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ARS Home » Pacific West Area » Parlier, California » San Joaquin Valley Agricultural Sciences Center » Water Management Research » Research » Publications at this Location » Publication #390563

Research Project: Improved Management, Quality and Utilization of Alfalfa for Dairies in the Western U.S.

Location: Water Management Research

Title: Light interception, agronomic performance, and nutritive quality of annual forage legumes as affected by shade

Author
item ANGADI, SANGAMESH - New Mexico State University
item UMESH, MATHADA - University Of Agricultural Sciences
item Begna, Sultan
item Gowda, Prasanna

Submitted to: Field Crops Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/3/2021
Publication Date: 11/24/2021
Citation: Angadi, S., Umesh, M., Begna, S.H., Gowda, P.H. 2021. Light interception, agronomic performance,and nutritive quality of annual forage legumes as affected by shade. Field Crops Research. 275:108358. https://doi.org/10.1016/j.fcr.2021.108358.
DOI: https://doi.org/10.1016/j.fcr.2021.108358

Interpretive Summary: Annual legumes are potential crops often used in intercropping system setting to increase conversion efficiency of light interception into dry matter (DM) yield but legume species vary in their tolerance to shading. Forage legumes (lablab, cowpea, lima bean, pole bean and pigeonpea) were examined for agronomic, light interception, and quality of forage under reduced light. Field studies were conducted in 2009 and 2010. Twenty to twenty-five days after planting, a third of the plot length was covered with Aluminet shade cloth to reduce sunlight reaching the crop canopy to 30% of that of plots without shade. Leaf area index (LAI) and light interception (LI) were significantly different between species and shading up to 50–60 days after planting but not thereafter. Shading reduced DM forage yield by 31–39% and 26–35% in 2009 and 2010, respectively. Lima bean was affected the most with 43% reduction in DM, followed by pigeonpea (39%), while cowpea (29%) and lablab (17%) were affected the least. Leaves and pods plant parts were affected more than stems by shading. Shading had a marginal effect on crude protein, but resulted in an increase in fiber content. In general, lablab and cowpea were best adapted to reduced sunlight and can be suitable for intercropping system for efficiently converting light energy into forage dry matter.

Technical Abstract: Annual legumes can adapt to reduced light, a condition common in intercropping, by increasing the efficiency with which they convert energy into dry matter (DM). The performance of five forage legumes under reduced light–simulated by growing them under a shade net was evaluated in terms of agronomic adaptation, light interception, and the quality of forage. A third of the plot length was covered with Aluminet shade cloth 20–25 days after planting to reduce sunlight reaching the crop canopy to 30% of that without shade. Leaf area index (LAI) and light interception (LI) were significantly different depending on the species and shading up to 50–60 days after planting but not thereafter. Shading reduced DM significantly (p = 0.05), by 31–39% in 2009 and by 26–35% in 2010. Lima bean was affected the most (DM reduced by 43%), followed by pigeonpea (39%), whereas lablab (17%) and cowpea (29%) were affected the least. It affected dry matter in leaves and pods more than that in the stem. Shading had only a marginal influence on the concentration of crude protein, but increased the content of acid detergent fiber and neutral detergent fiber. Overall, lablab and cowpea were best adapted to reduced sunlight and therefore will be suitable for intercropping.