Efficiency of garden waste compost teas on tomato growth and its suppressiveness against soilborne pathogens

Abstract

The use of compost teas is of great interest to sustainable agriculture. Aerated compost tea (ACT) and aerated vermicompost tea (AVT) originating from garden waste have been analytically characterized and tested in vitro and in vivo on tomato plants to determine their suppressive effect on Rhizoctonia solani and Fusarium oxysporum f. sp. lycopersici. The nitrogen (N, 3840 ppm) and potassium superoxide (K 2 O, 5800 ppm) contents were relevant in ACT. Both ACT and AVT were shown to contain indoleacetic acid IAA (80-20 mg L-1), salicylic acid (5.85-1.33 ng L-1) and humic acids (190-140 mg L-1). Direct confrontation assays against the pathogens showed that ACT had a high suppressive effect on F. oxysporum f. sp. lycopersici (relative growth of the pathogen [RG]: 12 %) and AVT had a high suppressive effect on R. solani (RG: 18 %). These suppressive effects have been confirmed by tests performed in vitro and on potted tomato plants. Results of plants growth assays showed that both teas can be applied, in their concentrated forms, to the growth medium. The analysis of the growth effect of the teas on tomato plants clearly indicated that both ACT and AVT, when applied weekly, produce a positive effect on shoot and root dry weight (dry weights were tripled), chlorophyll content and stem diameter compared to untreated plants. These results support the use of ACT and AVT as potential alternatives to the application of synthetic fungicides, and as plant promoters in crop production, for attaining environmental sustainability for farming and food safety.

Compost Tea Quality and Fertility

“…Vermicompost usually causes little to no phytotoxic effect on plants; therefore, it is ready for use following harvesting. Remedios Morales-Corts et al [11] reported vermicompost tea having an EC value that was approximately fivefold lower than thermophilic compost tea from the same feedstock, inferring lower potential phytotoxicity. Thermophilic compost tends to require a prolonged mesophilic (curing) phase to ensure proper humification and reduction in phytotoxicity.…”

“…They also found decreased microbial concentration with dilution and temperatures above 28°C. In another study on compost tea properties, Remedios Morales-Corts et al [11] stated greater nutritional content, humic acids, salicylic acid and indole acetic acid (IAA) for aerated compost tea vs. aerated vermicompost tea, but the effect on tomato performance was non-significant.…”

Efficiency of Garden Waste Compost Teas on Potato Growth and Its Suppressiveness Against Rhizoctonia

“…The use of these teas in agriculture is also emerging because of their ability to suppress a wide range of both soil and airborne pathogens (Martin, 2014). Morales-Corts et al (2018) demonstrated the high potential of garden waste aerated compost and vermicompost teas on tomato growth and the suppressive effect on R. solani and F. oxysporum f. sp. lycopersici by "in vitro" and "pot" essays.…”

Spraying Agro-Industrial Compost Tea on Baby Spinach Crops: Evaluation of Yield, Plant Quality and Soil Health in Field Experiments

“…This behavior is related to the, the microorganisms within the compost tea, which lead to pest 2 of 15 suppression and enhancement of microbial communities improving nutrient uptake or production of bioactive compounds [6]. The potential of CTs for supplementing or substituting other types of fertilizers is also promising [7]. It is well documented, however, that effects of a given CT depend on the source of the cultures and raw materials used for its production [6][7][8].…”

“…The potential of CTs for supplementing or substituting other types of fertilizers is also promising [7]. It is well documented, however, that effects of a given CT depend on the source of the cultures and raw materials used for its production [6][7][8]. Composts from agro-industrial waste are considered more advantageous than other kinds of organic wastes [9], because they present a lower risk for pathogens, heavy metals and pharmaceuticals [8].…”