FOLLOWING a challenging potato blight year for many a new 'anti-drift' product has come through the problems of 2017 in good shape, according to growers and agronomists.

In its first full season of use, Interagro’s Crusade has been widely used in tank mix with a range of different potato blight fungicides, following the endorsement from SRUC’s Dr Ruairidh Bain earlier in the year. He had conducted trials in 2014 and 2016 as part of his potato blight research and Eurofins has also conducted a series of trials for manufacturers.

The combined results recorded a 19% improvement in blight control, an improvement in yield of over 2t/ha and Dr Bain recognised the product’s role as a 'valuable ICM option' and 'exciting for the potato industry, because products like these don’t increase the amount of fungicide being applied'.

Agrii’s John Mason, who advises growers in a dense potato growing area on the Black Isle and further into northern Scotland, said that Crusade had been a valuable asset to the seven-day application windows necessary in this high-pressure region. “The product works by reducing drift and improving leaf coverage and penetration, so more of the fungicide enters the leaf,” he pointed out. “I’ve recommended it in every tank mix, with the exception of Ranman, which already has a wetter incorporated.”

He said that crop coverage was noticeable, leaving a sheen on the leaf surface. “Where an area was missed, leaves looked duller and less healthy.” On one farm where a field had no Crusade, the crop quickly succumbed to blight, he added.

Mr Mason said the product not only encouraged fungicide uptake, but also allowed water volumes to be reduced to 170-220 litres/ha. “The old advice used to be to apply blight sprays in 300 litres/ha of water, in my view, these rates are too high and will cause the fungicide to run off the leaf.”

Based on his observations this year, Mr Mason will be recommending Crusade in every tank mix next year. “At a cost of £3-4/ha per application of Crusade, the additional spend makes perfect sense versus the alternative of ingress of blight and dealing with a curative situation that is hard to recover from.”

Growers are citing similar claims to agronomists. Mike Dagg, who farms at Crailing Tofts, near Kelso, in Roxburghshire, said that there was 'no doubt Crusade had an important place in our blight control programme.'

He grows 850-acres of ware potatoes for Greenvale AP, destined for Sainsbury and Tesco. All are pre-packed and need to be of the premium quality to meet the stringent demands of retailers. The total crop of 19,000 tonnes are refrigerated on-site, in store until they are ready to be marketed.

“We operate to the highest standards to keep potatoes fresh, blight and eye movement-free. Keeping late blight out of the crop is a top priority and is only achieved by close attention to detail and applying a robust fungicide programme that penetrates all of the crop. Even in marginal spraying conditions it's vital to keep going, especially with our large area of different varieties to protect."

Mr Dagg noticed that fungicides with Crusade had a spray pattern that was noticeably improved and with significantly less drift. “With the crop putting on new growth every week, it’s vital that every part of it is protected, which Crusade clearly achieved, using it also kept us spraying, even when weather conditions were wet and far from ideal.

"The leaves looked noticeably protected with a sheen like a polished car bonnet. We used Crusade throughout the programme. After two seasons of use, I will definitely be using it again in 2018”, he added.

* Interagro will be exhibiting on stand 143 at BP2017 at Harrogate on November 22 and 23.