Effects of spraying of machine oil emulsim on occurrence of tea red spider mite. Tetranychus kanzawai and yield of first tea were evaluated. The results were summarized as follows : 1. Occurrence of tea red spider mite moved from basal part of harvest surface of east in February. to middle and top part of harvest surface. 2. The population density of tea red spider mite was high on expanded upper second leaves(38%) and upper first leaves(29.2%). Horever, the density of tea red spider mite on unexpanded leaves and basal leaves was low. 3. Control value of machine oil emulsion applied on 15 March was 45%, but was 36.3% at routine application of 15 February. Two applications on 15 February and 15 march was betler than one application against tea red spider mite. 4. Control value of machine oil emulsion diluted to 20 to 40 times was 42.5~50%, but was getting lower at dilution of 60 to 80 times. The yield of fresh leaves of application at dilntion of 20 to 40 times was increased 6~7% than that of 80 times. 290kg/10a. 5. Phytotoxicity was detected with slitht wilting when machine oil tmulsin was applied at dilu tion of 20 times. However, there was on phttotoxicity in the other trials.
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