No abstract

Field experiments were conducted in 2013-14, 2014-15 and 2015-16 planting seasons to evaluate the efficacy of different sources of organic materials and a nematicide Furadan 5G in the control of Meloidogyne incognita infection on the major spices onion, Allium cepa L. The organic materials (poultry refuse, mustard oil cake, rice bran and sawdust) were incorporation with the soil 3 weeks before transplanting of onion seedlings whereas Tricho-composts were added in the soils 5 days before seedling transplanting. The results showed that different organic materials displayed varying levels of effective to the nematode infection. All the treatments gave satisfactory reduction of gall development on roots and increased plant growth as well as yield of onion. Among the treatments, Tricho-composts and poultry refuse appeared to be the best amendments for root knot nematode reduction and significantly influenced the growth of the onion with the highest yield. Saw dust, rice bran and nematicide Furadan 5G were also proved to be better amendment for reduction of root knot nematode which enhanced plant growth and increased yield of onion. These results suggest that exploitation of organic soil amendment in nematode management would be a useful control measure in onion production in Bangladesh.

Efficacy of individual and mixed substrates i.e. rice bran, wheat bran, grass pea bran and their combination with mustard oilcake (MOC), based Trichoderma harzianum bio-fungicides were tested against seedling disease (Fusarium oxysporum) of brinjal in plastic tray and seed bed during 2009 to 2014 in the net house of Bangladesh Agricultural Research Institute (BARI). The results of plastic tray and seed bed experiments revealed that four combinations of substrate based T. harzianum bio-fungicides such as (1) rice bran + wheat bran, (2) rice bran + wheat bran + mustard oil cake (MOC), (3) rice bran + grasspea bran, and (4) rice bran + grasspea bran +MOC were suitable for controlling the soil borne seedling disease (F. oxysporum) of brinjal in tray soil as well as seed bed soil conditions.

Sclerotinia sclerotiorum (Lib.) de Bary caused white mold disease with a wide distribution worldwide. For the control of the disease, it is fundamental to understand the identification, morphology, and genetic diversity of the fungus. The objective of this study was to collect and characterize S. sclerotiorum isolates from different regions of the country. The characteristics evaluated for the mycelium characterization were: the time required for the fungus to occupy the plate; density of the formed mycelium; coloration of the colonies and mycelia growth rate. Sclerotia assessments were based on the time for the formation of the first sclerotia total number formed per plate, the format of distribution in the plate, and the shape of the sclerotia formed by the isolates. Variability was observed for colony colour, type of growth, the diameter of mycelia growth, sclerotia initiation, and number and pattern of sclerotia formation among the isolates. The evaluated populations presented wide variability for the cultural and morphological characteristics, being predominant in the whitish colonies with fast-growing habitats. The majority of isolates produced a higher number of sclerotia near the margin of the plates and with diverse formats. Phylogenetic analysis revealed that the isolates belonged to a similar group of publicly available S. sclerotiorum and were dissimilar from the group of S. minor, and S. trifolium and distinctly differ from S. nivalis group. The present study is the first evidence for morphological and genetic diversity study of S. sclerotiorum in Bangladesh. Therefore, this report contributes to more information about the morphological and genetic diversity of S. sclerotiorum and can be useful in implementing effective management strategies for the pathogen which caused white mold disease.

No abstract