Silks have the greatest water content of any corn plant tissue and thus are most sensitive to moisture levels in the plant. Severe moisture deficits will slow silk elongation, causing a delay or failure of silks to emerge from the ear shoot.
If the delay is long enough, pollen shed may be almost or completely finished before receptive silks are available; resulting in nearly blank or totally blank cobs. In addition to causing silk emergence failure, severe drought stress, especially accompanied by high temperatures and low relative humidity, can also desiccate exposed silks and render them non-receptive to pollen germination. In the Eastern Corn Belt, this effect of drought stress on silk receptivity is likely more common than effects on pollen availability or viability.
The severity of drought stress required for significant silk emergence delay or desiccation can probably be characterized by severe leaf rolling that begins early in the morning and continues into the early evening hours. Silk Clipping by Insects. Severe silk clipping by insects such as corn rootworm beetle or Japanese beetle can interfere with the success of pollination by decreasing or eliminating viable or receptive exposed silk tissue.
Fortunately, unless the beetle activity is nonstop for days, continued elongation of silks from inside the husk will expose undamaged and receptive silk tissue at the rate of about one inch or more per day. Silk "Balling". Occasionally, silks fail to emerge successfully because they fail to elongate in their usual straight "path" from the ovules toward the end of the husk leaves. Instead, silk elongation becomes convoluted twisted, coiled, scrambled inside the husk leaves.
This silk "balling" phenomenon is not well-understood and hybrids tend to vary in their vulnerability to this type of silk emergence failure. Two different pieces of circumstantial evidence are often associated with the problem. One is a physical restriction imposed on silk elongation caused by unusually"tight" or long husk leaves in certain hybrids.
The other circumstance often correlated with silk "balling" is the occurrence of unusually cool nights during the time silk elongation is occurring, but prior to silk emergence. The physiological effect of such cool nights on silk elongation is not understood. It has been years since I last saw a field with a significant level of silk "balling" Nielsen, Abendroth, L. W Elmore, M. Boyer, and S. Corn Growth and Development. Iowa State Univ. Extension Publication PMR Nielsen, RL Bob.
Scrambled Silks, Anyone?. Corny News Network, Purdue Extension. Nielsen, R. Corny News Network, Purdue Univ. Unusually Long Silks in Corn. Why does corn have silk? I mean, I think it's fun to tear through the husk to reveal the ear, like unwrapping a present, but picking those sticky little strings off the kernels quickly turns tedious. So why doesn't someone invent silk-less corn, like seedless watermelon, to make life easier for lazy consumers like myself?
I've been wondering that. Here's an explanation from " The Book of Wonders ," aimed at children and published in by something called the Bureau of Industrial Education; it's correct but comically euphemistic:. Got that, kids? I raise corn for a living so I have the answer! Corn silk is simply one of the female parts of the corn plant. The male part of corn is the tassel which sprouts from the top of the plant. The pollen comes from the tassel. Corn silks are actually tiny tubes where grains of pollen will land.
The pollen will travel down the silk tube to the unfertilized ear inside the husk. I cover this process in more detail in another post.
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