Presowing Mechanical Seed Treatment Influencing the Emergence and Primary Seedling Vigor of Jujube (Ziziphus mauritiana Lam.)

Abstract

Rootstock preparation from seed is the prerequisite for fruit crop multiplication through grafting or budding, and hard seed coat in jujube has been the proven question for uniform seed germination and subsequent seedling growth. Therefore, the study aimed at successful and rapid production of uniform and healthy jujube rootstocks through applying mechanical seed priming at the presowing stage. The experiment was set in a randomized complete block design where scrapped seeds, cracked seeds, seed kernels, and intact seeds (control) were sown in polybags keeping five replications. The emergence and initial seedling growth were evaluated to sort out the best pretreatment methods for successful stock seedling production in jujube. Seed cracking resulted in the highest germination (69.00%) compared to other pretreatments and also showed better performance in respect of earliness of emergence (10.40 days (d) for the first emergence and 20.40 d for final emergence). Regarding the early plant vigor, significantly maximum seedling height (23.73 cm) and fresh (3.91 g) and dry weight (1.17 g) of seedling and the second-best leaf number (14.24 seedling−1) were also noted in seed cracking. Although seed kernel had the fastest emergence in 7.20 d, and statistically similar seedling vigor with that of cracked seed but it possessed very low germination percentage (27.00%) compared to the best treatment. Meanwhile, seed priming by scrapping exhibited statistically inferior germination rate (32%) as of intact seed (21%), and below par seedling growth compared to cracked seed. So, seed pretreatment by cracking can be suggested for commercial stock plant regeneration in hard seed-coated plant species.