Disease control mildew

Disease development often appears to be influenced by growth regulators. Most of these studies concern wilt diseases in various crops, especially caused by Fusarlum spp. and Verticilllum spp. (12). However, kinetin has been shown to be active against other types of diseases, such as the powdery mildews of cucumber (10) and tobacco (8). The mode of action of growth regulators in the disease control... 

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. 

Additional new systemic fungicides are being introduced for wheat disease control. One material CGA 64250 (Tilt),(l-(2-(2,4-di-chlorophenyl)4-propyl-l,3,-dioxolan-2-yl methyl)-H-l,2,4-triazole), is effective for control of powdery mildew, rust, and Septoria leaf blotch. However at this point in time, it is not certain whether U.S. EPA registration will allow a short enough interval between treatment and harvest for effective disease control by this compound. 

An important decision you must make is whether or not controlling a specific disease problem in your garden is worth the effort, time, expense, and possible hazards. Spraying lime-sulfur to control mildew, for example, may burn your plants leaves in hot weather. Over time, your experience will help you project how severe a problem will become later if you don t take steps to control it. 

Besides the intrinsic properties of each resistance mechanism, the economic impact of Qol resistance on the Qol market is also governed by the availability of alternative fungicidal modes of action for disease control and resistance management in each crop. For example, the early and rapid development of resistance of cereal powdery mildew (Blumeria graminis) in European wheat and barley production from 1998 on had a remarkably low impact on Qol consumption. The broad disease spectrum controlled by Qols and the availability of several other modes of action for the control of powdery mildews in cereals such as DMIs, amines, cyprodinil, quinoxyfen, and metrafenone resulted in a nearly unchanged use frequency of Qols in European cereal production. 

Fluquinconazole, a quinazoline-based triazole fungicide, was introduced to the public in 1992 [76] (Table 17.17). When used as a foliar fungicide fluquinconazole is particularly active against pome fruit diseases such as Venturia inaequalis and Podosphaera leucotricha. Other diseases controlled include powdery mildews, Mon-ilinia spp., Cercospora spp., rusts. 

The impact of this limited vascular unloading on biological performance is effectively illustrated in Figure 3, which compares the redistribution of radiolabel and P. viticola disease control of V after petiole injection with that of an experimental strobilurin with more desirable attributes. In the case of the strobilurin the vasculature appears white indicating that the majority of the injected radiolabel has unloaded into the leaf tissue to deliver complete disease control. In contrast, the majority of the radiolabeled V remains associated with the leaf vasculature with the result that the downy mildew was essentially uncontrolled in the inter-veinal regions of the leaf. 

Hazardous Decomp. Prods. Heated to decomp., emits toxic fumes of NOx Uses Systemic fungicide with protective, curative props. controls wide range of diseases (yellow and black sigatoka, pink disease, powdery mildew)... 

Table I shows the activity of the cyclic tertiary amine compounds described in this chapter as an eradicant treatment against barley powdery mildew (Ervsiphe graminis hordei). The results represent the concentrations of chemicals expressed in parts per million (ppm) required to give 95% disease control.

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