Studies were conducted to investigate seed longevity, seedling emergence and seed production of the weed Phalaris minor in wheat in northern India. The longevity of P. minor seeds buried in bags in the field was often limited to less than 1 year, although many seeds buried at 30 cm depth in a rice-wheat rotation remained viable for longer. The application of direct seeding in wheat reduced the seedling emergence rate of P. minor, when compared with conventional ploughing and sowing. However, a larger P. minor seedbank in the upper soil layer in plots under direct seeding partly reversed this positive effect in one of the two studies. Besides differences in relative distribution of weed seeds through the soil profile, it was likely that other factors such as reduced soil disturbance and soil characteristics associated with the application of direct seeding were also involved in regulating the emergence rate. Mature P. minor plants in wheat were found to invest a stable part (27%) of their aboveground biomass in seed, so that total seed weight was strongly linearly correlated with the aboveground biomass of the mother plant. Individual seed weight, however, was little affected by the weight of the mother plant.

Vermicompost is one of the ready to use organic fertilizers. The efficacy of vermicompost vis-avis other organic fertilizers for fish production has not yet been extensively explored. For this purpose, an experiment was performed on three Indian major carps viz. catla (Catla catla Ham.), rohu (Labeo rohita Ham.) and mrigal (Cirrhinus mrigala Ham.). The fry/fingerlings acclimated for 10 days prior to the commencement of experiment were stocked in 5.54×6.15 m size ponds with a stocking density of 30 fish per pond in a ratio of 3:4:3, respectively. Six treatments viz. a control (T 1) without any treatment, pig manure at 4,000 kg haG 1 yearG 1 (T 2), poultry manure at 6,000 kg haG 1 yearG 1 (T 3), cow dung at 10,000 kg haG 1 yearG 1 (T 4), vermicompost at 10,000 kg haG 1 yearG 1 (T 5) and vermicompost at 15,000 kg haG 1 yearG 1 (T 6) were used and their effect on growth performance of these fishes was recorded every month for a period of one year. All the six treatments caused significant monthly increase in fish growth; the three fish species gained maximal growth (length and weight) in ponds treated with vermicompost at 10,000 kg haG 1 yearG 1

Organic fertilizers are used to enhance the productivity of inland aquatic resources. These fertilizers directly influence the water quality parameters which in turn form the aquatic environment. Vermicompost is a new introduction to the list of organic fertilizers used in aquaculture production. However, its effects on water quality parameters have not yet been fully investigated. To accomplish this objective, the present study was undertaken. The experiment was carried out in 5.54×6.15 m size ponds with a stocking density of 30 fish per pond in a ratio of 3:4:3 of Indian major carps viz. catla (Catla catla Ham.), rohu (Labeto rahita Ham.) and mrigal (Cirrhinus mrigala Ham.). Different organic fertilizers used as treatments were: untreated ponds as the control (T 1 ), pig manure at 4,000 kg haG 1 yearG 1

Use of organic fertilizers has become very common in the modern piscicultural practices; vermicompost is a new addition to the list of such fertilizers. The efficacy of vermicompost was better than the other fertilizers both in keeping the hydro-biological parameters of treated waters in favourable ranges as well as in maximizing the fish growth. However, its effect on the pathogenic bacterial profile of treated waters is not known. To accomplish this objective, an experiment was performed in 5.54×6.15 m size ponds stocked with three species of Indian major carps viz. catla (Catla catla Ham.), rohu (Labeo rohita Ham.) and mrigal (Cirrhinus mrigala Ham.) at 30 fish per pond in 3:4:3 ratios, respectively. Six treatments viz. a control without any treatment (T 1), pig manure at 4,000 kg haG 1 yearG 1 (T 2), poultry manure at 6,000 kg haG 1 yearG 1 (T 3), cow dung at 10,000 kg haG 1 yearG 1 (T 4), vermicompost at 10,000 kg haG 1 yearG 1 (T 5) and vermicompost at 15,000 kg haG 1 yearG 1 (T 6) were used to monitor their effect on the pathogenic bacterial populations in the treated pond waters. One fourth doses of fertilizers were applied 15 days prior to the fish stocking and the remaining doses were given at fortnightly intervals; the supplementary feed was given at 2% of the body weight of fishes. The pure culture of bacterial isolates segregated from the pond sediments were identified by primary, secondary and tertiary tests and confirmed for their pathogenicity through in vitro and in vivo tests. Overall, seven gram negative pathogenic bacterial strains (viz. Aeromonas hydrophila, Escherichia coli, Enterobacter aerogens, Pseudomonas fluorescens, Klebsiella oxytoca, Pseudomonas aeruginosa and Shigella sp.) and three gram positive strains (viz. Micrococcus luteus, Staphylococcus aureus and Staphylococcus sp.) were isolated from the pond waters treated with different manures. The in vitro and in vivo tests confirmed the pathogenic nature of these bacteria. The abundances of the heterotrophic pathogenic bacteria were minimal in the pond waters treated with vermicompost at 10,000 kg haG 1 yearG 1 followed by those treated with vermicompost at 15,000 kg haG 1 yearG 1 ; the abundances of pathogenic bacteria were higher in waters treated with other fertilizers including under the control treatment. Under other than these two vermicompost treatments, the abundances of pathogenic bacteria were variable depending upon the bacterium-fertilizer type. On the basis of these results, vermicompost at 10,000 kg haG 1 yearG 1 seemed to be the best among the five organic fertilizer treatments in controlling the abundance of pathogenic bacteria in the treated pond waters.

Different organic manures vermicompost @ 15000, vermicompost @ 10000, cow dung @ 10000, poultry manure @ 6000, pig manure @ 4000 kg/ha/yr and control used to monitored their effect on growth performance of Catla catla, Labeo rohita and Cirrhinus mrigala. The results revealed that all the three species gained maximum length in vermicompost @ 10,000 kg/ha/yr followed by vermicompost @ 15,000 kg/ha/yr, cow dung @ 10,000 kg/ha/yr, poultry manure @ 6,000 kg/ha/yr, pig manure @ 4,000 kg/ha/yr and control. Among the 3 species C. mrigala showed maximum increase in body length which was 33.4 cm followed by L. rohita and C. catla was 32.1, 31.3 cm in vermicompost @ 10,000 kg/ha/yr treatment. The minimum length of C. mrigala, L. rohita, C. catla observed in pond treated control. But in case of C. mrigala, the result revealed that the maximum increase in body length in vermicompost > poultry manure > cow dung > pig manure and control, respectively. All the three species gained maximum growth in vermicompost. Among the 3 species L. rohita showed maximum growth followed by C. catla and C. mrigala. There was two times more growth of Indian major carps in pond treated with vermicompost @ 10,000 kg/ha/yr as compared to control.