In greenhouse floriculture production, Florel® has been the go-to ethephon formulation for years. It is available as a 3.9% active ingredient solution. Fine Americas introduced Collate® in 2013 which is a higher concentration (21.7%) product. Greenhouse label uses for Collate include inducing flowering of ornamental bromeliads; avoidance of stem topple of potted hyacinths; height control of potted daffodils; and flower inhibition, increase in axillary shoot development, and height control in a variety of ornamental crops. In order to get the most out of your Collate applications, below are some use tips to consider.
Application Parameters. Collate breaks down and becomes inactive with water pH conditions greater than 6.1. While all the registered ethephon products contain acidifiers, in areas with high levels of alkalinity, the alkalinity will need to be neutralized BEFORE mixing the solution. The ideal endpoint pH for a Collate solution is ~4.5 to 5.0. Be careful to avoid getting the solution pH too low though, leaf phytotoxicity can occur with ethephon applications when the pH is below 3.
Temperatures. In addition, Collate activity is linked to active plant growth. Applications made when temperatures are below 60F (15.5C) or higher than 95F (35C) will be less effective. Therefore during times when temperatures are excessive, make applications either early in the morning or late at night.
Timing. When used to promote axillary branching, the plants should be well rooted in the container. Typically rooting to the side of the pot will occur within two weeks. Applications made before plugs or plants are well rooted can result in retarded root development.
When used for prevention of early flowering, it should be noted that the last Collate application should be made 6 to 8 weeks prior to the intended sales date. Late spray applications will result in flower delay.
Suitable application windows should also be noted with stock plants. Ethylene can inhibit rooting, so applications should not be made within 7 days of harvesting cuttings.
Avoid Applications to Stressed Plants. When used correctly, Collate applications will result in enhanced plant growth. Because ethylene produced by Collate is a stress enhancer, it is important to have the plants actively growing and not under suboptimal conditions (heat, drought, environmental or disease stress). Lower leaf yellowing typically occurs when Collate is applied to drought stressed plants.
Optimal Concentrations. For most plants, Collate spray rates are typically at 500 ppm. Complete spray coverage is required because Collate is not translocated in the plant. This is especially important for plants such as garden mums. Incomplete spray applications will result in uneven growth and flowering. Research has shown that drench and pre-plant liner soaks application rates are lower, in the range of 50 to 250 ppm. While a label amendment has been applied for to allow drench applications of Collate, it has not yet been approved.
Phytotoxicity. Some cultivars have a greater sensitivity to Collate. Cupping and distortion of the young expanding leaves can occur. In addition, over application can also result in distortion and leaf bleaching.
Protective Equipment and REI. Collate is acidic and because of this it is a minor eye and skin irritant. That is the reason it has a longer REI of 48 hours. In addition, it should be noted that eye protection is required, along with protective gloves, coveralls, apron, shoes, and headgear for overhead applications. A box of baking soda should be handy to neutralize the acidity of Collate in case it comes in contact with your skin.
In summary, Collate is effective in controlling excessive growth of many greenhouse plants. Collate is an excellent and cost effective option for improving plant structure, preventing early flowering, and controlling excessive plant growth. It is easy to see why Collate has become an essential component of the floriculture PGR toolbox.