FROM AROUND THE STATE
ISSUE 7 June 18, 1998
Crop conditions have improved the past week with recent rains. Final precipitation amounts for the week range from 2 inches up to six inches in parts of Burke and Bottineau Counties. About 60 % of the small grain crop is in the five to seven leaf stage, 25 % in the three to five leaf stage and 15% seven leaf to heading.
Recent rains have caused moderate to high incidence of tan spot to show up in late planted fields (3_5 leaf). Some low rates of Tilt (2 oz/acre) or Mancozeb (1 lb/acre) is being mixed with herbicdes to prevent the spread of the diease, especially to the tillers. Most of small grain crop is ten days to three weeks from heading, so fusarium head blight is not a concern yet. Frost damage wheat is starting to show with crop that is now heading. The wheat field that the frost damage is showing up in was planted in late April and was in the 5 1/2 leaf stage when the frost hit. The results are parts of the head, usually the upper part of the spikelet, is white along with the awns. Parts of the head are emerging white and the spikelets appear sterile.
Most canola fields are bolting to early bloom. Two canola fields were tested for sclerotinia in Renville and Bottineau Counties and both tested positive for sclerotinia.
Recent rainy and windy weather this past week has growers trying to catch up with herbicide applications. Many questions on how late a specific herbicide can be safely applied is common. Also, another flush of weeds is coming. It's the second year in a row we are seeing wild oats emerging in late June.
Area Extension Specialist/Cropping Systems
Orange Wheat Blossom Midge Time to start field monitoring! Male midge should be emerging (1100 degree days) in most areas, and females are expected to emerge at 1300 DD June 27th through July 2nd in the more northern counties. As of June 22, 1998, the following DD (using a base of 40°F) have accumulated: Minot, Ward County = 1200; Mohall, Renville County = 1070; Bottineau, Bottineau County = 1089; Towner, McHenry County = 1068; Rolla, Rollete County = 983; Columbus, Burke County = 956; and Turtle Lake, McLean County = 1166.
Scout or monitor wheat fields for midge activity. For monitoring, white emergence traps or pie plate traps can be used to determine the presence or absence of midge. Coat the inside of the emergence traps or the pie plates with vegetable oil to capture midge. Check traps daily and record the number of midge. Midge are a small, orange fly with a dark brown head and about half the size of a mosquito. After you know midge are present, scouting needs to be conducted to determine if a field is at the economic threshold level of 1 midge for 4-5 wheat heads (10-15% yield loss). Female midges also need warm temperatures >60°F, calm winds <6 mph, adequate soil moisture, and wheat in the heading to flowering stages for good egg laying conditions.
A cooperative monitoring network is being set up through the county extension offices for growers who are interested in monitoring for midge. Daily midge counts will be released to the news media.
Cereal aphid populations are increasing with the recent favorable weather conditions, and need to be monitor during stem elongation to heading. Low populations of English grain aphids have been observed. After the wheat has headed, aphid impact on yield and quality is not economically important to justify the cost of control
Tan spot incidence increasing with the recent wet weather. Tan spot can be easily found in most wheat field now.
Diamondback moth Some larval mortality was observed in areas with recent heavy rains. Remember, trappers should change the pheromone lures every four weeks.
Bertha armyworm traps should be set out soon for early detection.
Sunflower beetle are still active! Adults are continuing to mate and lay eggs. One report of larvae was observed.
PASTURES AND FIELD CROPS
Grasshoppers Early 1st instars (young grasshoppers) to 4th instars are still common in "hot" spots. Continue to check field edges close to pastures, grassy borders, or other overwintering sites for threating numbers of young grasshoppers.
Janet J. Knodel
Area Extension Specialist Crop Protection
North Central Research and Extension Center
Soil moisture levels are adequate in south-central ND. Most of the region received at least 0.5 inches of rain during the past week. Portions of some eastern counties have continued receiving excessive moisture. Growth of warm-season crops including corn, soybean, and dry bean has rapidly accelerated. Hay harvest is frustrating growers because of continued poor drying conditions. Current farm activities include cultivation and herbicide application in warm-season crops.
Most of the region's canola is flowering and the current weather is conducive to sclerotinia infection. Leaf spot disease including tan spot, Septoria, and rust in small grain is common but currently continues to be present at low densities. A major concern is the decision to apply fungicides for scab suppression in barley and wheat. The majority of wheat in this region will be in the susceptible flowering stage within the next 10 days. Sufficient growing degree units have accumulated or will accumulate in the next several days to warrant monitoring wheat fields that are heading for the orange wheat blossom midge. European corn borer moths continue to be trapped at the Carrington Research Extension Center. Alfalfa weevil is being found in scattered alfalfa fields in Dickey, Logan, and McIntosh counties. Monitoring for grasshoppers should continue especially in the southwest part of this region.
Greg Endres and Jim Harbour
Area Extension Specialists
Carrington Research Extension Center