Most weather models six to eight weeks ago suggested a warmer than normal summer with below-normal precipitation. For much of northeast Kansas, the temperature part may have been true, but precipitation has come at just the right time. We dodged a disaster if you will.
Still, moisture stress isn’t out of the question. Much of our corn crop is in the blister to dough stage, with 40 plus days to maturity – or a point when moisture is no longer needed by the crop. The requirement for the crop at this point? Seven to ten inches of water is still needed.
Soybeans see a similar requirement. Much of the crop is more than 40 days away from maturity, requiring nine-plus inches of water to finish. Interestingly enough, soybeans, even at the full seed stage (pods contain a green seed filling the cavity in one of the four uppermost nodes on the main stem), require three and a half inches of rain to get to maturity. It’s one of the most critical stages of the soybean life cycle and can have huge impacts on yield.
What’s the forecast for the next 45 days? Most models show neutral moisture possibilities (equal chances of above or below normal). What actually happens is anyone’s guess, but few will argue with a good moisture profile in late July. For a more in-depth outlook, check out this article in the last KSU eUpdate at https://webapp.agron.ksu.edu/agr_social/article_new/kansas-weather-early-fall-2020-outlook-398-6.
Iris Division Window Now Open
As one growing season winds down, it’s time to start planning for another. If maintaining a healthy iris crop for 2021 is of interest to you, some work now is in order.
Iris grow quite well here and multiply quickly, requiring division (every three to five years) to help rejuvenate plantings. Failure to do so can result in loss of vigor in the centers of flower clumps and even reduced flowering. Late July through August is the window to do so.
Divide clumps by digging up the entire clump consisting of system of thick rhizomes and smaller feeder roots. Cut the rhizomes apart, leaving each division with a fan of leaves plus a section of the rhizome. The best divisions are made from a double fan consisting of two small rhizomes attached to a larger one, which forms a Y-shaped division. This leaves each of the small rhizome with a fan of leaves and tends to result in more flowers in the first year after planting (single fans take a year to build up strength).
Before replanting, inspect the root system for disease/insects. Some soft rot damage can be physically removed if not severe. The same is true for iris borers. Discard excessively affected root material.
Cut leaves back by two thirds before replanting in to a weed free area. Fertilize according to soil test recommendations or by applying a balanced fertilizer at the rate of one pound of nitrogen plus phosphorous plus potassium per 100 square feet. Fertilizer should be mixed into the soil to a depth of six inches. Avoid over-fertilization of areas previously fertilized.