Ecology of germination of weed seeds : I. Role of temperature and depth of burial in soil.

Merremia gangetia Linn. (Cuf) is one of the most important weeds invading cultivated lands of India. Temperature, both high (45° C) and low (15° C) exhibit a definite role in development of the weed, particularly during germination. Higher tempeeratures (45° C) during dry storage appeared to be the main factor in laboratory experiments as well as in nature. Low temperature induced secondary dormancy and its removal by incubation at 35° C helps to explain the ecological mechanism through which the weed endures winter conditions. Germination of buried seeds confirm that the atmospheric conditions were found to be more effective in upper layers of soil. Ecological adaptations of this weed via germination requirements are assessed in the paper.