Crops: Crop Scene Investigation - 18

Thursday, April 2, 2009

by CLARE KINLIN

It was a chilly day at the end of May when I got a call from Bert in Glengarry County. He suspected frost damage in his corn crop. "We've had some pretty cold temperatures. I thought we'd be OK, but some of the plants in my field are turning white," he said.

I agreed to go out and assess the frost damage on his seedlings. These calls typically involve me working with growers to evaluate whether replanting is in order. But what I found when I got to the field isn't at all what I had in mind.

Bert's stand was definitely thinning. The crop, which had reached the three- or four-leaf stage, had non-uniform emergence. But a closer examination of the affected plants told me that frost wasn't a factor.

"The giveaway is that the whorl of the plants is dead," I told a surprised Bert, who had been pretty convinced of his diagnosis. "In cases of frost, the tips are really only burnt – the whorl is never eaten out like these plants are."

With frost out of the question, it was time for a new hypothesis. "We used treated seed and planted into cool, wet conditions," said Bert. I asked about his planter set-up, but everything seemed in order. "Some grassy weeds got away from us," admitted Bert. "We were able to control them, just not as early as I would have liked."

The damage seemed to be most prevalent on the sandy knolls in the field. It was time to start digging for answers. We found lots of evidence of something feeding on the seedlings.

I expected I'd catch some insects at work. Bill bugs, millipedes, European Chafers, seed corn maggots all came to mind. But I found a culprit by a different name.

Can you figure out what had been eating Bert's seedlings? Send your solution along with your name address and phone number to Better Farming at: rirwin@betterfarming.com or by fax to: 613-678-5993.

Correct answers will be pooled and one winner will be drawn for a chance to win a Wireless Weather Station. The correct answer, along with the reasoning followed to reach it, will appear in the next issue of Better Farming. BF

Clare Kinlin, CCA, is a Sales and Agronomy Manager for NK® Brand, Syngenta Seeds. He is based near Prescott.