The Effect of Biochars and Endophytic Bacteria on Growth and Root Rot Disease Incidence of Fusarium Infested Narrow-Leafed Lupin (Lupinus angustifolius L.)

Abstract

The effects of biochar on plant growth vary depending on the applied biochar type, study site environmental conditions, microbial species, and plant–microbial interactions. The objectives of the present study were therefore to assess 1) the response of growth parameters of lupin and root disease incidence to the application of three biochar types in a loamy sandy soil, and 2) the role of endophytic bacteria in biological control of root rot disease incidence in lupin after the amendment of soil with different biochar types. As biochar types we tested (i) hydrochar (HTC) from maize silage, (ii) pyrolysis char from maize (MBC), and (iii) pyrolysis char from wood (WBC) at three different concentrations (1%, 2%, and 3% of char as soil amendments). There were no significant effects in lupin shoot and root growth in soils amended with WBC at any of the concentrations. MBC did not affect plant growth except for root dry weight at 2% MBC. HTC char at 2% concentration, significantly increased the root dry weight of lupin by 54–75%, and shoot dry weight by 21–25%. Lupin plants grown in soil amended with 2% and 3% WBC and MBC chars showed 40–50% and 10–20% disease symptoms, respectively. Plants grown in soil without biochar and with HTC char were healthy, and no disease incidence occurred. Pseudomonas putida L2 and Stenotrophomonas pavanii L8 isolates demonstrated a disease reduction compared to un-inoculated plants under MBC and WBC amended soil that was infested with Fusarium solani.

Diversity and Plant Growth-Promoting Ability of Endophytic, Halotolerant Bacteria Associated with Tetragonia tetragonioides (Pall.) Kuntze

“…It is well reported that endophytes can relieve plant stress by blocking the pathway of ethylene synthesis in plants [ 38 , 39 ]. Moreover, plant-associated beneficial microbes control soil-borne plant pathogens through several mechanisms, including the production of cell wall degrading enzymes, such as β-1,3-glucanase and lipase, and also protease [ 9 , 35 , 40 , 41 , 42 , 43 ]. In our study, three bacterial isolates from New Zealand spinach showed antifungal activity against V. dahliae , which indicates they may protect the plant from Verticillium wilt caused by Verticillium dahliae Kleb.…”

Bacterial endophytes from halophyte black saxaul (Haloxylon aphyllum Minkw.) and their plant growth-promoting properties

“…The tissues of various plants have their own unique communities of bacterial endophytes. There are many reports showing that endophytes play an important role in plant growth stimulation and their protection from phytopathogenic microorganisms [8][9][10][11][12][13]. Bacterial endophytes have advantages over the bacteria inhabiting the rhizosphere.…”

“…The strains did not show any plant growth-promoting (PGP) activity. Egamberdieva et al[11] reported on antibacterial and antifungal efficacy of endophytic P. kilonensis isolated from horseradish (Armoracia rusticana G. Gaertn., B. Mey.…”

The Integrated Effect of Microbial Inoculants and Biochar Types on Soil Biological Properties, and Plant Growth of Lettuce (Lactuca sativa L.)

“…Several studies reported induced changes in nutrient availability after biochar application, providing additional sources of N, P, and carbon sources for microbes associated with plant roots [ 31 ]. The improvement of plant-associated microbial activity in soil amended with biochar was reported in several studies for various crops [ 32 , 33 , 34 ]. It is well documented that biochar carbon-rich material provides favorable conditions for the proliferation of root-associated microbes involved in carbon, nitrogen, and phosphorus cycles in soil and thus increase nutrient availability for plants [ 10 ].…”