Search Results
You are looking at 1 - 10 of 76 items for
- Author or Editor: Mikal E. Saltveit x
The cessation of protoplasmic streaming is one of the first observable effects of chilling in sensitive plant tissue. If the lack of protoplasmic streaming contributes to the development of chilling injury, then impeding protoplasmic streaming at the chilling threshold temperature should induce chilling injury symptoms in tissue that would normally not exhibit symptoms at that temperature. A centrifuge was constructed to subject entire germinating cucumber (Cucumis sativus L., cv. Poinsett 76) seeds to centrifugal forces of up to 20 xg at 2.5, 10 and 12.5°C. Subjecting cucumber seeds with 5-mm-long radicles to high centrifugal forces (18 xg) at a marginal chilling temperature of 10°C for up to 3 days had no significant effect on subsequent radicle elongation of the entire population. In one experiment, spun seedlings were 7.4 ± 0.52 cm long, while the controls were 6.1 ± 4.3 cm long after 48 hr at 25°C. When analyzed by individual seed, the spinning treatments had no effect on high-vigor seedlings, while an 18 xg treatment significantly improved subsequent radicle elongation of low vigor seedlings. The effect of increased centrifugal forces on the respiration, metabolism and chilling sensitivity of cucumber seedlings will be discussed.
Abstract
Firmness of ‘Starkrimson Delicious’ and ‘Golden Delicious’ apples was not significantly different when tested at 0° and 20°C after 26 weeks of storage at 0°. The volume of bruises produced in these cultivars by mechanical impact injury increased with increasing temperature (0°, 10°, 20°, and 30°) when injured, and with increasing holding temperature (0°, 10°, 20°, and 30°) during bruise development.
Abstract
A survey was conducted to measure the variability among gas chromatographic analyses of ethylene and the variability among the ethylene gas standards used in 22 laboratories in the United States and Canada. The linearity of gas chromatographic responses to injections of 10.0, 1.0, and 0.1 μl/l ethylene in air mixtures had an average coefficient of linear determination (R 2) of 0.9984, with a SD among the R 2 values of only 0.33%. The ethylene concentrations calculated for the laboratory standards varied from 11.3% higher to 21.7% lower than the value assumed by the participant; with an average variance of about 6% lower.
Abstract
Gas samples are often extracted from horticultural produce for analysis of ethylene, carbon dioxide, oxygen, and other gases by gas chromatography. This paper outlines procedures for extracting gas samples either by using a syringe needle to puncture a cavity within the fruit or vegetable or by subjecting the fruit or vegetable to a partial vacuum.
Abstract
A device is described which maintains a set temperature ± 0.8°C from 5 to 30° above ambient in an inexpensive controlled-temperature chamber. Present construction cost is about $65. Ten chambers have performed satisfactorily during the past 3 years in research projects on chilling injury, seed germination, seeding growth, tissue culture growth, fruit storage, tree storage, and winter dormancy.
Abstract
A 39-week production schedule is described in which container-grown apple trees (Malus domestica Borkh. cvs. Red Chief Delicious, Sundale Spur Golden Delicious, and Paulared) are cycled through 4 weeks of cold acclimation, 7 weeks of chilling, 5 weeks of growth before flowering, 21 weeks of fruit growth and maturation, and 2 weeks growth after fruit harvest.
Abstract
A simple, inexpensive method is presented to prepare an effective chemical scrubber which oxidizes volatile organic contaminants in gases. The scrubber is made by mixing 100 ml of 1 M KMnC4 per liter of dust-free Perlite in a large clear plastic bag.
Abstract
Prolonged physiological studies using gas mixtures containing μl/liter levels of a specific gas component (e.g. ethylene or propylene) require a flowthrough system to ensure that the plant or plant part under study is exposed to a relatively constant gas concn. This prevents tissue incorporations and/or emanations (e.g. biosynthesis of ethylene or CO2) from altering the physiological effective gas concn (1).
Abstract
Standing freshly harvested 21-cm asparagus spears (Asparagus officinalis L.) in 50 ml of 1 mg·liter−1 to 10 g·liter−1 aqueous glyphosate solutions significantly decreased toughening and the amount of fiber and lignin in spears stored at 2.5°C for 10 or 20 days. The effect increased with storage time and concentration, but decreased with distance from the cut end. Depending on the time of harvest and length of storage, 1 g·liter−1 glyphosate increased the usable portion of the spear from 40% to 60%. Chemical name used: N-(phosphonomethyl)glycine (glyphosate).