Early Morning Sprays For Improved Coverage
Trying to control disease in a peanut plant is a challenge. The plant's structure makes it a difficult target to cover effectively. For leafspot, the sprayer must cover the entire canopy; limb rot affects the limbs; white mold can be on the pegs, pods and crown; and CBR affects the roots. Trying to spray and control disease effectively on the entire spectrum of the plant is not an easy thing to do.
To control disease more effectively may require taking advantage of what the plant does naturally.
Bigger Droplets, More Coverage
The peanut canopy is good at intercepting sunlight, and it is also very good at intercepting your fungicide. If you spray during the daytime, that’s where the bulk of the chemical is ending up.
Spraying at night allows more droplets to get down through the canopy and reach that bottom part of the plant.
Research has shown that droplets sprayed at night were consistently bigger, whereas during the day, the finer spray droplets were more subject to evaporation. The total overall coverage of the plant surface is much better when spraying at night. This is especially true later in the season, when the peanut plant gets bigger, the canopy gets deeper, and it is critical to get down through that dense canopy.
Early Morning Best
In research trials, morning sprays have tended to show better yield than evening sprays. Although night spraying is not going to automatically result in a yield increase, in problem fields where you are not getting the level of control that you would like, it can make a difference.
With night sprays, there is clearly a potential to improve white mold control. The more disease pressure you have, the more potential there is for a yield difference.
Researchers are continuing to look at other diseases, including the potential night spraying may have for improving Cylindrocaldium Black Rot control.