Stimulating plants to mobilise their natural defences against disease has the potential to halve fungicide use in winter barley, according to recent research carried out by Dr Neil Havis of SRUC.
When a plant is attacked by a pathogen, a recognition process occurs which can lead to plant responses such as strengthening the cell wall and producing anti-fungal compounds. Such responses are induced by agents known as elicitors, explained Dr Havis. “Elicitors cut out the middle man [i.e. the pathogen] and prime the plant to think it is under attack.”
Dr Havis is currently studying commercial elicitor products including Laminarin and Regalia. Two years of winter barley trials at SRUC looking at mildew, rynchosporium and ramularia disease levels using a number of seed treatments, followed by no fungicide, a full fungicide programme and an elicitor + half rate fungicide programme show there is a yield response with an elicitor seed treatment followed by the elicitor and half rate programme of 0.3t/ha over the untreated control. This compared favourably with full fungicide programmes which gave a yield increase of 0.4t/ha over the untreated he says.
Elicitors in the trial were applied as a seed treatment and as a foliar spray at T0. “Elicitors prime the plant so there is no point in waiting for T1 and T2.”
Elicitors have the potential to be used with fungicides, enable reduction of fungicide doses, protect chemistry and prolong the life of existing varieties with good quality characteristics but poor resistance genetics, said Dr Havis.
“There is a lot of interest in elicitors, for IPM and also potential to cut fungicide cost. Work at SRUC is investigating the potential of producing an IPM programme for disease control in barley. Elicitors along are not the solution but can be integrated with fungicides and varietal resistance.”