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Abstract
Color and firmness of Cortland apples were improved and storage scald greatly reduced by spraying trees at certain times during the 1964 growing season with N-dimethyl amino succinamic acid (also known as B-995 and more recently as Alar 50°) at the rate of 5,000 ppm. Sprays in early and mid-summer reduced fruit size, however, and late season sprays were not as effective in preventing scald.
Abstract
The level of endogenous root-promoting and inhibiting substances in 3 clones of rhododendron were compared at seasonal intervals in order to study the clonal and seasonal variation in rooting response of cuttings. The highest levels of 4 rooting cofactors in any season were found in both stem and leaf tissue of Rhododendron cv. ‘Cunningham’s White’ followed by ‘English Roseum’. The clone ‘Dr. H. C. Dresselhuys’ contained the least amount of the rooting cofactors. An inhibitor was often found in all clones, but it appeared less responsible for clonal differences in rooting response than variation in levels of the rooting cofactors. Rooting cofactor levels contained in the stem tissue of ‘Cunningham’s White’ were not less than those in the leaf tissue. In contrast, cofactor levels present in the stem tissue of ‘English Roseum’ and ‘Dr. H. C. Dresselhuys’ were less than those in the leaf tissue. The promoting activity of rooting cofactors in all tissues of the clones increased in September and decreased again in November to the level of July extract. The inhibitor found in the July extracts disappeared in September and reappeared in November.
Rooting of cuttings of ‘Dr. H. C. Dresselhuys’ was significantly improved by grafting a leaf and bud scion of ‘Cunningham’s White’. On the other hand, scions of ‘Dr. H. C. Dresselhuys’ resulted in decreased rooting of cuttings of ‘Cunningham’s White‘. Rooting capacity of ‘English Roseum’ was less affected by a leaf and bud scion of other clones of Rhododendron.
Abstract
One spray application of 5000 ppm succinic acid 2, 2-dimethyl hydrazide (Alar) on July 18 or August 22, or 2 spray applications, one on July 18 and another on August 22, significantly retarded new shoot elongation of ‘Collins’ and ‘Bluecrop’ highbush blueberries. The number of flower buds per unit length of new growth was increased. Blossom opening and ripening of the berries was delayed, but fruit size was not appreciably affected. All responses of the 2 cultivars to treatments were more pronounced when they received the 2 spray applications.