Growth of young lemon trees (Citrus limon Burm. f.) is extremely vigorous, and is characterized by the appearance of highly vigorous upright shoots that originate in the scaffold branches and trunk of the tree. While maturing, these shoots are considered to be in competition for photosynthates with smaller fruit in the spring and with mature fruit in the fall. During 1993 and 1994, we selectively removed these shoots 12, 6, 4, and 1 (1994 only) times per year, with the objective of increasing fruit size. Neither yield nor fruit quality was affected by the pruning treatments during 1993, but pruning trees 12 times per year increased fruit size by 30% compared to unpruned trees. In 1994, lemon trees pruned 4 times per year had 50% less cull fruit than unpruned trees, and 22% more fruit of size 140 or larger. However, >99% of the flowers and small fruit on trees pruned 4 times per year were aborted, compared with 95% abortion on the unpruned trees. Trees pruned 4 times per year also had 40% less yield compared with those that were unpruned.
Glenn C. Wright, Mark A. Wilcox, and Philip A. Tilt
James R. Schupp and T. Auxt Baugher
Hand-thinning of fruit is among the most labor-intensive orchard practices and consequently contributes significantly to peach (Prunus persica) production costs. Prior research conducted by the authors on string blossom thinners for managing peach tree cropload demonstrated that this new technology reduces labor requirement and also improves fruit size. Studies were conducted over two seasons in peach orchards trained to perpendicular V or open-center systems to evaluate possible pruning strategies to improve tree canopy access by string thinners. The objectives were to demonstrate if modifications in fruiting shoot orientation, pruning detail, and/or scaffold accessibility improved flower removal, reduced follow-up hand-thinning requirement, and/or increased fruit size. Blossom removal was improved by either detailed pruning or partial pruning (elimination of all shoots on the side of a limb inaccessible by the thinner spindle) in both training systems. Flower density and fruit set measurements revealed greater differences among pruning treatments compared with hand-thinned control treatments with both fruiting shoot orientation pruning modifications and detail pruning resulting in improved thinning. Thinning efficacy was unaffected by scaffold angle but increased as canopy accessibility ranking increased. Follow-up hand-thinning time was reduced by all treatment, system/cultivar, and year combinations except standard pruning in an open center-trained 2009 trial. Detail pruning consistently improved fruit size compared with hand-thinned control and other pruning treatments in both perpendicular V- and open center-trained orchard plots. The best treatments resulted in a thinning savings of $120/ha to $282/ha in perpendicular V plantings and $26/ha to $46/ha in open-center plantings. Realized economic savings beyond hand-thinning alone ranged from $473/ha to $2875/ha in perpendicular V trials and $28/ha to $293/ha in open-center trials.
Twenty-five-year-old `Cape Fear', `Desirable', and `Kiowa' pecan [Carya illinoinensis (Wangenh.) C. Koch] trees were either not pruned, or subjected to single selective or mechanical pruning using a mechanical hedger [or hedge pruning (HP)] in the dormant season 2003. Canopy light interception, yield, and nut quality were monitored during a period of three years. Leaf area index and light interception were significantly affected during the first growing season after treatment application, but after three years canopies grew back to control levels. In general, there were small positive effects observed on yield and nut quality after pruning. Minor improvements were recorded for `Desirable', in which yield was affected positively by both pruning strategies in 2004. However, most effects disappeared by the third year. `Desirable' responded better than `Cape Fear', whereas no beneficial effects were recorded on `Kiowa'. In 2005, yield was significantly reduced in HP trees of `Cape Fear' and `Kiowa'. Alternate bearing index was unaffected by pruning treatment or cultivar. Kernel percentage increased only in HP `Desirable' trees in 2003 and 2004. Kernel quality was improved in HP `Cape Fear' and `Desirable' in the first growing season after treatment application, but not in 2004. In 2005, quality was again improved in HP `Desirable'. The results of the current study indicate that one-time pruning of pecan trees induce positive short-term effect on light, but not necessarily an increase in productivity and nut quality.
