A smarter way to thin apples
Lindsay Hunt, a convert to the Adama New Zealand photosynthesis-inhibiting thinner Brevis and predictive web-based app BreviSmart, draws on many years of hands-on experience in his current role managing apple orchards for Kaiaponi Farms in Gisborne.
Lindsay started in the apple industry aged 15, pruning, thinning and picking in the school holidays for his father, an orchard contractor, beginning a lifetime passion. Kaiaponi has 67 ha of productive apples and 20 ha of young plantings spread over seven properties.
Asked by his Fruitfed Supplies Technical Horticultural Representative Hugh O’Donnell if he was interested in doing a trial with Brevis and BreviSmart, Lindsay was keen. He was motivated both by pollination issues caused by temperature, and limitations with his previously preferred thinner 6BA, which requires two days of 18°C, “which doesn't always happen”.
Brevis mimics shading to thin fruitlets around 8-14 mm in diameter. It’s easy to use and does not require the addition of surfactants. It is also rain-fast within two to three hours and block re-entry is possible after just three days, minimising disruptions to orchard routines. In addition, Brevis is non-toxic to beneficial organisms making it a good fit for integrated pest management programmes.
BreviSmart, Brevis’ new companion app, predicts the optimum timing to apply Brevis by factoring in solar radiation, temperature, fruitlet size and variety. The model was developed in conjunction with IBM and uses actual weather data and forecasts from The Weather Company, which operates an extensive network of weather stations globally and locally in New Zealand.
Actual weather data from local weather stations closest to the orchard from five days before the calculation and the forecasted weather for five days after (including the calculation day) are used to calculate the predictions.
BreviSmart also adjusts for fruitlet size and variety, predicting the best day to apply Brevis to achieve the desired thinning outcomes. In addition, growers will consider block history, varieties, vigour, cultural techniques, and spraying conditions, such as wind, among other things.
Lindsay was one of several growers to trial BreviSmart and received a BreviSmart prediction each morning to help inform his decisions on the timing and rate of Brevis.
Using this information, last season on Kaiaponi Farms, Brevis was applied to 1.3 ha of Royal Gala at a rate of 1.1 kg/ha, when king fruit were around 8 mm, directed at the top 50% of trees. What most impressed Lindsay was the resulting even fruit size and that the trees carried the crop through to harvest. Lindsay effectively cut-out four conventional thinner applications and only a light hand-thin was needed, saving time and cost. It was also the best crop in five years.
On a block of Galaxy, Brevis was applied at 2.2 kg/ha. This block had a history of being difficult to thin with Lindsay saying he normally “had to throw the kitchen sink at it”. In 2019/20 this block had a big flowering and a big crop. The result was the best he had ever had, with much less hand thinning required.
BreviSmart enabled Lindsay to predict thinning over a range of fruitlet sizes. He also appreciated assessments of when it would be wiser to wait for better thinning conditions. Before using BreviSmart, Lindsay says he was constantly monitoring his orchard blocks looking at the size and number of fruitlets daily, and the weather forecast to find the best spray window. With seven blocks across the Gisborne plains, that was a lot of walking. Using BreviSmart, he checked for the best spray day and simply looked at the orchard the day before. “It was an advantage.”
The new BreviSmart model will be available for orchardists locally ahead of the 2020 thinning season.
For more information about Brevis and BreviSmart, contact your Fruitfed Supplies Technical Horticultural Representative.