I have some very inconsistent breaks and branching on mostly prestige and red velvet.Two problems- Dominant branching and also in multiple plant pots some plants have shoots 1/4 " long and the other plants are just breaking, very inconsistent.At this point what can I do? Also has anybody used Hurricane Funcicide on POinsettias? Thanks

First, it’s important to evaluate why you are seeing the dominant breaks and inconsistent breaking. This time of year, stressful greenhouse conditions can have a negative effect on branching. Proper pinching techniques are also key.


Following is a piece we put together to help growers better understand branching in poinsettias:

Although modern poinsettia varieties branch freely, some growers experience branching difficulties with a small percentage of their crop. Occasionally, in a pinched crop, plants can be observed with only two or three main stems. There may also be smaller, under-developed shoots that don’t contribute to the final flower display. There are many different contributing factors to poor branching.


Contributing factors include:

• Excessively hardened cuttings. Axillary buds and stem tissue that is stressed during the end of propagation will not branch as well as buds that develop after propagation.
• Low light. If light levels are reduced following the pinch, the plant may not be able to support all the shoots that form. In the vegetative growth phase light levels should not be below 4,500 f.c.
• Tight spacing. If plants are tightly spaced for too long, the lower shoots don’t receive enough light to develop properly while the top two or three shoots become dominant.
• No growth regulators. Growth regulating can be used to even shoot growth. Spray applications can be targeted to the upper shoots which allow the lower shoots to catch up.
• Tall primary stem after pinch, and high pinches. If cuttings are allowed to stretch prior to pinch and the pinch height is high there will be several inches between the newly forming shoots and the lower lateral existing shoots.
• Hard pinch on stretched cuttings. If cuttings are allowed to stretch prior to pinch and a hard pinch is performed the tissue on the lower stem is more mature and woody. This woody tissue does not break as well resulting in fewer shoots.
• Environmental stress during propagation, establishment, and vegetative growth phases. High light levels, excessive temperatures, and reduced relative humidity can have an impact on the number of shoots formed after pinch.
• Warm finishing temperatures. Bracts can be very large when plants are grown above 68F (20C). These larger bracts crowd out smaller shoots and become the only flowering shoots easily seen. Cooler finishing temperatures create smaller bracts and a canopy where all shoots are visible.
• Loss of phytoplasm (MLO). Phytoplasm are organisms present in the phloem of the poinsettia plant. Phytoplasm reacts with a poinsettias genome and this reaction initiates a hormone responsible for “free branching”. Phytoplasm also may change the physical appearance of a poinsettia, and the response varies by variety. Heat stress conditions (high light, high heat, low moisture availability) during propagation and the establishing phase can actually eliminate phytoplasm resulting in poor branching, uneven branch development, and a physical appearance not characteristic of a particular cultivar.


Even branching can be easily achieved with proper cultural practices and a controlled greenhouse environment. Proper pinching techniques and timing, growth regulating, proper timing of plant spacing, and cool finishing temperatures are all factors that will contribute to even branching and flower display.

A controlled greenhouse environment can be difficult in many areas of the country during the summer and early autumn months. As excessive temperatures and light levels contribute to poor branching it is important to manage the greenhouse environment. Here are some tips for reducing stress from heat on a poinsettia crop:

• Shade crop immediately after transplant to about 3,000 f.c. Once cuttings have established and the crop is pinched, light levels should be closer to 4,500-5,000 f.c.
• Control greenhouse temperatures as much as possible. Young plants will tolerate very warm temperatures as long as the relative humidity is maintained at a high enough level to reduce the plants water loss. It is also important to avoid excessive light levels (above 3500 f.c.) when temperatures are high.
• Mist young plants with clear water in the warmest part of the day. This is especially important before root systems are established.
• Syringe plants with clear, cool water to cool root systems or consider adjusting watering schedule to irrigate plants in the afternoon rather than first thing in the morning. An afternoon irrigation will cool the plants without the risk of over saturating the media which could be the case if the plants are watered in the morning then syringed again if the afternoon.
• Wet walk ways to allow evaporation to cool the greenhouse and raise the relative humidity.

