The role of the different concentrations of GA3 on Seed Germination and Seedling Growth of Loquat (Eriobotrya japonica L.)

Abstract

Seed germination of loquat (Eriobotrya japonica L.) using concentration and soaking duration of Gibberellin acid (GA3) treatments was studied at the lathhouse of Agriculture Research Centre / Ainkawa / Erbil for the period from 15 th May to 14 th September 2010. Seed treated with GA3 (150, 200 and 250) mg.L-1 in addition to comparison treatment (zero mg.L-1) at three different soaking time (12, 24 and 36) hour to production strong seedling within a short period. The study relied on Complete Randomized Design (C.R.D) as a factorial experiment, 20 seeds were used in each treatment, each trial replicated three times that mean 36 trials. Average results were obtained in each trial based on less difference and 5 % approximate ratio was given (least significant differences). According to the results found in this study, the quick and uniform, germination of loquat seeds and growth of seedlings indicate high vigor of seeds. GA3 had a significant effect on germination rate as compared to control. GA3 at 250mg.L-1 gave best response (71.19, 86.80 and 98.75) % at 1 st , 2 nd and 3 rd weeks, but as the concentration increased above 250 mg.L-1 the germination rate decreased rapidly but shoots and root length of seedling and vigor index increased during300 mg.L-1. Soaking period did not affect significantly on loquat seed germination ratio at 1 st and 3 rd weeks while in 2 nd Week after germination the ratio increased significantly with increasing soaking period. Different effects of combined GA3 concentration and soaking period on the loquat seed germination rate and seedling growth parameters. More significant effect interactions were obtained in 250 mg.L-1 GA3 with different period times.