Search Results

You are looking at 1 - 10 of 31 items for

  • Author or Editor: Frank Kappel x
Clear All Modify Search
Author:

The effect of fruit on shoot growth, leaf area, and on dry weight (DW) partitioning into leaves, fruit, trunk, and branch sections was investigated using 7-year-old `Lambert' sweet cherry (Prunus avium L.) trees. Dormant trees were sampled in the spring, and fruiting and deblossomed trees were sampled and compared at fruit harvest and just before leaf fall. Fruiting reduced shoot growth, leaf area, and above-ground DW accumulation of the trees. The annual above-ground DW accumulated was 13.4 kg for fruiting trees and 16.0 kg for nonfruiting trees. The greatest proportion of above-ground DW was partitioned to wood, whereas the least was partitioned to fruit. Current-season's growth (wood and leaves) appears to be a greater sink for photosynthates than is fruit because a greater proportion of above-ground DW was partitioned to current-season's growth than to fruit.

Free access
Author:

Yield components of 8- to 10-year-old trees were compared among `Kieffer' [Pyrus communis (L.) x Pyrus pyrifolia (Burro.)] and `Harrow Delight' and `Harvest Queen' [Pyrus communis (L.)]. `Kieffer' set more fruit than the other cultivars, even though flower density was similar. `Kieffer' also had similar size or larger fruit than `Harrow Delight' or `Harvest Queen'. Path analysis showed that the direct and indirect effect of fruit number on yield was important for all cultivars. Flower density only had a small direct effect on yield and this was at times negative. Fruit size had a small effect on yield when compared to fruit number.

Free access
Author:

Spring frosts can be a limiting factor for sweet cherry production and very little is known about frost susceptibility of new sweet cherry cultivars. This study reports on floral bud injury of a number of recently introduced sweet cherry cultivars after 10 spring frosts in Apr. 2008. Floral buds at the first white stage were collected from late-ripening sweet cherry cultivars that were part of a randomized and replicated evaluation block. Blossoms were selected from various positions within a tree in a 1-m band centered around 1.5 m above the ground. The blossoms were brought into the laboratory, cut open, and placed into two groups: live (green) or dead (brown or browning) pistil. ‘Staccato’ and ‘Sentennial’ were the least affected followed by ‘Lapins’ and ‘Sweetheart’. ‘Sovereign’ was most susceptible to the subfreezing temperatures in the spring of 2008. There was a reasonably good relationship between the percentage of live buds per tree in the spring and yield at harvest later in the summer.

Free access
Author:

Abstract

‘Bartlett’ pear (Pyrus communis L.) branches were shaded at 0%, 30%, 50%, 65%, and 82.5% with polyethylene shade fabric from 50 days after full bloom until harvest. Fruit weight, firmness, and soluble solids concentration (SSC) were assessed at harvest. Stored and ripened fruit were assessed for SSC and total solids content (TSC), pH, and total acidity. Shading reduced the mean fruit weight and SSC of green mature fruit. The firmness of the green mature fruit increased as shading severity increased. TSC and SSC of the ripened fruit were reduced by the shading. The pH and total acidity were unaffected by the shade treatments. Leaf dry weight per area was also reduced by shading.

Open Access
Authors: and

Inbreeding and coancestry coefficients were calculated for 66 sweet cherry (Prunus avium L.) selections released from four breeding programs in North America (HRIO, Vineland, Ont., IAREC, Prosser, Wash., NYSAES, Geneva, N.Y., and PARC, Summerland, B.C.). Highly used founding clones were `Black Heart', `Emperor Francis', `Empress Eugenie', `Napoleon' and `Windsor'. Coefficients of coancestry between all selections and these clones averaged 0.038, 0.045, 0.060, 0.091, and 0.033, respectively. In these five founding clones, coefficients of coancestry in self-compatible selections were over twice as much as those in self-incompatible selections except `Windsor'. In the analysis of coefficients of coancestry between self-incompatible and self-compatible sweet cherry, almost 20% of self-incompatible selections represent more than a half-sib relationship (0.125) to self-compatibles. Increasing and maintaining genetic diversity is needed in sweet cherry breeding program in North America for continued breeding progress.

