James Boudreaux, Professor and Stephen Crnko, Extension Associate , LSU Ag Center School of Plant, Environmental and Soil Sciences, Baton Rouge, La.; Andre Brock, Assistant Extension Agent, West Feliciana Parish; Keith Hawkins, Assistant Area Extension Agent, Beauregard Parish; Randall Bellon, County Agent, Allen Parish; David Yount, Former Assistant County Agent, Red River Parish; Myrl Sistrunk, County Agent and Adam Lingefelt, Extension Intern, West Carroll Parish; Blair Buckley, Associate Professor, Red River Research Station, Bossier City, La.; Rafash Brew, County Agent, Union Parish, and Ernest Vargas, Visiting Scholar, Escuela Agricola Panamericana Zamorano, Tegucigalpa, Honduras.
Seedless (triploid) watermelons have become very popular in wholesale markets for watermelons throughout the country. Even though seedless melons have been around for a number of years, very little interest was expressed by Louisiana growers. With the development of more farmers’ markets and roadside stands, several growers have expressed an interest in seedless varieties that would make rather large melons -- 20-25 pounds. They also expressed the need for information on the production of seedless watermelon transplants.
Sixteen seedless watermelon varieties were planted at six locations across the state. Varieties were obtained from Abbott & Cobb, Hazera, Nunhems, Harris Moran, Seminis and Seedway. Growers participating in the demonstration plots were: Jerry Landrum, St Francisville, La.; Chuck Melsheimer, Reeves, La.; Jason Anderson, Coushatta, La.; Scott Ryan, Dixie, La.; Tony Brunini, Epps, La., and Calvin Hollis, Spearsville, La. The seed companies, growers and agents are recognized for their efforts in conducting this test. Without this type of cooperation, information on the performance of new varieties could not be generated.
The plants were grown at Burden Research Center, Baton Rouge, La. The seeds for south Louisiana plots were planted the week of March 9 while the north Louisiana plots were planted the week of March 16. The seeds were placed by hand 1 inch deep with the radical end pointed up and covered with a thin layer of warm and moist mix (Sunshine Mix #1) in 72 plastic cell trays. The trays were placed in a sweet potato curing room and held at 85-90oF and 85-90% relative humidity for 48 hours. The high temperatures and humidity are essential for successful germination of a high percentage of triploid watermelon seeds.
After 48 hours in the curing room, the roots emerged, and the trays were moved to a greenhouse with the nighttime temperature set 50-55o F. The seedlings emerged through the mix over the next three to five days. The plants were not watered until the seed leaves (cotyledons) appeared to prevent stretching.
A 200 ppm N solution of 20-20-20 was applied every other week (twice a month) once the true leaves developed. The plants were grown slowly (cool and dry) in the greenhouse for four weeks. The plants were moved outside to a screen house to be hardened (cool temperatures and withholding water) for seven days prior to planting. The plots in south Louisiana were planted the week of April 20 and the north Louisiana plots were planted the week of April 27.
The plants of each variety were set across the field on two or three rows. The plants from the outside row were turned toward the middle to make the location of the different varieties easier at evaluation. A plant of the pollenizer variety Polimax was set every three or four plants.
Plastic mulch was used at all of the locations. Drip irrigation was used at all plots except one.
The plots at Jerry Landrum in St Francisville, Chuck Melsheimer in Reeves, Jason Anderson in Coushatta and Scott Ryan in Dixie were evaluated the week of July 6, while the plots at Tony Brunini in Epps and Calvin Hollis in Spearsville were evaluated the week of July 13. The melons were evaluated for yield, fruit shape, fruit size, rind color, rind thickness, flesh color, foliage and soluble solids in the field.
Five to 10 hills of each variety were flagged to prevent harvest. This allows the varieties to be evaluated before harvest, but the grower can still harvest the majority of the melons as they get ripe. One melon of each variety from each location was brought to Baton Rouge and stored for a week at room temperature. These melons were cut and evaluated for shelf life and soluble solids.
The results from the different locations are combined to find an average determination for each category. The top varieties were determined by how many times that variety placed in the top of the different categories. Results of the evaluation appear in the attached table.
The overall performance of the melons in the test was somewhat disappointing. Fruit size in the plots was smaller than expected. Only two of the test plots produced a good commercial crop where the grower could make money. The other plots were borderline on making money. Many of the melons appeared bleached and light in color. This may have been due to the extremely hot, dry weather in late May and June. Also, two growers mentioned that mites were a problem in June. The mite damage may have enhanced the light color and bleached appearance of the melons.
The top variety tested was Revolution.
Revolution is an oblong, dark green melon with a light green stripe from Nunhems. Its main two attributes are the oblong shape and melon size. Revolution made good to fair yields of 15- to 17-pound fruit with some 17- to 20-pound melons. The shape and size were appreciated by growers who said their customers would buy it.
Super Seedless 7187 placed second.
Super Seedless 7187 from Abbott & Cobb made good to fair yields of round melons with a green stripe on a light green melon. A good percentage of the melons were in the 15- to 17-pound size with the rest in the 15- to 12-pound class. It has a thin rind and bright red flesh. The foliage on the plant was good. It also stored in good condition seven to 10 days after harvest. Its main drawback was the number of bleached, light-colored melons. This may be due to mite damage as well as the high temperatures.
The success of this test is limited. Growers were exposed to seedless melon production and learned it is a little more difficult than growing seeded melons. The majority of the growers also had trouble marketing the melons. One of the main factors in difficulty in marketing was the size of the melons. Louisiana consumers still want big melons. Consumers who got poor quality seedless melons in the large grocery stores are reluctant to try locally grown seedless.
However two growers said they would grow seedless if they have a prearranged market. One grower said he would definitely grow seedless next year because he has developed a clientele at his farmers’ market that prefers the seedless melon.
Growers are encouraged to plant a small number of these different seedless melons before planting large acreage to determine the performance of the varieties under their farm conditions.