Wpływ preparatu Silwet Gold na skuteczność fungicydów stosowanych do ochrony gerbery przed Erysiphe polyphaga

Gerbera plants with the symptoms of powdery mildew (Erysiphe polyphaga) were sprayed with the fungicides: Bravo 500 SC, Discus 500 WG, Dithane NeoTec 75 WG, and Domark 100 EC (without a wetting agent), or in a mixture with the adjuvant Silwet Gold 0.015%. After 2 spray treatments at 7-day intervals, the degree of infection observed on the leaves of the plants protected with the tested fungicides with Silwet Gold added to them was from 36.4 to almost 100% lower, depending on the experiment. All the tested fungicides with the addition of Silwet Gold completely covered the top and bottom sides of the leaf blade. In the case of the products: Bravo 500 SC, Discus 500 WG, and Dithane NeoTec 75 WG used alone, after the completion of spraying there were single drops, sometimes merging together, left on the leaves, and a considerable part of the leaf blade was not covered with the liquid. When the spray solution had dried, prominent white stains of concentrated residue were found remaining on the leaves of the plants sprayed with Dithane NeoTec 75 WG. In the case of the products Bravo 500 SC and Discus 500 WG, the residue stains were less pro-nounced. The fungicide Domark 100 EC without the addition of Silwet Gold did not leave any obvious residue on the protected plants.