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  • Author or Editor: R. L. Andersen x
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Abstract

High temperature prior to controlled freezing increased inner bark and xylem injury in twigs of both ‘Siberian C’ and ‘Redhaven’ peaches (Prunus persica (L) Batsch). ‘Siberian C had a lower natural moisture content than ‘Redhaven’. Artificially increasing moisture content did not affect xylem injury, but increased inner bark injury. Significant temperature by cultivar and moisture by cultivar interactions were found with inner bark. We concluded that the superior hardiness of ‘Siberian C’ was not due solely to its lower moisture content.

Open Access
Authors: and

Abstract

‘Siberian C’ was hardier than ‘Velvet’ or ‘Redhaven’ peach [Prunus persica (L.) Batsch.] on all 13 test dates during 2 winters. Within test dates, cultivar injury was positively correlated with twig moisture content. Moisture content of the bark was twice that of xylem; however, xylem suffered more injury than the bark. Changes in temperature response patterns of bark and xylem from late fall to winter indicated a shift in freezing processes occurred during acclimation. Differential response of fully acclimated bark and xylem to temperature decrease suggested that bark underwent equilibrium freezing while xylem deep supercooled. ‘Siberian C’ did not appear more susceptible than ‘Velvet’ and ‘Redhaven’ to fluctuating late winter and spring temperatures.

Open Access
Authors: and

Abstract

Seven clones of peach (Prunus persica (L.) Batsch) varying in hardiness, and 5 progenies derived from them were used to study the inheritance of cambium, xylem, and vegetative bud hardiness. Mean progeny cambium and xylem hardiness could be predicted from average parental performance, but vegetative bud hardiness could not. Injury within dates and tissues was highly heritable and environmental variation was very low. Correlations among injury ratings for different tissues, temperatures, and dates were low when based on individual trees indicating poor repeatability of individual genotypes over time. Correlations based on family means were higher. The low correlations based on individual trees indicate that selection based on individual phenotypic performance in a single test might be ineffective.

Open Access
Authors: and

Abstract

A single genotype peach (Prunus persica (L.) Batsch cv. Redhaven) was used to study non-genetic hardiness variation. Twigs from the upper southwest and lower northeast sectors of several randomly chosen trees were frozen on 4 dates from November to March. The basal, middle, and tip sections of each twig were examined, using tissue browning as an index of injury. An appropriate statistical model was used to separate the variance components. Trees and tree × sector interaction constitute only a small portion of the total random variation, while twigs and residual error accounted for the major portion. Variance estimates were used to determine sample sizes needed to detect browning differences of a desired magnitude. The lowest variance estimates were obtained when the basal section of twigs collected from the upper southwest sector were analyzed. Sample sizes between 6 and 21 twigs could be expected to detect important differences in injury as assayed via tissue browning.

Open Access

Small fruit size reduces fresh-market value and potential net income in sweet cherry. Several new rootstock cultivars for sweet cherry induce greater precocity, heavier blossom density, and a range of dwarfing but also may reduce fruit size. A field study was undertaken with sixth leaf `Hedelfingen' scions grown on Prunus avium L. `Mazzard' seedling rootstock or on one of 4 new rootstock cultivars: `Damil,' `Gi 148/1,' `Gi 172/9,' and `Gi 196/4.' Factorial treatments included (+/-) trickle irrigation when soil tensiometer readings reached 20 k Pa and (+/-) hand thinning to single fruits/cluster aat 7 days after full bloom. High natural precipitation reduced irrigation effect but fruit size was increased significantly by thinning. Yield differences were also seen between rootstock cultivars.

Free access

Abstract

Eleven suspected somatic mutations, consisting of 7 trees and 4 individual branches of the ‘Montmorency’ cherry, were compared with standard ‘Montmorency’ for phenotypic traits including tree height, trunk circumference, leaf area, crotch angle, resistance of flowers to frost injury, pollen germination, fruit set, individual fruit weight, fruit removal force, and yield. Differences occurred between some variants and ‘Montmorency’ controls for all characters except fruit removal force. All variants were tetraploid (2n = 32), as is standard ‘Montmorency’, with no evidence of cytochimerism.

Open Access

Abstract

‘Tophat’ is a spherical dwarf plant, about 30 cm in diam (Fig. 1), and is released as an ornamental plant for gardens or containers.

Open Access

Poor growth and high mortality of in vitro produced plants during acclimatization stage has troubled propagators. Studies were undertaken to improve growth and ex-vitro performance of `Gil48/1,' a new Prunus cerasus L. × P. canescens Bois (cherry) rootstock cultivar. Two experiments were conducted during the course of this study. In a specially designed apparatus growth reponses of shoot cultures to two CO2 levels (340ppm, 1200ppm) and five sucrose levels (0,2,5,10, and 20mg/l) were studied. Leaf area leaf dry weight, number of shoots and total plant dry weight were significantly increased with increase in sucrose concentration in the media regardless of the CO2enrichment.

In the other experiment Stage III shoots of the same cultivar were exposed to two CO2 (400-500ppm, 1200-1300ppm) and three different light levels (30-40, 60-75, and 85-100μmol.s-1.m-2) for 45 days. Significant increases in leaf area, leaf and shoot dry weight and total plant biomass were observed with CO2 enrichment and increased illumination intensity.

Free access

A fresh-market tomato trial was conducted in 2003 at two locations in Arkansas (Fayetteville and Kibler) to evaluate new and old tomato varieties of interest to home gardeners and farmers' markets. The observational trial consisted of 43 varieties, indeterminates and determinates. Heirloom tomatoes comprised a large portion of the trial due to increasing popularity. Heirlooms are unique and can be very eye-catching. There is immense variety in shape, size, and color. They can be large or small, many times the shape is irregular, and the fruits flawed (cracking, cat-facing, green shoulders). The fruit may not store or ship well; most are grown and sold locally. Some heirlooms are better than others. A few of the varieties that stood out in the trial were Costoluto Genovese, Abraham Lincoln, Dona, and Persimmon. Costoluto Genovese, a uniquely ruffled red tomato, was the highest yielding variety at the Kibler location. Fruit quality remained high even in the highest temperatures. One of the most promising was a orange variety called Persimmon, it produced large fruit and the plants provided excellent cover. Dona and Abraham Lincoln, both reds, yielded well and had good flavor. San Marzano and Arkansas 7985 were the best paste types. Arkansas varieties such as Bradley, Ozark Pink, and Arkansas Traveler 76 also did well. Brandywine varieties had low yields and lesser quality fruit. Green zebra, a green striped fruit with good flavor, yielded less due to Blossom End Rot. Cherokee Purple and Carbon were two from the purple/black category that did not do well; yields were low and the fruit cracked.

Free access

Abstract

‘Sweethaven’, ‘Newhaven’, and ‘Jayhaven’ are 3 new cultivars o f melting, yellowfleshed peaches [Prunus persica (L.) Batsch] distributed for public nursery sales as products of an ongoing, long-term breeding program in Michigan (Table 1).

Open Access