Search Results
Abstract
A major consideration in determining the number of entries in a yield trial is the amount of time and effort involved with each plot. Commercial methods of harvesting such crops as fresh lima beans and shelled peas are not suitable for experimental plots. The present experiment was designed to evaluate the feasibility of using indices (such as shelled weight/unshelled pod weight) in estimating yield of shelled seeds for large field plots from small samples.
Abstract
Twelve common bean cultivars were utilized to obtain estimates of outcrossing at Davis in 1971 and 1972. The maximum and minimum rates of outcrossing were estimated to be 0.007 and zero. Thus, outcrossing blocks cannot be used successfully in environments like that at Davis in 1971 and 1972, and little or no isolation is needed to obtain selfed seed.
Abstract
R/r alleles in kidney bean had no effect on seed yield. It should be possible to develop dark red kidney cultivars that yield as well as light red kidney cultivars. The interaction of genotypes with locations suggests that many locations will be required to evaluate the yield of breeding lines. While years and locations had the largest interaction, genotypes did not interact with years. The evaluation of kidney bean cultivars in California should be done at as many locations as possible and sampling many years is of minor concern.
Abstract
No significant differences in bean seed yield of field grown ‘Dark Red Kidney’ beans were observed in plants treated at the green or white bud stage or in full bloom with (2-chloroethyl)phosphonic acid (ethephon) at concentrations ranging from 300 to 2400 ppm. Plants treated with 300 and 600 ppm ethephon produced and retained more flowers and matured 7-10 days earlier than untreated plants. Treatment with 1200 and 2400 ppm reduced flower production and delayed pod maturity.
Abstract
(2-Chloroethyl)phosphonic acid (ethephon) at 250 ppm controlled bud and flower abscission but not young pod abscission of ‘Dark Red Kidney’ bean. Leaf abscission was unaffected, intemodal elongation was temporarily retarded, and the number of seeds but not the number of pods produced exceeded that of untreated plants but the difference in seed production was not significant. Treatment with 500 ppm ethephon resulted in a pattern of abscission similar to that of untreated plants. At higher concentrations (1000 and 2000 ppm) abscission of reproductive structures and of leaves was promoted. Seed production, seed maturity, and seed size were reduced. New leaves were pendant and were smaller than those of untreated plants.
Abstract
The high degree of self-pollination in Phaseolus vulgaris cv. Light Red Kidney is attributed to the fact that flowers are autogamous and to the following characteristics: proximity of anthers and stigma at time of maturity; simultaneous maturation of pollen and receptivity of the stigamtic surface; and, possibly, to the position and orientation of stylar hairs. A morphologically variant pistil, in which the stigma is receptive when the flower is fully open, develops in a few flowers. Such flowers may be cross-pollinated by bees or other insects. The sugary secretion of stigmatic epidermal cells appears to enhance pollen retention and may provide an environment conducive to pollen germination.
Abstract
Twenty-seven pure lines of lima bean collected over a wide geographical area were evaluated for response to photoperiod. The genotypes were grown in 6 chambers with photoperiods of 9, 11, 12.5, 14, 15.5 and 17.5 hours. Response to flowering among the genotypes was characterized by a polynomial regression model. Sixteen of the 27 genotypes were characterized as daylength neutral and 8 reacted sharply to daylength. Three genotypes reacted in a quantitative manner. Linear, quadratic, and cubic responses were observed.
Abstract
Lima bean, Phaseolus lunatus cv. Early Thorogreen, is primarily self-pollinated. Morphological characteristics of reproductive structures which facilitate self-pollination include the stage of floral development at the time of anther dehiscence and the relative positions of anthers and stigma within the keel at the time of pollen shedding. Coincidental maturation of pollen and receptivity of the stigmatic surface also enhance the capacity for self-pollination. The varying degrees of cross-pollination frequently reported may be facilitated by extrusion of the stigma from the keel, which occurs in connection with insect visitation at an thesis, and also by the prolonged period of stigma receptivity, which extends from the white bud stage through anthesis.