Guar Stand Establishment, Physiology, and Yield Responses to Planting Date in Southern New Mexico

Abstract

Guar ( Cyamopsis tetragonoloba L.) is a drought‐tolerant summer annual legume that can be grown for forage, green pods, or seeds. Galactomannans use in various industries such as food, cosmetic, paper, and oil etc. has attracted the guar production for seed. Currently, most of the United States’ demand for guar is met through imports. Preliminary research has shown that guar can be potentially grown in semiarid irrigated conditions in southern New Mexico (NM). A 2‐yr field study was conducted from 2014–2015 to evaluate stand establishment, physiology, and yield performance of eight guar genotypes under four planting dates in southern NM. In both years, mid‐June planting resulted in better stand establishment by having higher plant density than late‐April and mid‐May plantings. The mid‐June planting resulted in higher photosynthetic rate (P n ) compared to late‐April and early July plantings. Transpiration rate (T r ), leaf area index (LAI), clusters plant −1 , pods plant −1 , and seeds plant −1 were also higher for mid‐June planting compared to mid‐May and early July plantings in both years. Across genotypes and years, mid‐June planting produced 13, 27, and 45% higher seed yield than late‐April, mid‐May, and early July plantings. Across planting dates, genotype NMSU‐15‐G1 had highest seed yield among all genotypes in both years; however, it did not differ significantly from cultivar Matador. Introduction lines and cultivar Matador took more days to reach various stages. The mid‐June planting showed early maturity. Guar planted under mid‐June planting appears to increase seed yield along with having early maturity in southern NM. Planting date had a significant effect on guar seed yield. Significant genotypic variation for seed yield was observed across planting dates. Planting dates and genotypes showed a significant interaction for guar seed yield. Mid‐June planting increased guar seed yield over other tested planting dates.