Dryland Stand Establishment and Seed Production of Revegetation Species1

Abstract

Seed of species used for reclamation and soil conservation in the arid western USA often is collected from native stands. There is a need to produce more seed of known genetic identity under cultivation to meet this demand. The objectives of this research were to: (i) compare stand establishment of four species on three planting dates under dryland conditions (< 360 mm annual precipitation), and (ii) evaluate stand establishment and seed production at 0.76‐ and 1.52‐ m row spacing for 11 species used for dryland revegetation. Four species were evaluated for stand establishment in southwestern Colorado when planted in April, May, and October in 1982, and April, June, and October in 1983. Eleven species were evaluated for seed production. Rocky Mountain penstemon (Penstemon strictus Benth.) and Lewis flax (Linum lewisii Pursh.) had higher stand establishment ratings when seeded in October than in the spring. Indian ricegrass [Oryzopsis hymenoides (Roem. and Schult.) Ricker] established well at all planting dates. Fourwing saltbush [Atriplex canescens (Pursh.) Nutt.] established equally well in all months tested except April. The highest seed yields were obtained from small burnet (Sanguisorba minor Scop.) and tall fescue (Festuca arundinacea Schreb.). Orchardgrass (Dactylis glomerata L.) and Indian ricegrass generally produced more seed than either western wheatgrass [Elymus smithii (Rydb.) Gould] or basin wildrye [Leymus cinereus (Scribn and Merr.) A. Löve]. The latter two species declined in seed production dramatically in the third year. Seed production in 1983 and 1985 was greater in the 0.76‐ than in the 1.52‐m row width.