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Accueil du site → Master → Etats Unis → 2016 → Growth and yield performance of guar (Cyamopsis tetragonoloba (L.) Taub.) genotypes under different planting dates in desert Southwest

New Mexico State University (2016)

Growth and yield performance of guar (Cyamopsis tetragonoloba (L.) Taub.) genotypes under different planting dates in desert Southwest

Sudhir Singla

Titre : Growth and yield performance of guar (Cyamopsis tetragonoloba (L.) Taub.) genotypes under different planting dates in desert Southwest

Auteur : Sudhir Singla

Université de soutenance : New Mexico State University

Grade : Master of Science (MS) Plant and Environmental Sciences 2016

Guar (Cyamopsis tetragonoloba L.) is drought tolerant, summer annual legume that can tolerate high temperature and dry weather conditions prevailing in the semi-arid regions such as New Mexico. Guar has multiple uses. Fresh pods are used as vegetables, whole green plants are used as protein rich, high quality forage for animals, and seeds are used to produce guar gum. Guar gum is an industrial ingredient, which acts as a binder and stabilizer in many industrial products. Recent use of guar gum for hydraulic fracturing in natural gas industries has increased the demand for guar. A field study was conducted in 2014 and 2015 to evaluate the yield performance of various guar genotypes under different planting dates at Las Cruces in southern New Mexico and at Clovis in eastern New Mexico. At Las Cruces, eight genotypes (HES 1123, Kinman, Lewis, Matador, NMSU-15-G1, NMSU-15-G2, NMSU-15-G3 and NMSU-15-G4) were tested on four different planting dates (April 25, May 15, June 16 and July 1 in 2014 ; and April 27 ; May 14, June 15 and july 1 in 2015) ; while at Clovis, four genotypes (HES 1123, Kinman, Lewis, Matador) were tested under three different planting dates (June 18, July 7 and July 22 in 2014 ; and June 18, July 6 and July 20 in 2015). These dates will be referred to as late-April, mid-May, mid-June and early-July terms for Las Cruces planting dates : and as mid-June, early July and late-July for Clovis planting dates. At Las Cruces, probably favorable weather conditions such as higher initial mean soil and air temperature in mid-June planting resulted in comparatively better stand establishment, higher plant height, plant width, leaves per plant, leaf area index (LAI), dry leaf weight and above ground dry biomass per plant at 50% flowering stage compared to other plantings in both years. Physiological parameters such as photosynthetic rate, stomatal conductance, transpiration rate and chlorophyll content were also higher for mid-June planting than rest of plantings in both years. 1000-seed weight and harvest index did not differ among the first three planting dates in both years. Seeds per plant, clusters per plant, pods per plant and dry pod weight per plant were highest for the mid-June planting but did not differ from late-April planting in both years. Seed yield was lower in year 2015 compared to 2014. Yield differences were more apparent in 2014 compared to 2015. In 2014, the mid-June planting had higher seed yield than mid-May and late-July plantings. However, in 2015, the mid-June planting was better than late-July planting only. In both years, probably low soil temperature during planting affected late-April and mid-May planted guar seedling emergence. A viral disease caused by Potyvirus group was observed in all planting dates, but the effect of the disease was more pronounced in the mid-May planting, which might be reason for lower yield of guar genotypes under the mid-May planting. The mid-June planting matured earliest and had a minimum growing degree days (GDD) requirement to reach various growth and development stages in both years. The GDD requirement to reach maturity did not differ among planting dates in 2015 ; in 2014 however, mid-June planting had lower GDD requirement to reach maturity than mid-May planting. Genotypes also differed significantly for number of days and GDD requirement to reach maturity in both years. NMSU-15-G2 required highest number of days and GDD to mature, but did not differ from NMSU-15G-G1, NMSU-15-G4 and Matador in both years. Planting dates and genotypes had a significant interaction for seed yield in both years. In both years, in late-April and mid-May plantings, NMSU-15-G1 produced maximum seed yield, while in the mid-June and early-July plantings, Matador and Lewis had highest seed yield, respectively. Comparing planting dates within genotypes, NMSU-15-G1 consistently had higher seed yield in first three plantings than in early-July planting ; while Matador had higher seed yield in the mid-June planting compared to the other plantings. Lewis had consistent, but lower seed yield comparatively. At Clovis, the mid-June planting of guar consistently had better stand establishment, plant above ground dry biomass, leaves per plant, leaf area index (LAI), photosynthetic rate, stomatal conductance chlorophyll content compared to both of July plantings in both years. Apart from exhibiting better agronomy and physiology, the mid-June planting accumulated dry matter at a faster rate as shown by higher relative growth rate (RGR). The mid-June planting also had higher pod thickness, seeds per plant, pods per plant and dry pod weight per plant in both years. However, pod length, seed per pod, pods per cluster and harvest index were higher for the both, mid-June and early-July plantings in both years. The mid-June planting of guar attained higher seed yield than both of July plantings in both years. Across planting dates and genotypes, year 2014 had higher guar seed yield than year 2015. Genotypes did not show significant variation among themselves for seed yield in 2014, however, in 2015, Kinman had lower seed yield than other genotypes. Testing guar genotypes on earlier planting dates such as in April and May could reveal more information about potential planting date for guar in Eastern New Mexico. Delayed plantings (late-July at Las Cruces ; early-July and late-July at Clovis) reduced guar seed yield significantly in both years, which might be because of unfavorable weather conditions (lower mean soil temperature and air temperature). Unfavorable weather conditions could have affected translocation of photosynthates to economic parts and, therefore, might have led to reductionin guar seed yield and yield components

Présentation (NMSU Library)

Page publiée le 13 octobre 2016, mise à jour le 24 décembre 2019