Hayden
1. Two parent clones were selected from P.I. 235,736 and two clones were selected from a field of Sonora; the parent clones were selected for high general combining ability for forage production.
2. Adapted to the lower desert valley areas of southern Arizona for hay, greenchop or grazing.
3. Purple flowers, darker green foliage than Mesa-Sirsa. Pubescence and uniformity are similar to Mesa-Sirsa and El-Unico. Very nonwinter-dormant, upright in growth habit. Level of resistance to the spotted alfalfa aphid similar to that of Mesa-Sirsa and El-Unico. High level of resistance to four biotypes of the spotted alfalfa aphid.
4. Two-clone crosses from each of the two germplasm sources will be made in isolation. An equal amount of seed from each "single-cross" will be blended and classed as breeder seed. Breeder seed will be planted to produce the first synthetic generation of the "double-cross" combination and will be classed as foundation seed. Foundation seed will be planted to produce the second synthetic generation and will be classed as certified seed. Breeder and foundation seed will be grown in lower desert valley areas of southern Arizona. There will be no registered class of seed. Only breeder, foundation and certified seed may be called Hayden alfalfa.
5. Fall of 1971.