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Regina P. Bracy, R.L. Parish and W.A. Mulkey

A cultural system consisting of precision seeding on shaped beds, followed by cultivation using mechanically guided equipment, was developed and evaluated with several vegetable crops. The precision cultural system allowed for growing the crops at high plant populations by using precision planting and exact cultivation of multiple narrow rows of plants on wide beds. Eight field experiments were conducted from 1987 to 1989 on broccoli (Brassica oleracea var. botrytis L.), cabbage (Bra&a oleracea var. capitata L.), mustard (Brassica juncea var. crispfolia L.), and spinach (Spinacia oleracea L.) to evaluate production of these crops on single- and multiple-row configurations on narrow (1 -m) and wide (2-m) beds. The precision cultural system was assessed to be an excellent method for production of the small-seeded crops that were tested. Yield was highest for cabbage, mustard, and spinach planted in six rows on 2-m beds compared with four-, two-, or one-row beds. Multiple-row configurations did offer yield advantages over the single-row configuration for broccoli production.

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A.S. Devyatov

Apple orchard was planted in 1963 with treatments of 8, 6, or 4 m between rows and 8, 6, 5, 4, 3, and 2 m between trees in the row. Pruning of trees corresponded to the space requirement imposed by each treatment. Spherical canopy seldom formed in treatments of 8 × 2,3,4, or 5 m and the size of canopy was equal to the distance between trees. In treatment of row spacing 6 or 4 m the size of the canopy across the row was 3 or 2 m, respectively, with the length of the canopy equal to the distance between the trees. Tree height was 3 m in all treatments. The cultivar was `Antonovka' on Malus sylvestris rootstock. There were four replications. Fruiting in all treatments begun at the age of 8 years. During the 25 years of productive time of the orchard, there were 7 years without fruit. During the 33 years of orchard operations fruit yield was in treatments (in t·ha–1) 8 × 8 = 301, 8 × 4 = 417, 6 × 3 = 508, 4 × 3 = 612. Yield efficiency, based on crosssection of trunks in 1995 did not depend on orchard density or orchard design.

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Patricia Sweeney, Karl Danneberger, Daijun Wang and Michael McBride

Limited information is available on the performance under temperate conditions in the United States of recently released cultivars of creeping bentgrass (Agrostis stolonifera L.) with high shoot density for use on golf course putting greens. Fifteen cultivars were established in Aug. 1996 on a greens mix with high sand content to compare their seasonal weights and total nonstructural carbohydrate (TNC) contents. The cultivars were maintained at 3.1 mm height of cut. Shoot density counts were taken during Apr., July, and Oct. 1998. Root weights and nonstructural carbohydrate levels were assessed monthly from June 1997 through Nov. 1998. A cultivar group contrast between the high shoot density cultivars (`Penn A1', `Penn A2', `Penn A4', `Penn G1', `Penn G2', and `Penn G6') and the standard cultivars (`Penncross', `Crenshaw', `Southshore', `DF-1', `Procup', `Lopez', `SR1020', and `Providence') revealed that the former averaged 342.9 and 216.1 more shoots/dm2 on two of the three sampling dates. Root dry weights did not vary significantly (P ≤ 0.05) among the cultivars. Performing a contrast between new high shoot density cultivars and standard cultivars revealed greater root dry weight in the former during Mar. and May 1998. Differences (P ≤ 0.05) in TNC were observed on two of the 18 sampling dates, but no trends were evident.

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Jaume Lordan, Anna Wallis, Poliana Francescatto and Terence L. Robinson

was −$20,000/ha for 500 trees/ha, whereas it was −$50,000/ha when planting 3230 trees/ha. At year 5, cumulative NPV of ‘Honeycrisp’ almost reached a positive value for high-density plantings (>2500 trees/ha), and the advantage of high-density plantings

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T.A. Wheaton, J.D. Whitney, W.S. Castle, R.P. Muraro, H.W. Browning and D.P.H. Tucker

A factorial experiment begun in 1980 included `Hamlin' and `Valencia' sweet-orange scions [Citrus sinensis (L.) Osb.], and Milam lemon (C. jambhiri Lush) and Rusk citrange [C. sinensis × Poncirus trifoliata (L.) Raf.] rootstocks, tree topping heights of 3.7 and 5.5 m, between-row spacings of 4.5 and 6.0 m, and in-row spacings of 2.5 and 4.5 m. The spacing combinations provided tree densities of 370, 494, 667, and 889 trees ha. Yield increased with increasing tree density during the early years of production. For tree ages 9 to 13 years, however, there was no consistent relationship between yield and tree density. Rusk citrange, a rootstock of moderate vigor, produced smaller trees and better yield, fruit quality, and economic returns than Milam lemon, a vigorous rootstock. After filling their allocated space, yield and fruit quality of trees on Milam rootstock declined with increasing tree density at the lower topping height. Cumulative economic returns at year 13 were not related to tree density.

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Esmaeil Fallahi, W. Michael Colt, Craig R. Baird, Bahar Fallahi and Ik-Jo Chun

The influence of three rates of nitrogen (N) and fruit bagging on fruit peel and flesh mineral concentrations and fruit quality in `BC-2 Fuji' apple (Malus domestica Borkh.) trees on Malling 9 (M.9) was studied. Increasing N application decreased fruit peel red color, fruit N, iron (Fe), and manganese (Mn). Fruit from trees receiving 10.72 oz (303.9 g) N per year had higher evolved ethylene and respiration during poststorage ripening tests. Bagging of fruit reduced fruit peel red color, soluble solids concentrations (SSC), and dry weight as compared to nonbagged fruit. Bagged fruit had higher N, potassium (K), and copper (Cu) than nonbagged fruit. Fruit peel had a greater percentage of dry weight, and higher concentrations of all tested minerals compared to fruit flesh.

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D.M. Glenn, T. Tworkoski, R. Scorza and S.S. Miller

The lack of dwarfing rootstocks for peach ( Bassi et al., 1994 ; Grossman and DeJong, 1998 ) has led to cultural approaches that reduce tree size and vegetative growth to establish high-density plantings. Water management through irrigation

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David R. Bryla and Bernadine C. Strik

more leaf development at high density. Depending on how much leaf production is affected by planting density in blueberry, growing at higher density could substantially increase its water requirements. In a 4-year study on ‘Duke’, ‘Bluecrop’, and

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Kelly T. Morgan, Smita Barkataky, Davie Kadyampakeni, Robert Ebel and Fritz Roka

were measured before and after harvest for conditions 1 through 6. Fig. 1. Map of the low-, moderate-, and high-density blocks. Fig. 2. The irrigation main plots exemplified for the low-density block with eight hand-harvested and eight mechanically

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Adolfo Rosati, Andrea Paoletti, Giorgio Pannelli and Franco Famiani

The olive industry requires canopy reduction to allow super high-density orchards which permit earlier production and continuous mechanical harvesting ( Rallo et al., 2007 ; Tous et al., 1999 ). This has stimulated much research into reduced vigor