Mycorrhizae are symbiotic structure developed by the roots of plants and fungal mycelia. These mycorrhizae are often necessary for the growth of forest trees. This study was undertaken to determine the effect of the application of nitrogen and phosporus on the development of mycorrhizae in pinus merkusii. Andosol, collected in puncak, and latosol, collected in Darmaga, were used in this experiment. A seedling, transplanted into a pot containing 490 gr of dried soil, served as an experimental unit. Nitrogen ((NH4)2SO4) was applied at o ppm, 60 ppm, 120 ppm,
A number of legume species were inoculated with Phakopsora pachyrhizi Syd. the causal agent of soybean rust. The species showing rust symptom were Pachyrhizus erosus, Crotalaria juncea, Glycine max var. si Nyonya, Vigna unguiculata, Phaseolus vulgaris (green bean), P. radiatus (mung bean), P. aureus, Psophocarpus tetragonolobus, Vigna umbellata and Calopogonium mucunoides.
TKV-0 was identifled as the causal agent of a disease of Aranda Wendy Scott in Jakarta. Bioasssay showed that the virus prduced 10-1 lesirms m Cassia occidentalis, Chenopodium amzranticolor, Gornphrena ~l obosa , and Nicotiana glutinoaa . Observation of the "dig methoda preparation of diseaaed plant sap under the electron microscope indicated that the virus particles were rod-shaped and right with a length of about 300 mm.
The tidal swamp lands in Indonesia are potential areas for increasing food production especially rice. About 250.000 hectares of the swampy areas in suamtra and Kalimantan have been developed for rice production. Tidal swamp land has many interconnecting natural habitats wgich are economically and scientifically important. Agronomic activities in rice fields might have detrimental effects on other habitats. Therefore, agrochemicals especially pesticides for pest control, have to be carefully applied based on sound ecological approach. A Kind of pest management model is presented which consits of compatible combination of cultural control, use of resistant varieties, sanitation, and chemical control with environmentally least toxic pesticides if it is needed base on pest population count.
