Effect of Controlled - release fertilizers on growth, yield and fruit quality of guava cv. Sardar

Abstract

Three levels (200, 400 and 600 g / plant) each of urea,urea super granule and neem coated urea were applied in three years old plants of guava cv. Sardar in two equal split (ie in March and September) doses in ustocrepts. Correlation matrix between all possible pairs of vegetative growth were worked out. Significant increase in vegetative growth (plant height-61.83 cm in first year and 27.70 cm is second year, stem girth-20.50 cm in second year and plant spread (North-South) 163.66 cm in first year and 214.83 cm in second year) was recorded with 600 g neem coated urea. As regards yield, 102 fruits in first year and 125 fruits in second year weighing 28.35 kg and 31.93 kg / plant respectively and yield per hectare calculated to 11.33 t and 12.77 t / ha was recorded highest will 600 g neem coated urea, which was significantly higher than all the treatments and control. Fruit quality was also improved with application of slow releasing fertilizers. Total soluble solids at 14.85o Brix and 4.53 per cent reducing sugar were determined with 600 g neem coated urea. Maximum ascorbic acid content 326.74 mg / 100 g fruit with 600 g urea in first year and 339.90 mg / 100 g fruit were determined with 600 g neem coated urea compared to 258.95 mg and 237.12 mg / 100 fruit in control. Acidity in fruits was not affected by the different levels and sources of nitrogen. Leaf N increased to 2.11 per cent from 1.77 per cent. P and K content also increased after the application of treatments and fixed doses of P and K.