FROM AROUND THE STATE
ISSUE 12 July 23, 1998
It's harvest time ! Across the region rye and winter wheat swathing is occurring with harvest to begin next week. Swathing of barley, early spring wheat and canola is also starting. No reports of any yields as yet.
Crop conditions are still good for the most part. The hot temperatures has resulted in some area fields to begin to show signs of heat stress, especially on the knolls and side hills. Fusarium head blight is showing up in slight to moderate levels in area wheat and durum fields that were planted from April to mid May. The later crop, mid May_early June, that has headed in the last week or so far hasn't had any rain on the heads and hopefully won't have any fusarium. Fusarium head blight is very common in barley and can be found in almost every field in the area.
Tens of thousands of acres were sprayed for the wheat midge. Already reports of 30 + wheat midge larvae in a head are being reported.
Sunflower, dry bean, and soybean development has accelerated with the warm weather the past two weeks and now is normal to ahead of normal compared to the long term average.
Overall the potential for an average to above average crop is still there, all we need now is to get it in the bin.
Area Extension Specialist/Cropping Systems
Orange Wheat Blossom Midge Declining! After a prolonged emergence period, wheat midge is finally declining in most areas. A few reports, however, indicate some activity on later planted fields. The bottom line is that we still have a lot to learn about the wheat midge. For example, what environmental factors affect wheat midge emergence?; how can we develop a more efficient monitoring trap? Larvae can be readily found in wheat heads now.
Wheat Stem Maggot Damage Observed. Reports of the white heads caused by the feeding of the wheat stem maggot are frequent. Dont confuse it with root rot! The wheat heads of wheat stem maggot can be easily pulled out along the stem where the maggot has chewed. In root rot, the whole plant will be pulled out of the ground. Incidence is low, ranging from 1-10% of a field.
Leaf Spots Diseases (tan spot and septoria) and Scab are common in region. Diseases especially scab are showing up now. Incidence is usually low, but readily found field to field. An occasional field with a high incidence and severity has been reported.
Leaf Rust if becoming more prevalent on the bottom leaves of wheat.
Diamondback moth Trap counts were increasing in most areas during the past two weeks. This is the second flight. Fields need to be scouted for larvae if trap counts are high (>100 per week) and the crop is susceptible to damage, blooming to early podding.
Bertha armyworm trap counts have declined. Most areas have escaped high trap counts (>500 moth during trapping period). A few areas with high trap counts like Newburg, Bottineau County, should scout fields for potential larval infestations.
Sclerotinia observed in Bottineau County, about 10% of the field infected.
Sunflower beetle spraying continues! Many fields were above the 25-30% defoliation level and had to be sprayed in the region.
Seed weevils (both red and gray) have been observed on sunflowers. However, most fields are only in the bud stage of development (too early for seed weevil infestation).
Pupae of Sunflower maggots (Neotephritis finalis) have been observed in heads. Not economically important.
Sunflower Rust is here! Most fields are at relatively low levels. However, Mike Hutter noted that some fields have increasing rust levels in Bottineau County.
Downy mildew has been found near Bottineau, Bottineau County. Samples were submitted to Dr. Gulya for Apron tolerance testing. Typical symptoms are dwarf plants, yellowing (chlorosis) of the leaves, and white cottony masses on the lower leaf surfaces.
Some wilted sunflower plants caused by sclerotinia wilt has been found during early bud stages. Low incidence.
Thanks to Northern Ag Management and Ag Zone for their excellent pest reports!
Janet J. Knodel
Area Extension Specialist Crop Protection
North Central Research and Extension Center