Got leaf spot?
By David G. Hallauer
Meadowlark District Extension agent, crops and soils/horticulture
Gray leaf spot is showing up again this year, and that means it may be time for you to scout your corn fields. Scouting is imperative to determining treatment needs.
Now is a good time (if you haven't before) to check out your hybrid's gray leaf spot rating. Many have a good level of tolerance and may not require a fungicide. For those hybrids considered 'moderately' susceptible, apply a fungicide if lesions can be found on the ear leaf minus three on 50 percent or more of the leaves checked at tasseling. For intermediate hybrids, lesions need to reach the ear leaf minus two and, for moderately resistant hybrids, the ear leaf minus one. If you have lesions on the ear leaf at tasseling, you need to spray.
Tasseling is the optimum fungicide application window, though later applications (some beyond full blister stage) can be effective. Be sure to observe pre-harvest intervals on the label.
Wheat variety disease and insect ratings publication
Genetic resistance is the most effective and economical means of reducing the risk of yield losses resulting from disease and insect pests in Kansas, according to Kansas State University scientist Erick DeWolf. To aid you in your decision making process as it pertains to disease and insects on wheat, check out KSU's ratings from 2008 to 2009 in the Wheat Variety Disease and Insect Ratings, 2009 publication. Its available on the Web or at your District Office.
If you haven't sprayed your bagworms yet, time is short--if not already past. Bags have begun rapid elongation and growth, making them almost impenetrable. On small shrubs, your best bet is hand removal. Very high spray volumes and pressure would be needed on larger trees with large bags--and even then control may be difficult.
Lawn care for the long term
Its pretty tempting at times to lower that mower blade and crop that lawn as short as you can. Who wants to mow every week, anyway, right? The temptation may be greater if you're taking off for a while and won't be around to mow as you normally would. Avoid scalping if at all possible or long term damage can result. Instead, use a gradual approach to return that too tall lawn to a recommended height.
Shorter mowing heights cause a number of problems. It starts with diminished root growth that results in plants that crave more water. When it doesn't get it, the lawn weakens and weeds invade. Plants also try to compensate for removing more than a third of their growth by sending up new growth, further depleting root reserves. And as tolerant as fescue is to our 'abuse', it's actually the least tolerant to short mowing. It exhibits clumping and other problems that can make that year's investment in time and money a loss. The grass will no doubt get taller than you want at some point. When you get back to it, raise the mower up as tall as you can, getting as close as you can to only removing a third of the height at a time. Then bring the turf's height down slowly by cutting often and at progressively lower mower settings until you reach target height. Recommended tall fescue height is 3.5 to 4.5 inches tall.