Watermelon Yield Receives a Boost from Polysulphate

A crop trial in Malaysia demonstrated that the application of Polysulphate to a watermelon crop resulted in noticeably better crop growth, and increased yield by a third compared with control plots.

Big difference between control plot (right) and the watermelon crop fertilized with Polysulphate (left).

Easy Fruit, Tough to Grow

Watermelon is easy to prepare and enjoy but is a demanding crop for soil to sustain. For the creeping plant to thrive, flower, and subsequently swell the fruits to the perfect size for harvest it needs optimum nutrition. Without continued release of key nutrients it will not be able to sustain the vigorous growth of stem and leaves to develop into a plant perfectly poised to photosynthesize the sun’s energy for fruit formation.

Proving Innovation in Fertilizer Use

In a trial in on sandy loam soil in Kahang, Johor province, Malaysia, fertilizer practice was put on trial. Standard fertilizer practice, applying compound fertilizers at 600 kg/ha, was compared with combining that same rate of compound fertilizer with an application (top dressing before transplanting) of 100 kg/ha of granular Polysulphate to the watermelon crop.

In early growth stages the Polysulphate plot plants showed minimum mortality or root fungus infection, and plants grew greener and faster. Using Polysulphate provided a prolonged availability of potassium, calcium and magnesium which strengthened the plants. The magnesium improved light absorption and rate of photosynthesis.  A considerable time after application, granules of fertilizer were still visible in the soil showing that it dissolves gradually and releases the nutrients steadily for uptake by the crop.

Weighing up the Benefits of Polysulphate

At harvest, the control plot yielded 90 mt whereas from the Polysulphate plot of the same size 120 mt of watermelons were produced, a 33% yield increase. The fruit were observed to be bigger and are expected to be of better quality with improved shelf life.

Polysulphate fertilizer produces bigger and better-quality watermelon.