Root length and yield of cotton (Gossypium hirsutum) as influenced by genotypes, soil types and fertilizer levels in the coastal region of Karaikal

A field experiment was carried out at 3 sites (1 site in 2002 and 2 sites in 2003) at Karaikal, to evaluate the 7 genotypes [‘MCU 7, ‘MCU 12’, ‘SVPR 2’, ‘SVPR 3’, ‘LRA 5166’, ‘Anjali’ (‘LRK 516’) and ‘ADT 1’] of upland cotton (Gossypium-hirsutum L.) under 3 fertilizer levels (unfertilized control, 60:30:30 and 80:40:40 kg NPK/ha) in respect of root growth and seed cotton yield as influenced by soil types (soil characteristics). The root length did not differ significantly among cotton genotypes, but it was influenced significantly by soil characteristics and fertilizer levels. On the contrary, there was significant difference among the cotton cultivars for seed-cotton yield. The seed-cotton yield was also significantly influenced by soil type and fertilizer levels. Net income and benefit: cost ratio were higher in ‘MCU 7’ variety at 80:40:40 kg NPK/ha followed by the same variety at 60:30:30 kg NPK/ha.