Plant growth regulators are essential in the production of many protected ornamentals but can be much more effective and easier to apply when used with an adjuvant, such as Elasto G5 which Syngenta recently launched on the UK market.
Elasto G5 has been available for several years in the Netherlands where pot and bedding plant grower Martin Duijvestijn has already found it can reduce the number of plant growth regulator sprays required as well as the time needed to apply them.
Along with his sons Edwin and Rick, Martin grows a range of seasonal products on the family nursery Kwintplant. Since taking over a 4.8ha chrysanthemum nursery in the spring of 2021, Kwintplant now grows 6ha of bedding and pot plants under glass, across two locations in the Westland area. The crop mix varies by season. In addition to offering various spring-flowering plants, it includes capsicum, platycodon and the chrysanthemum varieties Anastasia, Deco and Zembla grown as pot plants. What makes these chrysanthemums interesting, though, is that they are cut-flower varieties which weren’t bred for pot mum production, so are naturally long stemmed and need a programme of growth regulation.
“It’s a small-scale and intensive crop,” says Martin. “Among other things, it includes removing the side shoots so that only the main bud flowers and you have to consistently suppress stem growth, otherwise you end up with a top-heavy pot. It’s the short stems that give our product its decorative value.”
Martin uses daminozide to control growth, spraying the plants twice a week on average depending on variety and the prevailing conditions. In the past, he had always added a wetting agent to improve spray coverage. “It did help, but because of the natural differences in growth rates between varieties, we always had to make adjustments by giving some batches an additional treatment or by skipping treatments for others,” he says.
So when he heard about Elasto 5G he decided to try it. It’s not primarily a wetting agent, although it does reduce surface tension and helps the spray to spread on a leaf. But its main action is to improve the plant’s uptake of the active ingredients in plant protection products and growth regulators.
“The result exceeded our expectations,” he says. “Elasto G5 produces a more homogeneous crop response as a consequence of which we no longer need to make corrections. That saves us 25 to 30% of growth inhibitor a year, saves time and less effort is required to achieve a more predictable and uniform crop result. We simply have less to worry about.”
It was Kwintplant’s plant protection adviser Henk van der Meer from Dutch distributor Van Iperen who helped him make the switch and says Martin’s experience with Elasto G5 echoes those on other nurseries and with other crops. “If you want improved absorption of the product by your plant, Elasto G5 can clearly provide added value,” he says.
He points out that the plant’s uptake of other systemic products can also be improved in a tank mix with Elasto G5. In the UK, Elasto G5 is approved for use with all plant protection products authorised for use on ornamentals.
“Although Elasto G5 is not specifically a wetting agent, it has a somewhat comparable effect,” says Caroline van den Hoek, Syngenta crop adviser in the Netherlands. “As a result of the good leaf coverage, more of the plant comes into contact with the active ingredient. In addition to improved leaf-wetting, you see the plant dries quickly and more evenly.
“But it also ensures the active ingredient remains in solution so the plant can absorb it before it dries. Elasto G5 reduces the risk that the active ingredient will not be absorbed fully and remains on the leaves as ‘crystals’.”
In other crops too
According to Henk, growers of plants with waxy leaves, such as kalanchoe, can be nervous about the risk of scorch along leaf edges when using plant growth regulator treatments in combination with a wetting agent. Consequently they under-dose to reduce the risk of damage, which can lead to uneven growth. But he says he knows growers in the Netherlands who have had positive experiences with Elasto G5 on kalanchoe, thanks to its crop safety. This is achieved by the way Elasto G5 will help to pin the product to the leaf and reduces the run-off that wetting agents are designed to achieve.
Martin says he has the same worry about using plant growth regulators in combination with an adjuvant on platycodon and is looking at how it is affected by treatments by putting some trial plants in with the chrysanthemum crops. “I’m going to keep on doing this for a while,” he says. “If it goes well, I’ll have the confidence to treat batches of platycodon separately and figure out the correct recipe for them. Elasto G5 has really improved our handle on the pot chrysanthemums and delivers good savings. If we can use it more widely with comparable results, we will.”
Caroline warns that making the most of Elasto G5’s benefits depends on it being applied correctly. “If you want to cut the number of applications, every spray must count,” she says. “This means correct use of the products and application techniques. The Advice Hub on our website features our Art of Application series to help you get the most from your sprays. It is for both growers and advisers to take a look at, and new messages are posted regularly.”