Impact of foliar application of vermiwash on growth, nutrient uptake and yield of onion

The field experiment on onion, conducted at Post Graduate Research Farm, Department of Soil Science, Mahatma Phule Krishi Vidyapeeth, Rahuri during the period of 2022-23, to ascertain the effect of foliar sprays of vermiwash (VW) on growth and yield of onion grown in Inceptiosl with seven treatment combinations consisting of RDF @ 75 and 100 per cent along with vermiwash foliar spray concentration @ 10, 20 and 30 per cent and one absolute control (water spray) replicated thrice in randomized block design. Results showed significantly higher number of leaves (10.80) to onion at 40 days after planting with the application of 100 per cent RDF along with two foliar sprays of vermiwash @ 20 per cent taken at 30 and 45 days after planting. Application of 100 per cent RDF with two foliar sprays of vermiwash @ 20 per cent concentration resulted significantly higher plant height (55.33 cm) at 30 days after planting, which was statistically at par with 75 per cent RDF + 30 per cent foliar spray of vermiwash (52.01 cm). Data revealed that, addition of 75 per cent RDF with two foliar sprays of vermiwash @ 30 per cent was significantly higher total soluble solids (15.46) in onion. Higher equatorial (67.08 mm) and polar diameter (66.66 mm) of onion was reported in the treatment receiveing 100 per cent RDF with two foliar sprays of vermiwash @ 20 per cent. It could be concluded from the data that the treatment receiveing 75 per cent RDF with two foliar sprays of vermiwash @ 20 per cent showed significantly higher onion yield and uptake of nitrogen, phosphorus, potassium, manganese and copper. However, application of 100 per cent RDF with foliar spray of vermiwash showed higher manganese and copper uptake by onion at harvest.