The main cereal crops in the world are wheat, maize, millet, rice and barley. Cereals, such as sorghym, rye, oats are grown on a smaller scale. Great annual loss to world crops occurs as a result of disease, and much of these losses are due to fungal infections. Leaf rust (Puccinia recondita f. sp. tritici) cause considerable damage to wheat. There have been reports of losses of up to 55% in the United States of America. Various methods of controlling leaf rust have been used, but it appears that the future control will be with systemic fungicides. Better fungicides and knowledge of how they work are being sought in the continuing struggle to keep one step ahead of the fungi. Triforine (CW 524) and RH 124 have been used to control leaf rust elsewhere. The availability of these fungicides to control leaf rust under New Zealand conditions was investigated.