To find out optimum sowing time and suitable moisture regime for Bt-cotton and to assess their effects on growth, yield and fibre quality parameters, field experiment was conducted at Agriculture Research Station, Dharwad for two years (2005-06 and 2006-07) under irrigated conditions. Sowing time had a significant influence on seed cotton yield. Early sown crop produced significantly higher yield (2227 kg/ha) than late sowing in July (1809 kg/ha) and August (1004 kg/ha). Irrigation at 0.8 IW/CPE ratio produced significantly more seed cotton yield (1807 kg/ha) as compared to 0.4 or 0.6 IW/CPE ratios but was on par with 0.6 IW/CPE ratio (1731 kg/ha). Productivity was affected to a greater extent by date of sowing than irrigation levels. Loss in yield due to late sowing was not compensated with increase in irrigation level. Different moisture regimes did not affect the fibre length, fibre strength, fibre fineness and uniformity percentage. Whereas, fibre maturity was significantly increased with 0.6 and 0.8 IW/ CPE ratio. Cotton with best fibre quality can be produced with June sowing at 0.6 IW/CPE ratio, which can produce highest fibre length, fibre strength, uniformity percentage and maturity ratio under transitional tract of Dharwad.