Succinic Acid-2,2-dimethylhydrazide Research Articles

Effects of Succinic Acid-2,2-Dimethylhydrazide on the Color, Firmness, and Uniformity of Processing Peaches1

Abstract Application of succinic acid,2,2-dimethylhydrazide (SADH) to peaches at the onset of pit hardening advanced maturity and caused more rapid softening during ripening on the tree. Flesh color at a given firmness was improved by SADH over a wide maturity range. The color difference was maintained after processing; canned halves from SADH trees had a higher USDA color grade than control fruit of comparable firmness. Uniformity of firmness and flesh color among fruit within trees varied with crop maturity, but uniformity was not substantially affected by SADH. However, enhancement of flesh color by SADH improved the quality of fruit obtained by once-over harvest and tended to concentrate the grade distribution of canned halves in USDA color grades A and B.

Long-Term Growth-Retardant Effects of (+)-Limonene Derivatives on Citrus1

Abstract The growth-retardant effects of succinic acid-2,2-dimethylhydrazide (SADH), 1 n-alkyl and 2 benzyl quaternary ammonium derivatives of (+)-limonene were determined after application of 2 foliar sprays on young grapefruit (Citrus paradisi Macf.) seedlings which were subsequently pruned to remove all growth. Only the n-alkyl derivative, l-p-menthanol-2-dimethylamino heptyl bromide (Q-58), caused dwarfing and marked internode shortening of new growth on all treated plants 71 days after the second foliar spray. A similar experiment on a larger scale using Q-58 and 2 new n-alkyl derivatives of (+)-limonene produced retardation of new growth for 136 days after the second foliar spray. However, true dwarfing was only apparent in a few of the treated seedlings. These results indicate that n-alkyl quaternary ammonium derivatives of (+)-limonene are stored in the roots or lower stems of grapefruit seedlings and can continue to retard terminal shoot development for about 4 months after treatment.

Factors Influencing the Level of Succinic Acid-2,2-Dimethylhydrazide Residues in Apple Fruits1

Abstract The level of succinic acid-2,2-dimethylhydrazide (SADH) in ‘Spartan’ apples treated according to commercial practice with Alar-854 was higher in fruits treated in July or August than in fruits sprayed in late May, when measured at harvest and after storage. SADH was very persistent in apples stored at 0°C. Fruit from trees treated at comparable times in 2 seasons did not have higher SADH residues than those treated only in the second season, but fruit size reduction was more severe following some treatments applied in both years. Adding the wetting agent Tween 20 to the spray solutions increased uptake of SADH in most experiments as evidenced by increased fruit residue levels.

The Effect of Succinic Acid-2,2-Dimethylhydrazide (SADH) and Other Growth Regulating Chemicals on Peach Fruit Maturation1

Abstract Succinic-acid-2,2-dimethylhydrazide (SADH) applications hastened the maturity of peach fruit when trees were sprayed during fruit growth stages I, II and III. The greatest hastening of fruit maturity was evident with high concn of SADH (4000 and 8000 ppm) applied between the mid-point and the end of stage I. The optimum concn during stage II for hastening maturity was 1000 ppm. Applications of SADH in stage III hastened fruit color development but had little effect on other indices of maturation. Five of 6 SADH analogues were effective in hastening fruit maturation when applied in the first half of stage II. The growth retardants Amo 1618 and £CC did not hasten peach fruit maturation.

Modification of Succinic Acid-2,2-Dimethylhydrazide Growth Inhibition of Bean Plants by Surfactants1

Abstract The effects of surfactants on spray retention and penetration of succinic acid-2,2-dimethylhydrazide (SADH) were determined by following growth inhibition of the first and second internode following SADH treatment of the primary leaves of an indeterminant bean (Phaseolus vulgaris L. cv. Blue Lake) plant. Surfactants (0.1%) decreased the retention of the SADH treating solution by the primary leaves thus reducing the potential dose delivered. The initial rate of SADH penetration was increased with surfactants, but the total amount penetrating was not significantly altered. Internode elongation of the ‘Blue Lake’ bean was enhanced by surfactants per se. Surfactant enhanced penetration of SADH resulted in increased inhibition of internode extension only when the absorption period was limited to 4 hr or less.

