STUDIES OF NEMATODES IN RELATION TO BROWN ROOT ROT OF TOBACCO IN ONTARIO

1954 ◽  
Vol 32 (6) ◽  
pp. 737-759 ◽  
Author(s):  
W. B. Mountain
Keyword(s):  
Soil Temperature ◽  
Root Rot ◽  
Parasitic Nematodes ◽  
Resistant Variety ◽  
Soil Organisms ◽  
Lesion Nematode ◽  
Rot Disease ◽  
Tobacco Roots ◽  
Host Parasite ◽  
Brown Root Rot

The root-lesion nematode, Pratylenchus spp. is proved to be the primary causal agent of the brown root rot disease of tobacco in Ontario. The root lesions resulting from nematode attack are undoubtedly further broken down by the activity of other soil organisms. At least two species of Pratylenchus are involved, differing significantly in pathogenicity and morphology. Nine other parasitic and potentially dangerous nematode genera also were found associated with tobacco roots in Ontario, but they occurred in very low numbers. The effect of the preceding crop upon brown root rot of tobacco was found to be related to nematode populations; and for eight preceding crops, significant effects upon the growth of tobacco occurred only in the presence of high populations of parasitic nematodes. Since Pratylenchus minyus Sher and Allen, 1953, is the more pathogenic species, the relation between this nematode and the tobacco host was studied in some detail. The optimum soil temperature for this nematode is at least 100° F. and it causes little stunting of tobacco below a soil temperature of 70° F. In a resistant variety of tobacco studied, an unusual mechanism of resistance upholds a host–parasite equilibrium wherein, despite high populations of parasitic nematodes within the roots, normal plant growth is maintained.

scholarly journals BROWN ROOT ROT DISEASE OF CASHEW IN WEST NUSA TENGGARA: DISTRIBUTION AND ITS CAUSAL ORGANISM

2016 ◽  
Vol 5 (1) ◽  
pp. 32
Author(s):  
Supriadi Supriadi ◽  
E.M. Adhia ◽  
D. Wahyuno ◽  
S. Rahayuningsih ◽  
N. Karyani ◽  
...  
Keyword(s):  
Root Rot ◽  
Causal Agent ◽  
Causal Organism ◽  
Disease Symptoms ◽  
Root Rot Disease ◽  
Lannea Coromandelica ◽  
Leaf Yellowing ◽  
Medicinal Crops ◽  
Rot Disease ◽  
Brown Root Rot

Brown root rot disease is a major constraint on cashew plantation in Pekat District, West Nusa Tenggara. Its causal agent has not been characterized. This paper describes efforts to study the pathogen, distribution and loss. Field study was conducted in Pekat District in 2003. Laboratory  experiments to isolate and test the causal agent were conducted in the Indonesian Spices and Medicinal Crops Research Institute, Bogor.  Research results showed that the disease was found widespread in several villages in Pekat District, such as Pekat, Beringin Jaya, Sorinomo, and Nangamiro. Total number of died cashew trees was 1,075 equals to 5,106 kg kernel yield lost, worth Rp20.5 million. Infected trees showed leaf yellowing and defoliation leading to die. The lateral and taproots near collar were encrusted with gravel, earth, and brown mycelia sleeves. The fungus produced arthrospores and brown pigmentation on agar medium containing 0.05% gallic acid. An isolate of the fungus induced typical disease symptoms following inoculation on 5 month-old cashew seedlings. These results indicated that the causal agent of mass decline of cashew in Pekat District is Phellinus noxius. In field, the fungus also infects a barrier tree (Lannea coromandelica [Houtt.] Merr.) (Anacardiaceae), locally known as kedondong pagar or kayu bantenan.

A ROOT ROT OF SWEET CLOVER AND RELATED CROPS CAUSED BY PLENODOMUS MELILOTI DEARNESS AND SANFORD

1933 ◽  
Vol 8 (4) ◽  
pp. 337-348 ◽  
Author(s):  
G. B. Sanford
Keyword(s):  
Root Rot ◽  
Ph Value ◽  
Practical Importance ◽  
Early Spring ◽  
Good Growth ◽  
Sweet Clover ◽  
Alkaline Reaction ◽  
Rot Disease ◽  
The One ◽  
Brown Root Rot

