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20201
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Subject: Zoology × Author: Anshu × Start date: 2000 × Type: Thesis × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    Effect of herbicides, organic wastes and seasonal variations on growth parameters and fecundity of E.fetida
    (CCSHAU,HiSAR, 2020-06) Anshu; Dharambir Singh
    Earthworms are major contributors to soil biodiversity; they are basic driver of abiotic and biotic soil properties,therefore also known as major ecosystem engineers in terrestrial soils due to their contribution in pedogenesis. E. fetida minimizes the pollution danger caused by organic wastes degradation and internationally used as reference animal for toxicity tests. Environmental variations in temperature and organic waste affect the respiration, metabolism, growth parameters and reproductive potential of earthworms. Use of agrochemicals like pesticides, herbicides and inorganic fertilizers on large scale to enhance agriculture production have negative effects on earthworms and they are killed as non targeted organisms. Non judicious use of agrochemicals could induce the damage at genetic level, disruption in enzyme activities, reduction in survival, reproduction and growth rate and ultimately decrease in the total earthworm biomass. The present study was carried out to investigate the effect of herbicides, organic wastes and seasonal variations on survival, growth parameters, fecundity and immune system of E. fetida. Different doses of herbicides viz. Pendimethalin and Glyphosate were used individually and in combinations. Survival and fecundity were affected and minimum number of survived adult earthworm and cocoon collected were 17.6±0.33 and 19.6±0.66, respectively in worms treated with Pendimethalin+Glyphosate @1.50+2.50 μl/kg after 90th day of experiment. Similarly, minimum body weight (0.40±0.06 gram) and length gain (6.56±0.34 cm) were observed in the same treatment. Immune system was also affected and significant reduction in the total number and types of coelomocytes (65.6%), eleocytes, amoebocytes-I, amoebocytes-II, granulocytes-I and granulocytes- II was recorded in worms exposed to Pendimethalin+ Glyphosate @1.50+2.50μl/kg. Different season and substrates significantly affected the growth and survival of earthworms. Mixed substrate (Cow+ Buffalo dung) among the three was found most appropriate for rearing earthworms and maximum survived adult worms, cocoons count, length and body weight was 48, 69.6, 79 cm and 0.82gms, respectively during summer season. Buffalo dung was more suitable in summer season whereas, cow dung in winter.