A new bioregulator, cyclanilide (CYC, Bayer Environmental Science, Research Triangle Park, NC 27709), was compared with a proprietary formulation of 6-benzyladenine and gibberellins A4 and A7 [Promalin (PR), Valent BioSciences, Walnut Creek, Calif.] for branching effects on sweet cherry trees. CYC stimulated the formation of lateral shoots on current-season's shoot growth under both orchard and nursery conditions. In the nursery CYC was as effective or better for feathering compared to PR in all cherry cultivars tested. There were no synergistic effects of CYC/PR tank mixes on feather development. Crotch angles of induced feathers were not different from the angles of feathers that formed spontaneously. The growth of CYC-induced feathers was sufficient to produce acceptable quality feathered trees. Trunk caliper of nursery trees was either not affected or reduced to a very minimal degree. CYC is effective for lateral branch induction in sweet cherry, especially in the nursery. Chemical names used: 1-(2,4-dichlorophenylaminocarbonyl)-cyclopropane carboxylic acid (cyclanilide); N-(phenylmethyl)-1H-purine-6-amine + gibberellins A4 and A7 (Promalin); polyoxyethylenepolypropoxypropanol, dihydroxypropane, 2-butoxyethanol (Regulaid).
Fruit removal force (FRF) and percent leaf drop (LD) of fruit-bearing olive (Olea europaea L.) shoots were examined 120 hours after being sprayed with ethephon at 600 mg·liter-1 and held under controlled-environmental conditions analogous to those found in the field in California at harvest time in mid-October. FRF was not significantly affected by solution pH, but FRF of all treated shoots was significantly lower than that of the untreated controls. Only at pH 5 was percent LD significantly greater than that of the controls, but, of the shoots treated with ethephon, the lowest percent LD occurred at pH 3. Percent LD after treatment with ethephon at pH 3 was not affected by application time, but FRF was significantly less than the controls' when shoots were treated at 7 am or 12 pm but not at 5 pm or 10 pm. Adding NAA to the ethephon solution raised FRF and adding BA lowered FRF compared to ethephon alone. Adding NAA or BA did not mitigate percent LD significantly. Adding BA advanced anthocyanin production in fruit. Ethephon penetration of rachides was ≈70% that of petioles. Correlation between ethephon penetration of petioles and percent LD was greater than that between penetration of rachides and FRF. Correlation was significant for both tissues only in the 12 pm pH 3 treatment; correlation was also significant for petiole penetration and percent LD at pH 5. Autoradiographic studies of the 14C-ethephon penetration showed no pH effect, greater penetration into petioles than rachides, and that radioactivity was limited largely to intercellular spaces, with accumulation in vascular bundles, especially xylem. Regardless of treatment, FRF and percent LD are negatively correlated (r 2 = 0.615). Mean results to be expected using ethephon as an olive harvest aid under these conditions are an FRF of ≈3 N and a percent LD of ≈15%. The desired low FRF and percent LD were obtained by applying ethephon alone at pH 3 at 7 am. Raising ethephon solution pH does not increase harvest effectiveness. Chemical names used: (2-chloroethyl)phosphonic acid (ethephon), naphthalene acetic acid (NAA), 6-benzylaminopurine (BA).
inherent tissue culture-induced problems, such as leaf chlorosis and growth retardation, and to increase production ( Monteiro et al., 2000 ). Cytokinins are a class of plant growth regulators widely used in Passiflora tissue culture. Benzyladenine (BA
squares ANOVA at P ≤ 0.05. Mean separation for main effects and interaction using Student's t test. Study 2: Influence of cytokinin and auxin on flowering Expt. 1: Influence of benylamino purine, triiodobenzoic acid, and naphthaleneacetic acid on
presence of oxygen and epinasty results. *Statistical significance when compared with the control. Additional PGRs or signals may participate in facilitating the epinastic response in tomato. Cytokinin ( Neuman et al., 1990 ) and ABA levels ( Else
the analogous synthetic growth regulators that may be added to the medium ( George, 1993 ). The induction of DSE in C. arabica is strongly associated with the addition of cytokinins to the culture medium, in the absence of auxins ( Almeida and
closure and conservation of water. Cytokinins exhibit antisenescence properties ( Musgrave, 1994 ). Cytokinins delay the senescence process probably by maintaining the integrity of the tonoplast membrane ( Thimann, 1987 ). Zeatin and its sugar derivatives
then transferred to fresh medium with the same concentration. Each experiment was repeated three times. For studying the effects of TDZ and cytokinin, one cluster of shoots having three to five shoots was incubated in 125-mL flasks with 25 mL liquid
. erectus explants were significantly influenced by cytokinins type and concentration ( Table 1 ; Fig. 1D and E ). Supplementation of medium with 1.0 and 2.0 mg·L −1 BAP induced the highest number of axillary shoots (3.5 and 4 per explant, respectively
Spearman’s correlation coefficient using SAS PROC CORR. All data were analyzed as randomized complete block experiments with replication as a random effect. Rootstock and medium were considered fixed effects. For the percentage of regeneration, cytokinin