2010 Volume 9 Issue 4 Pages 467-475
We evaluated the effects of training and culture methods on tree growth, yield and dry matter production in the Japanese pear ‘Kousui’. We adopted two culture methods: conventional culture and rhizosphere restricted culture, and two training systems: pergola and Y-shape, to make four test plots: 1) pergola/conventional (P/C), 2) Y-shape/conventional (Y/C), 3) pergola/rhizosphere restricted (P/R), and 4) Y-shape/rhizosphere restricted (Y/R). Leaf Area Index (LAI) in Y/R was 4.9, more than double that of the other test plots. Brix in Y/R was the highest. Fruit bearing rate per m2 in Y/R was 18.5, about double that of the other plots. When the leaf/fruit ratio (L/F) was set to about 35 in all the plots, yield in Y/R was as high as 61 t·ha−1, being 2.2 times P/C. Though shoot number and tree vigor in Y/R were between those of the other test plots, Y/R trees demonstrated superior shoots and the greatest number of flower buds per m2. Dry matter production per ha in Y/R was the greatest. Partitioning rate of the assimilates to the fruit was 43.0% in Y/R and 39.1% in P/R. Assimilate partitioning rates to fine roots in the rhizosphere restricted culture methods were higher than those in the conventional methods. It was concluded that a high yield of 61 t·ha−1 and a high Brix of 12.5% was attained as a result of 1) increase in fruit-bearing shoots due to an increase in fine roots by appropriate irrigation methods, 2) increase in dry matter production due to an increase in LAI and 3) increase in partitioning rate of assimilates to the fruits due to a compact tree.