To date, Agrovista’s mycorrhizal inoculant, RG Pro, has been limited for use in new orchards, with product granules being applied to tree roots pre-planting, because of limitations in applying the product via drip lines or direct application to the soil surface.

Following an ingenious retro-fit of a Stocks Ag Rotor Meter placement system to a conventional root pruning machine by Agrovista’s Tom Johnson, growers can now inoculate established trees to extend their productive life.

“The system works by applying granules in behind the root pruning blade as the machine moves through the orchard in the vicinity of the small fibrous roots which are towards the top of the soil profile,” Mr Johnson explains.

“The system can also be used as a way of applying RG Pro, even if root pruning isn’t necessary; the contractor simply inserts the blade vertically into the soil near the tree roots, delivering product close to where it needs to be.”

According to Paul Bennett, Agrovista’s technical head of fruit, Mycorrhizal fungi are associated with about 80% of plant species and can greatly augment root volumes, attaching themselves to plant roots and giving the plant access to a much bigger volume of soil.

“Orchards inoculated with mycorrhiza demonstrate better nutrient and water uptake, as well as improved resilience to waterlogging and other soil health issues. Trials suggest that they increase root uptake area by 700 times.

“Mycorrhizal fungi are the most understood of soil microbes. Too small to be seen with the naked eye, they form a symbiotic relationship with plants, colonising their roots while penetrating soil, enabling them to swap carbon for valuable mineral nutrients, particularly phosphorous and nitrogen, and water.”

The fungi can reduce the effect of stresses such as pathogens and drought, and can help improve heavy metal tolerance. There is also evidence that they can reduce infection by soil-borne pathogens.

Unlike other mycorrhiza inoculants on the market, RG Pro contains simply the fungi with an inert carrier and doesn’t contain any fertiliser. “Also, the fungi in RG Pro are UK derived which isn’t the case for the majority of products on the market,” Mr Bennett adds.

The Agrovista root pruning and RG Pro application service will be ready for the coming pruning season. The work will be carried out by a third-party contractor at a work rate of 5km/hr.