[Study on increase yields and quality of feed crops in tropical zones]
1993
Suwapong Swasdiphanich (Kasetsart Univ., Bangkok (Thailand). Faculty of Agriculture. Dept. of Agronomy)
Studies on effects of salinity on the germination of seeds and seedling growth of pasture grasses and legumes were conducted on the Kamphaengsaen soil series and sand. Ther were 3 levels of salt concentrations in each growing media viz., 0.113, 0.21 and 0.25 percent for the Kamphaengsaen soil and 0, 0.051 and 0.113 percent for the sand. There was a considerable high salt content in the Kamphaengsaen soil and adversely affected the germination of Panicum maximum, Brachiaria ruziziensis Dactyloctenium aegyptium and Echinochloa colona, although the highest germinations were obtained from Dactyloctenium aegyptium and Echinochloa colona. Increase of salt concentration up to 0.43 percent totally prevented the grass seed from germination. The germination of tropical pasture legume seeds were better and higher than 50 percent, except Leucaena leucocephala, Gliricidia sepium and Sesbania aculeata which germinated only 33.3, 23.3 and 3.3 percent respectively. S. rostrata germinated 88.3 percent and was the highest. For the and culture, the germination of the grasses at the salt concentration 0.113 percent were poorer than at the concentration 0 and 0.05 percent. The germinated seedlings, however, grew well and having B. ruziziensis was the highest ie. 13.3 cm at 42 days old. At the same time, the pasture legume seeds germinated satisfactorily at the 0 salt concentration and showed poorly at the concentration 0.113 percent. The germinations (averaged 3 levels of salt concentrations) of all the legume seeds were not different statistically, even though, Stylosanthes hamata germinated up to 46.7 percent and S. rostrata germinated 31.1 percent. The growth of the seedlings were adversely affected by the salt concentration 0.113 percent. From the field experiments, the growing rate of S. grandiflora was maxiumum within 3 weeks, but the rates declined and maintained throughout at the rate that less than 1 cm/day. L. leucocephala gave the growing rate 0.2 cm/day and grew well if there is no further increase in salt concentration in the soil.
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