Carrington Research Extension Center
North Dakota State University
NDSU Extension Service
North Dakota Agricultural Experiment Station

Ag Alert


5 August, 1999

CREC WATER AND WEATHER UPDATE

According to the North Dakota Ag Weather Network (NDAWN) at the Carrington Research Extension Center (CREC) location, rainfall totaled 0.05 inches during the past week (July 28 to August 3). This minimal rainfall has coincided with the start of area hay and small grain harvest, and canola swathing operations. Rainfall at the CREC from April through July this season has totaled 10.7 inches compared to the long-term average (1961-90) of 10.1 inches. Daily crop water use at the CREC on August 3 for wheat emerged May 1 was 0.07 inches, and for corn emerged May 15 and dry bean emerged on May 29 was 0.25 inches.

Recent air temperatures at the CREC have been considerably cooler compared to late July, with maximum temperatures ranging from 74 to 77 degrees F and minimum temperatures ranging from 47 to 57 degrees during August 1-3. Growing degree day units from May through July for corn have totaled 1227 units this season compared to the long-term average of 1262 units.

Weather data for your area may be obtained through the NDAWN system at the website: www.ext.nodak.edu/weather/.

SEPTORIA LEAF SPOT IN SUNFLOWER

As you scout your early-bloom sunflower for seed weevils, sunflower beetles, and rust you may detect another pest. Septoria leaf spot, a fungus disease, can be found in area sunflower fields. The disease first develops on the lower leaves and later may spread to the upper leaves. The spots begin as water-soaked areas (greasy green in appearance). The spots are somewhat diamond shaped, brown on the upper surface and a lighter grey-brown on the lower surface. A narrow yellow halo often surrounds newly-developed spots. Mature leaf spots may contain tiny, indistinct dark-brown specks called pycnidia, which are visible with a hand lens. Moderately high temperatures and abundant rainfall are required for rapid disease development. The disease develops more rapidly after flowering. Fortunately, this disease rarely is severe enough to cause economic loss and currently fungicide treatment is not recommended.


Greg Endres, Area Extension Specialist/Cropping Systems, Email: gendres@ndsuext.nodak.edu
1999 Ag Alert Archive * Carrington R&E Center Home Page * NDSU Agriculture