Avaliação de microrganismos antagônicos, Saccharomyces cerevisiae e Bacillus subtilis para o controle de Penicillium Digitatum

Citrus fruits are affected by diverse diseases, mainly the fungal infections, which affect productivity and quality, especially when it targets the market of fresh fruit. Among the fungal diseases that occur in postharvest, there is the green mold caused by Penicillium digitatum. The control measures are based mainly in the treatment of fruits with different combinations of fungicides in packing-house. Due to restrictions on the presence of residues of fungicides in citrus fruits and the increasing development of resistant strains of pathogens to the fungicide used, it is necessary to search for control alternatives such as biological control. Therefore, this study aimed to: (i) verify the antagonistic effect of biological control agents (BCA), being 13 isolates of Bacillus subtilis and 06 isolates of Saccharomyces cerevisiae against P. digitatum, (ii) study in vitro interactions between pathogen and BCA (iii) determine the effect of integration of antagonists with sodium bicarbonate and carnauba wax in the control of green mold. The results showed that the majority of the isolates, and all yeast isolates inhibited the mycelial growth of the phytopathogen. Only one isolate of B. subtilis (ACB-84) was able to inhibit the germination of P. digitatum (72% of inhibition), whereas ACB-K1 and ACB-CR1 (S. cerevisiae) were the most effective with inhibition from 78 and 85.7% respectively. The addition of sucrose (0.5%) favored the inhibition of conidia germination by the yeast isolates. The results from the in vivo control showed the viability of S. cerevisiae ACB-K1 and ACB-CR1 to control P. digitatum in 'Tahiti' lime fruits and orange 'Hamlin' fruits, respectively. The combination of sodium bicarbonate and biocontrol agents did not result in improvements in the curative control of the green mold. Carnauba wax (18% of TSS) favored the antagonistic activity of S. cerevisiae, and this effect depended on the variety of fruits in the study and of the yeast isolate used for the biocontrol.

Sensibilidade de stenocarpella macrospora a fungicidas

The application of fungicides in the aerial organs is control strategy to macrospora spot caused by fungus Stenocarpella macrospora. The objective of this study was to determine the sensitivity of S. macrospora to fungicides by inhibition of mycelial growth (MG) and conidial germination (CG). It was eval uated 12 fungicides belonging to the chemical groups of the benzimidazoles, triazoles and strobilurins, six concentrations and two isolates of the fungus (SC and MT). The fungicides were diluted in sterile distilled water and added to the culture medium of potato dextrose agar (mycelium) and water-agar (spore) after sterilization. The percentage of inhibition of MC and CG was calculed in comparison with control, estimating of 50% inhibitory concentration (IC50). The fungicides tested were effective in inhibiting the MC. The IC50 was less than 1 ppm for all fungicides. There was no difference between isolates. The inhibition of CG had higher fungitoxicity strobilurins, and the IC50 was between 0.0035 and 0.03 ppm, and the isolated SC showed the higher sensitivity to the fungicides. The IC50 values obtained for fungicides and specific S. macrospora will be useful in monitoring the sensitivity of the fungus, especially in regions with intense demand for fungicides in corn.

Chemical control of pathogens and the physiological performance of peanut seeds

The establishment of a peanut crop may be unsatisfactory due to poor seed performance in the field and among the factors attributed to this are a reduction in seed vigor during storage and the presence of pathogens. The objective of this study was to evaluate the efficiency of treating peanut seeds with fungicides and the effect on physiological performance and disease control during storage. In a completely random experimental design, two seed batches of the Runner IAC 886 peanut cultivar were submitted to five fungicide treatments (1 control - untreated; 2 thiram; 3 carbendazim + thiram; 4 fludioxonil + metalaxyl-m; 5 fludioxonil + mefenoxam + thiabendazole) and evaluated after zero, 30 and 60 days of storage. The seeds were stored untreated but treated before the evaluation of physiological performance from germination, vigor (first germination count and accelerated aging), field seedling emergence and seed sanitation tests. The results showed differences in batch performance potential during storage, with batch 1 being superior. The sanitation test showed that all the chemical seed treatments controlled pathogens efficiently (Aspergillus spp. and Penicillium sp.), but only thiram did not affect peanut seed performance in the laboratory evaluations.

Controle de mofo-cinzento (amphobotrys ricini) da mamoneira (ricinus communis l.) por métodos químico, biológico e com óleos essenciais

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeitos fisiológicos da piraclostrobina em plantas de feijão (Phaseolus vulgaris L.) condicionado sob diferentes tensões de água no solo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Investigação da toxicidade reprodutiva do fungicida Procloraz, com ênfase sobre aspectos morfofuncionais do epidídimo de ratos adultos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Adsorção de cádmio e disponibilidade de cádmio e bário em latossolos sob mata nativa e cultivados

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Controle químico de doenças de Eucalyptus spp. em viveiros e seus efeitos morfo-fisiológicos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Evaporação de gotas de caldas contendo fungicidas e adjuvantes depositadas em superfície

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Eficiência do flutriafol e do flutriafol + tiofanato metílico aplicados com gotas finas ou médias no controle da ferrugem asiática da soja

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

Herança da resistência a oídio em ervilha e aspectos relacionados à patogênese

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeitos fisiológicos de fungicidas no desenvolvimento de plantas de melão rendilhado, cultivadas em ambiente protegido

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeitos fisiológicos de fungicidas no desenvolvimento de plantas de pepino japonês enxertadas e não enxertadas, cultivadas em ambiente protegido

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estudo da herança da resistência ao crestamento gomoso do caule em melancia

Pós-graduação em Agronomia (Horticultura) - FCA

Fungicidas de efeitos fisiológicos no desenvolvimento de plantas de pimentão enxertadas e não enxertadas sob cultivo protegido

Pós-graduação em Agronomia (Horticultura) - FCA