Titre du document / Document title
Pruning and skirting affect canopy microclimate, yields, and fruit quality of 'Orlando' tangelo

Author(s) / Author(s)
MORALES P. (1) ; DAVIES F. S. (1) ; LITTELL R. C. (2) ;
Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)
(1) Horticultural Sciences Department, University of Florida, Gainesville, FL 32611-0690, ETATS-UNIS
(2) Department of Statistics, University of Florida, Gainesville, FL 32611-0339, ETATS-UNIS

Résumé / Abstract
Pruning and skirting (removal of low-hanging limbs) effects on canopy temperature, relative humidity (RH), and fruit yield and quality of Orlando' tangelo trees (Citrus paradisi Macf. x Citrus reticulata Blanco) on 'Carrizo' citrange rootstock [Poncirus trifoliata (L.) Raf. x Citrus sinensis (L.) Osb.] were studied at the Univ. of Florida Fifield Farm in Gainesville, Fla., in 1996-97. In the first season, treatments consisted of skirted and non-skirted trees. In the second season, two skirting (skirted and non-skirted) and three pruning (gable-top, flat-top, and non-pruned) treatments were evaluated. Neither RH nor air temperature was affected in the lower canopy by any treatment. However, temperature in the upper canopy of flat-topped trees was higher than that in gable-topped or non-pruned trees, and reached >45 °C during spring and summer. Fruit number and yield were decreased by pruning and skirting in one season. Skirted, gable-topped trees had the lowest yields, followed by skirted, flat-topped and non-skirted, gable-topped trees. All other treatments produced yields similar to those of non-skirted, non-pruned trees. Pruning increased the percentage of large fruit and reduced the percentage of small fruit. Skirting and pruning had no effect on blemish incidence with the exception of wind scar, which was higher in skirted than in non-skirted trees in the first season. During both seasons the main causes of packout reduction were rust mite and wind scar damage. Regardless of treatment, rust mite damage was much higher in the lower than in the upper canopy because of lower average temperatures and higher RH. Pruning effects on fruit quality were similar to those reported previously, but skirting had no effect on most fruit quality factors.
Revue / Journal Title
HortScience ISSN 0018-5345 CODEN HJHSAR
Source / Source
2000, vol. 35, no1, pp. 30-35 (38 ref.)

Skirting is the practice of pruning lower branches to remove foliage and fruit in direct contact with the ground. A skirting machine is used to remove the lower 18 to 20 inches of the canopy. Skirting is becoming an accepted practice with citrus grown for the fresh fruit market, because it improves fruit quality. Lifting the skirts results in less mechanical and chemical damage to fruit from fertilizer and herbicide applications, and less disease from direct contact of fruit with the ground. Skirting is required for mechanical harvesting of fruit, to allow visibility for trunk shaking and to provide room for the catch frame. Topping heights of 14 to 18 feet are common, and is commonly done shortly after the harvest of early and mid-season varieties, but before major bloom development. Trees at these heights are easily managed and can be harvested with standard ladders. The rule of thumb for topping height is to maintain a 2:1 ratio of tree height to middle row width. This height-width ratio with a hedging (pruning) angle of 10 degrees allows good distribution of light to all parts of the tree. - Millet (1,366-)

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