Science Links Japan | Relationship between Planting Density and Fruit Yield of 'Starking Delicious' Apple Trees Grafted on Dwarfing and Semidwarfing Rootstocks.

Relationship between Planting Density and Fruit Yield of 'Starking Delicious' Apple Trees Grafted on Dwarfing and Semidwarfing Rootstocks.

Accession number;99A0922063

Title;Relationship between Planting Density and Fruit Yield of 'Starking Delicious' Apple Trees Grafted on Dwarfing and Semidwarfing Rootstocks.

Author; KURODA HARUYUKI (Minist. of Agric., For. and Fish., Hokkaido Natl. Agric. Exp. Stn.) CHIBA KAZUHIKO (Minist. of Agric., For. and Fish., Hokkaido Natl. Agric. Exp. Stn.) NISHIYAMA YASUNAO (Minist. of Agric., For. and Fish., Hokkaido Natl. Agric. Exp. Stn.)

Journal Title;Journal of the Japanese Society for Horticultural Science

Journal Code:F0626A

ISSN:0013-7626

VOL.66;NO.1;PAGE.35-43(1997)

Figure&Table&Reference;FIG.3, TBL.5, REF.23

Pub. Country;Japan

Language;Japanese

Abstract;The relationship between planting density and fruit yield of 'Starking Delicious' apple (Malus domestica Borkh.) grafted on dwarfing (M.9 and M.26) and semidwarfing (M.7 and MM.106) rootstocks was studied. 1. On all four rootstocks, the yield per tree decreased with increasing density, the decreasing rate becoming significant at a certain density. As the trees aged, the density at which the yield per tree decreases abruptly shifting to the lower density plots. This relationship between the density (.RHO.) and the yield per tree (X) could be represented by the following reciprocal equation, 1/X=Ax.RHO.+Bx-(1), where Ax and Bx depend on the tree age and rootstocks. 2. In regard to the yield per hectare, the existence of the optimum planting density (.RHO.opt) was recognized on all four rootstocks. The .RHO.opt shifed to lower density with the progression of tree age. 3. Regardless of the differences in tree age and rootstock, the relationship between the yield per tree (X) and the trunk cross-sectional area (.THETA.) could be prescribed by the following equation, X=H.THETA.h.-(4), 4. From Eqs. (3), (4) and (5), the relationship between the density (.RHO.) and the yield per hectare (Y) can be expressed by the following equation, Y=H.RHO./(A.RHO.+B)h-(6), where A, B, H and h depend on the tree age and rootstocks. On all rootstocks, theoretical curves given by Eq. (6) fit well with curves derived from the experimental data, indicating that Eq. (6) can satisfactorily explain the density effect on fruit yield. 5. The .RHO.opt is given by the following equation, .RHO.opt=B/A(h-1).-(7). The .RHO.opt decreased exponentially with the progression of tree age and this decrease rate was accelerated in trees on M.26, M.7 and MM.106, compared with trees on M.9. The slopes of the time trend of the decrease changed abruptly at age 10 regardless of the rootstocks. 6.... (author abst.)

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