Vol. 70 No: 6

Title:
Trunk Strangulation Responses to the Detrimental Effect of Heavy Shade on Fruit Size and Quality of ‘Tosa Buntan’ Pummelo

Authors:
O.K. YAMANISHI and K. HASEGAWA

pp: 875-888

Abstract:
Trunk strangulation was performed under artificial shading (80% shade) and unshaded conditions from mid-July to harvest time to determine whether strangulation treatment could overcome the negative effect of heavy shading on fruit development and quality in six year old ‘Tosa Buntan’ pummelo (Citrus grandis (L.) Osbeck) budded on trifoliate orange. Strangulation of the trunk with steel wire of 1.6 mm diameter was applied to the depth of the wire's diameter. The wire rings were removed two months later. Chlorophyll content of 80% shade leaves decreased after exposure to full sun and increased after reimposing shading; the shaded first flush leaves retained more chlorophyll than unshaded ones. Specific leaf weight of the first flush leaves, shoot growth of second flush and fruit size significantly decreased in strangled trees with 80% shade. However, either trunk strangulation with full sun or trunk strangulation with shade hastened the degreening of the fruit rind and increased the sugar and citric acid contents in fruit juice. Thus, although strangulation was effective in improving fruit quality in low light intensity, it could not overcome the shading effect on fruit growth. Trunk strangulation showed a positive response to the heavy crop (L/F = 36) effect on flower formation under full sun but not under 80% shade.

Full text: JHSB Subscribers     ISHS members & other users
(PDF 759459 bytes)

Translate:

Go back to previous page