Andrew Brown’s (left) rain gun injector for Nemaslug Xtra, a biocontrol slug killer, should make the product more user-friendly to use, hopes Andy Barker of Branston.

A purpose-built injection system has been developed to apply the biocontrol slug killer Nemaslug Xtra through a rain gun.

The active ingredient in Nemaslug Xtra, a 1mm parasitic nematode, needs enough moisture to be able to move through the soil profile to attack slugs, making applying it with irrigation water a natural solution.

It was a much more user-friendly solution than waiting for rain to apply the product, Andrew Brown from Nemaslug Xtra producer’s Becker Underwood said.

The injector, which he had spent two years developing, had a 600 litre mixing tank and generated its own power, he explained. “A computer system monitors how much water is going on the crop, and makes sure the correct amount of Nemaslug is injected so it is evenly applied.”

At a cost of £5,500, the injector is aimed at bigger potato growers facing a

constant slug problem, Branston’s Peter Cocks said.

The product is also expensive compared with slug pellets, costing £111/ha. But with the nematode moving through the soil profile to find slugs to attack, it did have the advantage of being able to control slugs attacking tubers, he pointed out. “Slug pellets sometimes don’t work at all in that situation.”

For best results Branston‘s Andy Barker suggested three applications starting with at 50% crop coverage for population control, followed by a second application four to six weeks later if there is a sudden rapid increase in slug activity.

“But the most important application is two weeks before burn-down,” he stressed. That was the application that controlled slugs moving down from the haulm to attack tubers, he explained.

PCN Control

Plant Solution’s blends of mustards could help with PCN control, says Alec Roberts

Positive effects have been seen against key potato pest potato cyst nematode and rhizoctonia and black dot from the use of biofumigants, according to Alec Roberts of Plant Solutions.

The firm breeds several varieties of Caliente mustards, which, when flailed and incorporated into soil, produced a toxic gas, isothiocyanate, he explained.

The biggest problem was fitting the crop into the rotation. “There is an effective space after winter cereals, sowing the mustard in late July and incorporating pre-frost by mid-October.”

An alternative was to grow it over-winter, planting at the end of September, and incorporating before potato planting. “The problem is trying to grow a big enough crop in the spring. This year is didn’t do that, but we’ve seen the best effects the closer you incorporate before planting.”