Effect of pretreatments on seed dormancy and seedling vigour in Anjan grass (Cenchrus ciliaris)

Abstract

Anjan grass (Cenchrus ciliaris L.) is native to tropical and sub-tropical Asia as well as Africa. It can be grown on wide range of soils and is a palatable and nutritious grass for grazing animals. Germination of freshly harvested seed of Cenchrus grass is very low due to dormancy. Present study was undertaken to determine the effect of various pre-soaking treatments on germination and seedling parameters of freshly harvested seed of Anjan grass. Pretreatments viz., soaking in distilled water; KNO3 (0.2, 0.4 & 0.6%); Thiourea (0.2, 0.4 & 0.6%) and GA3 (100, 200 & 300 ppm) for 6, 12, 18 and 24 hours at 25°C in dark were applied to fresh seed for evaluating their effect on germination and vigour. Highest germination (44.8%) was recorded with GA3 (200 ppm) soaking for 24 hours as compared to 12.8% in control and 18.0% in distilled water. All pretreatments showed significant increment in seedling length and dry weight compared to control. Seedling length of 11.9, 11.9 and 12.1cm were recorded with GA3 (300 ppm) and KNO3 (0.4%) soaking for 24 h, and Thiourea (0.6%) for 18 h respectively as compared to 10.0 cm in control and 10.7 cm in distilled water for 24 h. Highest seedling dry weight ranged from 5.4 to 5.8 mg/ 10 seedlings was observed with KNO3 (0.6%), Thiourea (0.6%) and GA3 (300 ppm) soaking as compared to control (3.4) and distilled water soaking (4.4 mg). Highest vigour index (534.3) was recorded in GA3 (200 ppm) for 24 h soaking. Thus, pretreatment with GA3 (200 ppm) for 24 h or GA3 (300 ppm) for 18 h is effective for overcoming dormancy in the fresh seed of Anjan grass.