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Mastering thinning chemistry BreviSmart®: The science optimising thinning timing
Finding the elusive ‘sweet spot’ between over-thinning and under-thinning apples has tested even some of this country’s most experienced and successful orchardists.
When traditional approaches, hand thinning and highly weather-dependent plant hormone-based thinners weren’t working, ADAMA New Zealand took a different tack, an innovative approach backed by data, science and collaboration.
It began with photosynthesis-inhibiting fruitlet thinner Brevis®, now used in 30 countries worldwide. Applied when fruitlets are about 8-14 mm in size and mimicking the effect of shade, Brevis reduces the production of carbohydrates by the tree. Remaining carbohydrates are sent to shoots and to the largest, dominant ‘king’ fruitlets at the expense of smaller fruitlets, which start to drop in seven to 10 days after treatment. Growers welcomed the chemistry due to several advantages including easy measuring for tank mixing, no requirement for surfactants or other additives, and rainfastness in two to three hours.
ADAMA didn’t stop there, as Netherlands-based Global Brevis project manager Ton Besseling explains: “Growers everywhere were looking for a tool that recommends when and how to apply the thinner for best results. “With BreviSmart we can predict the optimum time to apply Brevis, the best day of application for the best thinning response.” In developing the BreviSmart algorithms, ADAMA amassed in-depth knowledge of the impact of weather and other factors on thinning efficacy. BreviSmart takes into account the effects of night-time temperatures, radiation (sunlight), fruitlet size, and apple variety. Weather data and forecasts from The Weather Company, an IBM business, support growers’ decisions on when and how much Brevis to apply. Data for five days (including the day of calculation) is sourced from the weather station closest to each orchard.
A report is then generated using a traffic light system (yellow for reduced thinning conditions, green for good thinning conditions, red for strong thinning conditions). Reports are produced daily during the thinning season. Over 800 trials worldwide have contributed to the BreviSmart programme to date. Ton says when a new variety has over 1,000 hectares planted, trials begin. “This ongoing work is critical to supporting advisor and grower decision-making.” He says growers appreciate the science BreviSmart brings to the thinning equation. “Ultimately, they feel more in control.”
New Zealand orchardists and advisors using the technology for the first time last season reported that BreviSmart had been an important tool backing their own assessments. BreviSmart significantly decreased hand thinning and also the time spent physically monitoring blocks. ADAMA New Zealand commercial manager Damian MacKenzie, National Lead for Brevis, says the more thinning knowledge gained the better. “That way we can further tailor our response to advisors’ and growers’ needs and enhance the quantity and quality of the fruit they take to market, and their profitability.”
