FIRST RECORD OF ROOT ROT AND WILT DISEASES OF THE MEDICINAL PLANT RUTA GRAVEOLENS L. IN EGYPT AND THEIR CONTROL

Surveying plantations of rue (Ruta graves:dens) exhibited a new record of root rot and wilt fungaf diseases for the first time in Egypt or elsewhere. Isolation trials yielded several fungi belonging to 10 genera. Fusarium moniliforme (21.3%), F. sotani (17.6) and F. oxysporum (17.2) showed the highest percentages of frequency, followed by Rhizactonia solani (13.3%) and F. semitecturn (11.1%), while Pythium debaryanum occurred at 10.9%. Pathogenicity studies using seeds or seedlings in planting indicated that F. oxysporum, P. debaryanum and R. sotani were the most aggressive fungi. In infested soil, the use of Topsin M and Vitavax/Thiram as seed dressing, significantly controlled damping-off diseases in case of F. mo­nth^-forme, F. oxysporum and Scierotinia scferotiorum, while Plant Guard (Trichederma harzianum, 3x11:1⁷ cluirril) or Rhizo-N (Bacillus subtilis, 3x10⁷ cfulgm) were the least effective. Also, these fungicides or bioa­gents successfully decreased infection significantly in comparison with the control when soils were infested with P. debaryanum or R. solani. On the other hand, dipping in Topsin M solution was generally the most ef­fective treatment for the transplants against rue diseases, although it failed to give sufficient control in some cases. Efficacy of Plant Guard and Rhizo-N as transplants dipping treatments varied according to the pathogen. Rhizo-N was generally the best one. Positive effective values of the bloagents were approximately equal to that of Topsin M. Moreo­ver, they were successful in some cases where fungicides were not.