Origin and Breeding
SW 5909 was developed from clonal parents evaluated for persistence following four years of testing in diverse US test locations. These highly persistent parent plants were also screened and selected for overall disease resistance to multiple alfalfa diseases. SW 5909 is a very winterhardy variety with broad adaptation and strong overall disease resistance. In addition, SW 5909 has an HR rating for high resistance to stem nematodes, making it suitable for western irrigated production in situations where stem nematodes are present.
SW 5909 is a high yielding medium-fast recovery type. Regrowth initiation following cutting can vary depending on soil temperature and moisture. In general, hay producers who utilize long drying times exceeding 5-6 days should strive to minimize wheel traffic when baling to avoid damage to new stem shoots emerging from alfalfa plant crowns.
SW 5909 has very good overall disease resistance, with HR (Highly Resistant) ratings for most of the major alfalfa diseases common in the US. SW 5909 has good overall root rot resistance that contributes to persistence in most growing situations. SW 5909 also has an HR rating against stem nematode, making it well-suited to western irrigated situations where the irrigation water source includes tail waters from upstream fields infested with stem nematodes.