The historic drought that plagued row crop farmers from north Florida to central Virginia throughout the 2007 season continues to create planting problems, and possibly disease, insect and weed problems for fall wheat and other small grains.
Being aware of the characteristics of the wheat variety planted is of increased importance, if planting and early growth periods are significantly impacted by drought. Drought mandated late planting, likewise can reduce stands and potentially limit yields.
North Carolina State Small Grains Specialist Randy Weisz says the drought has delayed planting in parts of North Carolina and without late October and November rains growers may expect a number of production related problems.
“It would be ideal if there was a freeze within a week or two of planting. That way insect pests like Hessian fly, and aphids carrying barley yellow dwarf virus (BYDV) would be killed back. If the weather has remained warm up to planting, remains warm during emergence, and the forecast is for continued warm weather, growers might consider applying a long residual insecticide like Warrior at the 2 to 3 leaf stage.”
“If BYDV or Hessian fly has historically been a problem for a grower, and warm weather looks like the order of the day, I would consider this course of action, especially if the wheat variety is susceptible to either of these two pests.”
No-till wheat has become a common practice in Virginia and is growing in popularity in North Carolina. Weisz says for growers who are no-tilling into sandy Coastal Plains soils, warm weather may also bring increased wireworm activity.
Wireworms begin to feed on no-till wheat in these soils shortly after emergence. Stands that initially look good will begin to thin if wireworms are a problem.
Typically, wireworms take out entire rows of wheat seedlings. After a few weeks of feeding, there will be large skips in rows that look like there was a problem with the drill and over time these skips get longer.
If wireworm damage shows up there isn't anything that can be done about it, but in future years, no-till growers should consider insecticidal seed treatments to give them wireworm protection in these fields.
Disease problems in particular may occur on into next spring because of the fall drought. Weisz says if warm weather persists through the fall and early winter, powdery mildew will most likely be problematic next spring.
If a powdery mildew susceptible variety is being grown, growers should keep a careful watch for this disease next March and April.
If the drought persists into November and December, if soil moisture is limited during November and December, fall tillering will be reduced.
“Growers should check their fields in late January. If the stand is thin, and we have had some rain by then, an early application of nitrogen (30 to 60 pounds) should be applied in early February to help stimulate tillering,” Weisz adds.
Growers who are planting late due to extended drought should increase seeding rate. Drought conditions may mask weed problems, and subsequent rains could produce some unwanted surprises for wheat growers. Weisz warns no-till growers to always use a burn-down herbicide, even if the field looks "clean" at planting time.
Staying ahead of weeds is always a challenge for growers, but may actually be of increased importance in drought situations, because weeds may be more competitive for valuable moisture than wheat.
“I believe the label for Harmony Extra has been changed to allow earlier application to wheat. If the weather slows wheat growth, don't let the weeds get the upper hand. Weed competition will hurt tillering,” Weisz warns.
“There are a number of things wheat growers can do to offset drought and delayed planting dates, but the bottom line is that we must have fall moisture to have a good wheat crop,” the North Carolina State small grains specialist concludes.
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