Management of pepper verticillium wilt by combinations of inducer chemicals for plant resistance, bacterial bioagents and compost

Abstract

Inducer resistance chemicals (IRCs) Bion (BTH), chitosan and salicylic acid, bacterial bioagents, i.e. Bacillus chitinosporus, B. megaterium, B. pumilus, B. subtilis, B. thuringiensis, Pseudomonas fluorescens and P. putida and compost tea caused a reduction to the linear growth of the fungus Verticillium dahliae, in culture plates. In general, P. fluorescens followed by B. subtilis were the most efficient in reducing the linear growth of V. dahliae. The viability of microsclerotia of V. dahliae was greatly reduced by the tested bacterial bioagents. In addition, B. megaterium, B. subtilis, P. fluorescens and P. putida were the most efficient bioagents, where no microsclerotia germinated three weeks after treatment with these bioagents. In addition, few of microsclerotia germinated when treated with B. chitinosporus, B. pumilus and B. thuringiensis. However, all the microsclerotia of the control treatment were viable even three weeks after treatment with bioagents. The combination and use singly of BTH, B. subtilis, P. fluorescens and compost resulted in a reduction of verticillium wilt in pepper and increase of fruit, photosynthetic pigments, and vitamin-C compared with the control treatment (infested with the causal fungus). Compost was the most efficient of single tactics in disease management. Moreover, no apparent infection was detected when BTH, the two bioagents B. subtilis and P. fluorescens and compost were used together and the fruit yield, photosynthesis pigments and vitamin-C were, similar to the control treatment (un-infested soil). Photosynthesis pigments including chlorophyll a, chlorophyll b and carotenoids as well as free and total ascorbic acid (vitamin-C) were greatly increased due to the tested treatments, i.e. BTH, both bioagents and compost in pepper plants grown in infested soil compared with those of untreated plants (grown in infested soil only). Compost was the best single treatment for minimizing the reduction in photosynthesis pigments in plants grown in infested soil with V. dahliae, as well as free and total ascorbic acid compared with plants grown in soil infested with the causal fungus without any another treatment.

Recent Approaches for Management of Tomato Fusarium Wilt

“…lycopersici: Poultry manure compost extract (PMCE), cow dung compost extract (CDCE), maize and rice straw extract (MRCE) and tap water as control (TW) were used. The three composts were prepared to compost extract (compost tea) (Abada et al, 2018;Weltzien, 1991). The filtrate of each compost was sterilized by 0.25 µm syringe filter and added to the calculated amount of PDA medium after sterilization at the concentrations of 20, 40 and 80 %, shake well and poured into the Petri-dishes (20 ml/plate).…”

“…Hence, to overcome these disasters, it is urgent to disseminate another management trials as alternative safe applicable methods against such disease. Nowadays, using of compost and biological management are considered important approaches of modern agricultural biotechnology for managing many soil-borne plant pathogens (Jha et al, 2018;Wang et al, 2020;Abada et al, 2018). Two formae speciales of the fungus Fusarium oxysporum i.e., Fusarium oxysporum Schlecht.…”

“…It is assumed that plant vindication response can be achieved by specific recognition of some biocontrol agents (Jacobsen et al,2004). This, this action could be activated by their secreted bio-products and/or whole bio-agents under the influence of plant defense response (Abada et al, 2018;Albersheim and Valent, 1978;Akram and Yousefi, 2015). A wide configuration of fungicides show efficiency against Fusarium wilt and they, generally, used frequently in alternative with crop rotation, resistant cultivars, sanitary methods, and other disease management strategies, especially in greenhouse plantations to manage this disease.…”

Role of Chemicals for Plant Resistance, Trichoderma Bioagents and Cow Whey Milk in Combination on Management of Tomato Powdery Mildew

“…Results shown in Table (3) show that the tested component of cow milk ,i.e. full cream, skim and whey caused significant reduction to the germinated conidia of the causal fungus.…”