Les poinsettias sont des plantes de jours courts dites nyctipériodiques, qui ne fleurissent que si la durée de la phase lumineuse durant un jour est de 12h à 13h. Plant size. The objective of this study, supported by the Massachusetts Flower Growers' Association, was to test Bonzi for late season height control by studying the effects of Bonzi concentration, drench volume applied, and number of doses. À l’approche du mois de décembre, nous avons probablement fait tout le nécessaire pour que les poinsettias soient prêts à amorcer la phase finale de leur cycle de croissance. Features - Poinsettias. Roll, Eds. Poinsettias (potted). The B-Nine is thought to act as a carrier for the Cycocel which increases its effectiveness and decreases the potential for phytotoxicity. PGRs must be applied uniformly in order to cause uniform inhibition to plant growth. Florida has demonstrated that applying growth retardants as a drench provides excellent height control and is safer than sprays. Several Massachusetts growers have been making these treatments for a number of years and are pleased with the results. This can be done when the plants are about ½ to 1 inch below the desired height and/or one to two weeks (up to three weeks in the south) before shipping. Very low rates of Bonzi are drenched on the poinsettia crop as often as once a week in combination with graphical tracking to achieve optimal crop height, with little or no risk of reducing bract size. Starting in late October, higher drench rates can be used to provide stronger hold if needed, with a slight reduction in bract size. Poinsettias Bonzi for regulation of poinsettia growth: Bonzi has shown growth retarding activity on a wide range of ornamental species and at very low dosage rates. Overall, bract diameter of was reduced by increases in Bonzi concentration, drench volume, and number of doses. Anyone had any luck with this? generally cortez varieties are resistant to late-season stretch. Also, because PGRs are treated as pesticides and have assigned re-entry intervals (12 hour REI - A-Rest, Cycocel, Sumagic; 24 hour REI - B-Nine, Bonzi), frequent use of PGRs may disrupt other work in some greenhouse operations. In the warmer temperatures of the deep south, we generally use chemical than would be used in cooler regions. Plant height and diameter reductions in this study were not excessive and would meet the objectives of late season stretch control for most growers. The amount of active ingredient applied in each dose are shown in Table 1. An unexpected outcome was that differences in height among Bonzi-treated plants did not result from different concentrations, drench volumes or number of doses. Section 13, pp.75-77 in: H.K. ft./pot). Growth medium drench treatments were 1, 2, or 3 ppm Bonzi applied in volumes of 3, 4, or 5 fl. apply the Bonzi at ¼ – ½ ppm in the North and ½ – 1 ppm in the … Christopher J. Currey and Roberto G.Lopez Controlling height is an important aspect of poinsettia production. The table accompanying this article, taken from the 2003-2004 edition of New England Floricultural Recommendations, provides the rates for use in New England and describes the specific conditions and methods for applying each PGR. All plants were treated twice in September with a foliar spray of B-Nine and Cycocel. The stretching is influenced by the plant hormone gibberellic acid. after the Bonzi drench the plants generally grow an additional ½ – 1"/1.27 – 2.54 cm depending on the drench rate used. My results demonstrate that Bonzi applied as a drench at low concentrations during the early stages of bract expansion and coloring is effective at suppressing the height and diameter of poinsettia. First, poinsettias begin to grow at their most rapid pace during this period, evident by the sigmoidal shape of poinsettia growth curves (some cultivars can be more vigorous during this time than others). Many growers report too tall or "stretching" poinsettias late in the season. Close spacing and inadequate light due to poor transmission by the greenhouse covering or cloudy weather are major causes of stretch late in the growing season. Root rots, nutritional issues, environmental stress and PGR mistakes can all be costly in this high-value crop. PGR use is most likely on cultivars such as 'Success', and 'Monet'. Use of BONZI effecttvely reduces internode elongation, re8ulting in more desirable compo ct plants. Read on for common pitfalls and how to avoid them. This distortion occurred on the bracts of some, but not all, plants drenched with one dose of Bonzi applied at 3 ppm and 5 fl. If Bonzi (or another growth-retarding chemical) is applied too early in the crop schedule, or at … Actual volume depends on pot size. POINSETTIAS - DRENCH APPLICATION General Information GENERAL INFORMATION Bonzi is a plant growth regulator for use on ornamental plants grown in containers in nurseries, greenhouses, shadehouses, and interiorscapes. Bonzi “micro-drenches” were developed and named by Dr. Jim Barrett from the University of Florida. Nos spécialistes ont réuni à votre intention des informations et conseils pour cultiver au mieux les poinsettias - afin qu'ils restent toujours beaux et en bonne santé! apply a late-season Bonzi drench one to two weeks before shipping when the plants are almost at finished height with at least two to three bracts in full color. Proper spacing is a key. All Bonzi-treated plants received 6.8 fl.oz. Bract size. It is used primarily as a soil drench application. A desirable level of plant size reduction without a reduction in bract diameter and no bract distortion resulted from one dose of 1 ppm Bonzi (all drench volumes) and 2 ppm (3 and 4 fl.oz.). Date d'acquisition. This site is maintained by Center for Agriculture, Food and the Environment in the College of Natural Sciences. Plant height, plant diameter, and bract diameter were measured at the conclusion of the experiment (9 December). He will explore the Internet with you as your very own friend and sidekick! z2.54 centimeters (cm)=1 inch.yA value that has been boldfaced