New insights into municipal biowaste derived products as promoters of seed germination and potential antifungal compounds for sustainable agriculture

Abstract

Background Municipal biowaste management may generate a negative impact on the environment; therefore, their biomasses could be valorised as an alternative feedstock to fossils to produce high performance compounds useful for agricultural applications. The main objective of this study was to evaluate the potential agricultural applications of bioproducts (BPs) obtained by alkaline hydrolysis of the solid anaerobic digestate of municipal biowastes (ADMBW) and of one oxidized (ozonized) product (ADMBW BP OX). Both products were chemically characterized and used for agricultural in vitro assays. Results BP preparations were tested for their potential effect as enhancers of seed germination process using five concentrations (1, 10, 100, 1000, and 5000 mg L−1) and three different species: cress (Lepidium sativum), tomato (Solanum lycopersicum), and lettuce (Lactuca sativa L.). At this aim several germination indices were calculated to establish the priming effect of these substances on the selected seeds. Moreover, the potential in vitro antifungal effects of BPs at three concentrations (100, 1000, and 5000 mg L−1) on many dangerous fungal phytopathogens of economically important cultivated crops were evaluated and compared to Benzothiadiazole, one of the most-used plant disease suppressants. Results show that these ADMBW derived BPs exert a seed specie-specific positive effect on germination process, inducing better performances in the several calculated indices at all the concentration tested, except for the ADMBW BP OX 5000 mg L−1, which showed at the highest concentration a strong phytotoxic effect on tomato seeds. Conclusions The fungicidal potency of ADMBW BP OX was for the first time clearly demonstrated on multiple targets as Botrytis cinerea, Sclerotinia sclerotiorum, Monilia sp., Sclerotium rolfsii, and Phytophthora nicotianae, by calculating their relative EC50 and, when it was possible, also EC95 and MIC values. These results are of great impact in the actual historical moment, as from a biowaste as DMBW, which is worldwide constantly produced, may be possible to obtain agrochemicals and fertilizers without the usual feedstocks, which are more and more expensive. Graphical Abstract

Effect of municipal biowaste derived biostimulant on nitrogen fate in the plant-soil system during lettuce cultivation

“…In brief, the digestate was hydrolysed in water at pH 13 and 60 °C, then separated from the insoluble residue by sedimentation, followed by centrifugation and ultrafiltration. The membrane retentate was dried at 60 °C, and the solid product was dissolved in water at pH 10 16 . The obtained BPs was characterised for its chemical composition according to previous works 21 , 22 .…”

“…leonardite), for the cultivation of several ornamental plant species, such as Euphorbia x lomi Rauh 6 , Lantana camara 7 , Murraya paniculata 8 , Hibiscus 9 , and vegetable species, such as tomato 10 , red pepper 11 , spinach 12 , maize 13 , bean 14 , oilseed rape 15 . These biobased products were reported also as potential enhancers of the seed germination process of cress, tomato, and lettuce at low concentrations ranging between 10 and 100 mgL -1 16 . On the other hand, they are also fungicides at 1000–5000 mgL -1 concentration against several pathogens as Botrytis cinerea , Sclerotinia sclerotiorum , Monilia sp., Sclerotium rolfsii , and Phytophthora nicotianae 16 .…”

“…These biobased products were reported also as potential enhancers of the seed germination process of cress, tomato, and lettuce at low concentrations ranging between 10 and 100 mgL -1 16 . On the other hand, they are also fungicides at 1000–5000 mgL -1 concentration against several pathogens as Botrytis cinerea , Sclerotinia sclerotiorum , Monilia sp., Sclerotium rolfsii , and Phytophthora nicotianae 16 .…”

Efficacy of Biological Control Agents and Resistance Inducer for Control of Mal Secco Disease

“…SAR is dependent on the signaling molecule salicylic acid (SA), and it is linked to the build-up of pathogenesis-related (PR) proteins, which are thought to be a factor in resistance [15,16]. Acibenzolar-S-methyl [benzo-(1,2,3)-thiadiazole-7-carbothioic acid S-methyl ester] is among the most well-known commercially available chemical resistance inducers that interfere with the salicylic acid (SA) pathway [17][18][19][20][21]. Acibenzolar-S-methyl has already been preliminarily and roughly tested on citrus against P. tracheiphilus [9], showing a reduction in mal secco symptoms.…”

Epidemiology and Control of Plant Diseases

“…As a consequence, life cycles of plant pathogens could be deeply altered or an increase of emerging plant diseases could be observed on many commercial crops in different agroecosystems [ 1 , 2 ]. Thus, a better understanding of plant pathogen epidemiology, as well as individuation of new bio-based products, forecasting models, deep learning and reducing chemicals use approaches exploited for plant protection could better satisfy the development of ecofriendly, safer, and sustainable management strategies [ 3 , 4 , 5 ]. In light of above considerations, researchers and technicians are invited to investigate on epidemiological cycles of airborne and soilborne plant pathogens with the aim of ensuring good agricultural productivity, maintaining effective management of plant diseases and, simultaneously, good economic and environmental sustainability.…”