As the rural farming population decreases and ages, there is a gradual decrease in watermelon cultivation. Although the production of small- and medium-sized watermelons is increasing, typical large-sized watermelons are still, which culminates in their cultivation being a burdensome task for elderly farmers. To address this issue, we developed a watermelon variety, namely, ‘Soonzero,’ that does not require pruning, as its secondary lateral branches do not occur in primary lateral branches after the growing point it cut. ‘Soonzero’ is a diploid and broad, elliptical watermelon; its uniqueness lies in its green skin and pinkish-red flesh. The conspicuousness of veining on the skin is weak, and the width of the fruit's stripes is similar to that of ‘Sambokggul.’ In terms of variable characteristics, in this study, this variety produced 452 seeds, a yield similar to that of ‘Sambokggul,’ with the length and width of the resultant fruit being 25.5 and 24.2 cm, respectively. Additionally, the pericarp of ‘Soonzero’ had a thickness of 1.0 cm and a total soluble solid content of 11.8 °Bx. The yield of ‘Soonzero’ was found to be 6,150 kg per 10 acres, similar to that of ‘Sambokggul.’ However, ‘Soonzero’ differs from the control in terms of the following traits: fruit stripe width, flower spot shape, and the conspicuousness of veining on the fruit. In conclusion, the secondary lateral branchless varieties developed at the Watermelon Research Institute are expected to be quickly distributed to farmers with excellent quality by making up for their shortcomings by transferring technology to breeding companies and giving consumers the opportunity to choose according to their purchasing preferences. Above all, since it can reduce the labor required to remove lateral branches, it will help farmers grow watermelons more easily by solving aging and labor issues, which are chronic problems in rural areas (Grant number 8807).

Removing secondary branch to produce commodity watermelons is labor-costing and time-consuming work in traditional watermelon cultivation. Moreover, because elderly farmers work for a long time with their backs bent, musculoskeletal disorders reduce the quality of life of farmers. To improve this working condition, we developed the watermelon 'Soonless' variety that does not need to be pruned because there is no secondary branch. For diploid oval watermelons, the stripe width of the fruit is wide, the color of it's skin is green, and the flesh is pinkish-red. It contains 480 seeds of ‘Soonless’, and the fruit weight is 8.6 kg, which is heavier compared to ‘Sambokggul’. The thickness of the pericarp is 1.3 cm, and the total soluble solids content is 12.0 °Bx, which is similar to ‘Sambokggul’. The characteristics which distinguish it from the control variety include the leaf blade length and width, the ovary size, the width of the fruit stripes, and the thickness of the pericarp. The yield was 6,450 kg/10a, an increase of 5.3% compared to ‘Sambokggul’. As a result of this research, ‘Soonless’ has been registered as a variety with the Korea Seed and Varieties Service in 2022 as it was filed for breed protection in 2019 (Registration No. 8808).