strawberries J. Amer. Soc. Hort. Sci. 113 770 774 Shaw, D.V. 1991 Genetic variation for objective and subjective measures of fresh fruit color in strawberries J. Amer. Soc. Hort. Sci. 116 894 898 Shaw, D.V. Larson, K.D. 2008 Performance of early-generation and
Vance M. Whitaker, Tomas Hasing, Craig K. Chandler, Anne Plotto, and Elizabeth Baldwin
Esnath T. Hamadziripi, Karen I. Theron, Magdalena Muller, and Willem J. Steyn
± se (n = 10). The average ambient temperature of 27 °C is indicated with a line. Fruit color and pigment concentrations. Outer canopy fruit were redder and contained more anthocyanins (assessed in 2010 only) than inner canopy fruit ( Tables 1 and 2
Tara Auxt Baugher, Kendall C. Elliott, and D. Michael Glenn
Three growth suppression treatments were compared during 1991 to 1993 on `Stayman' apple (Malus domestica Borkh.) trees grown in the T-trellis and the MIA trellis systems. All treatments—root pruning, K-31 fescue (Festuca arundinacea Schreb.), and K-31 fescue plus root pruning—suppressed tree growth compared to the nontreated control, but results were inconsistent between years and systems. Sod or sod plus root pruning reduced terminal shoot length in both systems in 2 out of 3 years. Root pruning decreased shoot length in the T-trellis in 1992. Sod decreased trunk cross-sectional area in the T-trellis in 1993. Treatments did not affect 3-year average yield efficiency but did appear to increase biennial bearing. Sod, with or without root pruning, decreased fruit cracking in the T-trellis 69% and 42%, respectively, in 1992, and sod plus root pruning decreased cracking in the MIA trellis 50%. Sod reduced fruit diameter in the T-trellis in 1992. Secondary effects of growth suppression treatments included increased light penetration and improved fruit color. Sod decreased leaf N and Mg and increased leaf P, K, and Cu. The Oct. 1993 stem water potential gradient from root to canopy was more negative in the sod plus root pruning treatment, and the osmotic potential of rootsucker leaves in the combination treatment was greater than in the control, indicating that sod plus root pruning alters the distribution of water within a fruit tree.
Eileen Kabelka, Wencai Yang, and David M. Francis
An inbred backcross (IBC) population derived from Lycopersicon hirsutum LA407 and L. esculentum was evaluated in replicated field trials to assess its potential for the improvement of red-fruited tomatoes. Significant phenotypic variation among genotypes was detected for the hue (tint), L (darkness), and chroma (saturation) of color. Significant effects due to environment and genotype × environment interactions also were observed. One superior inbred backcross line from this population, IBL 2349, was used to develop an F2 population and to explore the genetic basis of color. Two independent L. esculentum quantitative trait loci (QTL) associated with improved color were identified based on linkage to markers mapping to chromosome 4 and chromosome 11. Epistatic interactions were identified between the two L. esculentum loci. Unexpected epistatic interactions also were identified between L. esculentum loci and an LA407 introgression on chromosome 7 present within IBL 2349. The two L. esculentum QTL and the epistatic interactions were confirmed in replicated trials with F3 and F4 families. The loci identified in this study and their epistatic interactions may provide additional tools for the improvement of red-fruited tomatoes in breeding programs.
Bernadine C. Strik and Arthur Poole
Timing and severity of pruning in a 30-year-old commercial `McFarlin' cranberry (Vaccinium macrocarpon Ait.) bed were studied. Treatments in 1989 and 1990 consisted of early or late pruning and heavy, moderate, light, or no pruning. Yield component data were collected in Fall 1989 and 1990, just before harvest. Time of pruning did not affect yield components. In 1989, the unpruned and lightly pruned vines had a higher total plant fresh weight, fewer berries, higher berry yield, longer and more fruiting uprights, and fewer nonfruiting uprights (U,) compared with moderately or heavily pruned vines. Average length of UN and anthocyanin content of berries in 1989 were not influenced by pruning. In 1990, the effects of pruning severity were similar to 1989. In 1990, unpruned vines had a lower percent fruit set and berries contained less anthocyanin than pruned vines. Annual pruning with conventional systems in use decreases yield.
John R. Stommel and Robert J. Griesbach
practices. Table 1. Mean values and sd s for mature pepper fruit color, fruit length/fruit diameter at midpoint, number of fruit per cluster, leaf color, leaf length, leaf width, plant height, and plant diameter in parental, F 1 , F 2 , and
Bernard B. Bible and Suman Singha
Differences in color development between exposed and shaded fruit during the growing season were determined for `Loring' and `Raritan Rose' peach (Prunus persica L. Batsch). The surface color of fruit exposed to sunlight in the upper canopy, and in the shade in the lower canopy, was measured with a tristimulus calorimeter, and L* a* b* values were recorded for each fruit from 17 July through harvest. Color changes (ΔE* ab) during maturation for both cultivars at either canopy position were characterized by large changes in hue (Δ H*ab) and lesser changes in lightness (Δ L*ab) and chroma (Δ C*ab). Upper canopy fruit of both cultivars were redder and darker than the lower canopy fruit initially and at harvest. Flesh firmness for `Loring' and `Raritan Rose' tended to correlate with color change from initial sampling to harvest.
Francis X. Mangan, Charles S. Vavrina, and John C. Howell
The effects of transplant depth on lodging and yield were evaluated in five experiments in Florida and Massachusetts. `Cherry Bomb', `Jupiter', and `Mitla' pepper (Capsicum annuum L.) transplants were set at three depths so that the soil surface was even with the top of the rootball, the cotyledon leaf, or the first true leaf. Seedlings set to the depth of cotyledon leaves or to the first true leaf lodged less than did those set to the top of the rootball. No yield differences were recorded among treatments in Massachusetts; however, total weight of red fruit was greater in treatments that lodged less in 1 of the 2 years, suggesting that lodging delayed maturity. Soil temperature in Massachusetts declined at the level of the rootball as planting depth increased.
Peter M.A. Toivonen, Jared Stoochnoff, Kevin Usher, Changwen Lu, Paul A. Wiersma, and Chunhua Zhou
The market value of the apple (Malus ×domestica Borkh.) cultivar Ambrosia is closely linked to the characteristic blush on the skin surface. For ‘Ambrosia’ orchards that produce consistently low levels of surface blush, the implementation of reflective rowcovering has improved surface coloration, but the reflected wavebands responsible for this enhanced color production have not been confirmed. This study consisted of two separate experiments: one conducted in the field to confirm reflective rowcovering efficacy and the other in a controlled environment cabinet to determine which waveband was enhancing red blush production. The red blush production in orchards with and without reflective rowcovering was then directly compared with the red blush produced on the surface of apples that were poorly colored at harvest and then exposed to visible, fluorescent, ultraviolet A (UVA), or ultraviolet B (UVB) light sources within the controlled environment chamber. Consequent analysis of the red blush color within the Commission Internationale de l’Eclairage a* and b* color space was conducted to evaluate the quality of the red blush pigment under each treatment in the field and the controlled environment chamber. The analysis revealed that the red blush that developed on apples from the reflective rowcover treatment most closely matched the red blush that developed in response to UVB exposure in the controlled environment cabinet. Further analysis of gene expression and anthocyanin contents in the ‘Ambrosia’ apples support the hypothesis that the primary driver for the characteristic red blush development, when reflective rowcovers are used, is increased exposure to UVB light.