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- Author or Editor: Michael J. Burke x
Abstract
Methods were compared for controlling volunteer horseradish (Armoracia rusticana Gaertn, Mey. & Scherb.) resulting from commercial horseradish production. The most effective treatment was glyphosate [N-(phosphonomethyl) glycine] (4.5 kg/ha) applied in mid-September 6 to 8 weeks after discing. 2,4,5-T [2,4,5-trichloro-phenoxy acetic acid] was also effective, while dicamba [3,6,dichloro-o-anisic acid] and a dicamba plus glyphosate mixture provided less control. Horseradish roots can sprout from 90-cm deep and still be susceptible to a mid-September glyphosate application.
Abstract
Effects of deletion and enhancement of 280–315 nm ultra-violet (UV-B) radiation on pea (Pisum sativus L.), potato (Solanum tuberosum L.), radish (Raphanus sativus L.), and wheat (Triticum aestivum L.) plants were examined at a 3000 m elevation field site, which provided a 49% increase in midday effective (biologically weighted) UV-B radiation relative to near sea level. Wheat plants grown under Aclar or cellulose acetate film, which transmit UV-B radiation, were shorter than plants grown under Mylar film, which excludes UV-B radiation. Effective UV-B radiation levels at solar noon in the open and under the Aclar and cellulose acetate were 61, 55, and 44 mW m−2, respectively. There were no significant differences in potato, radish, and wheat dry weights attributable to UV-B radiation among the above treatments. The dry weights of all 4 species and pea and wheat plant height were not significantly decreased by a supplemental enhancement of 32 mW m−2 effective UV-B radiation from cellulose acetate filtered FS-40 sunlamps for 6 hours each day, relative to control plants that received only solar UV-B radiation. The results suggest that wheat plant height is more sensitive to deletion of UV-B radiation than the other parameters measured, and that the 4 species studied can tolerate the level of enhanced UV-B radiation used with concomitant high levels of visible radiation with no significant reduction in dry weight accumulation.
Abstract
In March of 1975, the News & Views newsletter of the American Horticultural Society offered the following anonymous tip under the heading of Cold Shower Treatment: “Here is a trick that will reduce the amount of damage caused by morning sunlight on frozen buds. Where plants have been lightly touched with frost, take a hand syringe and spray the vulnerable buds with water before sunlight strikes them.” The following spate of correspondence formed the basis of this “postal symposium.”