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Abstract

Ringing plants of the determinate tomato (Lycopersicon esculentum Mill cv. Summit) with copper wire when fruit had set on 3, 7 and 12 clusters increased early and total yield. Earlier ringing did not produce such increments. Ringing had no effect on fruit size and percent marketable yields.

Open Access

Medium-sized triploid watermelons were evaluated in southeast Pennsylvania in 2002 and 2003 to determine the best adapted cultivars for this region. The 2002 season was unusually hot and dry, while 2003 was unusually cool and wet. Yields and fruit quality were compared for the eight cultivars that were grown both seasons to determine the effect of weather on seedless watermelon. Cooler temperatures reduced total fruit number and total yield but not average fruit weight or soluble solids. Researchers evaluating triploid watermelons over several seasons can compare size and °Brix among cultivars, but will need to be cautious when predicting total yields.

Free access

Abstract

Twelve seedling populations involving large, intermediate, and small-fruited parental clones of tetraploid blackberries were evaluated for fruit size inheritance. The amount and type of variation and the significant deviations from the mid-parent means in seedling distributions indicated that inheritance was quantitative with partial dominance for small fruit size. Maximum heritability, estimated by the genetic variance/phenotypic variance, was 0.76. Narrowsense heritability, estimated by regressing progeny on the mid-parents, was 0.62, indicating that most of the genetic variability (82%) was transmittable through the sexual cycle (gametes). These results suggest that simple breeding procedures based on inter-mating parent clones selected on the basis of their phenotypic performance are likely to produce significant genetic gains in fruit size of blackberries.

Open Access
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Abstract

Fruit on shoots trained to grow above the main foliar canopy (exposed) of 6-year-old ‘pergola’-trained kiwifruit vines were significantly larger than fruit on shoots trained to grow below the canopy (shaded). Fruit size increased with seed number in both fruit groups, but fruit from exposed shoots were consistently larger than shade-grown fruit with the same seed count. Shade-grown shoots had smaller basal diameters and less dry matter than exposed shoots. Winter mortality among buds on formerly shaded and exposed shoots was 34% and 5%, respectively. Formerly shaded shoots had fewer mixed buds with less flowers per inflorescence than exposed shoots the following spring.

Open Access

The effect of root mass on tomato fruit size in tissue culture was studied. The root mass of the ovaries was changed either by growing in culture media containing different concentrations of NAA (α– napthaleneacetic acid) or by culturing the ovaries with and without sepals. The root mass increased with a decrease in NAA concentration from 10.0 to 2.5 μM and the ovaries with sepals developed more roots. The tomato fruit size was affected by the root mass. The greater the root mass, the larger was the fruit size. However, the larger fruit size from ovaries cultured with sepals could be attributed either to the presence of more roots (greater absorption of sucrose) or to the sepal (additional carbon fixation by photosynthesis), or to both the sepals and more roots. Moreover, it is possible that the presence of sepals induce root development. These results indicate that the presence of sepals and total root mass are two important factors that influence the fruit size in vitro.

Free access

The relationship between the number of commercially valuable sized fruit produced per unit land area vs. total number of fruit produced per unit land area for mature navel orange (Citrus sinensis) has not been documented. Knowing this relationship, referred to as the commercial fruit production function (CFPF) within this paper, may aid growers in making fruit thinning and tree pruning decisions and researchers in evaluating the interaction of fruit yield and size in response to fruit thinning, tree pruning, variety selection and tree spacing experimentation. For midseason navel oranges in the southern San Joaquin Valley of California, a reliable CFPF for total annual fruit production ranging from 14,000 to 130,000 fruit/acre was found to exist over multiple seasons in three orchards. The CFPF for two early maturing navel orange varieties was not significantly different with respect to slope or intercept from the CFPF for midseason varieties over the range of 12,000 to 63,000 fruit/acre, but became unreliable when fruit number exceeded 63,000 fruit/acre.

