A new leaf spot disease of Nyctanthes arbor-tristis caused by Myrothecium verrucaria from India

During systematic survey of parasitic fungi at Faizabad (U.P.), author came across a new leaf spot disease of harsingar (Nyctanthes arbor-tristis L.) caused by Mycothecium verrucaria (Alb. & Schw.)Ditam. ex Fr.

The small spherical yellowish leaf spots become visible in the month of September. With time the spots increase in size and finally become greyish followed by light brown and the death of the leaf tissues.  

The pathogen was isolated on PDA medium by usual method. Healthy leaves when inoculated artificially by spore suspension, developed spots characteristics in nature after 15 days. Reisolations of the artificially infected spots yielded Myrothecium verrucaria.

The morphological obsrvations were made in culture and in nature. The mycelium is septate, white to olive green and become olivaceous black with ageing. Conidiophore about 70-78 µ long, smooth, erect, septate and brached above penicillately producing conidia borne in chains, directly and on phialids. Conidia elongate, to ovate, smooth, dusky, olive green to olivaceous black and about 6-9.7X1.46-4.0 µ. 

On the basis of morphological characters the fungus was identified as Myrothecium verrucaria (Alb. & Schw.) Ditm ex Fr.

Myrothecium verrucaria  has earlier been reported from soil and perhaps not as parasite hence this has been described as a causal organism of leaf spot disease of N. arbor-tritis L. earlier not reported from India.

This fungus has been deposited in the Herbarium CMI as IMI. 209313 and Herbarium K.S. Saket P.G. College,Faizabad as RSK-154/S.

Cited this as: Kanaujia R.S. (1977):  A new leaf spot disease of Nyctanthes arbor-tristis caused by Myrothecium verrucaria from India. Indian Phytopathology. 30(2): 291-292.

 

 

 

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मेरी कलम 23:50  No comment

Notes on new fungal disease of Solanum tuberosum

In February, 1979, The author noticed stems of Solanum tuberosum L. infected by a fungus causing severe necrosis in his kitchen garden. On examination, the causal organism of the disease was identified as Mucor heimalis Wehmer. Earlier S. tuberosum has not been found to get infected by Mucor heimalis in India and this is new report. 

The disease appeared as small moist area on the stem just above the soil. The lesion enlarged radially and showed fluffy growth of fungus within a week followed by stem necrosis and ultimate death of plants desiccation. The pathogenicity tests were carried out as follows.

The stem of 15 days old potato plants were separately sprayed with spore suspension of freshly sporulating culture of Mucor heimalis without, and after making the injuries on the test plants. The sprayed plants were incubated in the field conditions. After 10 days, the characteristic disease spots were found on the stems in the plants which were injured before inoculation. Reisolation from the artificially infected plants gave Mucor heimalis, thus, the pathogenic nature of the fungus was confirmed by inoculation tests providing Koch's postulates.

Cited this as: Kanaujia R.S. (1979): Notes on new fungal disease of Solanum tuberosum. Indian Phytopathology. 32(4):611-612.

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मेरी कलम 23:13  No comment

Effect of extraneous matter on juice extraction and Pol% cane

The present study was carried out in the month of March, April and May consisting three elite sugarcane varieties, viz., CoS 8436, CoS 8432 and CoSe 92423 to evaluate the effect of extraneous matter (trash) on extraction % of juice and Pol% cane. The result revealed that the extraneous matter affected extraction % and Pol% cane adversely, at a significant level both at the varietal level as well as at staling hours. Both the aforesaid parameters decrease with the increasing months along with the data calculated over the varieties, therefore, it was concluded that the cane should be free from all the extraneous matter to get maximum juice and sugar from cane.

Cited this as: Siddhant, Srivastava R.P. and O.P. Ukaogo (2018): Effect of extraneous matter on juice extraction and Pol% cane. 41st Annual International Conference, Workshop and Exhibition on chemical sciences in an emerging economy: Issue, prospects and opportunities organised by University of Ibadan, Ibadan, Nigeria. September 16-21, 2018. p. 26.

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मेरी कलम 03:48  No comment