Nagpur' mandarin evaluation on commercial rootstocks in tropical central India.

Inconsistency in fruit yield and quality production in 'Nagpur' mandarin coupled with limited rootstock base is the problem throughout the country in general and central zone in particular. Therefore 'Nagpur' mandarin as in scion was evaluated on 18 diverse rootstocks during 2002-05 on an alkaline Inceptisol under the sub-humid tropical climate of central India. Canopy volume was observed directly proportional to fruit yield with respect to Rangpur lime (29.4 m^-3 and 156.3 kg tree^-1 with the yield efficiency of 5.3 kg m^-3) and trifoliate hybrid rootstocks (28.3 m^-3 and 79.5 kg tree^-1 with the yield efficiency of 2.81 kg m^-3). While the reverse was true with Cleopatra mandarin (21.7 m^-3 and 54.5 kg tree^-1 with the yield efficiency of 2.51 kg m^-3) and rough lemons (34.8 m^-3 and 102.4 kg tree^-1 with the yield efficiency of 2.94 kg m^-3), suggesting that trees with highest canopies are not always heavy producers. Different strains within the rootstock type exhibited a large variation in TSS/acid ratio. On all the strains of Cleopatra mandarin rootstock, Nagpur mandarin had significantly (P > 0.05) higher N and Zn content (1.99% and 21.5 ppm) than on rough lemon strains (1.70% and 14.5 ppm) and Rangpur lime (1.88% and 17.7 ppm) rootstock. Hybrid rootstock (Troyer and Carrizo strains) showed a much better nutrient foraging ability with trifoliate orange rootstocks. Rangpur lime (Tirupati and 8784 strains) was adjudged to be the most promising rootstock for Nagpur mandarin. [ABSTRACT FROM AUTHOR]