Different Management of Nitrogen Application Affected Growth Characteristic of Maize (Zea mays L)

A field study was conducted during Kharif 2019-20 at Professor Jayashankar Telangana State Agricultural University (PJTSAU), Rajendranagar, Hyderabad, Telangana, India to evaluate different handheld decision support tools for precision nitrogen management in rainfed maize (Zea mays L.). The study utilized a randomized block design and was replicated three times. The eight treatments included applying nitrogen through the State-recommended dose of 200 kg ha-1 in three splits (RDN), using a leaf color chart (LCC) based on N at thresholds 3 and 4, using a soil plant analysis development (SPAD) chlorophyll meter based on N at thresholds 35 and 40, and using a Green Seeker based on N at NDVI 0.6 and 0.8 in comparison with RDN and absolute control. Based on Green Seeker NDVI at threshold 0.8, the results showed that applying nitrogen resulted in considerably greater yields for maize grain (8408 kg ha-1), stover (9923 kg ha-1), and harvest index (45.8%). with higher yield and growth parameter viz., test weight (36.3 g ), No. of grain rows row-1 (36.7), cob length (18.9 cm), plant height (223.7 cm), leaf area (6385.75 cm2) and dry matter accumulation (18193 kg ha-1) as compared to RDN. Similarly, Green Seeker based N at NDVI 0.8 also registered higher net returns (Rs. 118961 ha-1) and B: C ratio (4.05).