Droopy Ears
Premature Ear Declination
With the onset of the second year in a row of drought conditions, a somewhat 'common' sight has become drooping ears in corn fields sooner than expected. Normally ears stay erect until sometime after black layer or physiological maturity. Currently ears are found hanging long before their time which will lead to; premature maturity, decreased test weights from lack of grain fill time, and overall reductions in yield depending largely on when the drooping takes place.
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"Droopy" Ears
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"Droopy" kinked shank
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Cross section of "droopy" shank
The main causes of droopy ears for 2013 have been the combination of heat and drought stress. The two of these lead to an overall lack of water coming into the plant and within plant tissues. Without this moisture there develops a lack of turgidity (cell swollenness) which leads to a weakened shank that kinks over. Another cause that seems to be abundant this year in areas of extreme rain early in the season are root rots caused by fusarium which affects the crown.
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Root/crown rot
As ears fill the final pipeline to get photosynthates into the ear is the shank, once this kinks over grain fill is essentially done. How much yield loss then depends on what stage the kernel is at and how many plants on average are drooping. If the ears are at full dent with a milk line barely visible then losses up to about 41% could be seen, whereas ears at ½ milk line would be expected to lose roughly 12%. So for example if a field had 25% of its ears drooping at ½ milk line then losses of 3% are not out of the question (12% yield loss x 25% of the field).
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