International Symposium on Virus Diseases of Tropical Crops International Symposium on Ecophsiology of Tropical Crops Symposium on Virus Deseases of Tropical Crops (Manaus)International Symposium on Ecophsiology of Tropical Crops Investigation of virus diseases of brassica crops International Symposium on Biological Control of Weeds International Symposium on Industrial Uses of Selenium and Tellurium International Symposium on Genetic Manipulation in Crops International symposium on Humidity and Moisture SID international symposium digest of technical papers