Fruit tree pruning

Abstract: Pruning is an unavoidable necessity of virtually all arboreal fruit crops. In the tropics and subtropics, pruning of mango (Mangifera indica L.) is particularly important due to its tendency for frequent flushes, especially in humid tropics. Commercial orchards must maintain control of both tree size and orchard productivity in order to remain productive. Tip, formation, and severe pruning can be used in a variety of circumstances to produce predictable and useful results for a variety of purposes. For example, tip pruning can be used to encourage frequent flushing and branching of young trees to bring them into commercial production years earlier than if left alone. It can also stimulate timely flushes of lateral stems in an annual program to maintain tree size and prepare trees for synchronous flowering. Formation pruning shapes trees in an overgrown orchard to receive the maximum amount of light for high productivity and sets them up for annual pruning in a flowering management program. Severe pruning coupled with subsequent tip pruning of huge, nonproductive trees facilitates rapid restoration of orchard production. Each of these types of pruning can be used to get mango trees into production quickly and thereafter maintain maximum annual production while maintaining their desired size.

Abstract: Effects of mechanical pruning and crop adjustment on Concord vine productivity were studied over a five-year period (1997 to 2001) in two mature vineyards in eastern Washington. Data showed that vines could sustain considerably higher yields than are achieved by balance pruning. Balance-pruned vines consistently produced relatively low yields with only marginally improved fruit composition, but fruit could be harvested somewhat earlier. Large, mechanically pruned single-wire or double-curtain-trained vines produced heavy crops and attained satisfactory fruit composition and shoot lignification in both warm and cool seasons. On average, mechanically pruned vines produced over 9 t/ha more fruit than balance-pruned vines. Yields of vines with fixed-node pruning (130 nodes) or mechanical pruning with crop adjustment were similar and 4.6 t/ha greater than yields of balance-pruned vines. Crop adjustment following mechanical pruning reduced yields but did not improve yield variation, fruit composition, and shoot lignification and therefore was unnecessary in all but the heaviest cropping season (1997). Yields for all pruning treatments varied almost in parallel from season to season, and the influence of pruning method on yield, fruit composition, and shoot lignification was less important than seasonal effects. There was no evidence of vine decline and alternate or biennial bearing due to overcropping of lightly pruned vines.

Abstract: The following pruning treatments were studied in mature 'Bluecropʼ (1996-2000) and 'Berkeleyʼ (1996-98) plants: 1) "conventional" pruning with removal of unproductive canes, thinning of 1-year-old shoots at the base of the bush, and removal of any unproduc- tive wood or thinning of excessive fruiting wood near the top of the bush, as required; 2) "speed" pruning involving removal of one or two of the most unproductive canes at the base of the bush; and 3) "un-pruned" where no pruning was done for the length of this study. Conventional pruning took an average of 6.4 min/plot, while speed pruning saved 88.8% time. There was no pruning treatment effect on the percentage of fruit buds in 'Berkeleyʼ (42%) or 'Bluecropʼ (34%) or percent fruit set (70% to 90%, depending on cultivar and year) in any year. Un-pruned plants of both cultivars had signifi cantly greater yield than conventionally pruned plants, depending on the year, while speed pruning generally re- sulted in intermediate yields. Un-pruned and speed-pruned plants produced berries that were 19% to 27% smaller than conventionally pruned plants, depending on year. The fruit harvest season of un-pruned plants began 3 to 5 days later and lasted a week longer than that of conventionally pruned plants. The harvest effi ciency of un-pruned plants was reduced as much as 51% in the later years of this study and was most closely correlated with berry weight. Conventionally pruned plants had a signifi cantly higher percentage of the above-ground dry weight allocated to 1-year-old wood and crown than un-pruned plants. In 'Bluecropʼ, N concentration tended to be higher in the crown of convention- ally pruned plants than in un-pruned or speed-pruned plants. Conventionally pruned 'Bluecropʼ plants had signifi cantly higher concentrations of K and P and lower N than un-pruned plants and 'Berkeleyʼ had lower concentrations of N, than un-pruned plants. Results indicate that not pruning mature plants may be an option in the short-term, but may have undesirable effects for long-term sustainability.