Free access
Authors: and

The effect of rootstock on the flowering and fruiting response of sweet cherries (Prunus avium L.) was investigated using 4-year-old branch units. The cherry rootstock Edabriz (Prunus cerasus L.) affected the flowering and fruiting response of `Burlat' sweet cherry compared to Maxma 14 and F12/1. Branches of trees on Edabriz had more flowers, more flowers per spur, more spurs, more fruit, higher yields, smaller fruit, and a reduced fruit set compared to the standard rootstock, F12/1. One-year-old branch sections had more flowers and fruit, higher fruit weight, and heavier fruit size compared to older branch portions.

Free access

Leaf nutrient concentration of `Bing' sweet cherry (Prunus avium L.) was affected by rootstock over 4 years in the Pacific Northwest. Trees on GM 79, GI 148/1, GI 195/1, and GI 196/4, which had higher yields than Mazzard, also had lower leaf K and, excepting GM 79, lower leaf Mg concentration. Use of GI 195/1 and 196/4 resulted in lower leaf N than use of Mazzard. These higher-yielding rootstocks will require greater attention to these macronutrients, especially on infertile soil sites. Micronutrient nutrition was little affected by rootstocks, which tended to have the low leaf Zn concentrations typical of irrigated Pacific Northwest orchards. GM 9 and GM 61/1 rootstocks were more dwarfing than Mazzard, with GM 9 leaves having lower K, but higher P, Mg, and Mn concentrations. GM 61/1 had lower leaf concentrations of most nutrients relative to Mazzard.

Free access
Authors: and

To determine how different training systems affected early growth and fruiting (first 5 years), `Conference' pear (Pyrus communis L.) trees on Quince A (Cydonia oblonga L.) rootstock were trained to angled trellis, slender spindle, vertical axe, or Y-trellis. The trees of the Y-trellis had the greatest spread after 5 years, and the vertical axe and slender spindle trees were the tallest. The Y-trellis trees had the highest light interception and had significantly higher yields in 1997 than the other training systems. Average fruit weight was inversely related to crop load.

Free access
Authors: and

Abstract

One-year-old peach [Prunus persica (L.) Batsch cv. Redhaven] trees were grown outdoors under 4 different shade levels (100%, 36%, 21%, and 9% of full sun). Shoot length, internode length, and node number were unaffected by shade, but heavy shade (9% full sun) reduced stem diameter 24%. Compared to those in full sun, average leaf areas were increased 18%, 30%, and 20% by 36%, 21%, and 9% shade, respectively. Shading caused a more horizontal leaf orientation and lower specific leaf weight. Both average and maximum photosynthetic rate per unit area or per mg chlorophyll decreased with shading, but increased with shading when expressed per unit dry weight. Chlorophyll content per unit leaf area increased with shading, but stomatal resistance was unaffected. Leaves from shade treatments became light-saturated between 400 and 600 µEs-1m-2; full-sun leaves became light-saturated at 700-900 µEs-1m-2.

Open Access

`Lapins' sweet cherry (Prunus avium L.) trees on Gisela 5 (Prunus cerasus × Prunus cansecens) rootstock were maintained for the first four growing seasons with eight different fertigation treatments. Treatments involved N application at low (42 mg·L-1), medium (84 mg·L-1), and high (168 mg·L-1) concentrations via sprinkler-fertigation of Ca(NO3)2 each year about 8 weeks after bloom. The medium N treatment was also applied with P fertigation in early spring or with K fertigation in June. Nitrogen was also broadcast in early spring at 75 kg·ha-1 or followed with medium N sprinkler-fertigated postharvest in August. As a final treatment the medium root zone N concentration was maintained for 8 weeks postbloom via drip fertigation. Throughout the study, irrigation was scheduled to meet evaporative demand based on an electronic atmometer. Drip fertigation, which wet a smaller portion of the orchard floor, considerably reduced per-tree water applications. Tree vigor and pruning weights were reduced for drip-fertigated as compared to sprinkler-fertigated trees although cumulative yield was not significantly different during the study. Fruit size, however, was smaller for this treatment when crop load was at a maximum at year 4. Future research is warranted to insure fruit size can be maintained for heavily cropping drip-fertigated trees. Leaf and fruit N increased linearly as N concentration of sprinkler-fertigating solution increased from low to high values. Optimum yield and highest fruit quality were associated with the medium N treatment. Sprinkler fertigation of P and K did not increase leaf and fruit concentration of either nutrient or meaningfully affect tree performance.

Free access