Influence of priming treatments on seed germination and growth characteristics of Moringa oleifera seedlings under laboratory and greenhouse conditions

Abstract

Seed priming is the treatment of seeds with various priming substances to improve germination and seedling quality, and plant growth. The procedure entails advancing the seed to an equivalent stage of the germination process to achieve rapid and uniform emergence when planted, which is required in the case of Moringa oleifera to reduce the damage of ageing seeds, stimulate their performance, and overcome uneven germination rate due to seedcoat hardening, that leads to wide variation in terms of commercial qualities in the planting field. Therefore, a series of seed priming experiments were conducted to determine the optimal methods of priming treatments that maximise Moringa oleifera total germination, germination rate, and seedling vigour. Moringa oleifera seeds were treated with hydropriming, osmopriming (KNO3), and nutripriming (SeedActivator) for 4, 8, and 12 hrs. Germinability was improved by priming treatments. Results indicated that the highest germination percentage was recorded on seeds subjected to hydropriming (63.25%), followed by nutripriming (61.75%) and osmopriming (60%) with the exact duration of 4 hrs soaking time. All pre-germination treatments have significantly early mean germination days (MGT) compared to the unprimed seeds. In the seed pouch study, seeds treated with hydropriming for 4 hrs had shown the best results to improve roots growth in total root length (cm), root volume (cm3 ), the number of forks, and the number of crossings with 240.52 cm vs. 163.64 cm, 0.47 cm3 vs. 0.29 cm3 , 517.80 vs. 271.47 and 59.20 vs. 28.53 respectively when compared to unprimed seeds. The positive effect of priming can also be seen in the seedling growth of M. oleifera grown in a pot with two different growing media.