Weekly in-season Updates
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INFORMATION |
June 17, 2007 Talkin’ Cotton J.C. Banks
I never expected to be discussing too much water, especially since the drought of last summer, but we have some areas that have waterlogged soils and the cotton is not growing as fast as it should. These plants are a dull yellow in appearance, especially in the new growth coming from the top of the plant. Water and oxygen are present in soil between the soil particles, and oxygen as well as water is needed for plant metabolism and growth. Oxygen is a key component of physiological reactions taking place in the plant. When oxygen is limited, these reactions are slow. Root growth is hindered as well as top growth on the plant. At this stage in development, cotton needs rapidly growing roots to explore the soil for nutrients. A waterlogged soil will normally show a deficiency in phosphorus and potassium, even when these nutrients are present in the soil in adequate amounts. Roots are not growing fast enough to expose the root hairs to enough nutrients. On clean tilled soils, normally a cultivation or rotary hoeing as soon as it is possible to get into the field will aerate the soil enough to allow the plant to recuperate more rapidly. In no-tilled areas the soil is normally oxygenated enough due to passages in the soil caused by decaying roots from previous vegetation and earthworm activity.
In our area we can’t complain about summer rain because we know it is replenishing soil profile water that will be needed later. For this reason, we are willing to tolerate a reduced growth rate now in favor for a strong finish in August.
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