Forecast temperatures are expected to change dramatically across the North Delta and west Tennessee over the next 36-48 hours. Highs are forecast to fall from the mid-upper 90’s with lows in the mid 70’s to highs in the mid 70’s and lows 60 or below. Remember that these are forecast temperatures and subject to change as such. Additionally, tropical storm Lee is coming on shore in the gulf that could impact defoliation with rain and wind depending on the forecast track. Currently little impact is expected across west Tennessee, but conditions could change at any time if the storm track changes.
With the coolest temperatures forecast for Labor Day, begin to think about changing defoliation products and/or increasing rates to achieve adequate defoliation and boll opening. If you are using Dropp or other thidazuron containing products (Ginstar) you may want to keep them out of the mix until temperatures increase. Folex rates should increase to maintain activity. If you have been running 4-5 oz of Folex consider changing to 6-8 oz to get similar results. Ethephon containing product rates should remain constant 24-32 oz. With the temperature change Aim (0.75 oz + NIS 0.25%) or ET (1.5oz + COC 1%) come into play on a 1st pass or single pass program as well. If you continue with Ginstar increasing the rate to 4-5 oz will help maintain good leaf drop.
The most sensitive time to change rates is when making application over the next 48 hours as temperatures will be changing while the defoliant is working in the plant. It will be a delicate balancing act to maintain activity without killing the leaf too quickly and causing a stuck leaf scenario. The best advice may be to delay defoliation until the temperature change happens to be sure we are using appropriate rates.
Please call, text or email me if you have questions about specific scenarios.
