July Cropping Notes from Chouteau County Extension
What is the status of the orange wheat blossom midge in Chouteau County for 2017? Only one wheat midge was documented in five traps across Chouteau County in 2017. If more than nine midge are found on a trap, the producer is required to go out at dusk and determine if populations exceed the economic threshold. The economic threshold is when one or more midge are observed for every 7 to 8 heads. Visit 3-4 different sites in the field.
How were wheat head armyworm numbers this year? Moth trap numbers northwest of Carter were low for the third year in a row in Chouteau County. I did catch five larvae in 50 sweeps along the field edge. According to Dr. Gadi Reddy at Western Triangle Research Center, the threshold levels are not developed for the wheat head army worm. There is a general threshold of 20 larvae/meter (6 per linear foot) of row for grain crops. He feels that 5 larvae in 50 sweeps is a low number and may not cause economic damage.
Will a light hail storm increase the intensity of fungal root rots in wheat? According to Mary Burrows (MSU Extension Plant Pathologist), hail makes plants susceptible to bacterial diseases due to the induction of wounds. Some foliar fungi may be splash dispersed by the rain associated with the hail, but she is not concerned with the spread of rhizoctonia or fusarium root rot since they are primarily on roots and lower stems.
I have a field with good subsoil moisture. What will 100 degree weather do to barley that is just heading? According to Kent McVay (MSU Extension Cropping Systems Specialist), it’s difficult to be certain which way the crop will go ahead of the stress. He would wait one week and see what happens. High heat during flowering is not a good recipe for higher yield. After flowering which happens in the boot on barley, the chances of decent yield are better.
What kind of crown rot has a black stain from the crown all of the way up to the first joint? According to Mary Burrows, this is an example of classic fusarium crown rot where the stem is solid brownish-black and stops at a joint. Fusarium crown rot cause patches of
wheat to die prematurely, resulting in areas of
white heads in the field.
Does crop rotation help with pythium, fusarium and common root rot diseases? According to Mary Burrows, pythium has a broad host range. If you have a cool wet spring, plants will get infected. Fusarium and common root rot have a narrower host range but are difficult to control with rotation since they’re stubble borne and it would take 3 or more years out of cereals to reduce inoculum. It’s been a bad fusarium year. The producer might look at cereal varieties more tolerant to the crown rots and use a good seed treatment if tillage and alternate crops aren’t an option. It’s just a balance.
Montana State University U.S. Department of Agriculture and Montana Counties Cooperating. MSU Extension is an equal opportunity/affirmative action provider of educational outreach.
