Darrin Dodds, Mississippi State University
Progress was made with respect to planting on Tuesday, Wednesday, and Thursday of this week. Some areas remained wet and little progress was made whereas in others favorable conditions facilitated tremendous progress. However, what began on Monday of this week as a 20% chance of rain for Friday (today) turned into between 0.25 and 2″+ of rain depending on your location with most of the rainfall occurring north of Highway 82.
Given that we are into the back half of May, some consideration should be given to managing for earliness. This is particularly true if you are one of the folks who will likely be out of the field until early next week due to the rainfall. Listed below are several areas that you should consider when thinking of ways to manage for earliness (or prevent delays in maturity).
Variety Selection: Generally speaking, the difference in maturity between the earliest variety and the latest variety that we currently have is about 14-17 days depending on weather and other factors. I would suggest choosing a variety based on performance as opposed to maturity. Having said that, if you are delayed until late next week or the beginning of the week after, you may consider an earlier maturing variety.
Nitrogen Rate: It is well documented that excess nitrogen can lead to several issues including delayed maturity. Several studies suggest that nitrogen application rates in excess of 80-100 lbs/acre do not increase yield. Soil texture can have a tremendous effect on cotton response to nitrogen with heavier soils typically requiring more nitrogen. You know your land better than anyone; however, if you suspect that you have been over fertilizing with nitrogen you may consider reducing application rates.
Plant Growth Regulators: Extensive research has been conducted on plant growth regulators. Plant growth regulator effects on cotton yield are conflicting in previous research. Some studies suggest PGRs provide a yield benefit while others suggest that no benefit on yield is present. The primary benefit of PGR application in nearly all previously conducted research is control of plant height. If you plant a variety that does not posses an overly aggressive growth habit, do not use excessive amounts of PGRs as you may cost yourself more yield. However, if your variety has an aggressive growth habit, increased application rates will likely be needed to control vegetative growth.
Insect Management: Be judicious in managing insects, particularly tarnished plant bugs. Fruit that are lost due to insect (or other factors) can delay maturity. Given the lateness of the calender date as well as unpredictable weather at harvest time, preventing yield and maturity delays due to insects is of paramount importance. Thresholds are in place for insect management and this is not the year to try to stretch out intervals between applications in an effort to save money. What money you save in July you may cost yourself at harvest in October (hopefully).