means that it is significantly different from the control by Dunnett's procedure, p=0.05. However, one might question if the "stretch" control gained offsets the time and labor involved in making the drench treatments. The dosage rate is 4 fl. On 24 September, when the lateral shoots were about four inches long, plants were sprayed with a solution of 1000 ppm B-Nine and 500 ppm Cycocel. An unexpected outcome was that differences in height among Bonzi-treated plants did not result from different concentrations, drench volumes or number of doses. Plants were grown using standard commercial practices under natural light conditions. These drench treatments can be applied after October 15 into early November without affecting bract diameter. Tayama, R.A. Larson, P.A. He even has the ability to compare prices on the products you love and help you save money! We want to suppress vegetative growth Fig. Cared-for properly, the poinsettia will give weeks of color and pleasure to its owner. Stock Solution Preparation: ppm Bonzi drench 1:100 injector Hozon using 5 gal bucket 5 gal bucket for hand dipping 1 3.33 oz per gal 2.5 oz per 5 gallons 1 tsp per 5 gallons 2 6.66 oz per gal 5.0 oz per 5 gallons 2 tsp per 5 gallons Here are guidelines to consider when using Bonzi: Applications should be uniform, especially if you are using a drip system. Additional specific precautions are discussed in the accompanying table. Best of all, he's FREE! This can be done when the plants are about ½ to 1 inch below the desired height and/or one to two weeks (up to three weeks in the South) before shipping. Plants potted in July and early August often end up too tall because of the extra time for vegetative growth between planting, pinching, and the initiation of flower buds. This site is maintained by Center for Agriculture, Food and the Environment in the College of Natural Sciences. Connect with UMass Extension Greenhouse Crops & Floriculture Program: UMass Research and Education Center Farms, Conservation Assessment Prioritization System (CAPS), Extension Risk Management/Crop Insurance Education, North American Aquatic Connectivity Collaborative, Civil Rights and Non-Discrimination Information. We want to suppress vegetative growth Fig. Based on my results, the use of two doses of Bonzi drench or any combination of Bonzi concentration and drench volume resulting in a level of active ingredient above 0.24 mg a.i./pot risks a reduction in bract diameter and bract distortion. He can talk, walk, joke, browse, search, e-mail, and download like no other friend you've ever had! Official tennis player profile of Benjamin Bonzi on the ATP Tour. Growers can try to control late season stretch by applying a very dilute drench of A-Rest or Bonzi. Email: email@example.com . However, some recent recommendations (Hammer, 1996; Moore, 1996) suggest that growth medium drench applications of very low concentrations (1-2 ppm) of Bonzi or A-Rest can be used late season stretch of poinsettia with minimal affect on bract diameter. There are several options for growth regulators on poinsettias and the chemicals and rates utilized vary considerably due to climate and grower preferences. Some of the reasons for stretch include: missed early season PGR applications, periods of unusually favorable growing conditions, or elongation due to too close spacing or low light intensity due to cloudy weather. Treatment effects on plant height were similar with one or two doses. All plants, with the exception of the control group, were treated with a Bonzi drench as soon as 2 or 3 of the uppermost leaves showed some red coloring (28 October). When used as directed, Bonzi produces no phytotoxic effects. When making PGR drenches, remember that the amount of active ingredient (mg a.i./pot) applied is more important than the concentration (ppm) of the drench solution. of PGR solution per pot at the time of treatment. Left in the car, however, it may not fair so well. ©2020 University of Massachusetts Amherst • Site Policies, Greenhouse Best Management Practices (BMP) Manual, New England Greenhouse Floriculture Guide, Pesticide Information (Labels, MSDS, WPS), Pesticide Licensing (Certification, Exams, Workshops), Soil and Plant Nutrient Testing and Diagnostics, Center for Agriculture, Food, and the Environment, Center for Agriculture, Food and the Environment. PGR use can be reduced or eliminated by the starting with good quality cuttings, use of a tighter schedule, and by providing the plants with as much light as possible by proper spacing and maximizing light transmission. Late applications may result in excessive height reduction and/or reduced bract size. Second, the growth during this time is vegetative (i.e. Never use a "spreader-sticker" unless directed to by the label. Poinsettias are shade-avoiding plants, which is why they tend to stretch on the nursery without a reliable PGR programme. Very low rates of paclobutrazol are drenched on the poinsettia crop as often as once a week, in combination with graphical tracking, to achieve optimal crop height, with little or no risk of reducing bract size. Welcome to the world of BonziBUDDY! Hard pruning my 21 year old Poinsettia Bonsai. Plants were pinched on 17 August leaving five or six nodes. C… Now that poinsettias are safely tucked into their prop trays and the threat of Erwinia (Pectobacterium) is almost over, it's time to think about other Poinsettia issues. of A-Rest or Bonzi. My results demonstrate that Bonzi applied as a drench at low concentrations during the early stages of bract expansion and coloring is effective at suppressing the height and diameter of poinsettia. We have also found that bract development is affected less by Bonzi sprays than bythe B-Nine/Cycoceltank mix. Using low levels of PGRs after the start of short days may help control stretch in these situations. Therefore, it is probably worthwhile to leave at least 10 representative plants untreated to evaluate the effectiveness of the low concentration drench treatments.
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