Enhancing Leaf Nutrient Levels in Polyembryonic Mango (Mangifera indica L.) Seedlings: The Impact of Saline Water Irrigation and 28-Homobrassinolide Spray

The leaf nutrients play a key role in the growth of a plant. Therefore, a study was undertaken to evaluate the effect of saline water and spray of 28-homobrassinolide on leaf nutrient status of polyembryonic mango (Mangifera indica L.) seedling during the years 2021-22 and 2022-23 at Agriculture Experimental Station, Navsari Agricultural University, Paria, (Gujarat). The experiment was laid out in Completely Randomized Design with factorial concept comprising of four salinity levels [S1: Best available water (control), S2: 2 dS m-1, S3: 4 dS m-1, S4: 6 dS m-1] and three spray concentration of 28-homobrassinolide [H1: No spray, (control), H2 : 0.5 ppm and H3 : 1 ppm]. Saline water application and 28-homobrassinolide spray was started at 80 days after sowing up to 240 days. The treatment containing application of water having lowest salinity (best available water) resulted in significantly higher leaf nutrient contents except Na up to 9 months after sowing during both years and in pooled analysis. Application of saline water having EC 6 dS m-1 adversely affected the growth of polyembryonic mango seedlings, reduced nutrient contents after 6 months of sowing. After 6 month of sowing, highest nutrient contents except Na was noted in mango seedlings treated with spray of 1 ppm 28-homobrassinolide during both years and in pooled analysis. The interactions of salinity levels and 28-homobrassinolide spray significantly affect leaf nutrient content of mango seedlings. Leaf nutrient contents except Na up to 9 months after sowing during both the years and in pooled analysis were recorded in treatment combination of best available water along with 1 ppm spray of 28-homobrassinolide. Maximum content of Na was observed in plants irrigated with 6 dS m-1 salinity level without spray of 28-homobrassinolide. Hence, it can be concluded that polyembryonic mango seedlings can be grown with saline irrigation having salinity up to 4 dS m-1 along with 1 ppm 28-homobrassinolide spray for better growth, biomass, nutrient contents and higher survival up to 9 months after sowing.