Showing papers on "Trichoderma harzianum published in 1981"

Biological control ofRhizoctonia solani in strawberry fields byTrichoderma harzianum

Abstract: Trichoderma harzianum preparations was used in two successive field experiments in commercial strawberry nurseries and fruiting fields. Disease severity ofRhizoctonia solani in daughter plants was reduced by 18–46 % in the treated nursery plots. Infestation of nursery soil with the pathogen, as tested by planting beans in soil samples was reduced by the Trichoderma treatment by up to 92% as compared to the untreated control. A rapid decline of the disease was observed in soil fromT. harzianum treated plots, successively planted with bean seedlings. More isolates ofTrichoderma sp. antagonistic toR. solani, were found in the infested field as compared to the non infested one.Trichoderma harzianum treated plants, transferred to the commercial field gave a 21–37% increase in early yield of strawberries. A combined treatment in the nursery and in the fruiting field resulted in a 20% yield increase as compared to control plots.

The soil microfungal community of a South Dakota grassland

Abstract: The soil microfungi of a western South Dakota grassland were quantitatively surveyed using the dilution plate technique. A 250-membered sample yielded 62 taxonomic entities. Principal forms included Acremonium sp. 4407, Aspergillus fumigatus, A. niveus, A. terreus, Chrysosporium pannorum, Fusarium oxysporum, F. solani, Mammaria echinobotryoides, Mortierella gracilis, Paecilomyces marquandii, Penicillium funiculosum, Penicillium janthinellum, Penicillium lilacinum, and Trichoderma harzianum. Comparison to other grassland surveys has revealed that the South Dakota community is most like that from the Pawnee National Grassland in eastern Colorado with less similarity to mycofloras reported for grasslands in Wisconsin and Oklahoma. Aspergillus terreus, A. fumigatus, A. niveus, Fusarium oxysporum, F. solani, Penicillium janthinellum, P. lilacinum, and Mortierella gracilis are prominent in temperate grassland communities worldwide. A slight seasonal trend was detected at the species level. Aspergillus fumigatus...

Protein enrichment of cassava root meal by trichoderma harzianum for animal feed

Abstract: A fermentation procedure to increase the protein content of cassava root meal (CRM) with Trichoderma harzianum is described. The organism was grown in a 4% CRM medium with inorganic nitrogen. The fungal biomass plus the rest of CRM were collected by filtration at the end of fermentation. Satisfactory results were obtained at 23 °C (pH 4.0-4.2) and a fermentation time of 60 h. The CRM/biomass contained about 38% crude protein (CP) on a dry matter basis. This should be compared with 2.4% CP in the untreated CRM. The sum of amino acids in the product corresponded to about 60% of the CP value. The estimated efficiency of conversion of the CRM into CRM/biomass was found to be about 30%. A substantial improvement in the protein content and quality of CRM can be made through submerged cultivation of T. harzianum on CRM.

Induction of premature phialoconidiogenesis on germinated conidia of Trichoderma harzianum

Abstract: Premature phialoconidiogenesis in Trichoderma harzianum was induced by applying a nutritional shock to germinated conidia. This early conidiation on germinating tubes without mycelial growth (microcycle conidiation) was achieved by a two-step treatment, (a) Incubation of dormant conidia for 9 h at 25 °C in 2% malt extract medium which led to their germination; synchronous swelling was followed by the emission of a germ tube reaching an average length of 1–2 times the width of the swollen conidia. (b) Transfer of these germinated conidia into a synthetic medium containing in addition 8% glucose and 0.05% KNO2; after 11 h in this transfer medium, more than 90% of the initial conidia formed microcycle conidiation. Only K or Na nitrates and nitrites were effective when tested at 0.05 %. All ammoniacal sources or amino acids tried at this concentration favoured vegetative elongation of the germ tube. The optimal 8% glucose was effectively replaced by 8% of the non-assimilable sugar D(−)-arabinose and a small amount (0.05%) of glucose. Light is also required for submerged culture conidiation of T. harzianum as in standard surface conidiation.

Nutritive value of cassava root meal enriched by trichoderma harzianum for chickens

Abstract: A study was conducted with chickens to establish the content of metabolisable energy (ME) and the content and apparent digestibility of crude protein (CP) and amino acids (AA) in cassava root meal (CRM) enriched by the fungus Trichoderma harzianum. The ME content of this enriched CRM was found to be about 9.1 MJ kg−1 dry matter (DM). This value was significantly lower (P<0.05) than that of non-enriched CRM (12.2 MJ kg−1 DM). The CP content of the enriched CRM product used was 37.6 on DM basis. The non-protein nitrogen content accounted for about 30% of the total CP value. The mean apparent digestibility coefficient of the CP was about 66% whereas that of AA was about 81%. Data from this study indicate that fungal enriched CRM could be used in chicken diets.

Effects of annual applications of sodium azide on soil fungal populations with emphasis on Trichoderma species

Abstract: The effect of a granular formulation of sodium azide, applied annually to pine nursery beds at rates of 0, 67.2, and 134.5 kg a. i. ha−1 under water seal or plastic seal, on soil fungal populations was determined over a 3-year period. Populations of fungi in the soil decreased following application of the sodium azide each year; the greatest decrease occurred at the highest rate of application. Populations of fungi in soil treated with the azide generally remained lower than in the controls throughout each of the 3 years; however, the population disparity between treated and control plots decreased in magnitude with each succeeding year. Populations of Trichoderma spp., in plots treated with 134.5 kg sodium azide ha−1, increased 2 weeks after treatment each year, and the population peaks increased in magnitude each year. In addition the effect of sodium azide (technical grade > 99%) at concentrations of 0, 2, 5, 10, 20 and 50 μg ml−1 in potato dextrose agar and blackstrap molasses agar media was determined in vitro for 14 isolates of Trichoderma harzianum. Growth and sporulation differed among the isolates and between the two media tested. Generally, the azide temporarily inhibited growth of the fungi, but the majority of the isolates were able to grow on either medium containing 50 μg sodium azide ml−1, although sporulation was more profuse on the molasses than on the potato dextrose agar medium.