The long-accepted standard for growth intervals between 1st position cotton fruit on consecutive nodes, or fruiting branches, is 3 days. The accepted interval between fruiting positions on the same fruiting branch is 6 days.
The basis of these intervals dates back to original research in 1916 which indicated the vertical interval between flowering was about 3 days and the horizontal interval was about 6 days. Thus, 3 UP and 6 OUT are widely, commonly accepted. Other investigations over the years have suggested slightly different intervals both vertical and horizontal.
In the early 2000s, research (Bednarz and Nichols, 2005, Crop Science) was conducted in Georgia with 9 varieties common at the time, including some of the first transgenic offerings. This detailed, 3-year study measured a vertical flowering interval of 2.1 to 2.6 days and a range of 3.2 to 4.4 days for flowering on adjacent horizontal fruiting positions.
This suggests that things can progress a little faster than we might expect, at least as compared to the accepted standards. This research also revealed slight variations within the crop canopy. “Mean vertical flowering intervals increased from main stem node 5 to about main stem node 11 and then began to decline.”
Does this indicate we can make a crop quickly? Yes. Most modern varieties fruit extremely rapidly but not for a long duration. With available Bt cultivars and in the absence of serious plant stresses or pest damage, early fruit retention is extremely high, quite often 95% or better through early bloom. While flowering may accelerate in the upper canopy, quite often the plant has already reached “near full capacity” in terms of fruit retention. We CAN make a rather full crop in as little as 4 weeks. This provides some hope and expectation even for a late crop, with assists from favorable fall weather and thoughtful management.
USDA estimates Alabama 2021 cotton plantings at 450,000 acres. It’s hard to argue with that number given the wide diversity of environments and geography in which our crop is grown.
Overall, the crop is LATE in every corner of the state. Planting delays, cool weather, rain, and then diminishing soil moisture pushed back planting, emergence, and early growth. Thrips ragged many fields, but with June rains and improving temperatures, cotton is beginning to look like cotton should. Warm temps and good soil moisture will likely nudge us a little back towards normal.