NDSU Crop and Pest Report


ISSUE 1  May 2, 2002


South-Western ND

Weather the past two weeks has been more like winter weather in early March than the last two weeks of April. The mean maximum temperature for the month just completed was 50oF, 4.5oF lower than the 103 year mean at the Dickinson Research Extension Center (DREC) and the mean low temperature was 25oF or 3.4oF lower than the long term mean. Between a large snow event on April 18 and other smaller snow and rainfall events, precipitation at DREC was very near normal at 1.43 inches. The 103 year mean for April is 1.44 inches. October through March all provided below normal precipitation levels totaling a departure from the long term total for those months of 1.29 inches. However if September 2001 rainfall, that is essentially precipitation since the 2001 wheat harvest through the month of April 2002 are considered, we are about 0.14 inches below normal. Other areas in southwestern North Dakota are not as fortunate in terms of precipitation.

With average April precipitation this doesn’t mean that we have moisture to "burn." Many producers in the southwestern part of the state understand moisture that is lost thorough unnecessary tillage is lost yield. Each tillage operation used in preparing the soil to establish a crop will result in the lost of about ˝ inch of stored soil water. Each inch of water lost means a reduction in yield of between five and seven bushels of wheat per acre.

A four year study at Dickinson 1995 – 1998 conducted by Pat Carr, DREC agronomist, Richard Horsley, NDSU scientist, and Chip Poland, area extension specialist at DREC, found that hard red spring wheat yields were enhanced by as much as 7.2 bushels per acre under no-till management compared with conventional tillage and reduced tillage programs when relatively dry conditions occurred, but not when over-winter and growing season precipitation exceeded the 30 year average. Over-winter precipitation has not exceeded the 30 year average in 2002.

Area livestock producers are asking, "When will grass be ready to graze this year?" Lee Manske, range specialist at DREC provides the following timely answer for this question.

The standard answer is the same every year, which is "after the tillers have 3 full new leaves with the forth leaf coming".

However, this is only the third year in 21 years that crested wheatgrass has not had 3 new leaves on 22 April. Spring crested wheatgrass pastures should be ready to graze on 1 May with most of the tillers at the 3rd leaf stage. The herbage weight will be below average during early May. Pastures that were grazed last spring and also hayed and/or grazed last fall will not have adequate herbage to support grazing on 1 May, and will require 3 to 6 weeks to produce adequate herbage.

Cool season grasses start next years growth during the previous fall after mid August. Usually 2 or 3 fall leaves develop. Last fall was very dry and less than 2 leaves developed. These fall leaves were damaged during the mild winter and have not provided much help for the new spring leaves. The first new leaf is also damaged from low temperatures.

We can expect average to below average herbage production this year from domesticated grass and native range pastures. Pastures that were used heavy last year, especially the heavy use fall pastures, will have below average herbage production. The double use crested and brome pastures will require several weeks to produce adequate forage.

The grazing readiness of perennial grass plants is determined by the leaf growth stage which is 3.5 new leaves. The leaf stage of grasses is primarily determined by the length of sunlight. The height and weight is determined by available soil water and air temperature.

Roger Ashley
Area Extension Specialist/Cropping Systems
Dickinson Research Extension Center

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