Abstract
The effect of tomato seedling treated with plant growth promoting rhizobacteria (PGPR) strains viz. Azotobacter sp. (AZM1),Bacillus cereus (BCM8), B. megaterium (BMM5) individually or combined with humic acid were evaluated for controlling wilt disease caused by Fusarium oxysporum f. sp. lycopersici, plant growth, fruit quantitative and qualitative (cv. Super Strain-B) during 2010-2011 and 2011-2012 growing seasons. Under greenhouse conditions, all treatments significantly reduced area under disease progress curve (AUDPC) and increased plant height, fresh and dry weights of survival plants growing in pots infested with the causal pathogen compared with control. Combination treatments of humic acid with PGPR reduced significantly wilt incidence and increased plant height, fresh and dry weights of tomato plants comparing with the application of each of them alone. Under laboratory conditions, all PGPR strains and humic acid able to inhibited leaner growth of the causal pathogen with different degrees and PGPR strains were more active than humic acid in this respect. Under field conditions, all PGPR stains individually or combined with humic acid significantly reduced AUDPC and improved plant growth (plant height, number of branches plant -1) quantitative (number of fruits plant -1, fruit weight plant -1, fruit weight, fruit yield fed. -1, Number of fruit Kg -1) and qualitative (degree of fruit’s color, fruit diameters, firmness, fruit height, total soluble solids) parameters of tomato fruits compared with untreated plants (control) in both growing seasons. Combination treatments of humic acid with PGPR strains increase the effectiveness of them in this respect more than used alone.
Highlights
Tomato is one of the most valued vegetable crops of the world
The treatment of mixed Plant growth promoting rhizobacteria (PGPR) strains, Azotobacter sp., B. megaterium and B. cereus recorded the highest significant reduction in area under disease progress curve (AUDPC) when combined with humic acid (68.02%) followed by treatment B. megaterium combined with humic acid (65.32%) and B. cereus + humic acid (63.89%)
An option for reducing pollution caused by the use of synthetic agrochemical in tomato disease management is biocontrol by using of antagonist rhizobacteria belonging to the Bacillus, Azotobacter genus and/or organic substances such humic acid, because they are considered the most efficient for their inhibitory properties (El-Mohamedy, and Ahmed, 2009), stimulation of plant growth and crop yield enhancer (Wahyudi et al, 2011)
Summary
Tomato is one of the most valued vegetable crops of the world. It has a very high nutritive value and has antioxidant and curative properties. The most effective method in preventing tomato from Fusarium wilt is to mix the seed with chemical fungicides. The use of Fusarium-resistant tomato cultivars can provide some degree of control of these diseases, the occurrence and development of new pathogenic races is a continuing problem, and currently there are no commercially acceptable cultivars with adequate resistance to F. oxysporum f. PGPR is a mixture of beneficial microorganisms which can increase the crop yield, plant growth and protect against plant pathogens (Seleim et al, 2011). The objective of this study was carried out to assess the efficacy of certain PGPR strains individually or combination with humic acid for the management tomato wilt disease as well as its effect on growth parameters, fruit yield and quality
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
