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 1999

Table 1. Precipitation and temperature.

Table 2. Growing degree units.

Table 3. Dates of last and first frosts.

Table 4. Irrigation water applied.

The winter of 1998 -1999 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 slightly below average in June, below average in September, average in April, May and August, above average in July and October. The maximum temperature surpassed 90F five times in July, and twice in August. The highest temperature was 95F on July 29. Precipitation was below average in April and October, average in July, and above average in May, June, August and September. Precipitation for September, 6.1 inches, was the second highest on record. The first frost was on September 30 with a hard frost on October 1. These frost dates were about one week later than average. Most crops matured before frost. Growing degree days (GDD) in 1999 were lower than average. We noticed that several of the crops produced smaller yields. This was probably due in part to the lower GDD.

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Table 1. Precipitation and temperature at the Oakes Irrigation Research Site.
Month Precipitation Average daily temperatures
1999 15-year average 25-year average 1999 15-year average 25-year average
inches oF
April 0.77 43.4
May 3.71 2.70 2.30 58.2 58.2 57.1
June 5.19 3.18 3.49 65.7 66.7 65.9
July 3.13 3.29 2.88 71.6 69.1 70.7
August 3.27 2.12 2.04 69.2 69.0 68.2
September 6.09 2.76 2.19 55.6 58.9 58.0
October 0.38 1.73


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 1999 10-year average 15-year average 20-year average
May 308 323 343 327
June 480 496 502 484
July 649 584 613 617
August 587 582 568 570
September 258 362 343 344
Total 2281 2346 2370 2343

†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.
1999 10-year average 20-year average
Last frost in spring
less than 32 F Apr 18 May 6 May 7
less than 28 F Apr 18 Apr 28 May 1
First frost in fall
less than 32 F Sep 30 Sep 28 Sep 26
less than 28 F Oct 1 Oct 6 Oct 1
Frost free period (days) 165 145.6 141.9

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                  Table 4. Irrigation water applied, 1999.
Study Irrigation water applied
inches
Asparagus preliminary trial 12.0
Broccoli performance trial 11.2
Cabbage cover crop study 16.2
Cabbage performance trial 16.2
Cabbage production field 15.0
Carrot benlate studies 13.6
Carrot fertility study 15.1
Carrot performance trial 12.4
Carrot tillage study 13.3
Edible bean weed control study 8.9
Edible bean white mold studies 13.0
Field corn performance trial 12.1
Garden pea preliminary trial 7.3
Onion performance trial and weed control study 15.7
Ornamental corn performance trial 13.8
Pepper performance trial 11.0
Pumpkin performance trial 13.0
Raspberry preliminary study 12.0
Soybean performance trial 8.7
Sweet corn performance trial 12.0
Tomato performance trial 11.9
Tomato weed control study 12.3
Winter squash performance trial 13.0

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Go to Oakes Irrigation Research Site 1999 Annual Report

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