Effect of different pre treatment on seed germination of some medicinal herbs

Present study investigate the effect of different treatments, such as uv radiations and temperature on seed germination of lemon grass and palmarosa (Medicinal herbs).

Normal and healthy seeds of two different species of medicinal herbs namely C.flexuosusstapf, and C.martiniiwats were irradiated with ultraviolet radiations (uv) at 96 erg mm-2 Sec-1 for two hours. Stimulatory effect of embryonic development in the form of plumule and radical growth was noticed. Initial faster root and shoot growth created better plant stands, leaf area development, higher oil yield in all the species. It was due to more linear growth (plant height) and moderate expansion of leaf growth. Higher leaf production was observed which finally improved the yield characters like number of leaf per plant. The different temp. were also tried and at 25°C germination percentage was highest at 16h light 8h dark for C.martinii. PRC-1 30°C temp. is suitable for C. flexuosus var. kranti. It’ is well established that different spectra of light exhibit various effect on different morphogenic processor of plant (Willman, 1983) u.v. exposure to different crops have multifacet effect which includes improvement of germinability of old seed (Padmaker et. al 1985) Higher photosynthetic rate coupled with high yield (Shatano 1979) increased nodulation efficiency (Benker and Patil 1979) and better root and shoot growth (Dirimonov 1979). Besides crop plants, the normal process of bacteria fungi are also greatly effected by ultraviolet light (Tyrrell 1980) u.v. radiation at shorter exposure can utilize as tool for short and long term advantages to crop growth. Critical level of exposure time to seed material is needed to evaluate the beneficial effect of uv radiation.

The Cymbopogon species seed germinability in major handicap for its productivity keeping this in view the present investigations were carried out to quantify the critical level of uv exposure for an optimum growth of Lemon grass seed material namely C.flexosusvarkranti, and C.martinii var. PRC-1. The study prove that seed treatment is necessary to improve the germination.