Manually and chemically pinched plants of 18 cultivars of Impatiens hybrids (Kientzler New Guinea impatiens) were compared to control plants to determine the effect of shoot apex removal on flowering, plant size, and branching characteristics. Either pinching treatment delayed flowering by ≈3 days compared with nonpinched controls. Pinching had no effect on plant height or fresh or dry weight. Plant diameter and form changes due to pinching depended on cultivar. Total branch count was increased by chemical but not manual pinching although both pinching methods affected mode of branching. The 18 cultivars of Kientzler New Guinea impatiens were best grown as 0.4-liter potted plants without the aid of pinching.
Terri Woods Starman
Mason Marshall, Terri Starman, H. Brent Pemberton, and Calvin Trostle
Manual pinching of apical meristems of horticultural crops removes apical dominance and promotes branching, increases flower numbers, and promotes the growth of a rounded, uniform plant canopy. However, manual pinching is a time-consuming and
Songul Sever Mutlu and Ece Agan
branched. Therefore, a technique such as pinching, manual removal of shoot apices, to overcome apical dominance and encourage lateral branching is a commercial recommendation in ornamental plant production ( Meijon et al., 2009 ) including pepper ( Larson
Ryan M. Warner
initiation of the experiment, plants received either manual decapitation (soft or hard pinch) at the initiation of the experiment or were treated with spray applications of ethephon at 0 (control), 250, 500, or 750 mg·L −1 of ethephon (Florel; Monterey Lawn
Terri W. Starman and James E. Faust
Our objective was to determine the effect of planting date and pinching on flowering dates and plant size of field-grown garden mums. Experiments were conducted in the field during two consecutive growing seasons in 1997 and 1998. In one experiment, 15 to 20 cultivars were planted on five dates (14 May, 4 June, 25 June, 16 July, and 4 Aug.) and received no pinching, one manual pinch 2 weeks after potting, or two manual pinches 2 and 4 weeks after potting. In another experiment, four cultivars were planted at the five dates. Pinch treatments were control, one manual pinch, two manual pinches, one Florel spray at 500 mg·L–1, or two Florel sprays at the same time as the manual pinches but on separate plants. Data were collected for days to first color, first open flower, 10 open flowers, and full bloom. Height and width were measured at 10 open blooms. Although the 1998 season was warmer and caused heat delay, the flowering data followed the same trends as the 1997 experiments. Pinching delayed flowering for the early plant dates. Pinching did not affect plant height or plant width. Planting date affected days to 10 blooms for most early season varieties but not late-season varieties. Planting early produced larger plants and more uneven flowering and resulted in greater heat delay of heat-sensitive varieties. Florel delayed flowering and increased plant size. We concluded that pinching was not required to produce high-quality garden mums of many new cultivars.
A-Young Lee, Sin-Ae Park, Hye-Gyeong Park, and Ki-Cheol Son
, 5) grasping and releasing, 6) pinching, 7) carrying cubes, and 8) manipulating a pegboard. The MFT kit (SOT-5000; Sakai Iryo Co, Tokyo, Japan), a standardized measurement tool designed for this assessment, was used. Each subtest included three test
Terri Woods Starman
Manually pinched plants of 18 cultivars of Impatiens hybrids (Keintzler New Guinea impatiens) were compared to control plants to determine the effect of apical meristem removal on flowering, growth and branching. Pinching delayed days to anthesis (first flower) of all cultivars, however, further delay in days to marketability (5 flowers open) was dependent upon cultivar. Plant area and fresh and dry weight were not affected by pinching plants of any cultivar. Cultivar influenced response to pinching treatments for plant height and plant width. Secondary branch number was increased by approximately 3 branches for all cultivars when plants were pinched. There were interactions between cultivar and treatment for primary, tertiary, and total branch number. Measured improvements in plant form determined two cultivars, Sylvine and Thecla, should be pinched. Chemically pinching these two cultivars with dikegulac at 780 mg·liter-1 was comparable to manually pinching plants.
Preliminary experiments with uniconazole (UNZ) at 5- and 10-ppm sprays on Bird Pepper indicated that UNZ could be used to enhance appearance and improve fruiting of Bird Pepper, but some refinement of UNZ rates had to be made. Another experiment was conducted to determine rates of UNZ needed to maintain a suitable plant size with manual pinching and improve yield and total number of red fruit produced. Best overall effects were on plants single-pinched 4 weeks after sowing and treated with a foliar spray of 4 to 6 ppm UNZ. Higher UNZ levels produced too compact plants in which individual branches had to be staked. More-attractive double-pinched plants may be produced if UNZ application is delayed after the second pinch. Bird pepper can therefore be produced as a dual purpose pot plant by pinching followed by foliar applications of of UNZ preferably at 4 to 6 ppm.
The effect of early pinching with 3 commercial formulations containing fatty alcohols or methyl esters of fatty acids applied to Brussels sprouts (Brassica oleracea L. Gemmifera group) was studied. Pinching was carried out at 2 stages of plant development. Pinching before the sprouts were visible, resulted in low yields of poorer quality, while manually topped plants gave excessive amounts of waste sprouts. At the second treatment date, when the basal sprouts were 0.3 cm in diameter, the same tendency was noted for every treatment, except Emgard 2077, which is a combination of methyl esters of fatty acids. The yield from ‘Topscore’ plants treated with 12% Emgard 2077 was slightly higher than that of the untopped plants. However, the amount of larger sprouts (> 30 mm) produced was greater than that obtained from untopped plants.
Lih-Jyu Shu, Kenneth C. Sanderson, and J. C. Williams
Applications of 0.5% dikegulac sodium (sodium salt of 2,3:4,6-bis-0-(l-methylethylidene-L-xylo-2-hexulofu-ranosonic acid) sprays produced significantly more new shoots on ‘Red wing’ or ‘King fisher’ azalea plants than manual pinching and other chemical pinching agents in 2 experiments. In 5 other experiments involving 5 other cultivars, dikegulac sodium-treated plants generally produced the most shoots, however, the shoot number was not different from shoot number on either manually pinched or 4.2% Off-Shoot-O-treated (mixture of C6 to C12 methyl ester of fatty acids) plants. Sprays of dimethyl dodecylamine caprylate at 0.2% and 0.5%, n-decanol at 2.5%, ethephon [(2-chloroethyl)phosphonic acid)] at 0.08%, and UBI-P293 (2,3-dihydro-5,6-diphenyl-1,4-oxathiin) at 1.0% gave inconsisent results but yielded shoot number comparable to dikegulac sodium in some tests. Off-Shoot-O, dimethyl dodecylamine caprylate, and n-un-decanol were destructive pinching agents at some concentrations and caused considerable plant injury. Dikegulac sodium caused minor injury and transient chlorosis. Ethephon, PBA [6-benzylamino-9(2-tetrahydropyran-2-yl)-9H-purine], and UBI-P293 did not produce any visible phytotoxicities. Shoots of plants sprayed with 0.5% dikegulac sodium and 1.0% UBI-P293 were of similar length or shorter than shoots of either manually pinched or untreated check plants 3 weeks after treatment.