The 2004-2005 winter was very mild in November, December, and February with 5.5 to 7.2oF above normal temperatures at Fargo. January through March was near normal, but April was 5.6oF above normal, which cause the alfalfa to initiate earlier than normal. Good snow cover during below-average temperatures resulted in good over wintering of alfalfa stands. The only winter kill occurred on experiments that had standing water in the spring.
Sixty to 80% of the 3- to 5-inch stems were killed by back-to-back 22 and 20oF freezes on May 2 and 3. Normally a 20oF freeze in the spring does not kill alfalfa stems, but the consecutive freezes apparently was too much. However, I was amazed how rapidly the alfalfa plants recovered with warm temperatures. One week after the freeze dead bleached stems laying on the ground could be seen, but new shoots 1 to 2 inches in height had already occurred. A week later you would had missed the freeze effects if you were unaware of the previous weather. September temperatures were 6.5oF above normal, which resulted in above-normal fall forage yields.
Rainfall for the growing season (September 2004 to September 2005) was 7.17 inches above normal due to 8.47 inches in June and 7.52 inches in August. Therefore, growing conditions were very good for most of the season.
Forage yield data for alfalfa cultivars and experimental lines tested at Fargo and Carrington are presented in Tables 1 to 5. Disease was not considered a significant production factor in 2005. Little problem with potato leafhopper occurred at Fargo, but there was some hoppers at Carrington in one replicate. One replicate of FA-02 and FA-03 at Fargo were discontinued in 2005 due to standing water in the spring depleting the stand. The water also impacted a few plots in the next rep of FA-02, which increased the coefficient of variation (CV).
Mean forage yields at Fargo were exceptional for the 10th straight year ranging from 7.25 to 7.54 tons/acre on established stands in 2005 (Tables 1, 2, and 3) The highest yielding treatment was AmeriStand 403T at 8.97 tons/acre (Table 3). Forage yields added across the seeding and three years of production in FA-02 experiment averaged 24.52 tons/acre, very similar to 2004. Forage yield in the seeding year at Fargo averaged 4.48 tons/acre, about 0.75 tons/acre above normal (Table 4). Forage yield in the seeding year at Carrington average only 3.00 tons/acre, partially due to the 4-week latter seeding date (Table 5).
Forage yield of FA-04 in its first year of production average 8.54 tons/acre on un- trafficked plots, the highest average yield ever in a variety trial (Table 4). However, the same varieties yielded 7.54 tons/acre on plots that received one pass of a tractor tire 5 days after harvest or a 12% lower yield. This experiment will be repeated in 2006 and a traffic treatment will be imposed on the FA-05 experiment also.
The 2005 North Dakota hay crop was estimated November 1 at 3.04 million tons, 56.2% higher than the 2004 crop, by the North Dakota Agricultural Statistical Service. Per acre yield at 2.1 tons/acre was higher than the 10-year average. Harvested acreage was estimated at 1.45 million acres, up 11.5% over 2004, and near the long-term average of 1.5 million acres.
Alfalfa varieties should be selected on stand persistence, multiple pest resistance, enhanced forage quality, and forage yield better than Vernal. See the following web site for additional information on these items:
http://www.maes.umn.edu/maespubs/vartrial/cropages/alfapage.asp