Growth Response of Major U.S. Cowpea Cultivars. I. Biomass Accumulation and Salt Tolerance

Abstract

Over the last several years, there has been increasing interest in amending the soil using cover crops, especially in desert agriculture. One cover crop of interest in the desert Coachella Valley of California is cowpea [Vigna unguiculata (L.) Walp.]. Cowpea is particularly useful in that as an excellent cover crop, fi xing abundant amounts of nitrogen which can reduce fertilizer costs. However, soil salinity problems are of increasing concern in the Coachella Valley of California where the Colorado River water is a major source of irrigation water. Unfortunately, little information is available on the response of cowpea growth to salt stress. Thus, we investigated the growth response of 12 major cowpea cultivars ('CB5', 'CB27', 'CB46', 'IT89KD-288', 'IT93K-503-1', 'Iron Clay', 'Speckled Purple Hall', 'UCR 134', 'UCR 671', 'UCR 730', '8517', and '7964') to increasing salinity levels. The experiment was set up as a standard Split Plot design. Seven salinity levels ranging from 2.6 to 20.1 dS·m -1 were constructed, based on Colorado River water salt composition, to have NaCl, CaCl2 and MgSO4 as the salinization salts. The osmotic potential ranged from -0.075 to -0.82 MPa. Salt stress began 7 days after planting by adding the salts into irrigating nutrient solution and ended after 5 consecutive days. The plants were harvested during fl owering period for biomass measurement (53 days after planting). Data analysis using SAS analysis of variance indicated that the salinity in the range between 2.6 and 20.1 dS·m -1 signifi cantly reduced leaf area, leaf dry weight, stem dry weight and root dry weight (P ≤ 0.05). We applied the data to a salt-tolerance model, log(Y) = a 1 + a 2 X + a 3 X 2 , where Y represents biomass, a 1 , a 2 and a 3 are empirical constants, and X represents salinity, and found that the model accounted for 99%, 97%, 96%, 99%, and 96% of salt effect for cowpea shoot, leaf area, leaf dry weight, stem dry weight and root dry weight, respectively. We also found signifi cant differences (P ≤ 0.05) of each biomass parameter among the 12 cultivars and obtained different sets of the empirical constants to quantitatively describe the response of each biomass parameter to salinity for individual cowpea cultivars. Since a signifi cant salt × cultivar interaction effect (P ≤ 0.05) was found on leaf area and leaf dry weight, we concluded that salt tolerance differences exist among the tested cultivars.

Effect of nanoparticle on growth, biochemical and anatomical characteristics of moringa plant (Moringa oleifera L.) under salinity stress condition

“…The reduction in most vegetative growth parameters may be caused by the reduction in the cell size which might be attributed to changes in osmotic cell enlargement dependent on solute accumulation (Asin et al, 2007) or due to drastic changes in ion relationship (Grossmann et al, 1994). High salinity causes both hyper-ionic and hyperosmotic stress and can lead to plant demise (Wilson et al, 2006). Moreover, salt treatment affects differently early growth stages of plants and has both osmotic and specific ion effects on plant growth (Dionisio-Sese and Tobita, 2000).…”

Trocas gasosas e teores de minerais no feijão-de-corda irrigado com água salina em diferentes estádios

“…As concentrações de sais que restringem o crescimento do feijão-de-corda variam entre os cultivares e parecem depender da composição iônica do meio (Dantas et al, 2002;Wilson et al, 2006a). A redução no crescimento de plantas de feijão-de-corda tem sido associada, em grande parte, ao acúmulo de íons potencialmente tóxicos, particularmente Na + e Cl - (Silva et al, 2003;Assis Júnior et al, 2007).…”

Change in Chlorophyll Content Over Time Well-differentiated Salt-tolerant, Moderately Salt-tolerant, and Salt-susceptible Cowpea Genotypes

“…Fresh pods are most desired in southern Europe (Karapanos et al, 2017), whereas consumption of dried seeds and leaves is common in Africa (Nielsen et al, 1997). In the western part of the United States, there is interest in developing cowpea cultivars as a cover crop (Wilson et al, 2006). Furthermore, previous reports have shown that cowpea is an excellent cover crop (Abdul-Baki et al, 1998;Hutchinson and McGiffen, 2000).…”

“…Evidence of the growing threat imposed by salinity-related issues for cowpea production has been reported in the Coachella Valley of California (Bower et al, 1969). Wilson et al (2006) reported that salinity impaired cowpea physiology and growth, thus limiting its use as a potential cover crop. A total of 12 cowpea cultivars in the United States, 'CB5', 'CB27', 'CB46', 'IT89KD-288', 'IT93K-503-1', 'Iron Clay', 'Speckled Purple Hall', 'UCR 134', 'UCR 671', 'UCR 730', '8517', and '7964', were evaluated by Wilson et al (2006) to determine salt tolerance based on above-ground trait reduction.…”