Influence of temperature, light and stimulators and their interaction on the germination and seedling growth ofAlternanthera sessilis

Abstract

Light has a pronounced effect on the germination ofAlternanthera sessilis, but low or high temperature treatments are not so successful. Potassium nitrate can act as a partial substitute and thiourea as a total and better substitute for light. The nature of response produced by these stimulators will depend upon their critical concentration and whether the treatment is followed in the dark. Both these compounds can reduce the inhibitory effect of far-red or red as well as high temperatures. But potassium nitrate-thiourea mixture can augment germination under all types of radiations and in the dark. There is a considerable amount of imbibition with 2 hours of pre-soaking, but germination becomes operative after 24 hours and thiourea gives the best result. On the other hand, only potassium nitrate can promote the growth of seedlings and increase the dry weight of plants.