Search Results
Abstract
The rest period and the development of cranberry flowers, Vaccinium macrocarpon Ait., cv. Stevens, were studied for 2 consecutive years. Long days were found to be necessary for the normal outgrowth of the fruit bud; no flowers were produced under short days. Increased chilling was required to produce bud break when the plants were given short days. Under favorable light conditions, 80% of the buds grew out after 600 hr below 45°F. Production of normal flowers was not ensured by satisfaction of cold requirement but also involved exposure of buds to temp above 45°F.
Gibberellic acid (GA3) caused 80% or more of the buds to break, regardless of chilling treatment, and caused faster bud break even after adequate chilling. Functionally “male-sterile” flowers with contorted anther tubes were produced occasionally from buds given adequate chilling and GA3.
Abstract
Phosphorus stress caused a general restriction of growth, pinkish tips and purplish leaves and was associated with low tissue P concn. Phosphorus concn for severe deficiency ranged from 0.034 to 0.08%, hidden hunger occurred from 0.09 to 0.11%, and sufficiency 0.12 to 0.27%. Phosphorus removed from the nutrient solutions was recovered in the plants. Soil test P at 50-70 kg/ha did not limit growth.
Abstract
Highly significant correlations were found between seed no. and berry vol in 5 cultivars of cranberry, Vaccinium macrocarpon Ait. A formula is given for the calculation of vol from longitudinal and transverse berry diam.
Abstract
Exudate was extracted from ‘East Mailing (EM) I’, ‘EM IX’ and ‘EM XXV’ roots by applying an external vacuum to the cut surface of the trunk. ‘EM IX’ exudate failed to stimulate leaf disc expansion. GA-like substances were highest in ‘EM I’ and lowest in ‘EM IX’ exudate.
Abstract
Cranberry cuttings grown in external solutions with several concentrations of Mn (0 to 1000 ppm), Fe (0 to 100 ppm) supplied as FeEDTA, and Al (0 to 150 ppm), showed tolerance to accumulations of high concentrations (8000 ppm from 1000 ppm in external solution) of Mn in the tissue and the ability to selectively exclude high level accumulation of Fe and Al from shoots. Root initiation by softwood cuttings was inhibited at high levels of Mn (275 ppm and above), Al (2.5 ppm and above) and Fe (2.5 ppm FeEDTA and above) in external solution.
Abstract
Rooted cuttings of blueberries (Vaccinium corymbosum L.) were grown in nutrient solutions containing different levels and combinations of NH4-N and NO3-N. Disappearance rate of the two forms from the nutrient solutions as determined by periodic analysis indicated that the plants absorbed the NH4-N more rapidly than NO3-N. Although both forms produced healthy plants, the plants receiving NH4-N were twice the size and dry matter yield of the NO3 plants after 15 weeks. Shoot N concentrations ranged from 0.99% to 1.29% for the N forms except where the blueberry plants had depleted the solutions of NH4-N before termination of the experiment. The N forms had a significant affect on the concentration of other plant nutrients, notably very low concentrations of Ca and Mg in roots with NH4-N and very high concentrations of Mn and Fe in roots with NO3-N plants. Expected levels of Mn and Fe and light brown roots were found with NH4-N plants.
Abstract
Treatments with (2-chloroethyl)-phosphonic acid (ethephon) in the field initially caused green berries of cranberries (Vaccinium macrocarpon Ait.) to turn pink. Untreated berries increased in redness up to commercial harvest. Preharvest ethephon applications on mature, red berries caused no change in redness, but rather a decrease in yellowness, resulting in a change in hue, which may indicate a difference in relative amounts of the various pigments. Ethephon decreased the L reading of the berries, compared to the controls. Increasing the amount of water, in which the ethephon was dispersed, from 1.87 to 3.74 kliter/ha proved beneficial for coloring berries located deep in the vines not exposed to full sunlight. Ethephon treatments did not result in more rapid breakdown of the berries during storage. Only at extremely high rates of ethephon was berry size reduced. The commerci
Abstract
Cranberry plants, Vaccinium macrocarpon Ait. ‘Stevens’ were grown in nutrient solutions with several levels of NH4-N and NO3-N alone and in combination. The nutrient solutions were sampled weekly and analyzed for concn of NO3-N and NH4-N. It was found that the plants absorbed NH4-N preferentially to NO3-N. Dry wt and number of new shoots produced were strongly favored by the NH4 form of N. Tissue N concn was low and the plants were N-deficient when the NH4-N was depleted from the nutrient solutions before termination of the experiment, and concn was high with a sustained NH4-N supply. Plants grown in NO3-N solutions were N-deficient and had tissue N concn interm ediate to those for the extreme levels of NH4-N. No NO3-N was detected in the plant tissues. Nitrate reductase activity was absent from the aboveground portions of the plants when the possible effect of microorganisms were removed. It is concluded that NH4-N is essential for cranberry growth.
Two native shrubs, Spiraea alba (meadowsweet) and Spiraea tomentosa (hardhack or steeplebush), have potential as landscape plants, but little is known about light requirements for these species. The performance of plants from four geographical seed sources of each species was evaluated in the field under six different light treatments: full sun; morning full sun; afternoon full sun; and 40%, 60%, and 80% shade. Provenance differences did exist for height, flowering, and leaf greenness. Growth, flowering, and canopy density were greater in full sun and 40% shade and least in 80% shade. Both species responded to shade with increased individual leaf area and higher specific leaf area. Relative leaf greenness decreased with shade in S. tomentosa but did not change in S. alba. Plants grown in morning or afternoon shade were shorter and smaller and had fewer inflorescences than did the full-sun plants. These species can survive in deep shade, but based on growth and appearance, they are best suited to full sun or light shade in the landscape.
Two native shrubs, meadowsweet (Spiraea alba) and steeplebush (Spiraea tomentosa), are currently grown for use in habitat restoration. Pruning could improve their form and encourage use in more formal gardens. Two seedling populations of each species were grown in the field or in containers outdoors. In Mar. 2009, plants were pruned to 3 or 15 cm or were left unpruned. By midsummer, there was no effect of pruning on plant height in field-grown plants. However, pruning did eliminate lateral growth in field plants and, therefore, improved overall form of the plants. Meadowsweet pruned to 3 cm had about half as many inflorescences as did meadowsweet pruned to 15 cm, with unpruned plants producing an intermediate number of inflorescences. Pruning container plants to 3 cm resulted in plants that were about half the height of unpruned plants, and total biomass was greatly reduced. In general, plants that were pruned had fewer inflorescences, although the total number of inflorescences in all plants was small. Pruning resulted in lower quality plant form in container plants. Species and seed sources within species responded similarly to pruning. Based on the data collected in this study, newly planted meadowsweet and steeplebush should be pruned to achieve good form in the first year. Despite the sometimes leggy growth habit in containers, these species should not be pruned before growing out in the spring, or maximum growth and good form will not be attained.