Abstracts Guava (Psidium guajava) a vitamin C enrich fruit tree is grown abundantly throughout Sudan. In fact, it is an important fruit in many parts of the world where the climate is suitable for its production. The present investigation was undertaken under laboratory conditions of Plant Protection Department, College of Agricultural Studies, Sudan University of Science and Technology to study the effect of different concentration of aqueous extracts of jatropha seeds and argel leaves conce...