Airing December 6 - 12, 2005

Herbicides on sorghum

This is Ag Outlook 2005 on 1420 KJCK, I'm Chuck Otte, Geary County, K-State Research and Extension Ag & Natural Resources Agent. The grain sorghum variety test result books are in and there is a very interesting table showing the results of a study examining the impact of using 2,4-D on sorghum. All the varieties that were in the grain sorghum test were planted in 4 row plots. At the optimum size for treatment, two of the four rows were sprayed with 1.5 pints of 2,4-D Amine. Keep in mind that Amine is going to be the least damaging of the 2,4-D formulations. Now I think we've all seen 2,4-D damage to sorghum, but we used to think that it grew out of the damage with no ill effects. This is the first test that I've seen that looked at the issue hybrid by hybrid. All the plots were also hand weeded so that there would be no weed competition to worry about - the only effect would be the impact of spraying with 2,4-D. The plots were treated on June 25 when the varieties were V3 to V5 or 8 to 10 inches tall. Ideal conditions. Then damage ratings were taken 8, 14 and 21 days later. All normal characteristics

were measured - days to bloom height, yield, moisture and test weight. The results tell you the differences between the treated and untreated of the same hybrid. The bottom line is that 2,4-D hurts sorghum yield. Sometimes not significantly, but on average - 4 bushels per acre and in some cases over 16 bushels per acre. The 2,4-D treatment, on average, caused hybrids to be 2 days later, 2.5 inches shorter with slightly higher moisture and test weight. If you are in a situation where you may have to use 2,4-D for added post emerge weed control, this table can help you select what varieties to use OR avoid. But if possible, I'd say not to use 2,4-D on sorghum. This has been Ag Outlook 2005 on the Talk of JC, 1420 KJCK, I'm Chuck Otte.

Roundup Ready Soybeans and Manganese

This is Ag Outlook 2005 on 1420 KJCK, I'm Chuck Otte, Geary County, K-State Research and Extension Ag & Natural Resources Agent. As most producers have switched over to Roundup Ready beans, we've started to seem some interesting things happen. How many times have you seen a mosaic like pattern show up on beans after spraying with roundup. They turned kind of pale, almost chlorotic and then seem to come out of it okay. We've often just written that off to generic glyphosate formulations or the weather or who knows what. Well, now we may be starting to find out what, and it's something we shouldn't be ignoring. So far we're going on one year's worth of data so proceed with caution. BUT, it appears that either the Roundup gene, or some of the other baggage that came along with the roundup gene changes the way the soybean plant takes up and metabolizes the micronutrient manganese. Yes, manganese - one of those elements we rarely talk about with crop production. In fact, if you apply even 2.5 pounds of manganese, per acre, on non-roundup ready soybeans, you will reduce yield. It's been well known, to a few scientists anyway, that the Roundup gene changes the way that roots interact with manganese in the soil and it also appears that an application of Roundup causes some funny things to happen in the plant for several days ala, the chlorotic looking plants. So here's what you might want to try. Take half of a field of roundup ready beans next year and apply somewhere between 2.5 and 5 pounds per acre of manganese either in a band or with the starter, but not in seed contact. And then see for yourself what happens. I'll be getting some more information on this, so stay tuned for some very interesting developments! This has been Ag Outlook 2005 on the Talk of JC, 1420 KJCK, I'm Chuck Otte.

Fertilization in general

This is Ag Outlook 2005 on 1420 KJCK, I'm Chuck Otte, Geary County, K-State Research and Extension Ag & Natural Resources Agent. Even though the ground may be frozen and fertilization is the last thing on your mind, I want to start planting a few seeds of thought for you to consider as we move into spring planting time. First of all on corn, that starter fertilizer is very very crucial. We are planting corn into probably the coldest soils of any of our crops. And by the way planting corn in early to mid April may not be the best thing going - recent studies indicate that for our part of Kansas late April, up to the first few days of May might be the best. Regardless, even if a soil test shows good nutrient levels in the soil, we really need to be getting some starter applied. Cold soils will cause young corn roots to not take up nutrients nearly as readily and if they have to really go looking, they may just go without. And I would even include a little potassium in that starter mix. We often don't think of our soils being potassium deficient, but again, we might have a cold soil induced issue here. So get the starter fertilizer applied. One thing that we are seeing in no-till fields is stratification of nutrients. If you keep planting about down the same row, year after year, we are finding that those zones are getting depleted of nutrients. Deeper down or in between the rows we will find higher levels, but right in that planting row zone, nutrients aren't showing up that young plants, with limited roots, really need. In days gone by, where we tilled regularly, that soil was getting mixed up. But now, that isn't happening and stratification of nutrients is real. So, if you are soil testing, pull that sample right from the area where you intend to plant. Don't go taking samples between the rows as these might show higher levels. Let's make sure that we're getting a good read and getting the right starter applied. This has been Ag Outlook 2005 on the Talk of JC, 1420 KJCK, I'm Chuck Otte.

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