The Characteristics of Small-Sized Watermelons in Quality and Yield according to Planting Density, Stem Number, and Node Number of Fruit-Setting

Abstract

There is a rapid change in the preference of watermelons from large-sized ones (6 kg or more) to small-sized ones (2–4 kg), however research on the cultivation techniques for small-sized watermelons is insufficient. In order to cultivate high-quality small-sized watermelons, this study was done to ascertain the planting density, stem number, and node number of fruit-setting methods. The ‘Banjeonmaeryuk’, a long and elliptical small-sized watermelon variety that grown in South Korea was grafted to ‘Bullojangsaeng (Lagenaria siceraria Standley)’ with its characteristics in growth, development and yield analyzed according to plant density and stem number. The results showed that the group cultivated at 1,333 plants/10a, three stem training sessions in planting density, and 130 leaves made a 2.6% increase in the marketable rate and 4.5% in the amount than the group cultivated at four stems under the same transplanting distance with the same fruit weight at 3.4 kg. As for the fruit- setting node order of small-sized watermelons, when two pieces of fruit were set in the third female flower (fruit-setting node: 19–20) of the second stem of three, it recorded an 85% fruit-setting rate, 11.5°Brix of sugar content, and 16–20 more in amount than other fruit-setting methods. In addition, the study examined three varieties of small-sized watermelons in fruit quality and amount to test the productivity of cultivation techniques for small-sized watermelons and found that one fruit per stem recorded as high as 97.5% average fruit-setting rate, an average fruit weight of 3.2 kg, and that two fruits per stem recorded 35.4–82.6% fruit-setting rate, which shows big differences among the different varieties. When two pieces of fruit were set per stem, the resulting fruit weight dropped down to an average of 1.8 kg. The three varieties recorded an average yield of 4,559 kg/10a, and a high sugar content of 11.6°Brix. These findings indicate that one can cultivate high-quality small-sized watermelons in large amounts by setting the transplanting distance at 30 cm, training three stems, and setting two pieces of fruit in the third female flower at the same time.