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  • Author or Editor: S.D. Davis x
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Abstract

The effect of time of harvest prior to complete field drying of 2 cultivars of dry bean (Phaseolus vulgaris L.) was analyzed relative to the quality of the processed product produced. Early harvest did not significantly affect yield (at 10% raw product moisture); however, it did have a significant effect on the quality of the processed product. Typically the processed dark red kidney and pinto beans were more intensely pigmented with later harvest dates, were firmer, and had fewer split seeds. The respiratory rate of the raw product was highly correlated (r = 0.993) with the raw product moisture level. Only small differences were found in the degree of pigmentation of the processed product when comparing the spring with the fall crop of pinto beans. The fall crop of pinto beans had a substantially lower incidence of split beans in the canned product.

Open Access

Seeds of Aquilegia chrysantha Gray were germinated under a variety of temperature regimes. Germination was nearly 90% under a day/night temperature regime of 25/20C but was reduced to 40% or less under constant 25C or a 25/10C day/night temperature regime. At day temperatures between 25 and 29C (night temperature = 20C), germination percentage dropped gradually to about 60% with increasing temperature. Above a day temperature of 29C, germination declined dramatically such that no germination occurred at 31C. Neither kinetin (1-10 mg/liter) nor ethephon (1-30 mg/liter) were able to reverse the inhibitory effects of a 33C day temperature. Our results indicate that seed germination of A. chrysantha is quite sensitive to temperature and that germination percentages of 75% or greater can be obtained under a 25-27C day/20C night temperature regime.

Free access

Nodal explants were taken from both vegetative and flowering shoots of `German Red' carnation and placed on MS medium supplemented with 2.0 mg/L benzylaminopurine (BAP) and 0.5 mg/L naphthaleneacetic acid. The explants taken from flowering shoots invariably produced flower buds in vitro and were of no value for micropropagation. With the vegetative explants, microshoots were observed after about 15 days. These were subcultured and the effect of cytokinins (kinetin, BAP, thidiazuron [TDZ]) on subsequent shoot production was evaluated. The cytokinins increased the number of shoots formed with TDZ and kinetin being the most and least effective, respectively. Shoots produced in vitro were rooted with 100% success in vitro or ex vitro. About 98% of the plants rooted in vitro or ex vitro survived transfer to the greenhouse and were successfully transplanted outdoors. In summary, starting from explants, well-branched flowering plants can be obtained in as little as 5-6 months. These results suggest that in vitro mass propagation of `German Red' carnation is feasible.

Free access

Abstract

Orchard floor management has been found to affect the microclimate both seasonally (4) and on radiation frost nights (1, 3). Altering orchard climates by floor management could potentially modify bud hardiness and development due to radiative and convective heat transfer from the soil to the bud. However, information is unavailable to support this contention. This study was designed to investigate peach bud development and hardiness under two different orchard floor management systems.

Open Access

Abstract

Field-grown spinach (Spinacea oleraceae L.) sprayed with ethylenebisdi-thiocarbamate fungicides was washed to reduce the carbamate residue ethylenethiourea (ETU) in canned spinach. The spinach was washed with water, water + sodium hypochlorite, detergents, or detergents + sodium hypochlorite. After washing, the spinach was canned and evaluated for ETU residue and quality. ETU residue was 63 ppm in non-washed carbamate field-treated spinach, 6.9 ppm in water-washed samples, and only 0.1 ppm in washing treatments containing detergents. Washing treatments had little effect on the quality of the canned spinach; only titratable acidity was reduced significantly.

Open Access

Seeds of Aquilegia chrysantha Gray were germinated under a variety of temperature regimes. Germination was nearly 90% under a day/night cycle of 25/20C, but was reduced to ≤ 40% under constant 25C or a 25/10C day/night cycle. With days between 25 and 29C (night = 20C), germination percentage dropped gradually to ≈ 60% with increasing temperature. With days >29C, germination declined dramatically such that no germination occurred at 31C. Neither kinetin (4.6 to 46 μm) nor ethephon (6.9 to 207 μm) was able to reverse the inhibitory effects of 33C days. Our results indicate that germination of A. chrysantha seed is sensitive to temperature and that germination ≈ 75% can be obtained under a 25 to 27C day/20C night regime. Chemical names used: 2-chloroethylphosphonic acid (ethephon); 6-furfurylaminopurine (kinetin).

