Root morphology of greenhouse produced muskmelon under sub-surface drip irrigation with supplemental soil aeration

- Several possible optimal supplemental soil aeration, irrigation and depths of drip tubing levels for muskmelon root morphology were evaluated.
- Drip tubing placement, artificial supplemental aeration and irrigation level significantly affected total length, surface area of the root system of muskmelon.
- Primarily changes in morphological parameters for the ≤1 mm diameter roots.

A fractional factorial experiment was designed to study the response of greenhouse-produced muskmelon root system to 3 levels of sub-surface drip irrigation in combination with drip-tubing placed at 3 different depths in the soil, and 4 frequency levels of supplemental soil aeration. Drip irrigation (I) levels were 70, 80, and 90% of field capacity (I70, I80, I90) in combination with sub-surface tubing placement depth (D) at 10, 25, and 40 cm (D10, D25, D40). Supplemental aeration frequency levels were none, daily, and at 2 and 4-day intervals (AN, A1, A2, A4). Total root length, surface area, and root volume and their distribution by diameter of the root system were measured using the WinRHIZO image analysis software. The results showed that the total length and surface area for D40 increased by about 48% and 24%, respectively than D10. The two root parameters for A1 increased by 83% and 63%, respectively than AN. For the I70 treatment, the two parameters increased by 10% and 20%, respectively than I90. These effects were primarily due to changes in these morphological parameters for the ≤1 mm diameter roots.