Effect of sap test based application of nitrogen on phenology andyield components in maize (Zea mays L.) genotype

Abstract

The plant nutrient especially nitrogen in sufficient and balanced amounts is one of the key factors in increasingcrop yield and decreasing adverse environmental effects. Therefore, current study was conducted to assess the effects ofnitrogen on phenology and yield parameters on maize genotype at College of Agriculture, Vijayapur. The experiment wasconducted with combinations of nitrogen levels 100, 75, 50, 25 and 0 kg per hectare with soil and foliar applications. Sapnitrate content was maximum at 40 DAS and decreased at 55 DAS and 70 DAS. Higher sap nitrate value of 1350 ppm wasobserved in the treatment T8i.e., T6 + rest of N in foliar application based on sap test at critical stages, whereas, at 0 kg N/ha the sap nitrate value was 420 ppm. The increasing nitrogen rates showed reduce days for tasseling and silking. Thesignificant short period of tasseling (49 DAS) and silking (53 DAS) was observed in T1 (100:50:25 NPK kg ha-1). However,nitrogen rates significantly affected the anthesis-silking interval. The treatment T8i.e., T6 + rest of N in foliar applicationbased on sap test at critical stages showed significant higher cob length (22.35 cm), cob girth (15.95 cm), number of rowsper cob (13.93), higher test weight value (38.19 g), grain yield per hectare (63.519 q ha-1) as compared to T11 (0:50:25 NPKkg ha-1). It was concluded that, sap test based application of nitrogen can reduce excess nitrogen application as well asenvironmental pollution