STUDIES ON POWDERY MILDEW DISEASE ON TOMATOES IN EGYPT

Abstract

Tomato powdery mildew disease is considered one or the most important diseases, which attack tomato Nile plantations in Egypt causing great damage to foliage and yield. The results of the present pathological, physiological, and control studies can be summarized as follows :-

I. Tomato powdery mildew disease was more severe in both Ismailia and El-Fayoum governorates than in middle and govcrnora!cs or Upper Egypt (Giza. lkni-SucL 1 1-Minia •1nd Sohag). Whilst the least disease severity was found in EI­ Minufiya and Qalubiya governorates.

2. Disease severity increased progres ively trom June until September, then begin to decrease to reaches its minimum value during November. The infection and development of tomato powdery mildew disease seemed be correlated with the prevailed averages of both temperature and the relative humidity.

3. According to the observed disease symptoms and characteristics of the conidial stage. the causal fungus identified as L!!veillu/a tauricu.

4. Investigations revealed the absence of the perfect stage of L. taurica (Lev-) Arnaud under greenhouse and field conditions.