Intervarietal Mixtures of Rice and Incidence of Brown-spot Disease (Helminthosporium oryzae Breda de Haan)

Nature ◽  
1966 ◽  
Vol 209 (5029) ◽  
pp. 1265-1267 ◽  
Author(s):  
G. GRÜMMER ◽  
SUBODH KUMAR ROY
Keyword(s):  
Brown Spot ◽  
Spot Disease ◽  
Brown Spot Disease ◽  
Helminthosporium Oryzae

Variation of leaf angle and incidence of rice blast disease

1982 ◽  
Vol 98 (1) ◽  
pp. 225-227 ◽  
Author(s):  
C. R. Mohanty ◽  
S. Gangopadhyay
Keyword(s):  
Rice Blast ◽  
Pyricularia Oryzae ◽  
Seedling Stage ◽  
Blast Disease ◽  
Brown Spot ◽  
Leaf Angle ◽  
Spot Disease ◽  
Brown Spot Disease ◽  
Helminthosporium Oryzae

Blast, caused by Pyricularia oryzae Cav., one of the major foliar diseases of rice, appears sometimes in a devastating form in the seedling stage. The angles subtended by leaves may affect the establishment of the pathogen. Ono (1965) observed that leaf angles of rice plants, among many other factors, influenced deposition of spores. Gangopadhyay & Chattopadhyay (1974) found that brown spot disease (Helminthosporium oryzae) incidence in rice increased with increase in leaf angles. The present study is intended to find out the role of leaf angles in rice on the incidence of blast disease at the seedling stage.

scholarly journals Studies on the isolation, identification and enzyme activity of bioagent Pseudomonas fluorescens used for controlling brown spot disease of rice caused by Helminthosporium oryzae

2021 ◽  
Vol 12 (2) ◽  
pp. 458-461
Author(s):  
David Kamei ◽  
Archana U Singh
Keyword(s):  
Enzyme Activity ◽  
Grain Yield ◽  
Pseudomonas Fluorescens ◽  
Fungal Pathogen ◽  
Brown Spot ◽  
Spot Disease ◽  
Major Disease ◽  
Brown Spot Disease ◽  
Helminthosporium Oryzae

In the present investigation studies was carried out ontheIsolation, Identification and Enzyme activity of bioagent Pseudomonas fluorescens used for controlling Brown spot disease of Rice caused by Helminthosporium oryzae(Breda de Haan).This is a fungal pathogen causing major disease that causes enormous losses in grain yield (upto 90%) particularly when leaf spotting phase assumes epiphytotic proportions.

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

Brown spot disease in ‘Rocha’ pear Portuguese orchards

2021 ◽  
pp. 335-342
Author(s):  
P. Reis ◽  
C. Rego ◽  
M. Mota ◽  
T. Comporta ◽  
C.M. Oliveira
Keyword(s):  
Brown Spot ◽  
Spot Disease ◽  
Brown Spot Disease
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