Statistical basis of production sustainability of citrus orchards 217

Reduced longevity coupled with poor efficiency of commercial 'Nagpur' mandarin orchards collectively render the economics of cultivation non-remunerative more often quite untimely due to unsustainability in production. Quadratic regression of orchards age with fruit yield and tree efficiency revealed an increase in fruit yield from 37.7 to 66.3 kg tree-1 and tree efficiency 8.6 to 11.0 % within 6 to 17 years, and beyond that, both parameters declined invariably. Other biometric relations viz., orchard age versus tree volume and tree volume versus fruit yield followed a similar curvilinear quadratic pattern with peak fruit yield coinciding with the orchard age of 17 to 20 years. Such statistical basis can be effectively applied for yield forecasting of citrus orchards on a long term basis.