Effects of climate and agricultural practices on the ecophysiology of pigeonpea in the southeastern United States

Abstract

Many factors such as climate and agricultural practices influence the ecophysiology of legume crops. As an important legume crop, pigeonpea (Cajanus cajan) has been grown mainly in arid, semi-arid tropical and subtropical regions of the World. However, performance of pigeonpea in southeastern United States has not been extensively investigated. To test the effects of climate and agricultural practices on the ecophysiology of pigeonpea, we conducted a two-year field experiment in Nashville, Tennessee. Precipitation during the growing season showed contrasting patterns with fall drought in 2010 and frequent precipitation in 2011. Four pigeonpea varieties at three planting densities were evaluated in both years. Measurements included maximum net leaf photosynthesis, stomatal conductance, transpiration, water use efficiency (WUE), leaf area index (LAI), and soil respiration. We found strong interannual variations in all variables investigated. Leaf photosynthetic rates, stomatal conductance, transpiration and LAI were significantly higher in 2011 than in 2010. The high values observed in 2011 were mainly due to high precipitation rates during and after the flowering time. Pigeonpea varieties G1 and W3 had higher photosynthetic rates and LAI while variety W3 had the highest WUE. Planting density did not influence these ecophysiological variables except for plant transpiration. Our results indicated that variety selection could improve pigeonpea performance under varying climatic conditions. Although pigeonpea varieties are adaptable to drought, irrigation and growing in moist climatic regions could significantly enhance its ecophysiological performance and yield.

Evaluación agronómica de 15 genotipos de gandul [Cajanus cajan (L.) Millsp.] en Isabela y Lajas, Puerto Rico

“…Los promedios de rendimientos en vaina fresca y semilla seca fueron superiores durante las siembras de noviembre 2017, en relación a abril 2018, tanto para Isabela como para Lajas. Por lo tanto, el incremento o disminución en los rendimientos podría estar relacionado con factores como las condiciones de clima y suelo, tipo de suelo, disponibilidad de agua, época de siembra, prácticas agrícolas, ataque de plagas, entre otras condiciones que pueden afectar los procesos fisiológicos del gandul (Kaur et al, 2017;Manalili et al, 2018;Ojwang et al, 2016;Pal et al, 2018;Saxena et al, 2010;Viteri et al, 2019;Wilson et al, 2012aWilson et al, , 2012b. De hecho, durante los meses de enero, febrero y marzo de 2018 se observó menor cantidad de lluvias, tanto en Isabela (9.30, 11.53, 1.04 cm de precipitación) como en Lajas (3.86,5.51,8.20 cm de precipitación), en comparación con los meses de agosto, septiembre y octubre de 2018 (11.94, 8.38, 17.47 cm en Isabela, y 3.04, 11.38, 13.72 cm en Lajas), cuando la cantidad de lluvias fue mayor.…”

Field Performance and Yield of Four Pigeonpea Varieties in Middle Tennessee

“…Four replications were used. Each plot size was 3 by 2 m. Normal field operations and maintenance of the plots are as described in Wilson et al (2012a, 2012b). No N or irrigation was applied.…”

“…Leaf photosynthesis, stomatal conductance, and transpiration were measured using a Li‐6400 Portable Photosynthesis System (Li‐Cor Inc., Lincoln, NE). Two fully expanded young leaves of two to three selected plants in the center row of each plot were measured between 1000 and 1500 h during the peak flowering time in September and October (Wilson et al, 2012a, 2012b). Light in the leaf chamber was set at 2000 photo/m 2 /s.…”

“…A number of pigeonpea varieties have been tested for grain and forage production in Georgia, Florida, Oklahoma, and Virginia (Salunkhe et al, 1986; Lucier et al, 2000; Foster et al, 2009; Bhardwaj et al, 1999). Many physiological processes of pigeonpea haven been known to change with variation in agricultural practices and climate (Wilson et al, 2012a, 2012b). However, studies on pigeonpea leaf physiology, growth and yield over multiple years in the southeastern United States are still limited.…”