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  • Author or Editor: D.R. Layne x
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The objective of this experiment was to design orchard systems and tree shapes that optimize production based upon light interception. `Montmoreney' on `Mahaleb' rootstock was established at the Clarksville Horticultural Research Station in 1982. The following factors were investigated: a) tree shape; free form, Δ triangle and • rectangle, b) tree height to clear alleyway width ratios; 1.5, 2.0 and 2.5, and c) tree density 3.0×4.5 m, 3.0×6.0 m. Tree shape was established beginning in the 3rd leaf by summer hedging on an annual basis at the end of stage II of fruit growth. Beginning with the 4th leaf, light interception in each system was estimated by measuring the light interception below the canopy at hourly intervals after full canopy development. In 1989, yields ranged from 14,000 to 22,000 Kg ha-1. Ripening was delayed for rectangle shaped trees, with a height to clear alleyway, width ratio of 1.5, spaced 3.0×4.5 m, likely because hedging reduced leaf to fruit ratios. Within a tree form, yield was linearly related to % light interception, however rectangular trees were more productive than triangle shaped trees. The relevance of this study to orchard design will be discussed.

Free access

Abstract

Eleven peach scion-rootstock combinations were evaluated for cold hardiness by controlled freezing after acclimation in controlled environments at temperatures of 20/14 or 10/4°C day/night and photoperiods of 9, 12 or 15 hours. Temperature and scion cultivar had much greater effects on cold hardiness of buds and bark than did photoperiod or rootstock. Trees held at 10/4° were more cold hardy than those held at 20/14°. ‘Siberian C’ scions were more cold hardy than ‘Harrow Blood’ or ‘Elberta’ scions. Short days increased cold acclimation of fruit buds at 20/14° but not at 10/4°. Rootstock influence on scion acclimation was small but some cultivar differences were apparent.

Open Access

Abstract

Four hedgerow types: oblique fan, canted oblique fan, modified central leader, and open center, in a peach (Prunus persica (L.) Batsch cv. Olinda) orchard were evaluated in 1975 and 1977 for their effect on deposition of captan (N-trichloromethyl-4-cyclohexene-l,2,dicarboximide). Within hedgerows captan residues on leaves were generally higher on bottoms than tops of trees but among hedgerows, leaf residues were higher on oblique fan. The higher leaf residues resulted in 10.8% more of the captan applied per tree retained by oblique fan compared to 31.7% intercepted by the other hedgerows. Ground deposits for oblique fan and open center averaged 11.7% but were 6.3% higher for canted oblique fan and modified central leader. Ground deposits did not relate to area below trees or hedgerow type but leaf residues and that unaccounted for related to tree canopy volume. Compared to the standard open center, oblique fan was 41% more efficient at intercepting captan, modified central leader 20% more efficient and canted oblique fan showed no improvement in efficiency. Hedgerows with smaller tree canopy volumes increased captan interception, reduced spray drift and thereby provided economic and environmental gains through more efficient captan use.

Open Access

Abstract

Bearing trees of ‘Loring’, ‘Redhaven’ and ‘Babygold 5’ peach trees (Prunus persica (L.) Batsch) on Siberian C seedlings defoliated earlier than those on the other seedling rootstocks. Early cold acclimation of scions in the fall and scion cold hardiness in mid-winter were enhanced more by Siberian C seedlings than by those of the other seedling rootstocks. Bud survival and fruit set of ‘Redhaven’ and ‘Bablygold 5’ scions were greater on Siberian C seedlings than on any of the other seedling rootstocks following an outdoor cold stress at -23.4°C in January. The cold hardiness of phloem, cambium, and xylem stem tissues were closely correlated with each other in the fall, but were not correlated with cold hardiness of flower buds on the same shoots. Seedlings of Siberian C appeared to enhance early scion dormancy and they increased scion bud hardiness by as much as 4.7° in the fall, and 1.3° in mid-February, compared with those of other rootstocks tested.

Open Access

Abstract

An 8-year study was made to assess the performance of Harrow Blood and Siberian C rootstock seedlings in comparison with the commercial seedling rootstocks Rutgers Red Leaf, Veteran, Halford and Bailey. Rootstocks significantly influenced tree size of ‘Loring’, ‘Redhaven’ and ‘Babygold 5’ peach (Prunus persica (L.) Batsch). Siberian C had the largest influence on size control, reducing tree volume by about 20%. Tree height and spread, trunk circumference and trunk cross-sectional areas were also influenced by rootstocks, but annual growth of terminal shoots was not. Rootstocks influenced crotch angle development of ‘Loring’, but had no effect on crotch angle development of ‘Redhaven’ or ‘Babygold 5’. Cropping efficiency of ‘Babygold 5’ was influenced by rootstocks but cropping efficiency of ‘Redhaven’ and ‘Loring’ were not. Yields were significantly influenced by rootstocks. The highest cumulative yields of ‘Loring’ were on Veteran seedlings, the highest of ‘Redhaven’ were on Rutgers Red Leaf and the highest of ‘Babygold 5’ were on Halford. Yields were also a function of tree size with the highest yields being obtained on the largest trees. Trunk circumference and crosssectional area were the only growth measurements that were significantly correlated with the yield of each cultivar. Tree survival was best on Harrow Blood and Siberian C and poorest on Rutgers Red Leaf and Veteran. Tree mortality was associated with winter injury and canker (Leucostoma spp.) infection but not with incompatibility.

Open Access

Abstract

An inexpensive chamber for controlled freezing of large container-grown plants up to 2 m in height was constructed using liquid nitrogen as a refrigerant. A microcomputer-based system was developed to control the cooling sequence and to collect data on tissue temperature, air temperature, and exotherms. Versatile software was written that allowed the programmed rate of temperature drop to be based on either tissue temperature or air temperature.

Open Access