Prospects dwindle for corn planted on lighter soil

Friday, July 29, 2011

by SUSAN MANN

This month’s high temperatures have helped push Ontario’s corn crop development particularly in fields planted late in the growing season but more rain is needed.

Greg Stewart, Ontario agriculture ministry corn specialist, says most areas across the province have been significantly short of the rain that’s needed this month. Corn on light, sandy soils south of Highway 401 in the Cambridge and Norfolk County areas has been significantly hurt by the dry weather and probably isn’t going to recover.

“There’s been some significant impact on yield on the lighter soils,” he says.

On the heavy clay soils, the plants looked pretty tough because those soils have a hard time releasing their water to the roots.

Sixty per cent of the corn throughout Ontario was planted May 8 to 13. But rain delayed some planting and a fair bit was left to finish off in June.  Some corn was planted into tacky soils and those soils hardened in the dry spell.

Growing conditions started out tough with too much rain. Even on loamy soils where water isn’t usually a problem there are many holes in the fields where water sat and either killed the corn or farmers couldn’t plant in those areas.

Fields were much more variable than normal due to excessive spring rains. Then came the dryness.

“You never really want to follow a wet spring with a really hot, dry July because the soils are tight and elevated water tables in the spring prevent root growth,” Stewart says.

But on the positive side corn planted late is benefiting from the hot weather. Growers were hoping for heat to push development so “you don’t have the crop maturing too late into the fall,” he explains.

On Wednesday, fairly widespread rains hit areas from Essex to Elora and that’s taking some of the pressure off.

For corn planted in May it’s in the critical pollination period and it’s “trying to determine how many kernels are going to be on the cob,” Stewart says. Dry conditions now can impact the number of kernels that set on the ear. Even if conditions turned around marvelously on August 10 the number of kernels on the ear can’t be changed.

Still with improved weather, the kernels can be filled better and will be bigger. BF