By now most most cotton producers have finished defoliating their crops, so what is defoliation in cotton and how is it done.
Defoliation is the process where leaves are removed from the cotton plant in order to allow for effective picking, as well as lowering the risk of boll rot, it also promotes even plant development and allows for earlier picking. This achieved through the aerial application of a chemical onto crop, the chemical works upsetting the hormone balance in the leaves of the plant causing the abscission process to begin. The abscission process involves creating an imbalance in hormones and enzymes that cause the cell walls to dissolve causing the leaf to fall off, however if too much chemical is applied to the crop the leaf may die before it falls off leaving it stuck to the plant. To minimize this problem defoliants are often applied in two lots with the first application is to remove the upper canopy and the second application to remove the lower canopy. There are other factors that can affect the how well defoliation works.
For defoliation to work effectively a least seventy percent of the cotton bolls should be cracked, there should be no new leaf growth, most of the nitrogen in the plant and soil has been used up and the application needs to be applied on a warm sunny day. If these these conditions are not met it the poor level of defoliation can cause stuck leaves leading to staining of the cotton and high level of trash.
The plane that that is most often used in Australia to apply the defoliants to the crop is the Air Tractor, while this remarkable plane is mainly used in agriculture different versions of them are also used for fighting fires, aerial surveillance and even aerial attack. They use GPS technology to accurately and evenly apply chemicals to the crop, this helps to avoid the overlapping of sprays and excessive chemical usage.
Please feel free to leave any comments or questions below, hopefully if the weather holds out I will be able to write about cotton picking next week and will have some new pictures and video’s to put up as well but until then please enjoy this video I found on YouTube today, it doesn’t involve the spraying of cotton but is still an excellent video. Also if you’ve never visited them please feel free to check out my other sites Farming Photo’s and Cotton Careers’s.