Further Experiments on Black‐leg Disease of Sugar‐beet Seedlings

Soaking sugar beet seed for 20 min. in ten times its weight of water containing 40 p.p.m. ethyl mercury phosphate to control seed‐borne Phoma betae gave better seedling emergence than surface treatments with commonly used organo‐mercury dusts or with Panogen (methyl mercury dicyandiamide), thiram, Granosan M (ethyl mercury p‐toluene sulphonanilide), captan, Dow 9B (zinc trichlorophenate) or Cerenox (acylphenylhydrazone). In 4 years' field trials, soaking seed in ethyl mercury phosphate solution followed by dusting with an insecticidal dust, compared with a routine mercury‐plus‐insecticidal dust, increased seedling emergence at fifty‐three of fifty‐nine sites by an average of 10% under good emergence conditions and by 20–30% under adverse conditions. Final plant stand was increased each year by an average of 5.8, 3.4, 1.8 and 0.6%, respectively.