Oakes Irrigation Research Site
Carrington Research Extension Center * North Dakota State University
P.O. Box 531, Oakes, ND 58474-0531, Voice: (701) 742-2189, FAX: (701) 742-2700, email: rgreenla@ndsuext.nodak.edu

WEATHER AND IRRIGATION 1998

Table 1. Precipitation and temperatures

Table 2. Growing degree units

Table 3. Frost dates and growing season

Table 4. Irrigation amounts

The winter of 1997-1998 was mild. Frost depth in the soil was shallow throughout the winter. Spring tillage and planting times were close to average. Early summer temperatures were good for crop growth. Warm, but not hot, weather from May through September pushed the crops along. Temperatures were below average in June, slightly above average in May, July, August and October, and above average in April and September. The maximum temperature surpassed 90F six times in July, and three times in September. The highest temperature was 94F on September 10 and September 18. Precipitation was below average in July and September, and above average in April, May and August. Precipitation for June (10.21 inches) and October (6.65 inches) set record highs for those months. The first frost was on October 1 with a hard frost on October 13. These frost dates were about one and two weeks later than average. Most crops matured before frost.

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Table 1. Precipitation and temperature at the Oakes Irrigation Research Site.
Month Precipitation Average daily temperatures
1998 25-year average 15-year average 1998 25-year average 15-year average
---------------- inches --------------- ------------------ F ----------------
April 2.33 48.7
May 3.47 2.51 2.29 60.4 57.9 56.9
June 10.21 3.28 3.32 63.1 66.7 65.9
July 1.69 3.23 2.79 72.1 70.3 70.9
August 2.32 1.96 2.01 71.4 68.6 68.0
September 0.78 2.43 1.95 64.0 58.2 57.9
October 6.65 1.95 48.1

The 15 and 25-year averages are not available for April and October.

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Table 2. Growing degree units† at the Oakes Irrigation Research Site.
Month 1998 10-year average 15-year average 20-year average
May 370 325 341 328
June 423 495 501 485
July 666 591 610 616
August 660 583 571 569
September 458 372 343 345
Total 2577 2365 2365 2344

†Growing degree units = (Tempmax + Tempmin)/2 - 50. If Tempmax is greater than 86, then Tempmax = 86. If Tempmin is less than 50, then Tempmin = 50. Temperature is in degrees F.

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Table 3. Dates of last and first frosts.
1998 10-year average 20-year average
Last frost in spring
less than 32o F Apr 18 May 8 May 9
less than 28o F Apr 16 Apr 30 May 2
First frost in fall
less than 32o F Oct 1 Sep 28 Sep 25
less than 28o F Oct 13 Oct 5 Oct 1
Frost free period (days) 166 143.0 139.5

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Table 4. Irrigation water applied, 1998.
Study Irrigation water applied
inches
Asparagus preliminary trial 15.0
Cabbage cover crop and weed control studies 15.6
Cabbage performance trial 16.3
Carrot fertility study 17.4
Carrot performance trial and Benlate studies 21.7
Cauliflower performance trial 15.0
Edible bean white mold study 17.6
Field corn hybrid performance trial 14.8
Herbicide carryover study 16.7
Lettuce performance trial (1st planting) 10.0
Lettuce performance trial (2nd planting) 12.5
Onion studies 17.3
Ornamental corn performance trial 16.5
Pepper weed control study 17.8
Pepper performance trials 16.2
Potato weed control studies 16.0
Pumpkin performance trial 16.2
Radish performance trial 2.3
Raspberry preliminary study 15.0
Seed onion production study 14.6
Sweet corn performance trial 11.8
Tomato performance trial 17.9
Tomato weed control study 18.2
Winter squash performance trial 16.2

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Go to Oakes Irrigation Research Site 1998 Annual Report

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