The Wonderful World of Watermelons

07/07/2011 3:23:00 PM by John Nance – Eastern Region Sales & P.D. Manger

John NanceHi all. My name is John Nance and I am the new professional manager of Hazera Seeds Inc. A bit about myself: I was raised on a farm in Texas and received a M.S. in Agriculture from Texas Tech University. I have been in the vegetable seed business since 1986, and with Hazera Seeds Inc since 2004. I live in Fernandina Beach Florida with my wife Natalie.

 

Watermelon is one of nature’s tastiest treats and provides multiple nutritional benefits along with its sweet, crisp flavor. A 2 cup serving of watermelon contains only 80 calories, and provides significant levels of vitamins A, B6 and C, as well as measurable levels of potassium. In addition, it is also an excellent source of Lycopene (an anti-oxidant) providing twice as much lycopene as the same size serving of tomato. Watermelon also provides another anti-oxidant named citrulline, which can help promote sexual stamina and is sometimes used to treat erectile dysfunction.

It is believed that watermelon originated in South Africa, due to the wide genetic diversity of watermelons found there. There is evidence of watermelon cultivation in the Nile valley in the 2nd millennium BC, and watermelon seeds were discovered in the tomb of King Tutankhamen.

Watermelon was probably introduced to the Americas in the 16th century, possibly by African slaves. Today, watermelons are grown in almost every state in the U.S. and most countries around the world. The United States is the world’s fifth largest producer of watermelon, behind China, Turkey, Greece and Brazil (respectively).

Watermelons grown today can be divided into 3 main categories: Open Pollinated (OP), Hybrid Diploid and Hybrid Triploid (seedless).

Production of Open Pollinated watermelon seeds is easy and economical. Companies that produce OP watermelon seeds maintain genetically pure stocks of seeds to use in production fields. These seeds are planted with no other watermelons within 1 mile of the field. The flowers are pollinated naturally (bees and crawling insects). The watermelons are left to mature in the field, and are then mechanically harvested. The seeds are then washed and dried, cleaned, treated and packaged.

Production of Diploid Hybrid seeds is more costly and labor intensive. A hybrid is a cross between 2 parent lines (such as Charleston Gray and Crimson Sweet). To produce these seeds, plants of both lines are grown in close proximity to each other. One of the parents will be used for seed production (Crimson Sweet), and the other (Charleston Gray) just for pollen.

Workers identify female flowers on the Crimson Sweet which are almost ready to open (usually the day before the flower opens naturally). They mechanically pinch these flowers closed so that no insect can pollinate the flower. The next morning, they collect male flowers from the Charleston Gray, open the female flower on the Crimson Sweet, and pollinate the flower (much like dabbing a paint brush on a canvas). After pollinating, they close the female flower again, and place a plastic clip on the base of the flower, to indicate that it is hand pollinated (hybrid). From here, the process is identical to the OP production process.

University of Florida IFAS department describes the production of seedless watermelons this way:

The seedless condition is actually sterility resulting from a cross between two plants of incompatible chromosome complements. The normal chromosome number in most living organisms is referred to as 2N. Triploid watermelons are produced on highly sterile triploid (3N) plants, which result from crossing a normal diploid (2N) plant with a tetraploid (4N). The tetraploid is used as the female or seed parent and the diploid is the male or pollen parent. Since the tetraploid seed parent produces only 5 to 10% as many seeds as a normal diploid plant, seed cost is considerably more than for diploid watermelon hybrids. Tetraploid lines are usually developed by treating diploid plants with a chemical called colchicine.

Whether seeded or seedless, watermelon is always a sweet, delicious treat, that can now be enjoyed year round.