This study was conducted in the Faculty of Agriculture Orner AI·Mukhla(
University. EI-Beido City-Libya during the period from 1998-1999 Plant diffusatss
were tested tor their fungicidal action to control early blight disease of tomaot causing
by Altemaria solani that was wide spread in this region. Aqueous diffusates from
different parts of 21 ptant species in a concentration of oo', 10"2 and 10'1 were
tested on conidial germination. number of germ tubes and germ tube length of
Altemaria sotet». Results indicated that the diffusates of Trigonella faenumgraecum.
Allium sativum, Capsicum annaum, Thymus vulgaris and Thapsis garganica inhibited
comp!etely spore germination at low concentration, while other diffusates had little
effect on such phenomena. Tomato plants were sprayed under field condition by the
best five plant diffusated in addition to control plants sprayed by water and other
plants were sprayed by Rovral (0.15%) or Dithane M4s (O.25%) to lest their efficacy on
the disease incidence of early blight on three tomato cultivars. Results showed that
diffusates of Thapsia garganica. Rivoral and Dithane M45 gaves the high level of
protection and led to decrease disease incidence and increased plant yield. Results
also indicated than no significant differences was observed between the other
diffusates on the percentage of infection. Results indicated also that Dithance M45 was
the best fungicide against early blight under field condition in reducing disease
incidence and increased plant productivity.