Calendar | Logan County Extension Unit | Ag News Elsewhere [fresh daily from the Web]

Time to begin spring pest and disease control

By John Fulton

Send a link to a friend

[May 19, 2008] 

InvestmentAdult Japanese beetle control

Application of imidacloprid (Merit and other brand names) and other systemic insecticides is effective in controlling Japanese beetle adults. Although the imidacloprid occasionally doesn't work in a tree to control this pest, it does over 80 percent of the time. However, a soil application of imidacloprid typically takes six to eight weeks to move completely up to the leaves of large trees. With Japanese beetle emergence typically starting the fourth week of June in our area, time is quickly passing to achieve control in that manner. This would be a prime option for linden trees, crab apples, rosebushes and other favorites of the Japanese beetle.

Imidacloprid can be soil-applied either as a drench or by injection. Because imidacloprid is easily tied up on organic matter, any mulch and other dead organic matter must be removed from around the base of the tree before a drench application is made. Removal of turf around the tree would also be recommended for a drench. Soil injections should be made deep enough to get below mulch, turf thatch and other organic matter, but not deeper than 3 to 4 inches. Apply to the soil within one to two feet of the trunk, where the greatest concentration of fine feeder roots is located.

Anthracnose and other leaf problems

Anthracnose starts as dead leaf areas between leaf veins or on the tips of leaves. When severe enough, leaves will fall. The good news is that it rarely harms trees. If enough leaves drop, a new set comes out in four to six weeks and we start all over. The next set of leaves may also get the disease, but they may not. Treatments when you see the symptoms of this disease are simply wasted time and money.

Apple scab is a similar disease that can cause premature leaf drop in apples and crab apples. The same scenario applies here. If you are on a regular spray schedule for fruit trees, it should prevent most of the problems. You could also spray crab apples this way, but you would have to weigh the cost and benefit since no fruit production is involved.

[to top of second column]


Plum pockets is caused by a fungus on trees in the stone fruit family. This would include mainly peaches and plums. It is rather striking with the bright red swellings on the green leaves. This disease can only be prevented with a dormant-time application of a fungicide on your trees. Seeing it now means that you probably should have sprayed before the buds began to swell (meaning before leaves actually came out).

What's the end result? Trees get leaf diseases each year. Very rarely are any trees killed by these problems, and those that die are usually one foot in the grave to begin with. The only things that help the trees at this point are fertilizing moderately and watering during extended dry spells (which might be a while!). The fertilizer helps trees cope with some of the lost energy from lost leaves and the effort to put out a new set.

Mosquito reminder

The mosquito season has started in earnest. Of course mosquitoes aren't pleasant to begin with, but throw in the West Nile virus, and many people are rightly concerned about West Nile virus and how to control mosquitoes. For now, if you are using a program in stagnant water, with no fish, the wiggler stage is present and controls such as the Bt israeliensis should be started. Also, continue to remove development sites such as standing water, old tires and other containers that hold water. The Bt israeliensis can be applied to areas you can't drain, and it won't affect people, pets or livestock.

[By JOHN FULTON, University of Illinois Extension, Logan County]



< Recent articles

Back to top


News | Sports | Business | Rural Review | Teaching & Learning | Home and Family | Tourism | Obituaries

Community | Perspectives | Law & Courts | Leisure Time | Spiritual Life | Health & Fitness | Teen Scene
Calendar | Letters to the Editor