Hindawi Publishing Corporation Journal of Marine Biology Volume 2013, Article ID 429850, 10 pages http://dx.doi.org/10.1155/2013/429850 Research Article Bioagents and Commercial Algae Products as Integrated Biocide Treatments for Controlling Root Rot Diseases of Some Vegetables under Protected Cultivation System Mokhtar M. Abdel-Kader and Nehal S. El-Mougy Plant Pathology Department, National Research Centre, El-Behouth St., Dokki, 12662 Giza, Egypt Correspondence should be addressed to Mokhtar M. Abdel-Kader; mokh nrc@yahoo.com Received 26 April 2013; Revised 6 October 2013; Accepted 25 October 2013 Academic Editor: Jakov Dulˇ ci´ c Copyright © 2013 M. M. Abdel-Kader and N. S. El-Mougy. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Integrated commercial blue-green algae extracts and bioagents treatments against vegetables root rot incidence when used as soil drench under greenhouse and plastic house conditions were evaluated. All applied treatments reduced signifcantly root rot incidence at both pre- and postemergence growth stages of cucumber, cantaloupe, tomato, and pepper plants compared with untreated check control. In pot experiment, the obtained results showed that treatments of Trichoderma harzianum or Bacillus subtilis either alone or combined with commercial algae extracts were signifcantly superior for reducing root rot disease for two tested vegetable plants compared with the other tested treatments as well as control. It is also observed that rising concentrations of either algae products, Oligo-X or Weed-Max, were refected in more disease reduction. Promising treatments for controlling root rot disease incidence were applied under plastic houses conditions. As for feld trails carried out under plastic houses conditions at diferent locations, the obtained results revealed that the applied combined treatments signifcantly reduced root rot incidence compared with fungicide and check control treatments. At all locations it was observed that Weed-Max (2g/L) + Bacillus subtilis signifcantly reduced disease incidence of grown vegetables compared with Oligo-X (2 mL/L) + Trichoderma harzianum treatments. An obvious yield increase in all treatments was signifcantly higher than in the control. Also, the harvested yield in applied combined treatments at all locations was signifcantly higher than that in the fungicide and control treatments. 1. Introduction Vegetable crops are grown worldwide as a source of nutrients and fber in the human diet. Fungal plant pathogens can cause devastation in these crops under appropriate environmental conditions. Root rot in vegetables strikes quickly and then ruins a whole crop. Several fungi may cause root rot in veg- etable plants, transmitting the disease through the soil. Some common fungi include Fusarium, Rhizoctonia, Sclerotinia, and Pythium, each of which causes a root rot named for the specifc fungi that cause it. While the presence of one of these fungi is the primary cause for disease, plants exposed to poor growing conditions, such as a soil that does not drain well, are most susceptible to root rot. Te best way to avoid root rot is by eliminating these contributing causes and practicing sound cultivation techniques. It was reported that the soil- borne pathogens Rhizoctonia solani, Pythium ultimum, and Fusarium spp. can cause severe economic losses to feld and greenhouse cucumber [1]. Also, Fusarium stem and root rot on greenhouse long English cucumber (Cucumis sativus L.) cvs. Bodega and Gardon was observed at four commercial greenhouses in Leamington, Ontario, Canada. Losses of 25 to 35%, representing 2.5 ha, were noted. Fusarium spp., Rhizoc- tonia spp., and Pythium spp. were isolated from tomato plants showing root and crown rot symptoms [2]. Te pathogens, Alternaria solani, Fusarium solani, F. oxys- porum, Rhizoctonia solani, Sclerotium rolfsii, Macrophomina phaseolina, and Pythium sp. were isolated from cucumber, cantaloupe, tomato and Pepper plants grown in plastic houses and showing root rot disease symptoms [3]. Diferent