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Eight staked, determinate tomato (Lycopersicon esculentum Mill.) cultivars were harvested when green (before breaker stage) or when pink (breaker stage and riper) in two replicated field studies. In general, total yield and average fruit size were reduced when fruit were harvested at the green stage. Harvest maturity had only a small effect on occurrence of most fruit defects, except fruit cracking, which was more severe for pink than for green fruit in the early season experiment. Although total yields for pink harvested fruit were higher than for green harvested fruit in the early season study, the high incidence of fruit crack in pink fruit resulted in similar yields of U.S. combination grade (U.S. no. 1 and U.S. no. 2) fruit for both treatments. Because the largest fruit often bring a premium price, harvesting fruit when pink probably will result in a higher price per kilogram than harvesting fruit when green. Fruit harvested green, however, are generally firmer, more crack resistant, and require fewer harvests than fruit harvested pink.

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Effects of three sterol-demethylation inhibiting (DMI) fungicides and a contact fungicide were compared over two years at each of two locations to determine if fungicide treatments had differential effects on productivity, fruit size and shape, or gross returns for `Empire' apples (Malus ×domestica Borkh.). Treatments were applied four to five times per year during the primary apple scab season. Effects of treatments were assessed by comparing fruit set efficiencies, number of fruit per tree, total harvested fruit weight, and fruit length: diameter ratios at harvest. No significant differences were noted among individual treatments in any of the four trials. However, when treatments were contrasted by grouping individual treatments, significantly larger fruit size was noted for triflumizole treatments vs. combined fenarimol and myclobutanil treatments in one of the four trials and for captan or mancozeb compared to fenarimol and myclobutanil treatments in two trials. None of the DMI fungicides compared in these trials had any consistent adverse affect on fruit size, total yield, or estimated gross return per hectare. We conclude that the plant growth regulator effects of DMI fungicides are inconsistent and are unlikely to have significant economic impact on commercial apple production.

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Abstract

Hand thinning during late June drop increased fruit size and improved quality of ‘Stanley’ plum as indexed by soluble solids and color development. Crop load within the range of 200 to 990 g of mature fruit per cm2 trunk cross-sectional area was negatively correlated with fruit size, soluble solids and color. The percentage of mature fruits with cheek diameter less than 35 mm increased as crop load increased. Total flower buds and flowers per spur, and flowers per flower bud, were not significantly affected by fruit load in the range of 0.5 to 2.0 fruits per spur the previous season. However, a weak negative relationship was found between fruits per spur and flower buds produced per spur with a wider range (0 to 8 fruits/spur) in fruit load.

Open Access

A field experiment was established in 1992 with `Empire' apple trees on either M.7 or M.9 rootstock. Preplant fertilization with NPKB plus lime compared to the lime only control did not increase tree growth during the first 4 years, but did increase cumulative yield (10%) and average fruit size (7%). The addition of annual applications of ground-applied NKB after planting increased total shoot growth 17%, as well as yield (26%) and fruit size (14%) compared to the lime only control. Trickle irrigation significantly increased trunk cross-sectional area (17%), shoot growth (16%), yield (18%), fruit size (5%), and yield efficiency (7%). The interaction of ground fertilization and trickle irrigation showed that trickle irrigation increased the benefits of ground applied fertilizers. Without trickle irrigation, ground-applied fertilizers increased shoot growth only 6% and yield 14% compared to the unfertilized controls, but, with the addition of trickle irrigation, the ground-applied fertilizers increased shoot growth 21% and yield 21% over the irrigated but unfertilized control. Ground fertilization increased yield efficiency and fruit size by the percentage by whether or not trickle irrigation was present. Fertigation gave similar results as the trickle plus ground fertilizer treatment on tree growth, yield, fruit size, and yield efficiency. Our results indicate that trickle irrigation in the eastern United States can improve tree growth, yield, and fruit size in the first few years after planting. The addition of ground-applied fertilizer or fertigation can improve tree performance even more. However, in the humid New York climate, there does not appear to be a significant benefit from injecting the fertilizer into the trickle water compared to applying the fertilizer on the ground.

Free access