Lawn care professionals should be gearing up for the spring herbicide strategy as soil temperatures start to rise in the spring.
Weeds can be among the first to kick off – and especially visible until regular lawn mowing is underway.
Once soil temps are regularly above 6⁰C, weed seeds will also start to germinate and fill the gaps from over winter wear and tear.
That start of consistent spring growth is essential for timing of Overtake control treatments, since actively growing weeds will translocate the herbicide through the plant to achieve a more complete kill, advises Syngenta Turf & Landscape Technical Manager, Sean Loakes.
Targeting newly germinated seedlings in spring is also the most effective time for optimum control, and once a healthy growing lawn has filled in over the patches there will be less chance for reinvasion.
“The first step in any strategy is assessing just how much weeds are an issue for individual customers,” Sean suggests.
“In some instances, it will be zero tolerance and want a full control programme for an immaculate lawn; for others a certain level of weeds may be acceptable, or even desirable in designated areas.
“Lawn professionals can design the intensity or selectivity for what to treat where, to best meet the customer’s demands. Weed identification and keeping a record of weed populations year on year for individual lawns can help build a picture for the spring treatment.”
Spring application of Overtake has been shown in trials to control common lawn weeds, including chickweed; speedwell; purple and white clover; daisy; creeping buttercup; mouse ear and dandelion.
“Overtake fills an important gap following some significant regulatory withdrawals in the past couple of years for herbicide options available to professional lawn care in commercial and residential situations, particularly for the most common knapsack applications.”
Sean advocates professionals use the free Turf Advisor App to monitor soil temperatures in their area, along with the Growth Potential model and assessing moisture, from rainfall and evapotranspiration data in the App, to identify suitable timings to start treatments.
“Although you do have to consider that in urban situations temperatures can be significantly higher, and particularly warmer nights, which will initiate growth earlier.”
Since it is important to apply Overtake to a dry leaf, to prevent run off and allowing uptake of the herbicide into the plant, Turf Advisor can help with an indication of leaf wetness, humidity and rainfall.
As the season progresses the Turf Advisor App can be tailored to provide data to support lawn overseeding, nutrition and watering strategies, as well as Primo Maxx II growth regulator programmes where they are being used. “That’s also a key part of the overall weed control approach,” says Sean.
“A strong and healthily growing lawn, with a dense sward, can effectively shade out weed seeds in the soil from germinating, as well as limiting the movement of seeds from outside into the lawn."
"Long term, it gives a more integrated approach to overall lawn management,” he adds.
Overtake contains two active ingredients, Fluroxypyr and Florasulam, that increases the spectrum and enhances reliability of broad-leaved weed control in spring conditions. It can be applied by knapsack or self-propelled pedestrian sprayer by suitably qualified professionals; Overtake is not approved for use by amateurs.
For knapsack treatment, apply at a rate of 20 ml Overtake per 100m2 in a water volume of two to four litres (equivalent to an Overtake application rate of 2.0 l/ha in 200-400 l/ha water volume).
