INTRODUCTION Earthworms are an important soil organism that has the capability of maintaining soil fertility and playing a key role in sustainability. It converts the low quality organic matter into a nutrient rich product by developing a mutualistic relationship with soil microflora (Singh et al., 2014). It improves soil aeration, infiltration, soil structure, nutrient cycling, water movement and plant growth.The combined activity of earthworms and microbes helps to the retention of nitrogen and gradual release of phosphorus from the soil (Bajsa et al., 2003). They are also known as farmer’s friend, ploughman of the field, intestines of the earth, ecological engineers and biological indicators. They are hermaphrodite animals and reproduction normally occurs through copulation and cross-fertilization. Cocoons hatch after an incubation period that varies according to the earthworm species and environmental conditions. In Eisenia fetida cocoon production started during the 6th week and ceased after the 12th week. The incubation period of Eisenia fetidais about 18-26 days and the number of hatchlings from one cocoon is 2-4 (Fetida, 2018). Herbicides are used to control the weeds in agricultural fields but the heavy use of herbicides without considering the long or short term effects in soil medium degraded the soil. Most of these herbicides may cause harm to nematodes, earthworms and other biological organisms (Kumar and Kumawat 2018). In India about 6704 tons of herbicides were applied to the agricultural field in the year 2010. Of these herbicides, glyphosate is the most commonly used one in tea plantations and non-cropped fields.Over the last decade, about 6.1 billion kilograms of the herbicide glyphosate have been applied worldwide (Benbrook, 2016). Glyphosate is a broad-spectrum, non-selective and post-emergence herbicide, directly applied to plant foliage. In plants, glyphosate disrupts the shikimic acid pathway through inhibition of the enzyme 5-enolpyruvylshikimate-3-phosphate (EPSP) synthase. The shortage in EPSP production leads to reductions in aromatic amino acids that are vital for protein synthesis and plant growth. It degrades at a relatively rapid rate in most soils, with a half-life estimated between 7-60 days (Giesy et al., 2000). Many studies have indicated that the presence of glyphosate in the soil may be toxic to the earthworms, which some studies have also shown glyphosate did not affect the earthworm population in the soil but it gradually reduce the bodyweight of the earthworms (Correia and Moreira 2010). Glyphosate has been considered an environmentally safe herbicide because it is assumed tobe inactivated quickly after spraying due to rapid sorption onto particles in the soil and its fast degradation by microbes (Hagner et al., 2015). Hence this trial was conducted to find the effect of glyphosate on earthworm population and reproduction under laboratory conditions. MATERIALS AND METHODS The laboratory experiment was conducted from November 2021 to January 2022 at the Department of Agronomy, Tamil Nadu Agricultural University. For this experiment, 15 Eisenia fetida earthworms were selected and weights of fifteen worms were measured and introduced into each pot. The known weights of earthworms were placed on each potcontaining 500 grams of soil. Four levels of glyphosate viz., 1000 ppm (T1), 500 ppm (T2), 100 ppm (T3) and 10 ppm (T4) were prepared from glyphosate 46% SL potassium salt with one absolute control (T5). Ten ml of glyphosate at different concentrations (1000, 500, 100 and 10 ppm) were added to each pot containing fifteen earthworms. The experiment was conducted in a completely randomized design (CRD) with three replications. Earthworm population and juvenile count were observed up to 60 days at an interval of 15 days. Observation on earthworm count, earthworm body weight and juvenile count were recorded during this experiment. The experimental data were statistically analysed by adopting Fischer’s method of “Analysis of variance” as per Gomez and Gomez (1984). Wherever the treatment differences were found significant, the critical differences were worked out at a 5 percent probability level. RESULTS AND DISCUSSION Effect of different concentration of glyphosate on earthworm Eisenia fetidapopulation and earthworm juvenile Different concentrations of glyphosate did not significantly affect the earthworm population (Table 1) and earthworm juveniles (Table 2). Glyphosate at the rate of 10 ppm has the highest earthworm (21.3) and juvenile population (6.3) at 60 days after herbicide application (DAHA) compared to control (21 and 6, respectively). There is no mortality in the earthworm population during this experiment at the same time the reproduction capacity of the earthworm did not affect by glyphosate. A similar finding was reported by Correia and Moreira, 2010 the different rates of glyphosate (0, 10, 100, 500 and 1000 mg kg-1) did not kill the earthworm Eisenia fetida. Pochron et al. (2021) reported that twice the recommended dose of glyphosate (12 ml of Roundup Ready in 4 kg of soil) did not impact on earthworm mortality rate. Glyphosate 100, 10 and 1 ppm did not effect on earthworm Allolobophora caliginosa population when herbicide mixed with soil (Martin, 1982). In the treatments with glyphosate (6 litres per ha and 12 litres per ha), the number of cocoons per adult is higher than control but the survival of juveniles and adults and the fertility are lower than in the control treatment (Santadino et al., 2014). Morse (1998) points out that hormesis orhormoligosis takes place when small quantities of astressful agent, among them pesticides, can be useful for an organism in suboptimal environments. This occursin numerous invertebrates (Abdullah et al., 2006) and E. fetida, much like other earthworms, usuallyresponds to different stress factors, increasing their reproductiverate. Effect of different concentration of glyphosate on earthworm body weight: Earthworm body weight did not significantly affected by different doses of glyphosate (Table 3). Fifteen earthworm’s weights were measured before introduction into each pot. Earthworm body weight was reduced gradually up to 30 days after herbicide application including control treatment. This is might be due to earthworms inside the closed potcreatinga stressful environment. After 45 days after the application of herbicide, the weights of the worms were increased because thenumbers of juveniles in each pot were increased. Roundup Ready-to-Use III® (12 ml glyphosate into 4 kg of soil) contaminated soil did not impact on earthworm Eisenia fetida body mass after 7 days of exposure. Both contaminated and uncontaminated soil has a mean body weight of 0.13 g. At 21 days of exposure, the contaminated soil has 0.14 g of mean body weight and uncontaminated soil has 0.12 g of mean body weight (Pochron et al., 2021). Pochron et al. (2020) reported that soil treated with pure glyphosate lost 14.8- 25.9% of their earthworm Eisenia fetida biomass. At the same time soil treated with Roundup Ready-to-Use III® and Roundup Super Concentrate® (26.3 mg of glyphosate per kg soil) did not lose body mass of the earthworms (0.28 and 0.27 g of mean body mass respectively) at 40 days after glyphosate exposure compare to control (0.25 g of mean body mass). The soil treated with glyphosate at different concentration (10, 100, 500 and 1000 ppm) reduce the 50% of the earthworm Eisenia fetida body weight. The decrease in mean weight may indicate a chronic effect of this herbicide (Correia and Moreira 2010).