21 February 1997

Growth stimulant works – thats official

LATEST in a burgeoning list of products aimed at enhancing potato yield comes from Newman Agrochemicals.

Based on a zinc/ammonium complex developed in the US, Yeald is said to have boosted output by 9.9% in 28 UK grower trials in the past two seasons.

Neither a growth regulator nor a fertiliser replacement, the product is believed to work by stimulating auxin production, which in turn encourages rooting, explains Newmans David Foster.

Trial marketing last year followed five fully replicated trials in 1995 at several independent research bodies, he says. "They showed that it worked."

For best results Yeald, which has also given benefits in sugar beet but "iffy" results in cereals, should be applied after full crop emergence but before tuber initiation, he says.

Application rate for potatoes is 0.4 litres/ha. "At £90 for three litres it is probably the cheapest of similar products."

&#8226 Commercial growth stimulants can give useful results, says NIAB potato specialist Tom Dixon. But much depends on variety, growing conditions and especially the timing of application, he warns.

Two years of UKtesting has proven the stimulating effect Yeald can have on potato roots, says David Foster of manufacturer Newman Agrochemicals.