The novelty of the present research is conducting a new method in the systemic resistance of plant diseases by using distinct marine extracts. The ability of two octopus extracts to reduce the wilt disease caused by Fusarium oxysporum was observed. The applied methods are soaked roots (SR) and foliar shoots (FS). The antioxidant enzyme activities, percent disease index (PDI), and growth parameters were measured. In vitro antifungal potential of the octopus extracts against F. oxysporum was examined. The obtained result shows that SR extracts reduced PDI. Additionally, all the tested treatments promoted the growth and photosynthetic pigments of the infected plants. SR (in ethanolic extracts) was the most prominent inducer which offered a high advancement in the total soluble protein contents. Also, SR (in methanolic extracts) was the most suitable inducer which provided a very necessary development not only in the total phenol but also in the peroxidase (POD) and polyphenol oxidase (PPO) activities. GC-MS investigation of the octopus extracts exhibited that the compounds which possess antifungal activity were furoscrobiculin B and/or eugenol. They demonstrated a notable antifungal potential against F. oxysporum with a maximum activity of 38.5 and 12.7 mm ZOI after the treatment with the ethanolic and methanolic extract, respectively. FTIR results illustrated the functional group of the compound responsible for the antifungal activity. Additionally, an atomic absorption result reveals that there are traces of metals detected such as Pb, Ag, Cu, Zn, and Mg. The antifungal activity was decreased as the concentrations were reduced. Accordingly, the present extracts may be used as the vital agents in the agricultural field to restrain the plant pathogenic fungi, especially F. oxysporum from a proliferation.

Fusarium wilt caused by the fungus Fusarium oxysporum f. sp. cucumerinum (FOC) is the most severe soil-borne disease attacking cucumber. To assess the positive effects of vinegar residue substrate (VRS) on the growth and incidence of Fusarium wilt on cucumber, we determined the cucumber growth parameters, disease severity, defense-related enzyme and pathogenesis-related (PR) protein activities, and stress-related gene expression levels. In in vitro and pot experiments, we demonstrated the following results: (i) the VRS extract exhibited a higher biocontrol activity than that of peat against FOC, and significantly improved the growth inhibition of FOC, with values of 48.3 %; (ii) in response to a FOC challenge, antioxidant enzymes and the key enzymes of phenylpropanoid metabolic activities, as well as the PR protein activities in the roots of cucumber, were significantly increased. Moreover, the activities of these proteins were higher in VRS than in peat; (iii) the expression levels of stress-related genes (including glu, pal, and ethylene receptor) elicited responses to the pathogens inoculated in cucumber leaves; and (iv) the FOC treatment significantly inhibited the growth of cucumber seedlings. Moreover, all of the growth indices of plants grown in VRS were significantly higher than those grown in peat. These results offer a new strategy to control cucumber Fusarium wilt, by upregulating the activity levels of defense-related enzymes and PR proteins and adjusting gene expression levels. They also provide a theoretical basis for VRS applications.

Fusarium wilt of cucumber caused by Fusarium oxysporum f. sp. cucumerinum J. H. Owen is one of the major destructive soilborne diseases and results in considerable yield losses. Methyl bromide was once the most effective disease control method but has been confirmed as harmful to the environment. Using suppressive media as biological controls to assist crop growth is becoming popular. In this study, Fusarium wilt of cucumber was successfully controlled by a newly identified suppressive media: vinegar residue compost-amended media (vinegar residue compost mixed with peat and vermiculite in a 6:3:1 ratio (v/v) vinegar residue substrate (VRS). Greenhouse experiments were carried out to evaluate the effect of VRS on the growth of cucumber seedlings and disease suppression. The control was peat/vermiculite (2:1, v/v). To identify the mixed media most suitable for the growth of plants and their suppressiveness indicators, we evaluated the biological characteristics of cucumber, the physicochemical and biochemical properties of the growth media, and the enzyme activities. Total organic C (Cₒᵣg), microbial biomass C (Cₘᵢc), basal respiration (Rₘᵢc), and enzyme (catalase, invertase, urease, proteinase, phosphatase, β-glucosidase, and hydrolysis of fluorescein diacetate) activities increased significantly after vinegar waste compost amendment. The compost media also showed a significantly positive effect on the growth of cucumber seedlings and the suppression of the disease severity index (DSI, 38 % reduction). The cucumber rhizosphere population of F. oxysporum f. sp. cucumerinum (FOC) was significantly lower in VRS than in the control. These results demonstrate convincingly that vinegar residue compost-amended media has a beneficial effect on cucumber growth and could be applied as a method for biological control of cucumber Fusarium wilt.

The research was conducted to evaluate in-vitro efficacy of numerous fungicides against Fusarium oxysporum f. sp. capsici. In present research, six treatments (T) viz. Carbendazim, Benomyl, Topsin-M, Difenoconazole, Nativo, and Alliete along with control, various concentrations (C), days (D), and their interactions, i.e., (T × C), (T × D), (C × D), and (T × C × D) were exploited in a laboratory through food poison technique. Alliete expressed maximum colony growth (1.93 cm) as compared to all other fungicides with respect to control. Interaction between treatments and concentration (T × C) exhibited maximum colony growth of all treatments (Carbendazim, Benomyl, Topsin-M, Difenoconazole, Nativo, and Alliete), i.e., 0.87, 1.23, 1.73, 2.20, 2.53, and 2.93 cm at 300 ppm as compared to 500 and 700 ppm concentrations, respectively. Similar trend was also observed concerning interaction between (fungicides × days) and (tested concentrations × days). Results of the present study revealed that among tested fungicides, Carbendazim at 700 ppm expressed significant reduction in fungal growth.

Fusarium wilt of cucumber caused by the fungus, Fusarium oxysporum, is one of the most destructive soilborne diseases and can result in serious economic loss. No efficient fungicide is currently available to control the disease. The aim of this study was to examine the disease suppression ability of pig manure and sludge composts in peat-based container media and explore the possible disease suppression mechanisms. Pig manure and sewage sludge compost were made in laboratory-scale tanks. Plant growth media were formulated with peat mixture and compost (or 60 °C heated compost) in a 4:1 ratio (v/v). Cucumber seedlings were artificially inoculated with F. oxysporum conidia (5 × 105 conidia mL−1) by the root-dip method. Cucumber Fusarium wilt was effectively suppressed in sludge compost-amended media, while the disease suppression effect of pig manure compost was limited. The ammonia levels in the manure compost-amended media were significantly higher than those of sludge compost-amended media, which could explain its lower disease suppression ability. Heated composts behaved similarly with respect to disease suppression. Adding composts increased microbial biomass, microbial activity, and the microbial diversity of the growth media. PCR-DGGE results indicated that the fungal community had a significant correlation to the disease severity. The artificially inoculated pathogen was retrieved in all treatments and one possible biocontrol agent was identified as a strain of F. oxysporum by phylogenetic analyses. The results indicated that the sludge compost used in this study could be applied as a method for biocontrol of cucumber Fusarium wilt.