Ag Radio programs for July 12 - 18, 2007

Insect Update

This is Ag Outlook 2007 on 1420 KJCK, I'm Chuck Otte, Geary County, K-State Research and Extension Ag & Natural Resources Agent. As the 2007 wheat crop fades as a bad memory to many of us, we can start to focus on insects in other crops. But before we do that, let's just remember to be controlling the abundant volunteer wheat to help control wheat curl mites and hessian fly for future wheat crops. Alfalfa producers have noticed a lot of yellow leaves in their alfalfa fields. These are caused by potato leafhoppers and we'll discuss those in another segment. I really felt that with a foot of rain during the month of May that every chinch bug in the county would be dead. Of course, that's never the case with these rascals and I was noticing damage on grain sorghum planted next to wheat recently. It was appearing more as stunting rather than outright killing. Is it worth trying to go in with drop nozzles and high volumes of water to get some control of these rascals? That is very questionable and my inclination is to just walk away from it and hope it keeps raining. I was also picking up feeding damage on soybeans, primarily from bean leaf beetles. A few holes can look pretty nasty, but in most fields I was in, new growth was coming on fast and appeared to be unaffected. It takes a lot more damage than I was seeing to justify spraying for bean leaf beetles. Later on we'll need to keep an eye on bean leaf beetles and green cloverworms, but that's a month away yet. Finally grasshoppers are also more abundant than I had expected. We seldom have to treat for them, but keep an eye on field margins, especially anyplace next to bromegrass or native grass - spot spraying may be needed. This has been Ag Outlook 2007 on the Talk of JC, 1420 KJCK, I'm Chuck Otte.

How Late Can I Plant?

This is Ag Outlook 2007 on 1420 KJCK, I'm Chuck Otte, Geary County, K-State Research and Extension Ag & Natural Resources Agent. I've had several calls since late June asking how late sorghum or soybeans can be planted. And sad to say, the best answer I can give is to ask the caller when they think we'll have the first killing frost. That's my honest answer because it is really a question that is up in the air. If we assume that we will have normal weather, whatever the heck that is, then July 15th is probably the absolute drop dead date that you don't want to plant after if you want any reasonable hope of having a crop to harvest. I can understand the desire to plant a crop after wheat harvest. The wheat crop was horrible and anything we can do to generate some more income looks pretty good right now. Well, let's assume that we have normal heat and precipitation from now through the end of October. Based on research from Harvey county, a little bit south of here, we could see sorghum yields of 50 to 91 bushels per acre and soybean yields of 13 to 31 bushels per acre. After wheat yields of 20 to 25 bushels per acre, either one looks good. If you plant a crop now, you need to go with a fairly short season variety because you are going to start to lose heat units that are needed for crop growth and maturity in about 45 days. And if sorghum, for example, is not blooming before September 1st, you probably aren't going to make a crop. Can I offer an alternative? If you have cattle or have a potential market for hay then consider planting some triticale or even some sudan grass. Get some growth and in September, you can go ahead and swath it and bale it and probably have more value than if you went with a grain crop. It's an alternative, and may be a profitable alternative. This has been Ag Outlook 2007 on the Talk of JC, 1420 KJCK, I'm Chuck Otte.

Potato Leafhoppers in Alfalfa

This is Ag Outlook 2007 on 1420 KJCK, I'm Chuck Otte, Geary County, K-State Research and Extension Ag & Natural Resources Agent. The past several weeks I fielded several calls about alfalfa fields turning yellow. In most cases, this was potato leafhopper, an annoying little insect pest that seems to have gained momentum in recent years. These insects are small, only about 1/8 of an inch long. They are yellow green and wedge shaped. They tend to move sideways, jump or fly when disturbed so it is hard to see them sitting on the plant but you can probably see them jumping or flying when you walk through a yellowing stand. A classic symptom on the alfalfa plant of leafhopper feeding is a V shaped yellowing on the leaf. This is a reaction to a toxin in the saliva of the leafhopper. In addition to discoloring the leaf, the toxin stunts the plant and decreases feeding value for livestock. I was advising most producers to just cut their alfalfa to get the damage out of there. Unlike alfalfa weevil that leave the field when summer weather arrives, leaf hoppers will stick around and feed on future cuttings. Normally we would do a sweep net evaluation of populations, and it doesn't take very many leaf hoppers to justify treating. In this case, if your alfalfa was turning yellow before you cut it, just plan to come in with a post cutting stubble spray to get the problem knocked down. Good control can be expected with any of the standard insecticides. Now here is where it will pay to plan ahead. Older alfalfa varieties, like Kanza and Riley had some potato leafhopper resistance so it took more leafhoppers to cause damage. Newer varieties have even more resistance to leafhoppers. When you start making plans for a new planting of alfalfa, spend the extra bucks for one of those varieties. This has been Ag Outlook 2007 on the Talk of JC, 1420 KJCK, I'm Chuck Otte.

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