Response of ginger and turmeric to organic versus traditional production practices at different elevations under humid subtropics of north-eastern India

A field experiment was conducted at seven distinct locations of north-eastern states of India to assess the effect of organic versus traditional production practices on plant growth, yield and quality attributes of turmeric cv. Megha Turmeric-1 and ginger cv. Nadia for two consecutive years during 2011-13. Among the treatments, organic practices i.e., seed rhizomes treated with Trichoderma harzianum (at 5 g kg−1 seed rhizome and soil application of organic manure {FYM (7.5 t ha−1) + vermicompost (2 t ha−1) + Neemcake (250 kg ha−1)} enriched with PSB (phosphorous solubulizing bacteria) and Azospirillum at the rate of 10 kg ha−1 each was found to be superior over traditional practices (without any use of organic manure and biofertilizers). Under organic practice for turmeric, significant improvement was observed with 21.98, 17.42, 11.54 and 40.31% increase in yield (20.13 t ha−1), dry matter (19.34%), curcumin (5.44%) and oleoresin (16.86%) content, respectively, over traditional practices. Similarly in ginger, the increase in yield (19.29 t ha−1), dry matter (19.93%) and oleoresin content (6.62%) was recorded 36.54%, 12.81% and 6.04%, respectively, under organic over traditional practices. The difference of average annual temperature between lowest (23 m) and highest elevation (960 m) was 5.36 °C with non-significant (p < 0.05) correlation between elevation/temperature of testing locations to growth, yield and quality attributes of ginger and turmeric. Hence, under mid-hill conditions, yield and quality attributes of ginger and turmeric will not be affected significantly by rise in temperature due to global warming. Moreover, quality ginger and turmeric production in the region can be enhanced by promoting organic package of practices with ensuring the availability of quality inputs such as planting material, biofertilizers etc.