Free access

Abstract

Ammonia volatilization from urea-N applied to Kentucky bluegrass ( Poa pratensis L. ‘Bensun’) was investigated using a chamber trapping procedure. Urea was spray-applied in a 0.2 cm depth at N of 5 g·m−2 with and without additional irrigation of 0.5, 1, 2, or 4 cm. Losses up to 36% of the applied N occurred when urea was applied without irrigation. Supplemental irrigation of as little as 1.0 cm reduced the loss to 3-8%, while a 4.0-cm irrigation further reduced losses to about 1%. Of the ammonia volatilized, most was lost in the first 24 hr. Maximum N loss was associated with the thatch layer, a zone having high urease activity.

Open Access

Factors affecting the greenhouse propagation of firebush (Hamelia patens) by leafy stem cuttings during winter were studied. Without bottom heat (BH), mid-day rooting medium temperature was 22 ± 3 C. About half of the auxin-treated cuttings without BH rooted. Maintaining the rooting medium at 29-39 C increased rooting for auxin-treated cuttings to 96-100% and increased root length and visual rating scores several-fold. Rooting percentage, root length, and visual ratings were consistently high in perlite and low in peat. Stem-tip cuttings and sub-terminal stem segment cuttings with basal stem diameters of 3-5 mm rooted slightly better than stem segment cuttings with basal diameters of 6-8 mm. Stem-tip cuttings not treated with auxin but with BH had rooting percentages of 81-86%. Treatment of stem-tip cuttings with auxin generally yielded 90% rooting or above. Despite this, plants grown from auxin-treated cuttings were indistinguishable from plants grown from non-treated cuttings 2 months after the rooting period. Of the variables studied, BH had the most dramatic effect on rooting of firebush cuttings during winter months.

Free access

Fairy ring is a common and troublesome disease of turfgrasses maintained on golf course putting greens. Type-I fairy ring is especially destructive due to the development of hydrophobic conditions in the thatch and root zone, thus contributing to turfgrass injury and loss. The objective of this 2-year field study was to evaluate the application and novel delivery method of two fungicides and a soil surfactant for curative control of type-I fairy ring in a 20-year-old creeping bentgrass [Agrostis palustris (synonym A. stolonifera)] putting green. In both years, all treatments were applied twice on a 28-day interval. In 1998, flutolanil and azoxystrobin fungicides were applied alone and in combination with Primer soil surfactant by a conventional topical spray method, and fungicides without Primer applied via high-pressure injection (HPI). Acceptable type-I fairy ring control was observed in plots treated with flutolanil plus Primer, HPI flutolanil, azoxystrobin alone, azoxystrobin plus Primer, or HPI azoxystrobin. In 1999, treatments were HPI flutolanil, HPI flutolanil plus Primer, HPI azoxystrobin, HPI water only, and aeration only. Acceptable type-I fairy ring control was observed in plots treated with HPI flutolanil plus Primer or HPI azoxystrobin. HPI of fungicides alone or in combination with a soil surfactant may be a viable option for alleviating type-I fairy ring symptoms on golf course putting greens.

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Abstract

The depletion of N applied to a moderately N-deficient Kentucky bluegrass (Poa pratensis L.) turf was measured using a soil sampling procedure. Nitrogen as either Ca(NO3)2 or (NH4)2SO4 was applied in solution at 5 g N/m2 and washed into the thatch and soil with an additional 0.3 cm of water. Both N forms were located primarily in the thatch and upper 1 cm of soil. The NO 3 was present in the soil solution, while the NH 4 + was mainly exchangeable (86%). The concentrations of NO 3 and NH 4 + in the soil solution were 452 and 56 μg N/ml, respectively, in the upper 1 cm of soil. Depletion of both NO 3 and NH 4 + from the turf was very rapid, with 70% to 80% of the applied N disappearing during the first 24 hr. Essentially all of the applied N was depleted by 48 hr. Results using (l5NH4)2SO4 indicate that ≈75% of the NH 4 + depletion is attributable to absorption by the turf. Similar results were obtained following fertilization of perennial ryegrass (Lolium perenne L.), tall fescue (Festuca arundinaceae Schreb.), and creeping bentgrass (Agrostis palustris Huds.).

Open Access