Boll rot is a problem that may begin to frustrate cotton producers in Sampson County and the surrounding areas. Boll rot is caused by excessive wet conditions or insect damage during the growth of the cotton boll. Once a cotton boll is infected, there is little that can be done to alleviate this problem, and it is too late to control this disease once discovered. Boll rot typically starts with small brown lesions that expand until the entire boll becomes blackened. Bolls can either hold on to the stalk or drop from the plant, and be unharvestable. There are three factors necessary for this disease to strike our area. The pathogen must be present, there must be a host, and environmental conditions must fall within a certain range for the disease to grow or progress.
According to Dr. Guy Collins, the crop science extensions specialist for cotton at NCSU, boll rot is primarily caused by environmental conditions. When bolls begin to crack the carpels (outer shell of the cotton boll) need dry weather to fully open, which allows the lint to be harvested. During times of extreme moisture, the carpels do not have time to dry and will not fully open. This can lead to boll rot and other fungi invading the cotton boll. Dr. Collins stated that he has observed boll rot the last two growing seasons due to wet weather patterns, across all varieties of cotton. No variety is less susceptible to boll rot than another; the driving factor is excessive wet weather.
The recent rains and high moisture levels are setting the stage for another year conducive to boll rot for our area. If you suspect that you have boll rot in your cotton fields, you should contact your local extension office for assistance with identification and strategies to mitigate losses. For more information on cotton, visit the NCSU cotton portal at https://cotton.ces.ncsu.edu/