Feb 29, 2016

Penn State conducts seedless watermelon variety trial

Today’s consumers expect to purchase high quality, flavorful, locally grown produce. One of the staples of summer produce markets are watermelons. In current American culture, seedless watermelons are preferred.

This was not always the case, but has been for about the last decade or so. Vegetable growers are constantly expanding produce offerings, and the market is demanding more seedless watermelon production.

In 2015, researchers from Penn State Extension conducted a replicated variety trial at theSoutheast Research and Extension Center in Landisville, Pennsylvania to compare 29 different seedless watermelon varieties and 3 seeded varieties, most of which are commercially available. Most of the varieties performed well, and produced flavorful fruit which would be marketable.

Methods

Seedless watermelon transplants and the pollenizer variety SP-6 were seeded in plug trays on April 30th, 2015. Transplants were placed in the field on May 26th, on 3 foot spacing within the row, with 9 foot spacing between the rows. A seeded pollenizer (SP-6) was planted every 6 plants to ensure proper pollination of the seedless varieties. Black plastic raised beds with double-row drip tape were used as well. All plots received season long applications of insect and disease control sprays consistent with the Pennsylvania Commercial Vegetable Production Guide.

Fertilization was provided through the drip tape as needed. Weed control was performed both prior to and after planting, but proved to be less than desirable. Melons were harvested three times over a three week period, utilizing several ripeness indicators. Disease pressure was relatively low, with sporadic downy and powdery mildews, which did not affect melon yield.

Results

Seedless=(S) Seeded=(SD) Orange Flesh=(O)

Other notes

Informal tasting of each watermelon variety occurred after performing brix readings. Notable flavorful varieties included Bingo, Harvest Moon, Orange Crisp, Traveler, and Crispy Winner. Two orange flesh varieties were planted; Orange Glo is a large, seeded variety, and Orange Crisp is a round, seedless variety. Amish Moon and Stars is an heirloom seeded variety with large, oblong fruit. Throughout the entire trial, almost no hollow heart was observed, with Neptune showing some symptoms, but not enough to be unmarketable. Overall, the trial was very successful, and proved that quality seedless watermelons can be grown in Pennsylvania with favorable yields.

— Steve Bogash and Tanner Delvalle, Penn State University