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Abstract
Concentrations of several elements in orchid plants (Dendrobium nobile Lindl) were determined by instrumental neutron activation analysis, a rapid and sensitive method for Na, K, Mg, Ca, Mn, Zn, Fe, Cl and Br. Among young and old leafless shoots, an increase in content of Br and a decrease of Fe and Zn were found with age.
Abstract
Radioactive (2–chloroethyl)phosphonic acid (ethephon) was applied to leaves and fruits of ‘Tiny Tim’ tomato and ‘Pioneer’ cucumber and to seedlings of ‘Yellow Crookneck’ summer squash. During the first day, slightly over 21% of the applied 14C-ethephon was converted to 14C-ethylene by the squash plants, and 10 to 15% was converted by the tomato plants. A week after treatment the rate of 14C-ethylene production decreased rapidly to less than 1% per day. Increases in rates of production of total ethylene following treatment were attributed to the decomposition of ethephon. Radioactive CO2 production was small, amounting to about 0.1% of the 14C applied.
Seven days following treatment of tomato leaves, about 15% of the 14C was translocated to developing fruits and lesser amounts to other parts of the plant. In the squash seedling, from 3 to 9% was translocated after 2 days from the site of application to other tissues. Twenty–five days after application to cucumber leaves, the fruits containted only 0.3% of the applied 14C–ethephon. In the tomato tissue the radioactivity was present as 14C–ethephon, but in the squash seedling tissue much of the radioactivity was present in a new compound.