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- Author or Editor: Dean E. Knavel x
- Journal of the American Society for Horticultural Science x
Short-internode (SI) muskmelon (Cucumis melo L.) genotypes Ky-P7 (si-1 gene for SI) and Main Dwarf (si-3 gene for SI) were compared with the normal-internode (NI) cultivar Mainstream at various plant spacings or planting densities over 3 years. SI `Honey Bush' (si-1 gene for SI) and `Bush Star' (si-1 gene for SI) were included in 2 years. At double the population, SI plants (si gene type) produced ≈35% fewer fruit than `Mainstream' plants grown at one-half the population density. Spacing generally had no effect on average fruit weight, but increasing plant density of SI genotypes decreased the number of fruit per plant. Generally, doubling the density reduced leaf area and total plant dry weight, but had minimal effect on the amount of shaded leaf area. Ky-P7, `Honey Bush', and `Bush Star' plants had more leaf shading than `Mainstream' and Main Dwarf plants.
Abstract
Tomato transplants were grown in soil-substitutes of peat moss-Turface and peat moss-perlite. Nutrients were added to the mixtures in factorial combinations by varying the levels of N, P, K, and dolomite. Plants grown in peat-Turface were taller and heavier than those grown in peat-per-lite. In either medium, plants grown with the high level (10 lb./yd3) of dolomite were taller than the plants grown with the low level (5 lb./yd3) of dolomite. Plants grown in peat-Turface contained more N, K, and Ca than did the plants grown in peat perlite. Plants grown in peat-perlite contained more P than plants grown in peat-Turface. The growing medium had no influence on Mg content of plant tops. The highest and earliest yielding plants were those grown in peat-Turface. The 10-lb. rate of dolomite was essential for high early yields in peat-Turface, but the additional increment of dolomite had no effect on early yields for plants grown in peat-perlite. Interactions existed between media and nutrient levels for growth, nutrient uptake, and early yields.
Abstract
Plants of the ‘Allgold’ sweetpotato were grown for 60 days with 3 levels of N and K in a peat-perlite medium to determine the influence of these nutrients on plant development early in the stage of root enlargement. Dry vine and fresh root weights were highly correlated, with high N and medium K resulting in the largest vine and root weights. The numbers of roots were influenced more by K than by N, but the size of roots was influenced more by N than by K. The addition of N without K was responsible for long roots, and the addition of K reduced root length at all N levels.
Abstract
Tomato transplants were grown at different fertility levels in mixtures of peat moss-turface and peat moss-perlite. Growth retardants, Cycocel and Alar, were applied to young plants when they attained the 3 true leaf stage. Cycocel was more effective in reducing growth than was Alar, regardless of the fertility level. Alar was effective in reducing growth of plants in both growing media. Cycocel treated plants were more drought resistant than were the Alar-treated plants. Plants treated with either Cycocel or Alar were more drought resistant and darker green in color than control plants. Chlorophyll content was measured on Alar-treated and control plants. Alar-treated plants contained more chlorophyll, and their leaves had more palisade cells than plants of the control.
Cycocel-treated plants contained more N, P, Ca, and Mg, but less K than the control plants. Alar-treated plants contained more N and P than did the control plants and more K than control plants when grown in peat moss-perlite. In only 1 of 3 experiments did Alar-treated plants contain less Ca than control plants, but the chemical had no effect on the Mg content of the plants’ stems and leaves.
A single spray of Alar at 2500 ppm increased yields of early fruits in 1 of 3 experiments. In this experiment, both early fruit number and weight were increased, but the fruits were smaller than those from Cycocel treated and control plants. Growth retardants and fertility rates used in these studies had no effect on total yields, although interactions existed between growth retardants and nutrient rates in their effect on nutrient uptake.
Abstract
Pepper transplants grown with 240 or 300g N/m3 were the tallest, and subsequently the highest yielding when grown to maturity with 155 kg/ha soil N. At 100, 210 or 265 kg N/ha, transplants grown for 6 weeks with N level of 300g/m3 were the highest yielding. The optimum level of leaf N for 6 week-old transplants is approximately 3.7% dry wt.
