Productivity and forage quality of sorghum irrigated with saline Waters

Abstract

The dry matter yield and the chemical composition of two sorghum genotypes, CSF 18 and CSF 20, irrigated with waters of different salt levels, 0.90 (well water), 2.60, 4.20 and 5.80 dS m^-1, were evaluated. A completely randomized block design, in a factorial arrangement (2 x 4), with four replicating was adopted. The experiment was set up in the field, during the dry season, in spacing of 0.80 x 0.10 m. At 112 days after sowing, the plant height was measured and the plants were harvested to evaluate biomass production and chemical composition. Plants containing completely open panicles were harvested and pre-dried and triturated samples were used to perform bromatologic analysis. Increase in salt levels in irrigation water reduced plant height and yield, especially in CSF 18 genotype. Salinity also reduced crude protein and protein yield in both genotypes, but reduced soluble carbohydrates only in CSF 18 genotype. On the other hand, effects of saline water on the neutral and acid detergent fiber levels were not observed.

Key words:
salt stress; Sorghum bicolor; irrigation; bromatologic analysis