J. S. Sehgal , V. Shanker , H. S. Sehgal , T. C. Pokhriyal

Abstract

Enterolohium timbouva Mart. Seedlings raised under pot culture conditions were given different nitrogen treatments viz. 20, 40, 60, 80, and 100 kg per ha in three equal splits at fifteen days interval after 50 days of sowing. Two controls without N aplication one with sterile (NO-1) and another with normal (NO-2) soils were also maintained simultaneously. Periodical samplings for nodule growth, nitrogenase (Acetylene reduction) activity and rhizospbere microflora was taken after every fifteen days interval after the application of the last nitrogen dose i.e. 85, 100, l15, 130 and 145 days after sowing. Among different N treatments, maximum and minimum nodule fresh and dry weights and nitrogenase activity was observed at N-40 and N-1OO respectively as compared to control in all the five growth stages. However. An increase in the rhizospbere microftora (bacteria and fungi) was observed with the increase in the nitrogen doses.

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S. N. Khan , B. M. Misra , R. K. Tiwari , H. S. Sehgal

Abstract

Five fungi namely, Coleosporium evodiae Diet., Phyllachora infectoria Cooke, Guignardia calami (H & P. Sydow) Von Arx and E Muller, Alternaria cassiae Jurair & Khan and Clados. porium uredinicola Speg have been described for the first time from India together with some new host records for India.

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H. S. Sehgal , R. K. Tivari , S. N. Khan , B. M. Misra

Abstract

The diseases of forestry species (except poplars) in nurseries, plantations and natural forests in H.P. are described along with their control measures, giving details only of potential important ones. The importance of continuous surveillance of forests is stressed.

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A. N. Shukla , Sujan Singh , H. S. Sehgal

Abstract

This paper is a review of the work done on fungi associated with the ischolar_mains, rhizome, stem, culm and foliage of different species of bamboos occurring in India and the diseases and deterioration caused by them.

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H. S. Sehgal

Abstract

Eucalyptus spp. Raised in large scale plantations by Forest Departments, in agriculture farms by farmers and on all available vacant lands along roadside, railway tracks, canal banks etc, under social forestry programmes in most of the Indian States suffer from a number of diseases Brief accounts of pathogenic diseases and physiological disorders, reported so far from India. Are given. Cylindrocladium seedling blight caused by different species of Cylindrocladium and pink disease caused by Corticium salmonicolor are the most serious pathogenic diseases in high rainfall ares. Almost all the Eucalypts planted in India have been attacked. Eucalyptus deglupta and E. torelliana being mildly suspectible. Yellowing and die back in E. tereticornis is serious in North India. Unsuitable sites and deficiency of available micro nutrients are associated with this disorder. Little leaf and chlorosis is also considered a mycoplasma disease.

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Sujan Singh , H. S. Sehgal , P. C. Pandey , B. K. Bakshi

Abstract

Cashew (Anacardium occidentale Linn.) is a valuable cash crop and a foreign exchange earner. Recently, there was an epidemic outbreak of an anthracnose disease of cashew in plantations in South India. The disease kills the flush, tender twigs and inflorelcence and thus seriously affects the yield of the fruit. The symptoms of the disease consist of dark brown shiny lesions followed by resin exuclation on the affected parts. Causal organism is identified as Collelotrichum gloeosporioides Penz. And is described as it occurs in nature. The control of the disease can be secured by chemicals using Bordeaux mixture or lime sulphur sprays. Spraying in the vulnerable period, quick coverage and spraying all diseased plantations, both private and government, are necessary to make any spray programme successful. The pathogen perennates on dead parts of the plant. Removal of infected parts of the plant and provision of wind breaks will also help in controlling the disease.

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