Infection efficiency of Phaeoisariopsis personata and the influence of different wetness patterns on germ-tube growth of the pathogen

Controlled environment studies with P. personata [Mycosphaerella berkeleyi], the causal agent of late leaf spot disease of groundnut, showed that infection is enhanced if leaves are exposed to alternate wet and dry periods (intermittent wetness) compared with continuous wetness. Detailed investigations to elucidate this phenomenon revealed more germ tubes per conidium and more branching of germ tubes with intermittent wetness than with continuous wetness. With intermittent wetness there was clear evidence of tropic growth of germ tubes and branches towards stomata and subsequent penetration. With continuous wetness, germ tube growth did not appear to be directional and germ tubes commonly passed over the stomatal guard cells, therefore leading to relatively few stomatal penetrations. For both wetness regimes, stomatal penetrations continued to increase with increased leaf wetness for at least 6 d after inoculation and there was a linear relationship between the number of stomatal penetrations and the number of resultant lesions. Infection efficiency was markedly increased when the spore load was reduced to 0.1 conidia/cm² (c. 1 spore/leaflet)

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Not AvailableDiseases and insect pests of ginger and their management.Not Availabl

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Not AvailableDiseases and insect pests of gingerNot Availabl

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Not AvailableMushroom Cultivation TechnologyNot Availabl

Seasonal abundance of Scaphisoma tetrastictum Champ on oyster mushroom and its relation to meteorological factors

A study on the seasonal incidence of the beetle Scaphisoma tetrastictum Champ and the relationship of various meteorological factors with its incidence in oyster mushroom ( Pleurotus ostreatus Jacq. Ex Fr.) was conducted in the Department of Plant Pathology, Assam Agricultural University, Jorhat (India) during 1999–2000. Seasonal variation in the population density of adult beetles and per cent fruit body infestation by the adults and grubs were observed. Incidence of the beetle was recorded from March to November 1999 revealing the highest number (12.35) of adults per fruit body and per cent infestation (29.96) during July, 1999. The mushroom remained free from beetle incidence during the winter months. Beetle population per fruit body (10.43) and extent of infestation (26.03%) were higher during monsoon (June to August) where as the pre-monsoon period (March to May) recorded the beetle population and per cent infestation of 4.64 and 9.61%, respectively. Beetle population showed positive significant correlations with maximum ( r = 0.7460, P < 0.05) and minimum temperature ( r = 0.6884, p < 0.05) and number of rainy days ( r = 0.9102, p < 0.01). Per cent fruit body infestation by the beetle exhibited positive significant correlations with maximum temperature ( r = 0.8032, p < 0.05), minimum temperature ( r = 0.7666, p < 0.05), total rainfall ( r = 0.6823, p < 0.05) and number of rainy days r = 0.9299, p < 0.01)

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Not AvailableBikhakta kathphula aru abikhakta kathphulaNot Availabl

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Not AvailableMilky kathphular krishi pronaliNot Availabl