Leaf spot season

23 October 2014

Low levels of leaf spotting within some orchards in the Bay of Plenty region have been reported over the last week. Sepal browning is being reported for some blocks historically vulnerable to bud infection. Leaf spot symptoms are traditionally seen this time of year—often appearing after periods of wet weather and particularly if these are also associated with wind and cold conditions.

Research has shown that a good protective spray programme helps minimise leaf spot symptoms, reducing inoculum build-up within orchards. Maintain copper cover, and in high-risk situations the use of KeyStrepto™, is highly recommended at this time to avoid build-up of orchard inoculum levels. Actigard™ provides further support by eliciting the vine’s defence system through this critical pre-flowering period.

Growers intending to trunk girdle as an additional tool against flower bud and flower infection are recommended to leave some un-girdled vines, to allow measurement of the value of this tool on their individual site. Click here for Zespri’s methodology on the Canopy.