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  • Author or Editor: James N. Moore x
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Abstract

Seven seedling populations of strawberry were analyzed for ascorbic acid content and color intensity. The amount and type of variation found showed both characters to be controlled by quantitative genes. It is postulated that 2 genetic systems control the inheritance of ascorbic acid and that the 2 systems can interact with each other. Partial dominance was exhibited for high color intensity. Heritability estimates of 41% for ascorbic acid and 81% for color intensity were obtained. Flesh color and ascorbic acid content were not correlated characters.

Open Access

Abstract

Eighteen species of Prunus and 4 interspecific hybrids from the 3 main subgenera were used to ascertain the prezygotic mechanisms that maintain reproductive isolation. The percentage of pollen germination of pure species was very high (82% to 97%), and ranged from 1% to 97% for interspecific hybrids. Pollen tube growth rates differed greatly among species and ranged from 3.8 to 8.7 mm/day in vitro, and from 3 to 12 mm/day in vivo. These values were highly correlated with pistil length (r = 0.90) and pollen volume (r = 0.91). Evidence was obtained suggesting the existence of additional incompatibility mechanisms, the 1st preventing interspecific fertilization in the subgenus Cerasus. In P. avium L., the pollen tubes of some species are inhibited and finally arrested before they reach the first half length of the style. In crosses involving P. cerasus L. and P. serotina Ehrh., the use of the latter as the seed parent showed a 10-fold increase in fruit set when compared to the reciprocal. Secondly, differences in pistil length and in pollen tube growth rate among species provide a sound basis for explaining the phenomenon of unilateral incompatibility in Prunus. The use of male-sterile genotypes of P. persica L., which had a prolonged period of receptivity, gave increased fruit set and showed increased potential for overcoming the prezygotic incompatibility barriers.

Open Access

Abstract

‘Choctaw’ is the fifth in a series of erect-growing, high-quality, productive blackberry cultivars developed in the breeding program of the Arkansas Agricultural Experiment Station. Previous releases from this program are ‘Comanche’ and ‘Cherokee’ in 1974 (Moore et al., 1974a, 1974b), ‘Cheyenne’ in 1977 (Moore et al., 1977), and ‘Shawnee’ in 1984 (Moore et al., 1985). ‘Choctaw’ ripens its fruit earlier in the season than the previous cultivars, thus extending the blackberry fruiting season.

Open Access

Abstract

One objective of the Arkansas blackberry breeding program has been to develop erect-growing, thornless cultivars that produce self-supporting canes. ‘Navaho’ is the first such release from this program, and, to our knowledge, it is the first fully erect thornless blackberry to be developed worldwide.

Open Access

Abstract

A moisture accounting method was used to schedule trickle irrigation on 3-year-old highbush blueberry plants (Vaccinium corymbosum L.) ‘Bluecrop’ planted in 140-liter barrels. Crop coefficients (K) of 1.00, 0.75, and 0.50 were used to relate Class “A” Weather Bureau pan evaporation to consumptive water use during three growth stages. No significant differences were found in yield, total berry number, average berry size, berry pH, titratable acidity, total soluble solids (TSS), TSS : acids ratio, and vegetative growth among the irrigation treatments. Significant differences in initiated flower buds were seen, but no trends were noted. An average water savings over the entire season of 57.0%, 67.7%, and 78.5% of the currently recommended irrigation rate of 3.8 liter·day−1 was observed when irrigation was scheduled using K values of 1.00, 0.75, and 0.50, respectively. A K value of 0.75 was considered to be the optimum crop coefficient for young highbush blueberries growing under Arkansas conditions.

Open Access

Abstract

Buds of three peach clones (‘Diamante’, ‘Capdeboscq’, and Conserva 334) were sampled weekly during the summer in Clarksville, Ark. and Pelotas, RS, Brazil and classified according to their developmental stage. The percentage of buds at stage 3 (apex showing broadening and assuming a roundish shape) was calculated, and flower bud initiation was considered to be the date when at least 50% of the examined buds were at stage 3 or beyond. In Arkansas, flower bud initiation occurred in ‘Capdeboscq’ on 18 July and in ‘Diamante’ and Conserva 334 on 25 July. In Brazil, ‘Capdeboscq’ initiated flower buds on 30 Jan. and ‘Diamante’ and Conserva 334 on 23 Jan. By transforming dates to number of days from beginning of summer, a comparison was made between the two locations for three stages of flower bud development (broadening of the apex, onset of sepal formation, and sepal differentiation). No statistically significant difference was found between locations for time of occurrence of any of the developmental stages. The largest differences obtained were no greater than differences between years at the same location. Buds of ‘Diamante’ were notably variable in stage of development at the same collection date, with some in stages 3 and 4 and others in stage 6. The possible relationship between differential rate of flower bud development and avoidance of winter cold injury is discussed.

Open Access

Abstract

‘Saturn’ is the fourth in a series of seedless table grapes released from the grape breeding program of the Arkansas Agricultural Experiment Station. Previous releases were ‘Venus’ in 1977 (Moore and Brown, 1977), ‘Reliance’ in 1983 (Moore, 1983), and ‘Mars’ in 1984 (Moore, 1985). These cultivars are the foundation of an emerging commercial table-grape industry in the region. ‘Saturn’, a high-quality, red seedless grape with good storage and shelf-life characteristics, is expected to contribute to further expansion of the commercial industry.

Open Access

The Arkansas apple breeding program began in 1966 with objectives to develop high quality, dual purpose, adapted cultivars with a range of harvest dates and resistance to spring diseases. The program has two goals: 1) to develop red colored apples which are large, tart, firm and ripen between June and August; and, 2) develop yellow apples as a replacement for `Golden Delicious' which are large, typey, without russet and with a range of maturities from July through September. Apples with commercial potential are AA-18 (red, ripens 1-July), AA-44 (red, ripens 15-July), AA-58 (yellow, ripens 29-Aug.), AA-65 (yellow, ripens 11-Sept.) and AA-62 (yellow, ripens 15-Sept.). Data on time of bloom, harvest, fruit size, and fruit storage tests will be presented.

Free access