Powdery mildew against wheat

In France and Germany, disease control measures on cereals are directed primarily against foot rot and leaf diseases, or leaf and ear diseases. In the United Kingdom, treatments are generally made for the control of leaf diseases, such as powdery mildew. It should be mentioned that these data do not include the use of the azole-compound triadimenol as a seed dressing for early season protection against powdery mildew and rust fungi on wheat and barley. 

Products 115 protected tomato plants against Altermria solani and Botrytis cinerea, grape against powdery mildew, wheat against brown rust and Septoria leaf spot, barley against net blotch and rice plants against... 

Trichothecin is effective against several fungi, for example root rot of cereals (Helminthosporium sativum), loose smut of wheat (Ustilago tritici), diseases of sour cherry and cherry (Voros, 1955), fusarium wilt of Pinaceae (Belimova and Lopatin, 1963) and powdery mildew of tobacco (Manucharjan, 1964). Its most promising practical applications are the control Verticillium wilt of cotton and of the fusarium diseases of field crops (Askarova and Joffe, 1962 Bunina, 1960 1963). 

Crop. ProL Confi -Pests Dis. 1977, 593 R. G. Harris et al, ibid. 1979, 53. Efficacy against cereal powdery mildew D. M. Weigh ton et al, ibid. 1977, 25. Protective effect against blotch in winter wheat and barley R. G. Harris, G. Barnes, ibid. 1981, 267. Effect on cytochrome P-450 and sterol biosynthesis in Japanese quail J.-L. Riviere et al, Pestic. Sci. 15, 317 (1984). Review A. de Seint-Blanquat, J. My, Def. Veg. 37, 121 (1983). 

Structure-activity relationship (SAR) studies, correlating preventive fungicidal potency against wheat brown rust and barley powdery mildew, have been described only for special subclasses of N-benzyl-4-pyrimidine-amines [19, 20]. 

Table 1. SAR Protectant Activity of Substituted 7-Chioropyrido [l,2-a]pyrimidinones against Wheat Powdery Mildew...

In Table 5, the protectant activity of proquinazid is compared to that of other commercial standards against wheat powdery mildew. Proquinazid... 

Table 5. Protectant Activity of Proquinazid versus Commercial Standards against Sensitive Wheat Powdery Mildew Isolates...

Benzimidazoles. The best-known examples, which were introduced in 1967/8, are Benomyl and Thiabendazole. Both have been widely accepted as broad-spectrum systemic fungicides active against botrytis, powdery mildews, apple scab and as a seed dressing against common bunt of wheat. 

In 1976 the novel oxazoline 1 was foimd to exhibit interesting fungicidal activity in random screening. Especially noteworthy was its effect against powdery mildew disease on barley and wheat, which could be confirmed under field conditions with application rates as low as 125 g/ha. 

The library was prepared using automated liquid handling methods and active confounds were discovered in all three disciplines herbicide, fungicide and insecticide. One of the library numbers, conq)ound 14 depicted in Figure 9, was advanced to lead status based on its excellent preventative, curative and residual activity against wheat powdery mildew seen in our fungicide screens. 

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