Parsons, Kansas —
Wheat planting time will be here before we know it. I’m sure that for many producers there are lots of things to do prior to wheat planting. However, while we are waiting for things to dry out a bit so we can get back into the fields, it might be wise to at least spend a little time making plans for the 2014 wheat crop.
For most Kansas wheat farmers, a majority of the wheat disease control program is completed by planting time. By then you have chosen the crop rotation, residue management, volunteer management, variety, fertility program, seeding rate, seedbed preparation, planting date, seed quality, and seed treatments. Let's go through a few of these practices and discuss how they affect disease management.
Crop rotation is a “best management practice” and is very helpful in controlling many diseases. A few disease pathogens can crossover between different crops. Probably the most common one in our area is the head scab fungus that builds up in corn and can survive on the corn residue.
When wheat follows wheat, tillage that increases soil-residue contact and breaks residue into smaller pieces hastens decay, and reduces disease carryover. Of course, this practice also hastens soil erosion and many farmers wish to no-till their wheat, which makes another good argument for crop rotation. One year of rotation is enough to break the cycle for most diseases.
Tillage can also be used to control volunteer wheat which can be the source of many potential pest problems, especially wheat streak mosaic and Hessian fly. Herbicides are also frequently used to control volunteer wheat, especially in no-till situations. In either case, all volunteer wheat within half mile of the new wheat crop needs to be controlled at least two weeks prior to planting.
Some producers got a rude reminder of this last year in the form of wheat streak mosaic. While we normally think of wheat streak mosaic as a western Kansas problem, there were several instances of it in southeast Kansas last year. The extended drought last summer meant much of the volunteer wheat didn’t germinate until the rains came in late summer. So in many cases the volunteer wasn’t controlled in the summer like it normally is in this area. That doesn’t need to be an issue this year as ample rainfall the last few weeks should have much of the volunteer wheat germinated by now, allowing time to get it controlled way ahead of wheat planting.
Variety selection is one of the most important things that a producer can do in preparation for wheat planting — and also in disease and insect control practices. In the eastern half of the state, we need resistance to diseases like barley yellow dwarf virus, leaf rust, stripe rust, tan spot, septoria tritici blotch, head scab, and powdery mildew. We may also need resistance to soilborne mosaic and spindle streak mosaic. Hessian fly resistance would be nice, too. So when selecting wheat varieties — take a look at yield potential, but don’t forget disease and insect ratings as well.
Planting date can have a large effect on wheat streak mosaic, barley yellow dwarf, take-all, and of course Hessian fly. Therefore, we advise against planting too early unless wheat is for grazing. Obviously, planting too late is a problem, as well. The Hessian fly-free date is a good compromise between all the competing risk factors for early and later plantings. The Hessian fly-free date for most southeast Kansas counties is normally around October 10-13.
For additional information on wheat planting, visit with your local Extension agent. The 2013 Wheat Variety Performance Test and the Wheat Variety Disease and Insect Ratings for 2013 publications are also available at the K-State Research and Extension Website which is www.ksre.ksu.edu. £