Effect of nutrient solution (NPK) on biochemical changes and yield of hydroponic maize fodder cultivar

An experiment was conducted to study the effect of a nutrient solution (NPK 19:19:19) on the amylase activity and starch concentration in hydroponically grown maize cultivars (African tall, Ganga safed-2, Manjari composite and Panchganga). This study involved applying different levels of the NPK 19:19:19 solution spray and evaluation at 0-day, 7th day and 14th day of growth. It was observed that alpha-amylase activity (mg of maltose released/g of sample/min) for African tall, Ganga safed-2, Manjari composite and Panchganga was 1.13, 1.19, 0.93 and 1.07 mg/g/min, respectively, on day 0 (i.e., sprouted grains in hydroponically grown maize fodder). The amylase activity values were 2.40, 2.49, 2.17 and 2.31 mg/g/min on the 7th day and 1.95, 2.06, 1.80 and 1.90 mg/g/min on the 14th day, for African tall, Ganga safed-2, Manjari composite and Panchganga, respectively. It was concluded that the highest percentage of starch was recorded for African tall, Ganga safed-2, Manjari Composite and Panchganga at 0 day, with values of 64.60%, 60.38%, 54.70% and 65.69%, respectively. The starch content decreased on the 7th day to 49.29%, 43.28%, 32.19% and 50.56% and further declined on the 14th day to 46.59%, 48.37%, 41.15% and 30.46%, respectively, for the same cultivars. During the growth (germination) period, there was a decline in dry matter (DM) and starch content, while amylase activity increased, with the highest levels observed in Ganga safed-2 at 0 day (1.19 mg/g/min) and 7th day (2.49 mg/g/min), followed by a slight decrease at the 14th day (2.06 mg/g/min). Similarly, African tall showed the highest total sugar content of 8.66%, 10.21% and 11.24% at 0, 7th and 14th days, respectively. The nutrient solution significantly affected enzymatic activity and total sugar concentration. The application of 0.75% NPK to African tall was found to yield more fodder compared to other varieties.