In vitro screening of rice germplasm for resistance to brown spot disease using phytotoxin

1985 ◽  
Vol 71 (1) ◽  
pp. 133-135 ◽  
Author(s):  
D. H. Ling ◽  
P. Vidhyaseharan ◽  
E. S. Borromeo ◽  
F. J. Zapata ◽  
T. W. Mew
Keyword(s):  
Brown Spot ◽  
In Vitro Screening ◽  
Spot Disease ◽  
Rice Germplasm ◽  
Brown Spot Disease

scholarly journals Potential Application of Propolis Extracts to Control the Growth of Stemphylium vesicarium in “Rocha” Pear

2020 ◽  
Vol 10 (6) ◽  
pp. 1990 ◽  
Author(s):  
Marcella Loebler ◽  
Claudia Sánchez ◽  
Elisabete Muchagato Maurício ◽  
Eugénio Diogo ◽  
Mário Santos ◽  
...  
Keyword(s):  
Disease Incidence ◽  
Brown Spot ◽  
In Vitro Assays ◽  
Economic Losses ◽  
Yield Reduction ◽  
Stemphylium Vesicarium ◽  
Spot Disease ◽  
Brown Spot Disease

Stemphylium vesicarium (Wallr.) E. G. Simmons is the pathogen responsible of brown spot disease in pear and has become one of the main concerns for European pear producers. In Portugal, S. vesicarium is responsible for significant yield reduction and economic losses in “Rocha” pear (Pyrus communis L. cv Rocha) production. Considering the antimicrobial potential of propolis, the high incidence of brown spot in pears and the emergence of fungicides resistance in S. vesicarium, this study aimed to evaluate the potential of Portuguese propolis as an alternative strategy to control brown spot disease in “Rocha” pear. In vitro assays showed that propolis extracts were able to inhibit up to 90% the S. vesicarium mycelial growth. In vivo assays in artificially wounded and inoculated “Rocha” pears showed that, compared to the control, the disease incidence decreased up to 25% and the lesions diameter up to 57%, in fruits treated with propolis. Moreover, propolis seems to be more efficient in reducing the disease incidence when applied after pathogen inoculation (curative assay) than when applied before pathogen inoculation (prophylactic assay). Thus, the results suggest that propolis extracts have potential to be applied as part of an integrated approach for the control of brown spot of pear.

scholarly journals Effect of plant extracts on radial growth of Helminthosporium oryzae causative of Brown spot disease of rice under in-vitro

1970 ◽  
Vol 28 (3) ◽  
pp. 473-480
Author(s):  
C.C. Iwuagwu ◽  
C.C. Ononuju ◽  
C.I. Umechuruba ◽  
A.C. Nwogbaga ◽  
A.E. Obidiebube ◽  
...  
Keyword(s):  
Plant Extracts ◽  
Radial Growth ◽  
Crop Residues ◽  
Brown Spot ◽  
Alcohol Extract ◽  
Spot Disease ◽  
Brown Spot Disease ◽  
Neem Leaves ◽  
Helminthosporium Oryzae

Brown spot disease, caused by Helminthosporium oryzae, is worldwide problem capable of causing considerable damage to paddy in the nursery, field or grain yield. The disease is seed borne, and thus can be transmitted through infected seeds and crop residues, alternate hosts and contaminated irrigation water. The objective of this study was to evaluate the effect of plant extracts on radial growth of Helminthosporium oryzae on rice plants. An in-vitro experiment was conducted at the Plant Pathology Laboratory of National Root Crop Research Institute, Umudike, Abia State, in Nigeria. Treatments included water and alcohol extracts of Azardiractha indica (Neem leaves), Piper guinensis (seeds), Garcinia cola (Bitter cola seeds), Ocimum gratissimum (leaf) and Vernonia amygdalina (leaf); and synthetic fungicide (Benomyl) at a concentrations of 10, 25 and 30% of the extract applied to H. oryzae in culture. The test materials were administered on Helminthosporium oryzae, sourced from rice seeds and infected shoot system of rice. Alcohol extract of Piper guineensis had the highest radial growth inhibition (89.89%) by the fifth day, but was not significantly different from Azardiractha indica, which had an inhibition value of 81.02%. The least effective plant extract was Ocimum gratssimum with radial inhibition of 11.50%, which occurred also on the fifth day. Plant extracts were as effective as the synthetic fungicide in inhibiting growth of the test fungus. Therefore, the effective extracts, all of which are readily available to the farmers, should be promoted instead of the synthetic fungicides, which are in limited supply and invariably expensive for rice farmers in Nigeria.

scholarly journals Studies on host-selective toxins produced by a pathotype of Alternaria citri causing brown spot disease of mandarins.

1986 ◽  
Vol 50 (6) ◽  
pp. 1597-1606 ◽  
Author(s):  
Yoshiki KONO ◽  
J. M. GARDNER ◽  
Yoshikatsu SUZUKI ◽  
Setsuo TAKEUCHI
Keyword(s):  
Brown Spot ◽  
Spot Disease ◽  
Brown Spot Disease
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