IMPROVED APPLICATION TECHNIQUES WAYS TO HIGHER EFFICACY OF FUNGICIDES AND INSECTICIDES IN FIELD GROWN VEGETABLES

摘要

In field grown vegetables,fungicides and insecticides are,by and large,applied with standard field booms equipped with standard flat fan nozzles or flat fan air injector nozzles typically spraying top down.Results obtained in controlling pests and diseases are often not satisfactory and farmers then tend to increase the dose or spray more often.Until recently,farmers almost invariably blamed the pesticides for inadequate control levels achieved.They argued that modern products were too "soft",had low efficacy,or that resistances to key pests and diseases had developed.Preliminary tests with water sensitive paper in bush beans indicated that by applying fungicides with a standard boom to control stem and pod rot (Scterotinia sclerotiorum) may result in high deposits of active ingredient on the upper side of the leaves,but in rather low deposits on the lower parts of the stems,where the protection is most needed.Similar preliminary tests were carried out in Brussels sprouts,cabbages and onions.It was concluded that better spray methods would need to be investigated.