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Orchardist Mark Mudgway


Brevis and 6-BA cytokinin combination delivering successful thinning results in Honey Belle pears.
Orchardist Mark Mudgway

Pears are notoriously difficult to thin. So, when Agcrop Ltd. Orchard Manager Mark Mudgway and Fruitfed Supplies Technical Horticultural Representative Vaughan Redshaw found a solution for Honey BelleTM pears that looked promising, they also began cautiously using it as a secondary thinner on Fuji Supreme, Royal Gala  and Pacific Queen apples.

They say their chosen combination of Brevis® with a 6-BA cytokinin plant growth regulator isn’t the ‘be all and end all’, but, after three years of seeing the results across all varieties, they say they could be onto something. 

Brevis, from Adama, is a photosynthesis inhibitor for secondary fruitlet thinning in apples and pears, and the only product with metamitron as the active ingredient approved for pears in New Zealand.

Mark and Vaughan, who each have more than three decades of experience, take a strategic approach to thinning which is firmly grounded in commercial reality; packable yield, guaranteeing a marketable crop, and managing staff resources.

“You spray a few rows and if you have proof of concept, then you do more.” Vaughan explains. “I feel it’s the right way to do things. What we’re doing here is not a game-changer but it’s helping. We’ve seen the synergy between the two products.

“We’ll try a few other things, making some subtle tweaks. We are getting results but it’s a moveable feast – that’s what makes it exciting and challenging. “In perfect conditions 6-BAs are great. But the need for a slow drying morning and then a hot day meant with Hastings’ weather, we were sometimes short by just a few degrees.” That was enough to make a critical difference in thinning performance. 

“Putting Brevis and 6-BA together works well,” Vaughan says. “It’s still a matter of getting the right timing and reading the season. Brevis has a role to play, and Mark’s been willing to give things a crack if he has that proof of concept.” 

Mark oversees 26 ha of stonefruit, apples and pears across three properties. He says, in the 5 ha block of Honey Belle initially trialled, the combination with Brevis did

a better thinning job than 6-BA alone. “Overall combining Brevis and 6-BA was a successful thinning treatment that provided earlier access to blocks for an easier final hand-thinning operation.”

An early sugar pear, Honey Belle is primarily exported to Asia. Quality is important and the market is increasingly looking for larger pears which creates its own challenges. 

Mark says Brevis was used because it was a “slightly softer” option. “You never want to overdo it. We still want to get a crop. With the weather here, using 6-BA and Brevis gives us a foot in each camp. Dealing with nature means every year is different, and it can throw you a real curve ball sometimes.” 

Adama New Zealand Commercial Manager Damian MacKenzie says the more thinning knowledge gained and shared the better. “Then we can further tailor our response to advisors’ and growers’ needs and enhance the quality and quantity of the fruit they take to market and their profitability.” 

Brevis mimics shading, stressing the tree and reducing carbohydrate production which means remaining carbohydrates are sent to shoots and dominant king fruitlets at the expense of smaller fruitlets, which start to drop from the tree in seven to ten days. 

Applied when fruitlets are between 8 and 14 mm, Brevis can be sprayed over a wide range of temperatures between 10 and 25°C, offering the orchardist flexibility of application timing. The Brevis label covers single and split applications, this allows fine-tuning for weather conditions. Brevis is rain-fast within two to three hours and

blocks can be re-entered after three days. It is also non-toxic to beneficial insects. 

For more information on Brevis visit our Thinning Hub