Another hot week over here in Landmark’s southern territory with temperatures in the 90’s and looking like it will continue throughout the rest of the week. With the dry weather, we have been able to get all caught up with spraying and topdressing corn and soybeans. We are also racking up GDU’s, getting closer to our average, especially helping the later planted corn. On the other hand, there are areas which really need a good shot of rain and the corn is starting to show stress. The stress that it is showing is a combination of two things, the plant is not able to take up enough water needed and due to the 90-degree temperature, the plant needs more water than is available causing wilting and rolling of the leaves. When you see this wilting occurring, it can decrease yield 3% per day it and during silking it can cause 8% yield loss per day. Something I never thought I would say this year, but we need a good shot of rain to combat these high temperatures and have good pollination.
On the alfalfa side of things, we are continuing to see very high insect numbers and nearly every field we check is above threshold in leafhoppers, one of the most destructive alfalfa insects. We need to get out and spray these stands as soon as possible after second cutting. Early this week, a few growers have attempted to harvest some wheat but it’s still not quite ready yet at about 16% moisture. With a few dry days, the wheat harvest should be underway.
Things are starting to slow down, as some of the first planted corn starts to tassel out. So, this is the perfect time to be out scouting fields for disease pressure. It has dried out a little in some areas, but some of the benefits of fungicide is keeping the plant alive and green longer. This could help capitalize on some late season sun that it could have missed out on early in the season. Talk to your landmark agronomist if a tassel fungicide application is right for you!
Increased heat this week has improved crop conditions and sped up growth. We gained about another 0.5 inch of rain over the last few days.
Final post sprays on field corn were completed this week.
Post spray on beans mostly complete, though, depending on the spray program, water hemp escapes are everywhere.
Insects are mainly becoming an economic problem in hay fields where potato leafhoppers are found. Threshold for spraying is about 1 per sweep in alfalfa that is 8-11 inches tall. 2 per sweep over 12 inch tall alfalfa.
Good chance to consider growth enhancing foliar feed at the same time.
Looking ahead, we should scout for insect pressure. Usually, soybean aphids show up about now. Populations need to be growing from now through August 10 and spray when counts reveal 250 aphids per plant.
In another few weeks, we will be spraying fungicide on tasseling corn with airplanes.