Shade stress in various growth phases of peanut genotypes and its effect on agronomic characters and chlorophyll content

Abstract

Shading stress during plant growth is one of the factors that might decrease the peanut crop productivity. The growth phase of the peanut genotypes has different responses to shade stress. This research aimed to study the effect of shade stress in various growth phases on agronomic character and chlorophyll content of peanut genotypes. Shade stress was regulated in six conditions: no shade, shade from planting to harvest, shade from planting until 25 days after planting (dap) (vegetative phase), shade from 26 to 50 dap (flowering phase to pods formation), shade from 51 to 75 dap (seed filling phase), and shade from 75 to 100 dap (the ripening phase of the seeds to harvest). The shade was carried out using paranet which holds 35% of the sun's rays. The genotypes used were F3 generation plants from crosses (G200-I and G300-II x cv.Domba, Takar 1, Bison). The results showed that there were no significant differences in the interactions between shades in various growth phases and genotypes for agronomic traits, but there were significantly different interactions on the content of chlorophyll-A and total chlorophyll. All 12 peanut genotypes tended to produce more chlorophyll-A and total chlorophyll in shade treatment from planting to harvest. Shade at various plant growth phases had a significant effect on agronomic characters. The shade given from planting beginning to harvest produced the lowest dry pod weight (12.9 g/plant) or yield decreased to 23.7% compared to peanut grown without shading. The genotypes significantly affected agronomic traits and g6 genotype (G200-I x cv.Domba)7 produced the heaviest dry pod weight 17.2 g/plant.