EFFECTS OF GROWTH REGULATORS AND MULCHING ON TOMATO YIELDS

The use of clear polyethylene mulch greatly increased the total yield of transplanted New Yorker tomatoes. The growth retardant succinic acid 2,2-dimethylhydrazide (SADH) applied pretransplant at the three- to four-true leaf stage retarded earliness, concentrated ripening, and increased yields slightly. Another growth retardant, (2-chloroethyl) trimethylammonium chloride (chlormequat), reduced the size of the plants appreciably, increased earliness slightly, but significantly reduced total yields. Concentrated ripening of fruit was obtained 6–9 days after (2-chloroethyl) phosphonic acid (ethephon) was sprayed on tomato plants. The high concentration of 4000 ppm of this chemical reduced total yields and size of fruit appreciably. At 1000 ppm, ethephon produced an initial peak of fruit ripening but since plants were not destroyed, they produced another peak of ripe fruit later in the season.

Relationship between Carbohydrate Level and Floral Initiation in Broccoli1

Abstract Floral induction of broccoli (Brassica oleracea italica) ‘Waltham 29’ at low temp (5°C) was associated with increasing levels of starch and sugar in the shoot tip. This same relationship was found in experiments concerning plant age, duration of cold treatment, leaf removal before and during cold treatment, and treatment with succinic acid 2,2-dimethylhydrazide (SADH) or gibberellic acid (GA3). Greenhouse experiments with plants grown continuously at 16-21°C or 21-27°C indicated that high carbohydrate levels are not necessarily associated with flowering. Flowering was delayed at the higher temp with little difference in carbohydrate level.

Induction of Spur and Flower Bud Formation in Young Apple Trees with Chemical Growth Retardants1

Abstract The growth retardants 2-chloroethylphosphonic acid (ethephon) and succinic acid-2-2-dimethylhydrazide (SADH) increase flower initiation in young apple trees. At comparable rates, ethephon is more effective than SADH. High rates of ethephon cause flower and fruit abscission. When ethephon was combined with SADH and applied 4 to 5 weeks after bloom, satisfactory promotion of flower bud formation was obtained with lower rates of each chemical with a min of undesirable side effects.

Synergism and Antagonism of GA and Growth Inhibitors on Growth and Sex Expression in Cucumber1

Abstract The effects of gibberellic acid (GA3), 1,2-dihydropyradizine 3,6-dione (maleic hydrazide), succinic acid-2,2-dim ethylhydrazide (SADH), (2-chloroethyl)phosphonic acid (ethephon) and their combinations on the growth and sex expression of the monoecious cucumber ‘SMR-58’ were studied. Maleic hydrazide (MH), SADH, and ethephon inhibited growth and induced femaleness when applied to foliage at concn of 500 ppm, 2000 ppm, and 100 ppm, respectively. Foliar sprays of 1500 ppm GA3 stimulated growth and increased maleness. The effect of GA was generally enhanced in combination with either MH, SADH, or ethephon. Combination of SADH and ethephon resulted in plants that were as short as those treated with SADH alone and as female as those treated w ith ethephon alone. Ethephon-SADH combination reduced plant size to the same extent as SADH alone and coned maturity.

Interaction of Harvest Maturity, Cold Storage, and Two Growth Regulators on Ripening of ‘Bartlett’ Pears1

Abstract Ripening of ‘Bartlett’ pears at 20°C was assessed in samples harvested weekly beginning 4 weeks prior to commercial harvest maturity. Ripening was promoted by delaying harvest, by 1- and 2-week periods of storage at 4.4°C, or both. Early summer treatments with 750 and 7500 ppm succinic acid-2,2-dimethylhydrazide (SADH) delayed ripening but this effect was counteracted by both delayed harvest and postharvest storage at 4.4°C. It is concluded that SADH delays ripening by influencing an endogenous mechanism for controlling ripening in pears.

