lint yield. “Dryland producers probably shouldn’t consider planting early.”
As for fiber quality, early planting produced, on average, five percent weaker fiber.
“It would not have been in the discount range, but we also tended to see an increase in short fiber in about 50 percent of the situations,” Pettigrew says.
In most years, planting early, and only with the use of irrigation, offers producers the opportunity to increase yields and get the crop picked before harvest conditions deteriorate.
“It’s kind of an avoidance strategy, getting the crop set before the onset of stress situations and then getting it out of the field before bad weather begins in mid-to-late October,” he says.
Nematodes, Seedling Disease
Nematodes, rather than weather, can become a producer’s reason to plant early.
Rome Ethredge, County Coordinator for the University of Georgia Cooperative Extension Service in Seminole County, says that in fields with deep, sandy soil, producers plant early because of the presence of Southern root-knot nematode.
“They get in and get out before nematodes get worse later in the season, and they tend to get a better yield,” he says.
Ethredge says in some years early planting does better, and in other years, later planting does better.
“Producers really just try to spread out the risk,” he says. “Cotton planted early does tend to have more problems with seedling disease.”
Planting early or at the normal time depends on individual situations and the producers’ willingness to accept the risk involved.
Contact Amanda Huber at (352) 486-7006 or firstname.lastname@example.org.