Better targeting and reduced drift of pesticides in orchards is achievable with new innovations in sprayers, visitors to Edmund Allen’s farm near Portadown were told last week.

The orchard walk was organised by CAFRE and the Northern Ireland Fruit Growers Association (NIFGA) and focused on current developments in fruit growing.

The electrostatic technology used in Edmund’s Tifone Vector 1000 orchard sprayer uses a polarised rod that extends the entire span of the spray outlet.

This differs significantly from previous electrostatic sprayers that had individual polarised rings for each spray nozzle.

The polarised rod charges spray droplets positively, causing them to repel each other, resulting in a thinner, more uniform cloud of droplets.

Leaves that are naturally negatively charged attract the positive droplets, causing increased deposition on both sides and reducing drift of sprays, resulting in increased spraying efficiency.

Edmund said: “I can cover four to six acres per hour now with the electrostatic sprayer compared with just over three acres per hour with a conventional sprayer. I can also spray five or sometimes close to six acres with the same amount of spray that would only cover four acres with a conventional sprayer.”

As well as looking at spraying techniques, the farm walk covered crop storage. According to Edmund, the use of Smart Fresh in stores to control ethylene levels works well if stores are filled and treated within three to five days after harvest.

However, from March onwards he sees ethylene levels rise and has decided to use Fresh Extend potassium permanganate granules to remove excess ethylene from stores, giving a wider window for marketing apples.

The Fresh Extend system continually filters all air in the store through a V-shaped box on the ceiling containing the granules.

Disinfectant

Mark Staplehurst from SDL Ltd also outlined the potential of a disinfectant for fruit, boxes and stores, made from water and salt and which works through the process of electrolysis.

The “activated water” is pH neutral, non-toxic and environmentally sustainable and is already used widely in hospitals, food processing and other industries.

He said that the disinfectant kills sporicidal and bacterial infections and, although mildly saline, it does not affect the taste of food products that it is used on.

Fruit set

Simon Townsend from BASF spoke about Regalis Plus, the new formula of the growth regulator for shoots with water conditioner. He quoted a trial that found application during early fruit development and again at petal fall had significantly improved fruit set compared with traditional application times of Regalis at 90% petal fall and a follow-up spray three weeks later.

When questioned about management for fruit set after hard frosts, Simon recommended applying 0.5kg/ha of Regalis Plus immediately, and then continuing to spray at the conventional times as long as the limit of 2.5kg/ha for the season is not exceeded.

He also said that new regulations for seasonal application rate of Dithianon have meant a new product will be launched to replace Dithianon WG.

The old product will be removed from the market this November to be last used by November 2016.

The new product is to be applied six times at 0.5kg/ha compared with the old product, which was 12 applications at 0.75kg/ha.

Simon said that the new formulation will be just as effective, if not more.

Potassium

Speaking on potassium deficiency, Graeme Cross from CAFRE said that brown colouration of leaves occurring initially along the edges is characteristic of the problem. Symptoms appear first in older leaves but may move to younger leaves in severe cases.

“Potassium is easily taken up by trees but also easily leached out of soils in times of heavy rainfall. Supplementary potassium is best applied early in the season to help develop the bud. It can be applied in the form of potassium nitrate or sulphate as well as liquid potash,” Graeme said.

Deficiency can be quickly reversed if trees are treated as soon as the problem is spotted. Potassium is not toxic to trees but over-application may inhibit magnesium and calcium uptake, affecting tree health.