Influence of Succinic Acid-2,2-Dimethylhydrazide and Ethylene on Respiration and Ethylene Production by Developing ‘Bartlett’ Pear Fruits1

Abstract Ethylene-induced endogenous ethylene production was substantial in immature pear fruits, attaining a max rate in samples harvested 60 days after full bloom and declining thereafter. Ethylene production was not dependent on the occurrence of a respiratory climacteric nor related to the rate of respiration. Field applications of succinic acid-2,2-dimethylhydrazide (SADH) suppressed both ethylene production and fruit growth.

A Further Report on Blossom Delay of Tung Trees with Succinic Acid 2,2-Dimethylhydrazide in Spray Oil1

Abstract Inhibition of flower bud development increased with the concn of naphthenic or paraffinic oil. In some cases, additions of 1 or 2% succinic acid 2,2-dimethylhydrazide (SADH) in oil sprays reduced bud injury and resulted in more flowering terminals and fruit set than oil sprays alone. A January 1969 spray of 50% naphthenic oil with 1% SADH appeared to delay bud activity and prevent freeze injury to the flower buds in early February. Trees that were sprayed with 50% naphthenic oil and 1% SADH on February 18, 1971, withstood a freeze on March 5 and produced a partial fruit crop.

Effect of Growth Regulators on Citrus Seedling Cold Hardiness1

Abstract Citrus seedlings sprayed with chemicals which influence the cold hardiness of other plants were hardened in controlled conditions. Maleic hydrazide (MH-30) increased cold hardiness; however, growth retardants (2-chloroethyl)trimethylammoniumchloride (chlormequat) and succinic acid-2,2-dimethylhydrazide (SADH), and growth inhibitor abscisic acid (ABA) did not. ABA at high concns decreased cold hardiness as did gibberellic acid (GA3). Benzyladenine (BA), kinetin (KN), decenylsuccinic acid (DSA), and (2-chloroethyl)phosphonic acid (ethephon) had little or no effect on cold hardiness. These results are consistent with tests on citrus conducted under field conditions.

Effects of Succinic Acid-2,2-dimethylhydrazide and Photoperiod-Temperature Manipulation on Flowering and Vegetative Bypassing in Azalea cvs. Red Wing and Alaska1

Abstract Combinations of temp, photoperiod, and succinic acid-2,2-dimethylhydrazide (SADH) treatments were applied to plants of azalea cvs. Red Wing and Alaska during the flower bud development period. Plant quality as indicated by terminal and lateral flower bud development and lack of lateral vegetative growth was generally enhanced by SADH treatment and a 9-hr photoperiod (SD) at 65°F min temp. Quality of ‘Red Wing’ plants was less affected by deviation from this environment than those of ‘Alaska’. Flowering of plants not refrigerated at 45-50°F was hastened by 18-hr photoperiods at 65°F following 4 or 6 weeks of 65°F-SD. Exposure to 50°F min temp during early bud development brought about changes in morphology of ‘Red Wing’ flowers.

Effect of Combinations of Growth Regulators on Maturity and Quality of ‘Tydeman's Red’ Apples1

Abstract Combination sprays of the growth regulators succinic acid-2-2-dimethylhydrazide (SADH), (2-chloroethyl)phosphonic acid (ethephon), and 2-(2,4,5-trichlorophenoxy)propionic acid (fenoprop) or naphthaleneacetic acid (NAA), applied on ‘Tydeman's Red’ apple trees 4 weeks before the estimated normal harvest date, advanced red coloration and maturity of the fruit sufficiently to permit harvest of approx ¾ of the fruit 2 weeks ahead of the normal harvest date. Of die materials tested the combination of SADH (2,000 ppm), ethephon (500 ppm) and fenoprop (20 ppm) produced the most pronounced effects.

Effects of Annual Sprays of Succinic Acid-2,2-dimethylhydrazide on Vegetative Growth, Fruiting, Fruit Quality and Pre-Harvest Drop of ‘Delicious’ Apple Trees1

Abstract Six consecutive, single, annual applications of succinic acid–2,2-dimethylhydrazide (SADH) were applied, commencing with 2-year-old trees, in mid-July (51-67 days after full bloom) or mid-August at rates of 1000, 2000 or 4000 ppm. Other trees in the same block received 3 consecutive annual applications of 500 or 1000 ppm SADH in mid-June (31-40 days after full bloom) or mid-July. All SADH treatments delayed fruit flesh softening and reduced the severity of watercore and pre-harvest drop, but had no effect on trunk circumference increase, amount of bloom and fruit set. There was no terminal growth suppression of practical significance. With the exception of 500 ppm in mid-June or mid-July, all SADH treatments depressed fruit size. SADH suppressed rate of fruit growth and induced the formation of flatter fruits with shortened, thickened stems.

