Using composts in agriculture to minimize organic wastes and to reduce the addition of fertilizers and fungicides in crop production is highly effective. Our results show that among those tested ...composts aged 0.5–1 year, cork compost reduced diseases caused by
Rhizoctonia solani in cucumber plants (53% of diseased plants) in comparison to peat (up to 89%). However, all composts aged 1.5–3 years (comprised of cork, grape marc, olive marc and spent mushroom) highly suppressed
Rhizoctonia disease, measuring 3, 11, 27 and 29% of diseased plants, respectively. Plant growth media enriched with the biological control agent
Trichoderma asperellum (strain T-34) reduced the incidence of
R. solani disease when amended at 10
3
cfu ml
−1. In composts aged 0.5–1 year, T-34 was only efficient when added to spent mushroom and cork compost, although it remained well established in all of them. The fact that T-34 rendered all composts aged 1.5–3 years highly suppressive is attributed to the low levels of easily biodegradable substances.
Rhizoctonia damping-off in cucumber plants can be reduced by using composts and/or the biological control agent
T. asperellum strain T-34. In addition, the extent to which composts suppress this disease depends on the nature of the composted materials, increasing with the composts’ maturity level.
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•Compost triggered eustress in tomato plants, improving growth and health.•Compost induced systemic resistance linked to SA pathway/ABA.•Trichoderma-enriched perlite improved plant ...growth and innate disease resistance.•Different mechanisms of induced resistance are involved in compost and Trichoderma.
Certain types of compost used as growth media can induce resistance to foliar pathogens in above-ground parts of a plant. The induction of resistance can sometimes be associated with growth impairment and yield reduction. The objective of this study was to establish whether plants grown in olive marc compost had enhanced resistance against Botrytis cinerea at the cost of growth or physiological performance.
Tomato plants grown in mature olive marc compost had approximately 60% less disease severity than plants grown in perlite. As a reference, plants grown in perlite enriched with the known inducer of resistance Trichoderma asperellum strain T34 (T34) had 35% less disease severity than plants grown in perlite. The salicylic acid (SA) pathway/abscisic acid (ABA) is involved in compost induced systemic resistance. Instead, perlite enriched with T34 is not linked to SA pathway/ABA. Physiological measures of water status, root/shoot ratio, stable isotopes of C and chlorophyll fluorescence showed that the plants grown in compost were close to a stress situation. However, growth measured as biomass and plant height of plants grown in compost was higher than in plants grown in perlite suggesting that plants in compost were not grown in a stress situation, but in a eustress. Tomato plants grown in perlite enriched with T34 had better growth, measured as total leaf area, biomass, height and nutrient uptake, than plants grown in perlite. Physiological measures showed that plants grown either in perlite or perlite enriched with T34 did not show any abiotic stress situation.
This study evaluated the performance of six culture media for the detection of actinomycetes present in composts of agro-industrial wastes. The composts were produced with orange wastes, olive marc ...and grass clippings, in the proportion of 2:1:1 in volume. Two compost piles were built with different ventilation systems: one with forced ventilation and the other with mechanical turning and natural ventilation. In order to quantify the population of actinomycetes, different growth media containing antibiotics were tested, and also one culture medium containing only half of the concentration of the Plate Count Agar (½ PCA). The incubation took place at two temperatures: 25° and 55°C. The population of actinomycetes was higher when incubated at 55°C and when the samples were inoculated in ½ PCA culture medium. Thus, the antibiotics showed no beneficial effect in the tested culture media. The results suggest the use of the ½ PCA culture medium as the most suitable in order to count actinomycete populations in these compost samples. This medium was also less expensive than the one that showed the fastest bacterial growth.
Olive jift is a solid by-product of olive (Olea europea) oil processing. Greenhouse experiments were conducted to evaluate olive jift effect on broomrape (Orobanche spp.) infections on three crops. ...Soil-jift mixtures were used as potting medium in ratios of 1:0, 1:1, and 3:1 soil to jift. Broomrape seeds were evenly incorporated in the potting media at 0, 150, 300, 450, 600, 750, and 900 seeds/kg. Pots planted with faba bean or pea were inoculated with seeds of O. crenata Forsk., whereas pots planted with tomato were inoculated with seeds of O. lavandulacea Reichenb. Jift in soil reduced broomrape germination and infection on all three hosts regardless of inoculation densities. Pea was not infected with broomrape in jift-containing media at any inoculation density, whereas only sporadic broomrape infections were observed in faba bean and tomato grown in jift-mixed soils. Fresh and dry weights of all crops were not adversely affected by mixing jift with soil. These results suggest a possible use of jift as an inexpensive organic material for broomrape control.
Physiological effects of the induction of resistance by compost or Trichoderma asperellum strain T34 against Botrytis cinerea in tomato Fernández, E; G. SegarraauthorUnitat de Fisiologia Vegetal, Departament de Biologia Vegetal, Facultat de Biologia, Universitat de Barcelona, Avinguda Diagonal 643, 08028 Barcelona, Catalonia, Spain; M.I. TrillasauthorUnitat de Fisiologia Vegetal, Departament de Biologia Vegetal, Facultat de Biologia, Universitat de Barcelona, Avinguda Diagonal 643, 08028 Barcelona, Catalonia, Spain
2015
Journal Article
The chemical composition of extracted dried olive pomaces, obtained from extraction of systems containing two and three phases, was similar. The main component was fibre, with values above 70% in ...both systems. Nitrogen values and extractability was low for both systems, although in vitro protein digestibility was high (75-80%). Amino acid composition was balanced except for lysine. The isoelectric point was low, centred around pH 2.0. Soluble sugars and organic acids contents were similar as well as fatty acid composition of the extracted oil from olive pomace. Therefore, an oil extraction of a system of two phases is advisable as environmental problems could be reduced with the elimination of vegetation water, and similar applications could be carried out with both types after drying
