Search Results

You are looking at 41 - 50 of 5,117 items for :

Clear All

Post-bloom fruit thinning of spur-type `Delicious' with NAA may occasionally result in excessive small fruit (50 - 67 mm) not correlated with crop load. We evaluated the effect of carrier volume and time of application on incidence of small fruit over three growing seasons. A constant dose of NAA (30 g·ha-1) was applied in 230 to 2100 liter·ha-1 at about 10 mm king fruit diameter (KFD). Amount of NAA-induced small fruit differed from year to year, but there was no significant effect of carrier volume in any given year. NAA (15 mg·liter-1) was applied as a dilute spray at 5 to 22 mm KFD. Time of application influenced fruit size distribution at harvest in only one of three years. The incidence of small fruit appeared more closely related to temperature during spray application than to carrier volume or time of application. The effect of NAA on growth rate of king fruit with minimal competition (branches hand thinned, no lateral fruit) was determined over the first month after thinning. There was no pronounced effect of NAA on post-treatment growth rate. In a related study, NAA caused a significant decrease in fruit size when two or more fruit were competing on the same spur, while fruit size in the absence of intra-spur competition was not significantly reduced.

Free access

Peach fruit softening appears to be associated with changes in cell wall polymers, particularly pectins and hemicelluloses. To determine changes of cell wall polymers associated with peach fruit softening, we conducted sequential extractions of pectin and hemicellulose from softening fruit. A more tightly bound hemicellulose fraction contained considerable amounts of pectin associated sugars. This fraction was separated into charged and neutral fractions, using anion exchange chromatography, and then fractionated into two apparent molecular weight classes by size exclusion chromatography. Virtually all of the charged fraction eluted in the higher apparent molecular weight fraction. The neutral sugar fraction segregated into both apparent molecular weight size classes, with a redistribution from the large to the small size class during softening. This redistribution was accompanied by changes in neutral sugar composition. A possible relationship between changes in this fraction and fruit softening will be discussed. Supported by USDA grant 92-34150-7190 and the Oklahoma Agricultural Experiment Station.

Free access

Abstract

In 3 ‘McIntosh’ apple (Malus domestica Borkh.) orchards, yield was positively related to fruit numbers, but negatively related to fruit size. Increases in fruit size from thinning were proportionately less than decreases in fruit numbers. Fruit thinning increased the percentage of larger fruits, but reductions in yield were such that the actual number of large fruits was either unchanged or reduced.

Open Access

Growth of young lemon trees (Citrus limon Burm. f.) is extremely vigorous, and is characterized by the appearance of highly vigorous upright shoots that originate in the scaffold branches and trunk of the tree. While maturing, these shoots are considered to be in competition for photosynthates with smaller fruit in the spring and with mature fruit in the fall. During 1993 and 1994, we selectively removed these shoots 12, 6, 4, and 1 (1994 only) times per year, with the objective of increasing fruit size. Neither yield nor fruit quality was affected by the pruning treatments during 1993, but pruning trees 12 times per year increased fruit size by 30% compared to unpruned trees. In 1994, lemon trees pruned 4 times per year had 50% less cull fruit than unpruned trees, and 22% more fruit of size 140 or larger. However, >99% of the flowers and small fruit on trees pruned 4 times per year were aborted, compared with 95% abortion on the unpruned trees. Trees pruned 4 times per year also had 40% less yield compared with those that were unpruned.

Free access
Authors: and

Number of cells and mean cell volume of strawberry receptacles were determined throughout the development of secondary fruit of three day-neutral cultivars grown in a greenhouse. Receptacle tissue was digested with pectinase and cellulase and number of cells determined with a Batch counting chamber. Cultivars differed in fruit size throughout development. The size of ripe fruit was small (3.8 g) in `Tillikum', medium (11.6 g) in `TriStar', and large (15.6 g) in `Selva'. Cell division continued in all cultivars for 15 days after anthesis (DAA) and was exponential during the first 10 days. The number of cell per fruit after 15 DAA averaged 0.71, 1.96, and 2.94×106 for `Tillikum', `TriStar', and `Selva' respectively. Mean cell volume, as estimated from number of cells and volume of receptacle tissue, increased rapidly between 10 and 25 DAA. Cells of the pith were larger than those of the cortex during early fruit development. Mean cell volume of mature fruit was approximately 6×106 μm3 in the three cultivars. Genotypic variation in fruit size was primarily due to the difference in number of receptacle cells.

Free access

Field studies were conducted in 1996 on two pumpkin (Cucurbita pepo L.) cultivars, `Howden' (vining-type growth habit) and `Wizard' (semi-bush growth habit), at two locations to determine the effect of plant population and row width on marketable yield. Increasing plant populations from 2990 to 8960 plants per hectare resulted in significantly greater fruit number and yield at both locations and for both varieties. Average fruit size declined at the highest populations. Increasing row width from 1.8 to 3.6 m resulted in a slight but significant decrease in number of fruit per hectare with no effect on other yield parameters. At one location, the effect of row width on yield and number of fruit per hectare depended on the population. At low populations, row width did not influence yield or fruit number; at high populations, wide rows produced lower yield and fewer fruit than narrow rows. The results demonstrate that growers may increase pumpkin yield by increasing plant populations but should use narrower row widths and wider in-row spacing. Growers who choose higher populations should ensure that all inputs are optimized to reduce potential plant-to-plant competition and use regionally adapted cultivars.

Free access

33 ORAL SESSION (Abstr. 391-397) FRUIT CROPS: GROWTH AND DEVELOPMENT I

Free access

production in the Florida panhandle. The objective of this study was to quantify yield, tree size, and fruit quality of mature (7th to 11th growing season) ‘Brown Select’ and ‘Owari’ satsuma cultivars on trifoliate orange [ P. trifoliata (L.) Raf

Free access

Poster Session 10—Fruit and Nut Breeding 18 July 2005, 1:15–2:00 p.m. Poster Hall—Ballroom E/F

Free access
Authors: and

Abstract

Progenies from crosses among 17 highbush (Vaccinium corymbosum L.), lowbush (V. angustifolium Ait.), and V. corymbosum/V. angustiforium hybrid parents were evaluated in 1983 and 1984 of dates for 50% bloom and 50% ripe fruit, length of the fruit development interval, and berry weight. Additive genetic variance was more important than nonadditive genetic variance, based on general combining ability (GCA) variance components. Heritability estimates were moderately high (0.44-0.78) for all traits. GCA effects were largely dependent on the parents’ ancestry. A long fruit development interval was not necessarily associated with large fruit size. Selection for large fruit size, late bloom period, early ripening, and short fruit development interval in this population should be successful. Parental phenotype should be indicative of relative progeny performance.

Open Access