Effects of (2-Chloroethyl)phosphonic Acid and Succinic Acid-2,2-dimethylhydrazide on Sex Expression in Muskmelon1

Abstract The effects of (2-chloroethyl) phosphonic acid (ethephon) and succinic acid-2,2-dimethylhydrazide (SADH) on sex expression in muskmelon were tested through a series of greenhouse and field experiments employing 2 experimental monoecious hybrids and 1 andromonoecious cultivar. Plants treated with 4,000 to 5,000 ppm SADH were severely dwarfed and produced fewer male, and in monoecious hybrids, fewer female flowers than untreated controls. Ethephon treatments at 240 or 480 ppm in the greenhouse and 500 ppm in the field completely inhibited male flowering and promoted female flower initiation for an extended period. The combination of SADH and ethephon affected flowering in a manner similar to ethephon alone. Ethephon induction of a temporary gynoecious condition in monoecious muskmelons has potential for development of hybrid muskmelons. The results do not support the contention that ethylene, the active product of ethephon, acts as a gibberellin antagonist in regulating sex expression. It is suggested that natural endogenous levels of ethylene might be involved in sex expression in cucurbits, and that applied ethephon would augment that involvement.

Prolonging Dormancy of Tung Trees with Spray Oil and Succinic Acid-2,2-Dimethylhydrazide1

Abstract Naphthenic oil with and without succinic acid-2,2-dimethylhydrazide (SADH) was applied to dormant tung trees in February or early March to delay bloom in the spring. A late frost occurred in March 1968; the only branches of the trees to flower and set fruit were those that were treated with napthenic oil and oil with SADH. By contrast, branches treated with aqueous SADH were not saved. In 1969, branch sprays of 10% oil with 1% SADH resulted in delaying bloom up to 5 days and in setting more fruit than the control. In 1970, sprays of 50% oil with 2% SADH delayed bloom on 5-year-old tung trees by approx 2 weeks.

Apple Abscission

Abstract A horticulturist assigned this topic 30 years ago would start with a brief review of the nature of the abscission zone in the ripening apple fruit, and then spend the remainder of the time telling about research and experience on ways to delay the abscission process. The principal concern of that era was the loss frequently experienced by growers from preharvest drop of ripening fruits of ‘McIntosh’, ‘Delicious’ and several other cultivars. Anatomical studies of the apple pedicel and abscission zone by MacDaniels (18) contributed to an understanding of the abscission process, and orchard studies on nutrition and production led to practices by which growers could reduce their losses during the harvesting period. Then the research by Gardner et al. (13) with growth regulators paved the way for the effective control of harvest drop through the foliar application of a spray solution containing an auxin such as a-naphthaleneacetic acid (NAA). Many other growth regulators have been added to the list and are being used in special situations or for specific cultivars. These include 2-(2,4,5-trichlorophenoxy)propionic acid (fenoprop) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) and the growth retardant, succinic acid-2,2-dimethylhydrazide (SADH).

The Effect of Succinic Acid-2,2-dime thy lhydrazide (SADH) on the Sensory Quality of ‘McIntosh’ Apples1

Abstract In November and December 1967, 32°F air stored apples from trees treated with 2,000 ppm succinic acid-2,2-dimethylhydrazide (SADH) were ranked significantly poorer in flavor than fruits from non-treated trees and trees treated with 2, 4, 5-TP, NAA and 2, 4, 5-TP plus NAA. Flavor was not consistently related to soluble solids, sugars, pH, or acid. In May 1970, CA-stored apples from trees treated with zero, 500 and 1,000 ppm were similar in flavor and superior in comparison with apples treated with 2,000 ppm SADH. None of the samples was characterized as “off-flavor”. All SADH treated samples were significantly higher in titratable acid in 1970 but not in 1967.