Kusum (Schleichera oleosa (Lour.) Oken) seed germination and seedling growth as affected by integrated nutrient management under acid soil of Jharkhand

Abstract

Not only seed germination, but also slow growth of the plant is a problem for raising plantation for lac cultivation and/or for other purposes. An experiment was laid out to generate information, if plant growth promoting rhizobacteria (PGPR) inoculations can increase germination percent of kusum seeds. At the same time, effort was made to see whether integration of PGPR (azotobactor, phosphobacterin and vassicular arbuscular mycorrhizae) and recommended dose of chemical fertilization (NPK @ 38-12-36 mg/ polytube) could increase seedling growth satisfactorily. Experiment was conducted in Randomized Block Design in factorial mode. By the end of the rainy season, Azotobacter, Phosphobacterin and VAM registered a mean reduction in germination to the tune of 9.5, 12.7 and 7.5 percent over control. Seedling mortality was not affected significantly due to any of the PGPRs. Application of chemical fertilizers reduced seedling survival 6 percent and basal shoot diameter 9 percent, respectively. But, its application could bring a remarkable change in mean tap root length and shoot dry weight of kusum seedlings in the month of February. Phosphobacterin proved to be the most significant factor affecting seedling growth. Shoot and root weight were affected the most; forty four and 46 percent reduction in weight was observed as compared to control. VAM affected seedling growth moderately and its effect was observed on shoot diameter, shoot dry weight and leaf dry weight. Maximum reduction was observed on leaf dry weight (31 percent). Interaction study in majority of cases showed that interaction of factors in its lowest level of application (control) performed the best followed by condition when applied in highest levels. Thus, a combination of no fertilizer application and no phosphobacterin inoculation performed as good as a combination of fertilizer application and phosphobacterin inoculation. Concerned bacteria/ micro-organisms of the PGPR treated seeds might have consumed sugar/ amino acids which might have led to a decrease of the germination processes. The study recommends to go for inoculation of PGPR after completion of germination.