Photo-selective nets influence physiology, growth, yield and quality of turmeric (Curcuma longa L.)

Turmeric (Cucruma longa L.) grown under various photo-selective nets, sprayed with different elicitors manifested significant differences in growth, yield and quality during both the years of experimentation. The pooled data over two growing seasons clearly revealed that, turmeric under red photo-selective net with chitosan at 1000 ppm manifested highest plant height (106.50 cm) and number of leaves (22.99). While, plants grown under blue photo-selective net without any elicitors outperformed as compared to other treatment combinations in respect of number of tillers per plant (6.58). Yellow net with salicylic acid at 100 ppm recorded highest leaf area (5602.8 cm2 plant-1). The blue net with 1000 ppm chitosan resulted in maximum chlorophyll content (SPAD value 42.11). The yellow photo-selective net had a most positive impact on the major yield determinant, the number of primary rhizomes per plant (16.68), while the metabolic elicitors had no influence. Yellow net was superior in terms of fresh (58.27 t ha- 1) and cured rhizome yield (15.53 t ha- 1) and none of the elicitors had any significant influence on yield. The dry recovery was highest in yellow net and sprayed with active dry yeast at 5000 ppm (27.78%). Curcuminoid content, the major quality determinant was highest in blue net (5.09%) sprayed with chitosan at 1000 ppm. Provision of yellow photo-selective net (25% shade) along with 5000 ppm active dry yeast applied at monthly interval starting from one month after planting up to five months after planting could be recommended for obtaining highest yield and better quality turmeric with highest net returns. Farmers growing turmeric crop under open field condition may spray salicylic acid at 100 ppm to realize higher yield and net returns.