Andrew L. Thomas, Patrick L. Byers, and Mark R. Ellersieck
long-term vigor and productivity, but yield may be somewhat compromised compared with a much more labor-intensive selective pruning system in which only old, unproductive wood is removed each winter. The objectives of this study were to evaluate that
Quality of stone fruit is defined by fruit size, color, firmness, flavor, shape, general appearance, adhesion and size of the stone and fruit surface characteristics (e.g. fuzz, abrasions, pest damage). Cultural practices, such as pruning, nutrition, irrigation, growth regulator usage and pesticide applications can influence these quality characteristics to a greater or lesser extent. Adequate potassium nutrition can improve soluble solids and fruit size in plums. Excess nitrogen fertilization can soften peaches. Well-timed calcium sprays are thought to improve the firmness of sweet cherries, as are applications of gibberellin. Ethylene synthesis inhibitor usage can alter the timing of ripening, reduce early fruit drop and improve storage. Irrigation scheduling is a tool that can be used to regulate final fruit size and firmness, as well as time of maturation. Selective pruning is used to structure a tree's architecture for improved light penetration to improve fruit size and color. These and other production practices will be discussed in relation to how they affect fruit quality in stone fruit.
Wilbur Reil, David Ramos, and Ronald Snyder
Two management systems were initiated in a 10 year old Juglans regia cv. Hartley orchard planted 8 m. × 8 m. in 1977. Annual dormant selective pruning was practiced for the next 8 years on all trees within one treatment (pruning) compared to dormant severe pruning on alternate temporary trees with no pruning on adjacent permanent trees (thinning). Temporary trees were removed in the thinning treatment in 1985.
Yield, trunk cross sectional area, pruning weight and nut quality factors were evaluated each year from the 5 replicate, completely randomized trial.
Yield and nut quality factors did not differ between the two treatments during the 15 years.
In 1990 the pruned trial was again pruned causing a 20% drop in production (p=.06). With no additional pruning yield returned to slightly above the thinned treatment in 1991.
This trial demonstrates that Hartley walnut trees (terminal bearing habit) continue to produce satisfactory crops under crowded canopy management but a tree thinning program offers other advantages which also should be considered.
Roberto Nuñez-Elisea and Jonathan H. Crane
Carambola (Averrhoa carambola L.) is native to the humid tropics of southeastern Asia, where it bears fruit year-round. In south Florida, winter conditions (strong winds and night temperatures below 15 °C) repress growth and flowering of the main commercial cultivar, Arkin, and fruit is produced from July to February. Off-season fruit would reach premium prices. We have previously demonstrated that selective pruning stimulates flowering of carambola at any time of the year. However, flowers produced during cool, windy weather have consistently failed to set fruit. This study was conducted in 1994–1995 to determine whether protected cultivation would help obtain off-season fruit. Four-year-old `Arkin' trees growing in 80-L containers were placed in a glasshouse or outdoors and pruned in November or December to force flowering during December–January. Glasshouse night temperatures during the winter were above 20 °C. All trees flowered in response to pruning. Outdoor trees produced less than one fruit per tree in late March to late April. Glasshouse trees produced 2.3 to 6.1 fruit per tree, 2 to 3 weeks earlier than trees outdoors. In the glasshouse, more than 98% of fruit were seedless, whereas all fruit produced outdoors were seeded. Production of seedless fruit indoors was achieved in the absence of insect pollinators, and yields were low compared to those of outdoor trees during the summer (at least 25 fruit per tree). We speculate that, under protected cultivation, the use of synthetic bioregulators during anthesis and insect pollinators may help increase production of off-season seedless and seeded fruit, respectively.
Ebrahiem M. Babiker, Stephen J. Stringer, Hamidou F. Sakhanokho, Barbara J. Smith, and James J. Polashock
cultivars and clean planting stock, and selective pruning of infected parts ( Weaver, 1978 ). Information about fungicide sensitivity could be used to reduce the severity of the disease when applied after pruning or injury to plants. Efficacy of fungicides
S. Kaan Kurtural, Geoffrey Dervishian, and Robert L. Wample
, respectively. The difference in the number of count shoots can be attributed to the selective pruning process with HP, compared with the nonselective hedge pruning accomplished with the MP treatments. The canopy management treatments did not affect the number
Hein J. Gerber, Willem J. Steyn, and Karen I. Theron
short. Therefore, development of C4 shoots will have to be stimulated by selective pruning. C1 shoots of ‘Noire de Caromb’ are productive relative to their length and yield a high average number of fruit per N + 1 shoot. C2 and C3 are fairly productive