Seedless Watermelon Cultivar Trials for Southwestern Indiana, 2000

Mario R. Morales and James E. Simon

Department of Horticulture, Purdue University

West Lafayette, IN 47907

and

Angie Thompson, Melborn K. Lang and Dennis Nowaskie

Southwest Purdue Agricultural Research Center

SWPAC, Vincennes, Indiana 47951

Introduction: Seedless watermelons continue to generate both grower and consumer excitement, and in many urban markets around the US the percentage of seedless melons has gained considerably. Indiana remains a strong producer of seedless (triploid) watermelons, and since 1994, we have conducted extensive annual variety trials for seedless varieties. This trial, along with the seeded (diploid) watermelon variety trial provides an objective and independent comparative assessment of new watermelons for the commercial industry. This year’s study included 32 seedless watermelons, with two yellow fleshed types (Tri-X-Chiffon and ASR 4598819.

Methods: Seeds of 32 seedless watermelon cultivars were sown in the greenhouse on April 18 and transplanted on May 15 into a randomized complete block design with three replications. Stars-N-Stripes was used as pollinator and planted in every sixth row and in the guard rows. For commercial production however, we recommend that every third row serve as a pollinating row. Plots were single rows 55 ft. long, centered eight ft. apart, and covered with 4 ft. black plastic mulch. Each plot had 11 plants five feet apart. The recommendations in the Midwest Vegetable Production Guide for Commercial Growers (ID-56, 2000) were followed for fertilization, weed, disease and insect control. Plots were harvested on August 2, 3, 14 and 21. The Purdue VARTEST computer program for variety testing was used in the analysis of the data. Trickle irrigation was used as necessary to provide ample water to the field plots.

Results and Conclusions:

Yields and Quality. Yields ranged from 27.6 to 37.7 tons/acre with 3003 to 4851 fruit/acre harvested across all the entries (Table 1), exceeding those of the seeded watermelon trial this year. Yields as expressed in tonnage and fruit number were higher this year than in the 1999 seedless watermelon trials, and this was also observed in the seeded trails. Average seedless fruit weight was 16.3 lbs/fruit, ranging from 13.7 to 18.5 lbs/fruit. The smaller weight per fruit led to the higher number of fruit in the seedless trial than in the seeded watermelon trial. Highest yielders included: ACX 7187, ACX 257, HMX 8915, Millionaire, EX 4203457, #5244, ACX 7167, SVR 4510759, Tri-X- Palomar, Peto 9356, Tri-X- Shadow and HMX8914. Most fruit were oval or round in shape and of medium size. #5244 was a higher yielder and exhibited high quality. Hollow heart was noted in ACX 257, ACX 2947, HXM 8915, EX 4203337, SVR 4590339, and ASR 4598819 (a yellow fleshed type). Above average varieties exhibited some degree of hollow heart also in this years’ adjacent seeded watermelon trails as well. While Millionaire has been available for several years and is a good seedless selection, other newer types that appeared promising in this year’s trial included: #5244, Palomar, Shadow, ACX 7167, Peto 1020, and RWM 8089. Of the two yellow fleshed types, Chiffon remains the top choice. Seedless watermelons should be a part of your melon production strategy as long as you have a market that will purchase the fruit at a higher price than the seeded watermelons.
 
 

Table 1. Comparison of Yield and Quality of Seedless Watermelon in Southwestern Indiana, 2000.
 

Randomized complete block design: 3 replications.