Crop Scene Investigation - 12 Solved: Why is Glen's corn corkscrewed?

Sunday, November 2, 2008

by DEAN SHANTZ

Cold injury caused Glen's corn to corkscrew, contributing to an uneven stand.
The cold nights and rains after planting caused the corn seed to absorb cold water and experience cold injury or "inhibitional chilling injury." This affected germination, delayed seedling growth and even caused some plants to leaf out underground and have a corkscrew appearance.

Damage due to cold injury is most severe when temperatures remain at or below 10 C for an extended period of time after planting. While this contributed to Glen's uneven stand, it wasn't the only factor. Cases like these often involve more than one culprit.

Untreated seed or deep planting can lead to emergence difficulties. However, these weren't problems for Glen, who had planted treated seed at an appropriate depth.

Compaction, surface soil crusting and saturated soils were all present in his field. These factors, combined with below-average temperatures, resulted in the poor stand.

The problem areas are explained by the presence of pockets of different soil types across Glen's largely clay loam field. Some soil types are more forgiving in the event of compaction or when spring conditions aren't ideal.

Replanting wasn't necessary in Glen's field. He had an adequate average population of 24,000 plants per acre. When I saw Glen at a fall harvest meeting, he was pleasantly surprised that the crop outgrew the injury and the yield was quite decent.

Planting early has its rewards, but there is always the risk of weather complications. Plant at a proper depth into an evenly worked seed bed to give your crop the best chance of coming through the ground – especially in the event of cool and wet spring conditions.

In addition, work with your seed specialist to identify the best hybrids for early planting. Choosing hybrids that have excellent ratings for emergence and spring vigour will protect you in the event that Mother Nature isn't kind. Congratulations to Debbie Running, Stokes Seeds, Thorold, for her correct answer. BF
 
Dean Shantz, CCA, is a Field Agronomist for NK® Brand, Syngenta Seeds. He is based in Tavistock.