Abstract
A short-internode (SI) muskmelon line was compared with a normal-internode (NI) cultivar in four seasons for growth and yield differences. Vines of both plant types were divided into leaves, petioles, and stems at 58, 72, and 86 days of age. Leaf dry weight and leaf area were generally the same for both plant types early in growth. NI plants had greater leaf and stem dry weights and leaf area at 72 days; however, only stem dry weights differed at 86 days. The leaf : stem and leaf area : leaf dry weight ratios were always greater for SI than for NI plants, but NI plants produced twice the number and weight of fruit as SI plants. Mean fruit weight for SI plants was slightly smaller than fruits of NI plants. Doubling the population of SI plants by either spacing plants 0.45 m within the row or planting two per hill reduced fruit number and total fruit weight per plant. Highest total fruit weight was obtained by spacing SI plants 0.90 m apart in a triangular fashion within double rows spaced 0.30 m apart on a mulch row. SI plants contained less K and more Mg in leaves and less N and Ca but more K in stems than NI plants. Both plant types had similar Mg levels in stems at each sampling. There were significant year effects and internode type × year interactions for fruit number, fruit weight, and elemental concentrations.
Cracking and scarring of pepper (Capsicum annuum L.) fruit are under genetic control in families having the cultivar Serrano Chili as the P1 parent. Fruit of `Serrano Chili' exhibited slight cuticle cracking or scarring, with no wall cracking, for an average rating of 2.2. Fruit cracking ratings of the P2 parents (`Anaheim Chili', `Red Cherry Small', and `Keystone Resistant Giant') were 1.0, 1.0, and 1.8, respectively, whereas ratings for F, (`Serrano Chili' × `Anaheim Chili'), F1(`Serrano Chili' × `Red Cherry Small'), and F, (`Serrano Chili' × `Keystone Resistant Giant') were 3.5, 2.8, and 3.5, respectively—an indication of overdominance. Cracking ratings in F2 and BCP2 populations were very similar and shifted toward the mean of the P2 parent within each family, while ratings in the BCP1 populations were similar to the F1 mean. Estimates of gene effects for cracking were mostly dominant, with some additive effects in `Serrano Chili' × `Anaheim Chili' and `Serrano Chili' × `Keystone Resistant Giant' families, and additive × additive epistasis in `Serrano Chili' `Keystone Resistant Giant'. Plants selected from segregating generations for either high and low scarring or high and low cracking produced progeny the following year with lower ratings than their respective mother's rating the previous year. Since cracking and scarring were significantly correlated with length, diameter, and length: diameter ratio of fruit in only a few generations and in segregating progeny of selected plants, fruit shape has minimal relationship to cracking and scarring.
Abstract
Muskmelon fruits were either dipped in or injected with 2-(4-chlorophenylthio-) triethylamine hydrochloride (CPTA) at half- and full-slip maturities prior to storage at various temperatures. Concentrations of 500, 1000, and 5000 ppm caused fruits to have more pink color and a higher ratio of red to yellow color than did those untreated. The greatest response to CPTA was in half-slip fruits. We believe that the pink color is associated with lycopene accumulation.
Abstract
Flowering was induced in the sweetpotato cultivar, ‘Allgold’, by growing plants with a N level of 280 mg/1 in a peat moss-perlite medium. Plants grown with other factorial combinations of N and K failed to flower. Analyses of plants from treatment N2K0 prior to and after flowering showed these plants to contain the highest percentage of N, the lowest total sugars, and the lowest starch in both tops and roots as compared with plants that failed to flower.
Abstract
Tomato seedlings of a selection from the plant introduction PI 244956 and the cultivar, ‘Floralou’, were grown for 5 weeks following cotyledon expansion under 2 different temperatures regimes, i.e., 42 to 56°F, and 68 to 80° and subsequently grown in the greenhouse at 68 to 80°. Plants of the PI selection grown at the 42 to 56° range as seedling bore more deformed fruits on the first and second clusters than those grown at 68 to 80°. The PI plants produced more deformed fruits in both temperature regimes than did ‘Floralou’ plants. Most fruits from ‘Floralou’ plants appeared normal regardless of seedling temperature. Flower buds from the first and second clusters of both warm and cold-treated plants were studied histologically. Buds with abnormal ovary development exhibited breakdown of tissue at the stylar base. Ovaries of such buds developed into abnormal fruits that were not marketable.