This study investigated the combined effects of irrigation methods and plastic mulches on growth, yield and quality of watermelon in summer season. The treatments of the study comprised with three levels of as main plot viz., Irrigation in furrows at 100% of CPE (I₁), Irrigation in alternate furrows at 80% of CPE (I₂) and drip irrigation with fertigation system at 80% of CPE (I₃) and five levels of plastic mulches as sub treatment viz., without mulching (M₀), mulching with black polythene of 80 micron thickness (M₁), mulching with black polythene of 50 micron thickness (M₂), mulching with white polythene of 80 micron thickness (M₃) and mulching with white polythene of 50 micron thickness (M₄). The highest values for growth parameters (plant length, number of nodes and leaves plant^-1) and yield parameters (number of fruits plant^-1, fruit weight and fruit yield) obtained when irrigation water applied through drip irrigation with fertigation at 80% CPE followed by furrow method at 100% CPE. The highest growth and yield were recorded with Mulching with white polythene of 50-micron thickness (M₄) followed by mulching with white polythene of 80-micron thickness (M₃) and mulching with black polythene of 50-micron thickness (M₂) while lowest values were recorded under without mulch treatment.