Fruit Growth Dynamics and Yield Relationships in ‘Shahf Litchi

The rate of fruit growth in ‘Shahi’ litchi was very slow upto the first 2 weeks after anthesis. During this period pericarp and seed grew together coherently. The seed grew rapidly upto 6th week and ceased to grow further after 7th week. The rate of peel enlargement was also remarkably slowed down by this period. Aril growth initiated towards the end of 5th week and continued till maturity. Upto 4th week length/diameter (L/D) ratio remained constant maintaining the length twice of the diameter but thereafter this decreased gradually and reached to a level of 1.25. The spatial shape factor (S_f) calculated from the volume ratios of the sampled fruit and its circumferential cylinder was examined for its use in calculating the fruit weight by simple length and diameter measurements. A Sf constant 0.6 could be utilized for fairly good estimation of fruit weight after 6th week stage. Yield was positively related to fruit number (r = 0.891, significant P = 0.01) in the two litchi orchards studied for the purpose, but average fruit weight was negatively related to fruit number/bunch (r = −0.6105) and yield/100 cm³ of trunk cross-sectional area (r = −0.753). Linear functions were derived to describe and discuss these relationships.