Effect of single-cross hybrids, plant population and fertility levels on productivity and economics of maize (Zea mays)

A field experiment was conducted during the rainy (kharif) seasons of 2013 and 2014 at Mudhol, Karnataka, to find out suitable maize (Zea mays L.) hybrids and to optimize plant population and fertility levels for higher produc-tivity and profitability of maize. Treatments comprised 3 maize hybrids ('NK 6240 ’, ‘Super 900 M ’and ‘Arjun’), 2 plant populations (111, 111 and 83, 333 plants/ha) and 5 fertility levels [(N₍₁₅₀₎ P₂O₅₍₆₅₎ K₂O₍₆₅₎, (150, 65 and 65 kg/ha of N, P₂O₅ K₂O respectively), N₍₁₈₇₎ P₂O₅₍₈₁₎ K₂O₍₈₁₎, N₍₂₂₅₎ P₂O₅₍₉₇₎ K₂O₍₉₇₎, N₍₂₆₂₎ P₂O₅₍₁₁₄₎ K₂O₍₁₁₄₎ and N₍₃₀₀₎ P₂O₅₍₁₃₀₎ K₂O₍₁₃₀₎)]. Among the hybrids, significantly higher grain yield (10.14 t/ha), stover yield (14.38 t/ha), gross returns (139, 487/ha), net returns (87, 560/ha) and benefit: cost ratio (2.68) were recorded in ‘NK 6240 ’. Plant population of 111, 111 plants/ha gave significantly higher grain (9.80 t/ha) and stover yields (14.68 t/ha), gross returns (135, 233/ha), net returns (84, 563/ha) and benefit: cost ratio (2.65) over 83, 333 plants/ha. Application of N₍₃₀₀₎ P₂O₅₍₁₃₀₎ K₂O₍₁₃₀₎ kg/ha showed significant improvement in growth and yield attributes and it was reflected in signifi-cantly higher grain yield (10.42 t/ha) and stover yield (14.08 t/ha). The similar trend was also noticed in gross re-turns (142, 969/ha), net returns (87, 859/ha) and benefit: cost ratio (2.65). Interactive effects of hybrids, plant population and fertility levels reveled that, combination of hybrid ‘NK 6240 ’under plant population of 111, 111 plants/ha supplied with N₍₃₀₀₎ P₂O₅₍₁₃₀₎ K₂O₍₁₃₀₎ kg/ha recorded significantly higher grain yield (12.14 t/ha), stover yields (16.65 t/ha) and uptake of nutrients (366.0 kg N/ha, 71.9 kg P/ha and 172.1 kg K/ha). Gross returns (166, 759/ha), net returns (109, 148/ha) were significantly higher in this treatment than rest of the treatments. However, benefit: cost ratio was higher (2.89) with ‘NK 6240 ’at 111, 111 plants/ha along with application of N₍₂₆₂₎ P₂O₅₍₁₁₄₎K₂O₍₁₁₄₎ kg/ha.