FROM AROUND THE STATE
ISSUE 13 July 27, 2000
Canola Insect Pests Update
- Trap catches for Bertha armyworm peaked during mid-July in the North Central area,
but cumulative trap catches are still in the low risk category (0-300 moths total). Only one
site near Mohall had a total moth catch over 300 moth total (432), which is still low. Some
larvae from canola fields have reported but very low levels.
- The second flight of Diamondback moth peaked mid-late July. There is usually a third
flight in August.
- Other incidental insects reported on canola include:
aphids on canola terminals but low infestation levels (<25%).
blister beetles. Note some fields required treatment.
Zebra caterpillar moth. This caterpillar was present during the Bertha
outbreak of 1995-96.
Orange Wheat Blossom Midge Flight near End in the North Central and Northwest
Regions. Hooray! Limited activity is still being reported in the northern counties, especially Divide.
Most of the spraying in Divide will be completed this week.
No reports of any red sunflower seed weevils infesting sunflower heads
yet. Most fields are not
flowering or shedding pollen yet.
There is a few scattered reports of spraying for the larvae of the sunflower beetle.
Thistle caterpillar and banded sunflower moth were found near Gardena
in Bottineau County,
but very low levels (source: B. Sund, CENEX Newburg).
Wheat and Canola Diseases
Assessments of losses from scab are being taken at Minot variety plots and are averaging
moderate-high levels (source: K. McKay).
Janet J. Knodel
Area Extension Specialist Crop Protection
North Central Research and Extension Center
Total rainfall as recorded at NDAWN sites in south-central ND during
July 19 to 25 ranged
from 0.10 inch or less at Dazey, McHenry, McLeod, and Oakes to 0.9 inches at Linton. The recent
reduced amounts of rain have been welcome to allow some field drying, haying to continue, and small
grain harvest to begin. On July 25, estimated daily water use ranged from 0.13 to 0.27 inches for corn
emerged May 15, dry bean and soybean emerged May 29, and sunflower emerged June 5.
Winter cereal harvest has begun south of I-94. Initial reports on
winter wheat yields are indicating
up to 75 bushels/acre. Barley swathing is rapidly advancing and swathing of wheat and oat has begun
south of I-94. Barley swathing is beginning in the northern part of this region. Canola swathing has
begun as far north as the Harvey area. Fields of flax and field pea are nearing maturity. Warm-season
crops continue to rapidly develop. Corn is tasseling, soybean are forming pods (R3 stage), and
sunflower are beginning to bloom.
Leaf spot disease (tan spot, leaf rust, and Septoria in wheat; spot
and net blotch in barley) severity is
rapidly increasing. Scab is easily detected in wheat but severity appears quite variable in the region.
Sclerotinia can be readily found in canola. Aster yellows also is present again this year in canola. Dry
bean growers should be carefully monitoring their crop for initial white mold symptoms.
Black light trap counts for European corn borer at Carrington
continue to indicate low moth counts.
Scattered reports have been received of leafhoppers in dry bean (Barnes County) and armyworms in
small grain (Steele County). Numerous small grain fields have patches of wild oat, kochia, Canada
thistle, and other miscellaneous weeds that growers will have to contend with during harvest.
Area Extension Specialist/Cropping Systems
NDSU Carrington Research Extension Center