Effect of light intensity and temperature on the photosynthesis of shaded and unshaded native sorghum

الملخص EN

Seed of an indigenous variety of sorghum from Jizun were grown in plastic pots.

After gcnrrination and thinning half of the pots were transferred to 30 % shade and the other half continued to be in the open sun.

Apparent photosynthesis (A P) was measured at heading on both groups of plants at five light intensities (12.22.27.30 and 40 K Lux) and three tempcrature levels (25.

35 and 4SOC).

Total dry weight and grain yield were higher for the open sun plants, while harvest index (III) was lower than shade plants, Leaf area.

However.

Was almost equal for both groups.

APdedined with the increase in temperature.

While it increased with the increase of light intensity.

AI' of shade plants remained always lower than open sun plants.

This explains the reduction in biomass and grain yield of shade plants.

Apparent photosynthesis (A P) could be taken as criteria for evaluating the adaptation of crop plants to environmental stresses such as temperature and light to be used or breeding adapted varieties.