These are all things to consider for the next crop you pinch. We also need to try and correct the situation you are dealing with now. You can consider spray applications of B-Nine or Cycocel alone targeted at the dominant shoots. You want to wait to make any applications until shoots are 3/4" to 1" long. When the new shoots are long enough you can get some light control using Cycocel at 1000-1500 ppm or B-Nine at 2,000-3,000 ppm. It is not easy and a tedious process but you want to target the application to the dominant shoots.

Regarding your question about Hurricane – it has been tested on several plant species but is not specifically labeled for use on poinsettias. We recommend you contact the manufacturer Syngenta for advise about its use on poinsettias.

Thanks so much for all the information. Would a Bonzi spray work directed to the dominant shoots?.

Bonzi is a much more powerful chemical that B-Nine and Cycocel. The effects of Bonzi tend to be much more residual than other growth regulators. We worry that you will get too much control with the Bonzi and that is why during this phase of growth we tend to recommend the B-Nine or Cycocel.

Hello,

We have a really warm climate, and i do not have any cycocel so this year I have decided to use bonzi to regulate the really dominant shoots , ONLY those that are really far more grown than others. I used 5ppm on freedom 2 days ago, and I shall keep you informed of the growththat I will get. I dont like cycocel+B9 sparays as they tend to stresst he leaves, causing them to curl in addition to the fact that they rarely stop the plants from growing.

2 questions, 1)spraying Bonzi is different than spraying cycoce lin that you have to cover the whole leaves and not only the growing points , is that correct??
2) If unsprayed what is the normal growing rate of freedom in this weather (g.H temp around 35-40 Deg. Centigrades)

Hi Jana -

Thorough coverage is important with Bonzi. You do need to be careful though and not spray to the point of runoff. If you spray to the point that the Bonzi drips off the foliage and into the media you will be getting more activity from the product because it is systemic and will be absorbed by the roots. You’ll get activity from the Bonzi absorbed through the foliage and stems as well as the product that is taken up by the roots. This is a common mistake that many growers make and the result is plants that are over growth regulated and too short.

Freedom is a variety that tends to stretch late in the season and the growth rate early on is a little slower. Many growers don't growth regulate Freedom early in the season but rely instead on Bonzi drenches after flower initiation to control the late season stretch.

Hi Jana,

A little technical point on Bonzi is that is not translocated (move) out of a leaf. It is not mobile in the phloem. Therefore, in a spray application where you are trying to control growth of individual laterals it is the spray that directly contacts on the growing tip and the stem below the tip that will be important. You are not trying to cover the leaf itself. The technique you are doing works better with Cycocel because it does move out of the leaf. I suggest making a little heavier spray with Bonzi than you probably do with Cycocel so that you get spray into the stem. As mentioned, you do not want to apply too much and have the spray running down into the pot because it will be more active and affect all of the shoots.

Your temperatures are higher than optimum for Freedom and other poinsettias so they are probably growing a little slow and will grow faster as the temperatures cool off to around 30 (86 F).

Jim

thank you for your replies. Does cycocel have an effect when sprayed alone to control the vaiation in the lengths of the lateral?

Jana, Cycocel does work well for this in cool climates. In warmer areas of the southern US using a mix of B-Nine and Cycocel works much better. To do selective sprays of individual laterals in hot climates my first choice would be B-Nine at 1,000 mg a.i./L with Cycocel at 1,000 mg a.i./L (This is 1,000 ppm of each in US terms). If I were going to use Cycocel alone, I would use 1,500 mg a.i./L and spray it 2-3 times at 4-7 day intervals. Jim

Hi this is to inform you that the 5ppm Bonzi spray gave me only 1/2 cm growth in one week.
I think that is satisfactory

I did see some inconsistent in my breaks also. So should points be pinched before the breakes get to long.I don't pinch my self but my production person does the pinching. My thoughts are that they are not pincing in a timely matter. It seems that they are waiting to long.

Some plants will be pinched before the lower laterals even begin to form. You should schedule your pinched base on root establishment and maturity of the cutting rather than when the lower laterals are forming and stetching. The plants are ready to be pinched when the roots have reached the edge of the pot and before the plants show any signs of stretch.