We are in the third week of April, and a few Wilcox county acres have seen the planter rig putting cotton seed in the ground. As of April 20, 2021, our UGA weather station in Hatley, read a 4 inch soil temperature of 72.2 degrees Fahrenheit, but we are expecting some low 40 degree nights and some good chances of rain this weekend, so those soil temperatures will probably drop as the week progresses. With the predicted forecast in mind, I would recommend waiting to plant until the cool weather and rain chances have passed. I wanted to leave you all with some great information on cotton seedling disease from our UGA Extension Pathologist, Bob Kemerait.
Seedling diseases in cotton are generally more severe during cooler/moist weather due the cool, wet soils slow germination and slow growth and development of the seed and seedling. Slow germination and emergence coupled with low vigor early on gives our most important seedling disease pathogen of cotton, fungus Rhizoctonia solani, the chance to attack and cause significant stand loss. Rhizoctonia can (and does) certainly cause losses even in warmer soils, but the impact is greatest in cooler and wetter soils. The key here about increasing risk to seedling diseases is less about “cooler and wetter” and more about ANYTHING that slows germination and development.
To minimize the risk of seedling disease there are some steps that should be taken:
- Make sure the soil temperatures at 4 inches are at least 65 degrees Fahrenheit.
- If possible, avoid planting in cool and/or wet conditions.
- Make sure the you have the best seed quality available.
- Smaller seed can be prone to greater stand problems when compared to larger seed.
- Insure a strong fungicide seed treatment
- If there is concern for seedling diseases, consider additional treatment options.