The effects of environment temperature and moisture to investigate seeds germination of jimsonweed

Abstract

To investigate the variation of the germination in Datura in the soil after the seed spreading, a factorial experiment based on a randomized complete block design was conducted in three replications, in 2011-2012 in Karaj, Iran. The first factor was three moisture regimes (dryness treatment, H1; alternate wetting and dryness, H2; wetting, H3) and the second factor was temperature in four levels, representing the temperature of various months (integrated the December and January, T1; February and March, T2; April, T3; and at the end of May and June, T4) were simulated on data seeds population from spreading time to re-growth period. All treatments were applied during 30 days and then the germination test was done in 8-35°C. Thereafter, according to the estimated parameters, the relationship between temperature and moisture was investigated with germination models. Results indicated that an estimate of the sigmoidal function parameters with three parameters could be a demonstrator for germination patterns. The results of the functions showed that a gradual increase in environmental temperature caused an increase in germination coefficient when the seed were completely dried. However, this increase was negligible in comparison with the increase that observed in response to other treatments (H2-H3).In all moisture levels, the seeds of Datura did not have a suitable germination in 4 and 7°C, but the rate of germination was increased when the temperature was increased up to 15 and 23°C, especially for alternate wetting and drying conditions.