Fungal communities on roots of wheat and barley and effects of seed treatments containing fluquinconazole applied to control take-all

Communities of fungi on roots increased in diversity between second and third cereals, and were more diverse on winter wheat than on winter barley in a field experiment conducted over 3 years. Seed treatment with formulations containing fluquinconazole or fluquinconazole plus prochloraz had little effect on these communities, which include potentially beneficial, antagonistic fungi. Seed treatment decreased take-all and increased yield of wheat, especially in the second wheat in which take-all was building up, and in the third wheat when take-all was at its peak. It was less effective in the fourth wheat when take-all appeared to be in decline in plots that had no seed treatment throughout the experiment, and in barley, in which take-all was usually less severe. Take-all increased in untreated fourth wheat crops grown after third wheat crops that had been treated, suggesting that treatment had delayed take-all build-up and eventual progress into take-all decline.