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  • Author or Editor: M. N. Westwood x
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Abstract

A 10-year study of 4 vegetation management regimes in an apple (Malus domestica Borkh.) orchard showed that a mowed sod ground cover resulted in less efficient trees than those with cultivation, residual or nonresidual herbicides. Considerable differences were found among treatments in the kind and population density of orchard weeds. Of the 6 rootstocks tested, seedlings produced the largest but least efficient trees. Trees on Mailing (M) 4, M 1 and M 7 rootstocks gave the greatest yield efficiency during the 10-year period. No interactions were found between rootstock and orchard floor management practices.

Open Access

Abstract

Repeated winter rain or water soaking in the laboratory reduced the time required for breaking winter rest of ‘Bartlett’ pear (Pyrus communis L.) and ‘Starkrimson’ apple (Malus domestica Borkh.). Possibly a water soluble inhibitor is leached from the buds.

Open Access

Abstract

Trunk cross-sectional area was found to bear a linear relationship to total above-ground weight of apple trees. From these data, it is suggested that trunk measurements can be used to estimate the potential bearing surface of any orchard tree as long as it has not been pruned heavily to prevent crowding. This relationship permits the calculation of yield efficiency as fruit weight per cm2 trunk cross-section. Estimates were made of maximum bearing surface potential (tree weight) per acre (as cm2 trunk area) for several kinds of tree fruits and nuts.

Open Access

Abstract

Disbudded ‘Old Home’ × ‘Farmingdale’ (OH × F) pear (Pyrus communis L.) cuttings rooted 96% before sufficient chilling to break rest and 84% after chilling. Rooting mass (as rated on a scale of 0 to 3) for disbudded cuttings was also less for chilled (1.22) than for nonchilled (1.94) cuttings. Disbudding of chilled cuttings reduced rooting significantly. Intemodal wounding failed to alter % rooting but reduced rooting masses for both nonchilled and chilled cuttings, relative to non-wounded controls. The rooting mass of nodally wounded chilled cuttings was suppressed even further.

Open Access

Abstract

A method for estimating sweet cherry yields was devised based on the calculation of a yield index value which incorporates estimates of the bearing surface of the tree and density of fruits on limb units. The relationship between yield index and actual yield was determined by regression analysis. The linear regression of yield index (Y) on actual yield (X) accounted for 84.6% of the variation.

Open Access

Abstract

Tests in 11 plots of ‘Italian’, ‘Early Italian’, and ‘Brooks’ prunes showed several influences of rootstock on tree growth, flowering, yield, fruit size, maturity, and quality. Of the 6 Prunus species represented by the 19 rootstocks tested, myrobalan roots usually resulted in larger trees, heavier bloom, but lower yield efficiency than did peach roots. Trees on Marianna and several P. domestica L. roots varied in size and yield, but most of them had greater bloom density than trees on peach root. ‘Italian’ fruit firmness varied inconsistently with rootstock. ‘Early Italian’ fruits were firmer on peach than on other roots, but ‘Brooks’ fruits were less firm on peach than on other roots. The tendency for internal fruit browning of ‘Italian’ was greater on plums than on peach roots. Other fruit maturity and quality factors varied by cultivar and by individual rootstock. Fewer trees on peach root died from trunk canker (Pseudomonas syringae van Hall) than did those on several clonal plum roots, but some plum-rooted trees outgrew the canker and survived as well as trees on peach stock.

Open Access

Abstract

Plantings of the ‘Italian’ prune (P. domestica L.) were established on seedling peach (P. persica L. Batsch) and clonal Myrobalan 29-C, B, 2-7 (P. cerasifera, Ehrh.); Marianna 4001, 2623, 2624 (P. cerasifera × Munsoniana?, Wight and Hedr.); and St. Julien A (P. insititia L. Bullace) rootstocks in 7 orchard sites in Oregon. Leaf samples were collected in the years 1968 to 1970 and analyzed for element content. Trees with plum rootstocks had greater leaf N, K, Mn, and Zn and slightly less B and Mg than those on peach. Plum clones, Myrobalan 29-C, Myrobalan B, and St. Julien A, were more efficient in the uptake of Ca. There were positive correlations between N and Ca, N and Mg, N and B, N and Zn, Ca and Mg, Ca and B, and Mg and B for most of the stocks. There was a negative correlation between K and Mg for Myrobalan 2-7 and the 3 Marianna clones. Myrobalan B and Marianna 2623 and 2624 had a negative corrleation for K and Ca whereas St. Julien A had a positive correlation.

Open Access

Abstract

The occurrence of solution pockets in brined sweet cherries has increased during the past 15 years. Affected fruits exhibit translucent pockets beneath the epidermis, filled with ruptured cell contents and brine solution. Pockets may occur anywhere in the fruit but are commonly at the suture. Affected fruits sometimes are not firm enough to pass through a pitting machine without being torn, increasing cullage and lowering grade. Sweet cherries are brined in a solution of sulfur dioxide and lime rather than the usual salt-brine method used on other crops (4).

Open Access

Abstract

Tests with pear on P. communis L. and ‘E. M. Quince C’ (Cydonia oblonga Mill.) rootstocks showed that early fruit thinning to 1 fruit per cluster increased ultimate % fruit set of ‘Comice’; thinning to 2 fruits per cluster did not increase ultimate set Limb girdling 3 weeks after bloom did not effectively increase set, but when used in combination with cluster thinning, increased ‘Anjou’ set beyond either treatment alone. Heading-back pruning of ‘Comice’ on ‘Quince C’ in a high density plot increased both fruit set and ultimate yield relative to thinning-out pruning.

Open Access

Abstract

Roots of most of the primitive Pynus species were infested with pear root aphid Eriosoma pyricola Bak. and David., and increase or decrease in number noted 30 days later. Although seedling populations varied somewhat, P. amygdaliformis, P. elaeagrifolia, P. syriaca, P. betulaefolia, P. calleryana, P. koehnei, P. ussuriensis, and P. nivalis can be considered resistant. P. communis, P. cordata, P. gharbiana, P. pashia, P. Fauriei, and P. pyrifolia were either susceptible or very variable in resistance. Only P. bucharica, P. dimorphophylla, and P. mamorensis had no resistant seedlings in the lots tested. Interspecific hybrid populations were predictable though variable in resistance.

Open Access