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, E-mail: Leonard.Besemann@ndsu.edu

The winter of 2004 - 2005 was mild with little snow cover. Spring tillage and planting times were about average. The last frost in the spring was on May 14, about two weeks later than average with a hard frost (19 F) on May 4. Except for the first half of May, summer temperatures were warmer through most of the growing season. The maximum temperature equaled or exceeded 90 F (32 C) ten times; twice in June and September and six times in July. The highest temperature was 95 F (35 C) on June 23 and July 16. Precipitation was above average in May, June and August; below average in April, July and October; and about average in September. Total annual precipitation was three inches above the long term average. Temperatures were below average in May. The temperature was about average in August and above average in April, June, July, September and October. The first frost on October 5 and was also a hard frost. The first frost was six days later than the ten-year average and the first hard frost was one day later than the ten-year average. Some early planted crops may have been affected by the later spring frost. All crops matured before frost. Growing degree units in 2005 were well above average.

Month	Precipitation			Average daily temperatures
Month	2005	15-year average	25-year average	2005	15-year average	25-year average
	---------------- inches --------------			------------------ F ------------------
April	0.58	1.50		48.1	43.8
May	4.55	3.27	2.76	54.0	56.6	56.8
June	7.93	4.10	3.58	68.5	66.3	66.1
July	2.41	3.63	3.33	72.2	70.1	71.0
August	3.14	1.83	1.93	68.0	68.8	68.9
September	2.30	2.81	2.47	63.1	59.5	58.6
October	1.72	2.14		47.7	46.1

Month	2005	10-year average	15-year average	25-year average

May	263	284	308	317
June	545	491	493	489
July	666	641	610	628
August	556	588	579	578
September	439	382	371	351

Total	2468	2386	2361	2363

¹Growing degree units = (Temp_max + Temp_min)/2 - 50. If Temp_max is greater than 86, then

Temp_max = 86. If Temp_min is less than 50, then Temp_min = 50. Temperature is in degrees F.

		2005	10-year average	15-year average	25-year average
Last frost in spring
	less than 32 F	May 15	May 2	May 4	May 6
	less than 28 F	May 4	Apr 30	Apr 28	Apr 30
First frost in fall
	less than 32 F	Oct 5	Sep 29	Sep 29	Sep 26
	less than 28 F	Oct 5	Oct 4	Oct 4	Oct 1

Frost free period (days)		143	151.5	147.7	143.8

Study		Irrigation water applied
		inches

Broccoli hybrid performance trial		7.5
Cabbage hybrid performance trial		7.5
Cabbage weed control studies
	Direct seed	7.5
	Transplant	6.6
Chinese cabbage hybrid performance trial		7.9
Carrot hybrid performance trial
	Baby carrot	5.0
	Cut and peel	7.0
	Cello	8.6
	Dicing and Jumbo	9.2
Carrot weed control study		8.2
Field corn hybrid performance trial		6.7
Living mulch studies
	Cabbage	7.7
	Carrot	7.7
	Sweet corn	7.0
Onion hybrid performance trial		8.2
Onion row spacing plant population study		8.2
Onion weed control study		8.2
Pepper hybrid performance trial		9.2
Pumpkin variety performance trial		6.0
Pumpkin weed control study		6.0
Soybean variety performance trial		6.9
Sugar enhanced sweet corn hybrid performance trial		4.8
Supersweet sweet corn hybrid performance trial		6.0
Watermelon hybrid performance trial		7.2