Integrated nutrient management in baby corn (Zea mays L.)

Abstract

The investigation entitled “Integrated nutrient management in baby corn (Zea mays L.)” was conducted at College of Agriculture, Vellayani to investigate the influence of integrated nutrient management practices on growth, yield, quality, storage life and economics of cultivation of baby corn (Zea mays L.). The field experiment was conducted from February to April 2018 at the Instructional Farm, College of Agriculture, Vellayani. The experiment was laid out in randomized block design with eight treatment combinations and one control, with three replications. The variety planted was baby corn hybrid, G-5414. The treatments comprised four organic sources for nitrogen substitution (s1 - 25 per cent N substitution through poultry manure; s2 - 25 per cent N substitution through vermicompost; s3 -12.5 per cent N substitution through poultry manure + 12.5 per cent N substitution through vermicompost and s4- 25 per cent N substitution through poultry manure + 25 per cent N substitution through vermicompost) and two biofertilizer treatments (b0- without biofertilizer and b1- seed treatment and soil application of PGPR-1). The organic manures were substituted on N equivalent basis @ 135 kg N ha-1 as per the treatments and the balance was supplied through fertilizer source. Phosphorus @ 65 kg P2O5 ha-1 and potassium @ 45 kg K2O ha-1 were supplied through chemical fertilizers in all the treatments. In the control treatment, nutrients were given @ 135:65:45 kg NPK ha-1 through chemical fertilizers. The results indicated that baby corn responded well to biofertilizer application (PGPR-1) which significantly increased the plant height at 15 and 45 DAE, leaves per plant at 45 DAE (11.70) and LAI at 30 DAE (2.61) compared with no biofertilizer application. This treatment also produced significantly higher total DMP at harvest (18.20 t ha-1), cob weight with husk per plant (244.33 g), cob weight with husk per cob (81.44 g), and marketable cob yield (5.82 t ha-1). Among different INM practices, combined application of chemical fertilizer and organic manures (vermicompost and poultry manure) with 12.5 per cent N substitution through each source (s3b1) along with biofertilizer application (PGPR-1) recorded significantly higher plant height (112.18 cm) at 45 DAE and was on par with s4b1, s2b1, s1b0 and s4b0. The same treatment recorded the highest DMP at harvest (19.94 t ha-1) but was on par with s4b0, s1b1 and s2b0 compared to other treatment combinations. The s3b1 also resulted in the highest cob weight with husk (85.11g per cob) and cob yield with husk (24.74 t ha-1) but it did not vary from s1b1, s2b1 and s4b0 with respect to cob weight with husk and was on par with s2b1 in case of cob yield with husk. However, adopting INM with 25 per cent substitution of N through vermicompost along with biofertilizer application (s2b1) produced the highest marketable cob yield (6.79 t ha-1), where it was on par with s3b1 and s1b1. The highest ascorbic acid content in baby corn cob (10.67 mg g-1) was recorded when 25 per cent of N was substituted through vermicompost (s2). Application of biofertilizer PGPR-1 produced significantly higher total soluble sugar (6.86 0 Brix), reducing sugar (2.89 per cent) and ascorbic acid content (10 mg g-1) in cob compared to no biofertilizer application. Organoleptic and shelf life studies indicated that the application of 50 per cent of N through chemical source combined with 25 per cent N substitution through poultry manure + 25 per cent N substitution through vermicompost along with biofertilizer (s4b1) recorded the highest organoleptic score in fresh samples and during storage upto three days. Application of nutrients through chemical sources (control) recorded the highest net income (₹ 8,43,182 ha-1) compared to other treatments and was followed by the application of 75 per cent N through chemical fertilizer in combination with 25 per cent N substitution through poultry manure and vermicompost (12.5 per cent N from each source) along with biofertilizer PGPR-1 (₹ 8,36,465 ha-1). The control treatment also resulted in the highest BCR (4.50) which was followed by the treatment with substitution of 25 per cent N through poultry manure and applying remaining quantity of N through chemical source without biofertilizer (3.67). The results of the study indicated that INM practice with 25 per cent N substitution through poultry manure and vermicompost (12.5 per cent N from each source) combined with 75 per cent RDN @ 135 kg ha-1and recommended dose of P and K (@ 65 kg P2O5 and 45 kg K2O) through chemical sources along with PGPR-1 or substituting 25 per cent N through vermicompost alone with PGPR-1 and recommended dose of P and K could be recommended for realising higher cob yield with husk, marketable cob yield and net returns. The net returns and the BCR produced by the control treatment (application of RDF only through chemical fertilizers) was however found to be higher than the other treatments due to low cost of cultivation. Application 50 per cent N through the poultry manure and vermicompost (25 per cent N from each source) along with biofertilizer PGPR-1 was found to be the best INM practice with respect to organoleptic characters and shelf life of baby corn.