Abstract:
Seed health status of stem amaranth (Amaranthus lividus), water spinach (Ipomoea
aquatica), Indian spinach (Basella alba), sweet gourd (Cucurbita moschata), snake
gourd (Trichosanthes cucumerina), ash gourd (Benincasa hispida), country bean
(Phaseolus vulgaris), yard long bean (Vigna unguiculata), radish (Raphanus
sativus) and carrot (Daucus carota) was determined by inspection of dry seed and
blotter seed health testing method prescribed by ISTA in Seed Pathology
Laboratory of Department of Plant Pathology, Sher-e-Bangla Agricultural
University, Dhaka during January 2016 to December 2016. The laboratory
experiment was conducted following Complete Randomized Design (CRD) with
four replications. Untreated, unknown grower’s/farmer’s bulk vegetables loose
seeds were considered for this experiment. Seeds were collected from five districts
viz. Dhaka, Rangpur, Thakurgaon, Panchagarh and Dinajpur. For Dhaka, truthfully
labeled seed of BADC (Bangladesh Agricultural Development Corporation) was
considered to compare the health status of collected seeds. In dry inspection,
fungal mycelium (white and cottony) and sclerotia were observed. No physical
abnormalities were found in BADC’s seeds, except sweet gourd, snake gourd, ash
gourd. In most cases, the highest pure seeds were observed in BADC’s seeds
whereas the lowest was found seeds from Thakurgaon district. Eight fungi viz.
Aspergillus flavus, Aspergillus niger, Fusarium spp., Alternaria spp. Curvularia
spp., Chaetomium spp., Rhizopus spp. and Cercospora spp. were recorded from
seeds by blotter method. Moreover one unidentified bacterium and one unknown
fungus were also found in collected seed. In all tested seed sample, the common
fungi were Aspergillus flavus, Aspergillus niger, Fusarium spp., Chaetomium spp.,
Rhizopus spp. However, Alternaria spp. were present in stem amaranth, country
bean, radish seeds. Curvularia spp. were present in water spinach, Indian spinach,
sweet gourd, snake gourd, yard long bean and carrot seeds. The prevalence of
fungi varied significantly with respect to seed categories and seed sources. The
lowest seed borne fungal infection were observed in BADC seeds followed by
seeds of different districts. Considering the findings, farmers are advised to collect
vegetables seeds from reliable sources and should check their seed health status
before sowing. Farmers are also suggested to do seed treatment by recommended
chemicals or botanicals before sowing to prevent seed borne diseases in the field.
Description:
A Thesis
Submitted to the Faculty of Agriculture,
Sher-e-Bangla Agricultural University, Dhaka,
In partial fulfillment of the requirements
for the degree of
MASTER OF SCIENCE
IN
PLANT PATHOLOGY
SEMESTER: JANUARY-JUNE, 2016