To answer that question, studies were conducted over three spring watermelon crops to assess transplant depth effects on yield. However, dramatic yield differences were not apparent.
Deeper plantings seem to reduce the stress exerted by wind on young plants.
This factor may explain the increased growth in vine and foliage noted in the field. More vigorous growth in the first 30 days or so also may be an advantage in combating early disease. This transplant depth work has not received the broad geographical testing that the pepper study did. Although the data are not convincingly strong to warrant wholesale conversion to deeper planting, watermelon growers statewide are encouraged to try a block of cotyledon depth planting. Commercial transplant growers generally do a good job of keeping plants short and stocky.