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Callus cultures of 7 potato cultivars were initiated from tuber tissue and maintained on Gelrite-solidified media with l-20pM picloram as the only PGR. Ten PM picloram was the optimal concentration for callus induction. By 4-6 weeks after explanting, there was suthcient callus produced for subculture to maintenance media which contained l-20pM picloram as the only PGR. When grown in the dark at 25'C, subcultured callus typically increased IO-fold in wet weight in 4-5 weeks. The callus produced was friable and a light grey to cream color. Callus cultures were used to establish cell suspension cultures. Callus and cell suspension cultures have been maintained for over 2 years on the picloram containing media.

Bark samples were removed from 1‐year‐old stems of Italian prune trees at intervals throughout the growing season (June–August). Glucose, fructose, sucrose, traces of raffinose and a polyol were detected in ethanolic extracts of the bark. The polyol was isolated and shown to be d‐glucitol. The use of insoluble polyvinylpyrrolidone proved to be the best method for decolorizing bark extracts prior to quantitative analysis of ethanol‐soluble carbohydrates by paper chromato‐graphic methods. Glucitol was the major carbohydrate in the bark throughout the season. Sucrose was the major sugar, decreasing gradually as the season advanced. Fructose and glucose were found in lesser and about equal amounts. The amount of glucitol, glucose and fructose was high in June, decreased to a minimum in mid‐July, increased sharply in late July and early August and decreased later in the season.