May 17, 2006 | By: Laura Skillman

Wet, cool weather conditions for more than a week have slowed corn growth, delayed soybean planting and added to disease problems in Kentucky’s orchards and vineyards.

Planting conditions in April allowed farmers to have timely corn plantings across most of the state. But the cool, wet weather has slowed down the growth of the corn. Most of the corn, if it hasn’t been fertilized yet, is showing some yellowing and root growth has also slowed, reducing the intake of nutrients, said Jim Herbek, grains specialist with the University of Kentucky College of Agriculture.

“But with the return of warmer weather, all this will pass away with negligible impact on the plant,” he said.

After a good start, the less than desirable conditions have put soybean planting somewhat behind schedule as well as delayed plant emergence, Herbek said.

“There hasn’t been a whole lot done since the first of May,” he said. “Some of those that were planted in late April and early May, with these cool temperatures, are probably struggling to emerge and come up with a good stand.”

Soybean seeds are not as tolerant of cool, moist conditions as corn seed. The longer they take to emerge, the more likely they will have seed rot.

“We like to see them emerge in seven days and with these conditions, it is taking 10 days and up to two weeks sometimes,” he said. “I don’t expect to see very perfect, consistent stands from soybeans that were planted during these conditions.” 

Soybean planting in the state is around 18 percent, behind last year’s 39 percent and the five-year average of 23 percent, according to the latest planting estimates by the Kentucky office of the National Agricultural Statistics Service.

Kentucky’s wheat crop, which will be harvested within the next four to six weeks, has been slowed some in maturing from the cool conditions. But the crop was somewhat ahead of schedule and so far, few disease or insect problems have emerged. That could change, however, in the coming weeks. Only time will tell, Herbek said.

Rain and threats of rain have made disease management efforts in orchards and vineyards difficult this spring, said John Hartman, UK plant pathologist. There are significant apple scab symptoms on unsprayed apple trees and the lesions are producing secondary spores. In eastern and central Kentucky fire blight shoot blight symptoms are visible.

In addition, although the fruits are still below 1-inch in diameter and are not yet showing symptoms, the fungi causing Sooty Blotch and Flyspeck are considered to be active.

In vineyards, growers are reporting significant black rot symptoms and signs on inadequately sprayed grapes and the lesions are producing secondary spores. Conditions have also been favorable for the development of downy mildew and powdery mildew, Hartman said.

Growers need to make decisions and take action depending on the weather and disease conditions present in their crop, he said. 

Commercial fruit growers may obtain copies of the tree fruit or grape spray guides from their county Extension office. These guides provide useful information on fungicides, application timing and rates for effective disease management.


Jim Herbek, (270) 365-7541, ext. 205, John Hartman, (859) 257-7445, ext. 80720