ALLELOPATHIC EFFECT OF Eucalyptus camaldulensis ON SEED GERMINATION, GROWTH AND YIELD CONTRIBUTING CHARACTERS OF RICE

Abstract

Two experiments were carried out at the Agroforestry and Environment laboratory of Hajee Mohammad Danesh Science and Technology University (HSTU), Dinajpur during 1st March 2016 to 31st July 2016 to find out the response of three rice varieties againist Eucalyptus camaldulensis allelopathic effect. For germination 1st, three rice varieties (Hybrid, BRRI Dhan 29 and BRRI Dhan 28) were sterilized in sodium hypochlorite solution for 5 minutes and finally rinsed with distilled water which were used as control at room temperature. Then seeds were placed in petridish which were tested in four allelopathic levels (0, 10, 15 and 20% concentration of eucalyptus leaf extract). The germination of all rice varieties were delayed and percentage of germination were reduced with increasing the level of eucalyptus leaf extract concentration compared to control. Shoot and root growth, and root number. Results on germination and seedling growth indicate that hybrid was more tolerant and BRRI Dhan 28 was more sensitive varieties to alletopathy effect of eucalyptus leaf. For determining yield contributing characters and yield of three rice varieties (Hybrid, BRRI Dhan 29, BRRI Dhan 28), another experiments were carried out at Agroforestry field of HSTU, Dinajpur during 1st March, 2016 to 31st July, 2016. Here 36 pots were used for planting seedling where the surface area of each pot was 0.14m2 . After 3 days of showing seedling in pots, seedlings overcome transplanting shock. Then the treatment were started after 7 days interval by using 0, 10, 15 and 20% concentration of eucalyptus leaf extract. Most of the growth and physiological characters viz, plant height, shoot length, root length, number of leaves, number of tiller, plant height at harvest time, number of tiller/ hill, number of effective tiller/ hill, number of sterile tiller/ hill, penicle length, weight of grain/panicle, number of spikelet/ panicle, number of unfilled grain/ panicle, number of filled grain/ panicle were performed better at control condition and showed the lowest performance in respect of all the treatments (10, 15 and 20% eucalyptus leaf extract) condition. More concentration of eucalyptus leaf extracts gave more inhabition on both yield contributing characters and yield of rice. The highest number of fill grain per panicle (139.6) was found in control whereas the lowest (111.8) was found at 20% leaf extract concentration. Again, among the three varieties of rice hybrid gave the highest fill grain per panicle (126.3) whereas BRRI Dhan 28 gave the lowest (120.7). Therefore, hybrid rice performed better in association with eucalyptus leaf extract than the other varieties (BRRI Dhan 29 and BRRI Dhan 28). So for eucalyptus plus rice based cropland agroforestry system, the amount of eucalyptus leaf present in the field and the variety of rice should be considered.