Suppression of Fusarium wilt of watermelon by a bio-organic fertilizer containing combinations of antagonistic microorganisms

Abstract

Fusarium wilt of watermelon commonly occurs in locations where the crop has been grown for many seasons. Its occurrence results in a severely decreased watermelon crop. The goal of this study was to assess the capability of a new product (bio-organic fertilizer) to control the wilt in Fusarium-infested soil. Pot experiments were conducted under growth chamber and greenhouse conditions. The results showed that the fertilizer controlled the wilt disease. Compared with control pots, the incidence rates of Fusarium wilt at 27 and 63 days following treatment of the plants with the bio-organic fertilizer at a rate of 0.5% (organic fertilizer + antagonistic microorganisms, including 3 9 10 9 CFU g -1 Paenibacillus polymyxa and 5 910 7 CFU g -1 Trichoderma harzianum) were reduced by 84.9 and 75.0%, respectively, in both the growth chamber and greenhouse settings. The activities of antioxidases (catalase, superoxide dismutase and peroxidase) in watermelon leaves increased by 38.9, 150 and 250%, respectively. In the roots, stems and leaves, the activity of b-1,3-glucanase (pathogenesis-related proteins) increased by 80, 1140 and 100% and that of chitinase increased by 240, 80, and 20%, respectively, while the contents of malondialdehyde fell by 56.8, 42.1 and 45.9%, respectively. These results indicate that this new fertilizer formula is capable of protecting watermelon from Fusarium oxysporum f.sp. niveum. The elevated levels of defense-related enzymes are consistent with the induction and enhancement of systemic acquired resistance of plant.

Effects of banana wilt disease on soil nematode community structure and diversity

“…Domínguez et al (2008) reported that banana wilt disease caused unfavorable soil conditions such as low pH, electrical conductivity, organic matter, soil fertility and high soil compaction. Wu et al (2009) also observed that soil enzymes activities, soil respiration and microbial biomass were significantly lower in watermelon wilt diseased area compared to un-diseased area. Complex infection caused by plant parasitic nematodes and FOC gave rise to a necrotic and reduced root system, which in turn, resulted in a reduction in the uptake and transportation of water and nutrients by the plant (Poornima et al, 2007).…”

Field Evaluation of Talc Formulation of <I>Trichoderma</I> for the Management of Fusarium Wilt in Watermelon

“…All the biocontrol treatments are at par with the chemical fungicide. Wu et al (2009) reported that a bio-organic fertilizer containing Paenibacillus polymyxa and Trichoderma harzianum reduced Fusarium wilt of watermelon. Role of elevated activities of defense related enzymes as a result of systemic acquired resistance was attributed as mechanism of action for this disease suppression activity.…”

“…Antagonists (Fravel et al, 2005) as well as compost amendments (Boulter-Bitzer et al, 2006) have been used but with inconsistent results. Several organisms such as Penicillium oxalicum (De Cal et al, 2009), Paenibacillus polymyxa (Wu et al, 2009), Pseudomonas fluorescens, P. chlororaphis (Tziros et al, 2007) and species of Trichoderma (Pandey and Gupta, 2012) have been evaluated for Fusarium wilt suppression. Trichoderma species are soil inhabitants, competitive saprophytes, and facultative mycoparasites that can colonize the soil and rhizosphere (Harman et al, 2004).…”

Effects of Bio-organic Fertilizer on Soil Microbiome against Verticillium dahliae

“…In our research it was shown that as fertilizer volume increases, the number of V. dahliae gradually reduced and all treatments showed a significant change in high, medium, and low organic matter content of the soils. This may be due to a direct inhibitory effect or the physiological and biochemical role of antagonist (Wu et al, 2009). It may be due to the organic matter addition to soil improved the microbial activity of original antagonist, thereby reduced the density of soil pathogens, inhibited activities of soil pathogen and reduced the incidence of disease (Ouhdouch, 2001).…”

“…Although microbial organic fertilizer was less efficient than chemical pesticides; it was clearly a better choice from the perspective of the safety of national agricultural products. Efficiency to control soil-borne disease of other microorganic fertilizer could reach more than 80% by improving the micro-organic fertilizer formulation and production process and optimization of application method (Yogev et al, 2009;Wu et al, 2009).…”