Abstract :
The occurrence of hardseedness and the low percentage of seed germination are major challenges when growing okra. This study was conducted to determine the effects of scarification methods in relation to time of harvest and plant parts on germination behavior of okra cultivars (Abelmoschus esculentus L.). The study was carried out at Agricultural faculty of Razi University in 2009. The experimental design was randomized complete block with a factorial arrangement with three replications. Four cultivars of okra namely, Boiatloy, Beloudo, Clemsson and Pleas and two treatments of 50, 75 and 100 oC hot water for 0-1-3 and 5 min., and dry heat of 50, 75 and 100 oC for 0, 6, 12 and 24 hours were studied. Results showed that hot water at temperature of 75 oC for 5 min was effective in broken of okra seedhardness, although by increasing temperature and duration of soaking, the percentage of germination reduced. Hot water at temperature of 100 oC for duration of 1 min increased percentage of germination than control, but by increasing duration of soaking the germination was reduced. Dry heat treatment at temperature of 100 ?C for 24 h resulted in higher percentage of germination (63.8 %) compared with other dry heat treatments. Effect of hot water treatment was more on seeds that harvest from the last harvesting time; In this case effect of dry heat treatment was more. Effect of hot water was more on varieties of Boiatloy and Beloudo that had more seedhardness, although dry heat was more effective on germination of varieties of Clemsson and Pleas that had less seedhardness. Effect of hot water treatment was more on seeds from the middle part of plant; in this case dry heat treatment did not caused a noticeable difference between plant parts. The result of present study showed that percentage of seedhardness between different cultivars of okra was different. Therefore, it seems that seedhardness has to broken before planting, and in this case implementation of treatment of hot water at temperature of 75 ?C for 5 min can be useful.
