The 2006-2007 winter at Fargo was very mild again with December (13.1oF) and January (6.3oF) above average temperatures. Snow cover was adequate whenever temperatures dropped significantly below normal. As a result little, if any, winter injury occurred on established varietal trials. Winter kill was not a factor at Carrington in 2007 also.
Rainfall was 3.75 inches above normal for the alfalfa growing season (October 2006-September 2007). Precipitation was below normal during October 2006 to January 2007, but it was above normal (6.33 inches) during March through June. July was dry (1.7 inches below normal) and September was 1.2 inches above normal. As a result, forage yields are above average in 2007.
Forage yield data for alfalfa cultivars and experimental lines tested at Fargo and Carrington, ND, in 2007 are presented in Tables 1 to 5. Potato leafhoppers were a serious problem in the first harvest at Fargo, which is extremely unusual, so all fields were sprayed with Asana at 5 mL/qt when first signs of symptoms occurred. Leafhoppers were not considered a yield factor thereafter and at Carrington so no future treatment was necessary. Fusarium wilt was significant in about half the Vernal plots in the second harvest of the 2005 seeding at Fargo, which increased the coefficient of variation for the second, third, and fourth harvest. Forage yield of Vernal was impacted in only one of the Vernal checks in the traffic-treated plot. Fusarium wilt was not a factor in the remaining experiments.
Forage yields on established dryland stands at Fargo averaged from 6.6 to 7.6 tons/acre (Tables 1-3), which is about average for the last 10 years. Forage yields of FA-04 seeded in 2004 averaged 22.1 tons/acre for the four years of production (seeding plus three productive years) (Table 1). The highest yielding variety was A4A21 at 6% greater than Vernal followed by 381 HYB at 4.3% greater than Vernal, but all varieties were considered equal yielding since the F-test for entries was nonsignificant. Likewise, entries were not significantly different in FA-05 (Table 2) and FA-06 (Table 3).
FA-04, FA-05, and FA-06 had a traffic treatment applied on half of all plots. The traffic treatment was one pass with a medium-size tractor 5 days after harvest. Forage yields averaged 0.59, 0.49, and 0.42 tons/acre less in FA-04 (Table 1), FA-05 (Table 2), and FA-06 (Table 3), respectively, when the traffic treatment was applied. The reduction in yield from traffic in 2007 was much less than in 2005 when the forage yield was reduced 1.0 ton/acre less with traffic (Table 1) and about the same as last year. The entry X traffic interaction was nonsignificant in all three experiments; yet, it is interesting to note that 4A421 was the highest yielding entry with traffic in FA-05, 381 HYB in FA-04, and Vernal in FA-06. AmeriStand 403T was included as the traffic check since it has been shown in other states to be very tolerant to traffic, but these preliminary data do not show this traffic tolerance, especially in FA-04 and FA-05 (Tables 1 and 2).
Forage yield in the seeding year at Fargo averaged 3.29 tons/acre (Table 4), slightly less than the average 3.56 tons/acre. Forage yield in the seeding year at Carrington averaged 3.14 tons/acre, which is close to the long-term average (Table 6).
The harvest date for the fourth harvest ranged from October 12 to October 25, which was when the alfalfa had initiate new growth (about 3 inches) from the crown. We have harvested the fourth harvest when the alfalfa reaches 40 to 50% bloom or regrowth is initiating (about 2-3 inches in height) for the past seven years and have yet to cause significant winter kill on the stands. This is a real change in fall management that appears to be working.
Irrigated forage yields at Carrington averaged 5.39 tons/acre with three harvests (Table 5), which is about normal for the second year of production. Entries were significantly different with 361 HYB the highest yielding.
The 2007 North Dakota alfalfa hay crop was estimated November 15 at 3.1 million tons, 78% greater than 2006, by the North Dakota Agricultural Statistical Service. Per acre yield at 2.0 tons is up 66% from 2006, and is about normal. Alfalfa acreage was estimated at 1.55 million acres, down 3% from 2006, but near the long-term average.
These data are also available in the near future at:
http://www.ag.ndsu.edu/variety/index.htm
Alfalfa varietal data from 2004, 2005, and 2006 are available at: