EFFECT OF FORMULATED PLANT OILS APPLIED ALONE AND IN COMBINATIONS ON WHEAT LEAF RUST DISEASE AND GRAIN YIELD

Antifungal activity of ~rtain plant oils and some of Iheir combinations on
wheat leaf rust, PlJccinia rocondita f.sp. friliciwas evaluated under field conditions. All
treatments of the tested plant oils. applied alone or in pairs, showed significant
redtJction in leaf rust severity of wheat cultivar, Giza 160. Of the fonnulated essential
oils 'applied singly, caraway oil and peppermint oil were the most effective at the rate
of 0.8% in reducing leaf rust severity which ranged from 76.3-86.0% in the plots
treated with caraway oil and 72.9-81.5% in plots treated with peppermint oil.
respectively. The mixtures of caraway + jojopa oils, caraway + pepper tree oils and
caraway + peppennint oils were the best combinations in controKing leaf rust disease
which gave reduction in leaf rust severity ranged between 81.4% and 100% during the
two growing seasons. Grain yield (ton/acre) was also increased by the application of
plant- oil combinations revealing an increase in grain yield ranged from 27.0-38.0% of
caraway + jojopa oil combination, 25.7-37.5% of caraway + pepper tree oil
combination and 25.9-34.8% of caraway + peppermint oil combination which,
subsequenlly, led to a relative increase in 100-kernel weight. There were no
significant differences were shown between Sumi-8 fungicide and the three oil
mixtures concerning fungicidal field efficacy and improvement of grain yield. II was
recommended that natural oils used and their combinations might be considered as
an effective and safe method for the management program of wheat rust.