The capacity of five white rot fungi species to degrade linuron, metribuzin and chlorpyrifos when applied both as single pesticides and mixed together in different concentrations on nutritionally poor media was investigated. Our results suggested that Pleurotus ostreatus, Pycnoporus coccineus, Phlebiopsis gigatea and Τrametes versicolor showed a remarkable tolerance to the pesticides, in all media tested. The EC50 values presented a noticeable difference in the mixtures as compared with the individual ones. The minimum growth rate in the mixture was obtained by P. ostreatus whereas P. coccineus appeared to be more efficient than the rest fungal isolates, when cultivated in the soil extract medium. P. coccineus, P. gigantea and T. versicolor produce high levels of polyphenol oxidase, but only T. versicolor was capable of decomposing linuron when combined with metribuzin and chlorpyrifos.
In this study, lettuce plants were grown in sawdust (Saw) and/or perlite (Per) mixtures (sawdust; Saw: Per 75:25%; Saw: Per 50:50%; Saw: Per 25:75%; Perlite) and in Nutrient Film Technique (NFT), in an unheated greenhouse. Plants grown in NFT were taller with greater leaf area resulting in greater fresh weight. Sawdust addition reduced leaf length, leaf area and as a consequence the fresh weight but not the leaf number. However, leaf dry weight increased as sawdust content increased into the substrate. Leaf chlorophyll reduced but leaf fluoresces increased in perlite and NFT. High sawdust content (75% or 100%) reduced photosynthetic rates and stomatal conductance. Nutrient uptake [potassium (K), sodium (Na), phosphorus (P)] was the greatest in NFT treatment, while perlite and Saw: Per 25: 75% increased elemental uptake (up to 74%) comparing with the remaining treatments. Leaf elemental analysis fluctuated among treatments. Thus, low content (i.e. 25%) of sawdust in perlite could improve inorganic substrate media properties.
The possible use of municipal solid waste compost (MSWC) in the production of marigold and basil seedlings examined. Six medium prepared from commercial peat (CP) and MSWC (0, 15, 30, 45, 60, and 100% v/v). There was not any plant growth when MSWC used alone (100%). The addition of MSWC in low content (15% and 30%) improved seed emergence for marigold and basil respectively, while greater content revealed opposed impacts. Mean emergence time delayed as MSWC content increased into substrates. Addition of MSWC (especially in content greater than 30%) into CP reduced (from 34 to 64%) plant height, leaf number and stem diameter as a consequence reduced plant fresh weight (plant biomass) for both species. The number of lateral stems decreased (up to 81%) in basil when MSWC added into substrate mixtures. Chlorophyll b content decreased (up to 58%) in substrates with MSWC content greater than 15% or 30% while similar reduction observed in content of Chlorophyll a and total carotenoids for basil with MSWC > 60%. However, Chlorophyll a and total carotenoids content increased as MSWC content increased for marigold. K and Na leaf content increased but P equivalent decreased as MSWC content increased. Nursery-produced basil and marigold seedlings grown in 15% MSWC; displayed quality indices similar to those recorded for conventional mixtures of peat and may act as component substitute.
Municipal solid waste compost (MSWC) and/or fertigation used in greenhouse pepper (Capsicum annuum L.) cultivation with five different substrates with soil (S) and/or MSWC mixtures (0-5-10-20-40%) used with or without fertigation. Plants growth increased in 10-20% MSWC and fertigation enhanced mainly the plant height. Fruit number increased in S : MSWC 80 : 20 without fertilizer. Plant biomass increased as MSWC content increased. There were no differences regarding leaf fluoresces and plant yield. The addition of MSWC increased nutritive value (N, K, P, organic matter) of the substrate resulting in increased EC. Fruit fresh weight decreased (up to 31%) as plants grown in higher MSWC content. Fruit size fluctuated when different MSWC content used into the soil and the effects were mainly in fruit diameter rather than in fruit length. Interestingly, the scale of marketable fruits reduced as MSWC content increased into the substrate but addition of fertilizer reversed this trend and maintained the fruit marketability. MSWC affected quality parameters and reduced fruit acidity, total phenols but increased fruit lightness. No differences observed in fruit dry matter content, fruit firmness, green colour, total soluble sugars and EC of peppers and bacteria (total coliform and E. coli) units. Low content of MSWC improved plant growth and maintained fruit fresh weight for greenhouse pepper without affecting plant yield, while fertigation acted beneficially.