Egypt. J. Biotechnol. Vol. 54, February, 2017

Egypt. J. Biotechnol. Vol. 54, February, 2017.

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EFFECT OF BIO AGENT CONTROL AND SALICYLIC ACID ON FUSARIAL WILT DISEASE IN TOMATO PLANTS BY Rashad M. Youssef, Youssef A. Arab and Hussien Y. H. Soliman

FROM Department of Agricultural Botany, Faculty of Agriculture, Al-Azhar University,Cairo.

ABSTRACT The tested F.oxysporum isolates significantly varied in their ability to cause wilt infection of tomato plants under greenhouse conditions. The most aggressive one was are Alexandria isolate where disease severity on shoot system and root system was 88% and 84%, respectively. All the tested inducing treatments were effective in reducing the wilt disease incidence and severity. The best treatment for tomato wilt disease control was of Bacillus subtilis + salicylic acid (SA). The combination of Trichoderma spp. (T. harzianum + T. viride) provided better disease control than alone isolates against Fusarium. Application of all the tested bioagents significantly promoted the plant growth parameters over untreated (inoculated controls). The best treatment was of P. fluoresecens. An increase in peroxidase and polyphenoloxidase enzyme activity in all treatments compared to control either relative to the infected or healthy control. On the other hand, the treatment by Rhizolex-T fungicide was the least effective in stimulating plants to produce the enzymes. Pseudomonas fluoresecens was the best treatment in the production of indole acetic acid (IAA) which exhibited compared with control. It could be concluded that combinations of biocontrol agents and chemical inducers could provide promising integrated alternatives in suppression of tomato Fusarium wilt disease due to multiple of mechanisms involved.

INTRODUCTION Tomato (Solanum lycopersicun L.) is considered as one of the most important economic vegetable crops for export and food processing in Egypt, it is widely grown in different seasons throughout the year in open field and under greenhouse conditions especially in newly reclaimed desert lands (Abd-El Kareem et al.,2006). According to the report of the Egyptian Ministry of Agriculture, Economic Statistical Department in 2013, the total cultivated area of tomato in Egypt reached 505823

feddans yielded 8053701 tons, with an average of 15922 tons/ feddan. Mandal et al. (2009) reported that Fusarium wilt of tomato caused by Fusarium oxysporumf. sp. lycopersici is the major limiting factor in the production of tomato. The disease causes great losses, especially on the susceptible varieties of tomato when soil and air temperature are rather high during the warm season. In Egypt, the losses due to tomato wilt disease reached up to 25-67%