2007 – The Oklahoma State Senate made watermelon its official state vegetable. The Oklahoma State Senate made watermelon its official state vegetable. 350.5 – the weight in pounds of the world’s heaviest watermelon grown in 2013. 300 – the number of types of watermelons grown in the U.S.9–10 – the sweetness measurement of most watermelons on the Brix scale. General DisclaimerThe information contained in South Florida Reporter is for general information purposes only.