The occurrence, hosts and symptoms of a hitherto undescribed root rot of Melilotus, Medicago and Trifolium, and the relation of temperature and the reaction of substrate to growth of the pathogen Plenodomus meliloti are discussed, and its pathogenicity demonstrated. It is suggested that the disease be called "brown root rot".Evidence is that the hosts mentioned are susceptible only during the winter and early spring dormancy stage. Normal roots of sweet clover, when frozen at −4 °C. for four days and subsequently kept at 2–3°, 9° and 16 °C., did not become susceptible. The brown root-rot disease is distinct from true winter injury resulting from insufficient hardiness to cold.The temperature range for vegetative growth and pycnidia of P. meliloti is from 0° to 27 °C., with optimum between 15° and 17 °C. Increasingly good growth occurs from 2 °C. to optimum temperature. Severe lesions are produced at 2–3°, 9° and 16 °C. The optimum pH value for growth in potato dextrose decoction is about 6.2, the other limits being approximately pH 3.2 and 8.2. Soils with an alkaline reaction apparently are unfavorable.The disease is characterized by brown lesions, on or within which are an abundance of black to dark brown pycnidia. These bodies, 0.5 to 2 mm. in longest diameter, may have one or more spore bearing chambers. Each chamber may have one to several ostioles, through which the one-celled spores, averaging 5.2 × 2.84 μ, exude. The hyphae do not bear spores.Dissemination of the pathogen by seed would not seem to be of practical importance. Control by crop sanitation is recommended, at least until varieties more resistant are available.

Effects of rice husk and rice husk biochar on root rot disease of ginseng (Panax ginseng) and on soil organisms

2017 ◽  
Vol 34 (1) ◽  
pp. 27-39 ◽  
Author(s):  
Jinu Eo ◽  
Kee-Choon Park ◽  
Myung-Hyun Kim ◽  
Soon-Ik Kwon ◽  
Young-Ju Song
Keyword(s):  
Panax Ginseng ◽  
Rice Husk ◽  
Root Rot ◽  
Soil Organisms ◽  
Root Rot Disease ◽  
Rice Husk Biochar ◽  
Rot Disease

scholarly journals BROWN ROOT ROT DISEASE OF CASHEW IN WEST NUSA TENGGARA: DISTRIBUTION AND ITS CAUSAL ORGANISM

2016 ◽  
Vol 5 (1) ◽  
pp. 32 ◽  
Author(s):  
Supriadi Supriadi ◽  
E.M. Adhia ◽  
D. Wahyuno ◽  
S. Rahayuningsih ◽  
N. Karyani ◽  
...  
Keyword(s):  
Root Rot ◽  
Causal Agent ◽  
Causal Organism ◽  
Disease Symptoms ◽  
Root Rot Disease ◽  
Lannea Coromandelica ◽  
Leaf Yellowing ◽  
Medicinal Crops ◽  
Rot Disease ◽  
Brown Root Rot

Brown root rot disease is a major constraint on cashew plantation in Pekat District, West Nusa Tenggara. Its causal agent has not been characterized. This paper describes efforts to study the pathogen, distribution and loss. Field study was conducted in Pekat District in 2003. Laboratory  experiments to isolate and test the causal agent were conducted in the Indonesian Spices and Medicinal Crops Research Institute, Bogor.  Research results showed that the disease was found widespread in several villages in Pekat District, such as Pekat, Beringin Jaya, Sorinomo, and Nangamiro. Total number of died cashew trees was 1,075 equals to 5,106 kg kernel yield lost, worth Rp20.5 million. Infected trees showed leaf yellowing and defoliation leading to die. The lateral and taproots near collar were encrusted with gravel, earth, and brown mycelia sleeves. The fungus produced arthrospores and brown pigmentation on agar medium containing 0.05% gallic acid. An isolate of the fungus induced typical disease symptoms following inoculation on 5 month-old cashew seedlings. These results indicated that the causal agent of mass decline of cashew in Pekat District is Phellinus noxius. In field, the fungus also infects a barrier tree (Lannea coromandelica [Houtt.] Merr.) (Anacardiaceae), locally known as kedondong pagar or kayu bantenan.

scholarly journals The Genetic Structure of Phellinus noxius and Dissemination Pattern of Brown Root Rot Disease in Taiwan

PLoS ONE ◽  
2015 ◽  
Vol 10 (10) ◽  
pp. e0139445 ◽  
Author(s):  
Chia-Lin Chung ◽  
Shun-Yuan Huang ◽  
Yu-Ching Huang ◽  
Shean-Shong Tzean ◽  
Pao-Jen Ann ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Root Rot ◽  
Root Rot Disease ◽  
Rot Disease ◽  
Brown Root Rot ◽  
Phellinus Noxius

Evaluation of dazomet as fumigant for the control of brown root rot disease

2012 ◽  
Vol 68 (7) ◽  
pp. 959-962 ◽  
Author(s):  
Chuen-Hsu Fu ◽  
Bau-Yuan Hu ◽  
Tun-Tschu Chang ◽  
Kai-Leen Hsueh ◽  
Wei-Tse Hsu
Keyword(s):  
Root Rot ◽  
Root Rot Disease ◽  
Rot Disease ◽  
Brown Root Rot
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