Abstract
The author previously reported that the decrease of surface tension of fungicidal suspensions is parallel to the deposit of fungicide on leaf surface. In the present paper the author reports on the influence of the quantity of the deposit of fungicide upon the control of citrus melanose.
1. Mixing Elsan, Vinyphate, Spracide, Azomite, and Citrazone with Dithane M-45 decreased its deposit on the leaves and reduced the effect for the control of melanose.
2. Mixing of various insecticides with M-Diphur also decreased its deposit on the leaves, showing 21.04r/2cm2 of M-Diphur alone, and 3-10r/2cm2 of the various mixtures. On the other hand, its mixture with Summer Oil showed much more deposit even 39 days after spraying. Effectiveness for the control of melanose seemed to be parallel to the quantities of the fungicidal deposit. And its mixture with Summer Oil showed the highest effect of all combination and superior to even Diphur alone.
3. For the purpose of compensating the decrease of fungicidal deposit of the mixtures, the concentration of Dithane M-45 in the mixture was increased as following dilutions: 1/360 in the mixture with Dimethoate, 1/240 in Supracide, 1/180 in Elsan, 1/180 in Citrazone, 1/120 in Vinyphate, 1/60 in Amiphos and Santokuten. All those mixtures proved higher effect than Dithane alone. While the mixture with Microdenapon or Eraditon showed less effect than the alone.
4. Adding the wettable spreader to Dithane M-45 or Dithane Z-78 showed much less effect than the alone for the control of citrus melanose.
