Integrated Plant Nutrient Management on Bulb Quality and Nutrient Uptake of Aggregatum Onion (Allium cepa var. aggregatum)

A field experiment was conducted in the Department of Horticulture, Pandit Jawaharlal Nehru College of Agriculture and Research Institute, Karaikal, U.T. of Puducherry, during the summer season of 2023 in aggregatum onion [Allium cepa var. aggregatum] cv ‘Perambalur Local’ with the objective of assessing the impact of soil fertility and integrated plant nutrient management on quality of onion bulbs and the plant response to nutrient uptake. The experiment was a 6 x 3 factorial laid out in a randomized complete block design and replicated two times. The treatments consisted of six fertilizer types and three bioenhancers levels with two replications resulting in eighteen treatment combinations. The study materials included vermicompost, poultry manure, panchagavya, jeevamirtham, as well as recommended farmyard manure (FYM) and N, P, K fertilizers. One of the notable findings was that the application of RDFYM + 75% N + RDP + RDK + 25% N through poultry manure coupled with the application of jeevamirtham at 500 L ha-1 as soil drench thrice during irrigation (at planting, 20 and 45 DAP), resulted in the highest Total Soluble Solids (TSS) and ascorbic acid content, measuring 12.64 oBrix and 15.81 mg 100 g-1 respectively. Moreover, this treatment also exhibited the highest uptake of N, P and K by onion bulbs, recording15.27 kg ha-1, 3.38 kg ha-1 and 15.27 kg ha-1 respectively (F3B2). Furthermore, post-harvest soil analysis indicated that the treatment RDFYM + 50% N + RDP + RDK + 50% N through poultry manure, combined with jeevamirtham at 500 L ha-1 as a soil drench thrice during irrigation (at planting, 20 and 45 DAP), showed the highest levels of available N, P and K. The recorded values were 179.60 kg ha-1 of N, 12.66 kg ha-1 of P and 171.58 kg ha-1 of K (F5 B2). In short-duration aggregatum onions, using a combination of jeevamirtham and poultry manure boosts nutrient availability, which in turn enhances yield, nutrient quality and nutrient uptake. This approach is recommended for optimal plant health and productivity.