The effect of moisture stress on growth and latex production of Hevea brasiliensis in Sri Lanka was investigated and suitable agronomic practices to overcome the adverse effects suggested. Among the different soil management practices, application of straw mulch resulted in higher girthing of plants, compared to other practices such as growing leguminous covers or natural vegetation. Similarly, tappability and yield were much higher in mulched plots. Mulching also contributed to soil nutrients, improved CEC and raised soil pH. Mulching also improved the potassium content and the water status of both plants and soil. A quadratic response to the application of K was observed. Under conditions of moisture stress, increasing the levelof K helped in restoring normal growth of rubber plants. These results were supported by observations on physiological parameters such as stomatal coductance, transpiration and leaf water potential.