Irrigation
Cucumber, Pumpkin, and Squash
All of the cucurbits require regular, uniform watering during the growing season. Water shortages during establishment can limit seed germination, transplant establishment, and early vine growth. Inconsistent watering around flowering and fruit set can cause misshapen fruits and induce blossom end rot, and affect fruit sizing, flavor, and color development. Overwatering encourages root rots, belly rot on fruits, and can cause edema or fruit cracking. Furrow irrigation is suitable for the cucurbits and some growers use sprinkler irrigation to aid in stand establishment. Growers who plant through plastic mulches commonly use drip irrigation. Later in the growth of the cucurbits, sprinkler irrigation (solid set, wheel lines, and center pivots) can contribute to foliar diseases and may interfere with bee activity thus reducing fruit set, shape, or size.
Soil water status should be monitored regularly to maintain consistent soil water. Soil moisture monitoring is easily done with a resistance block such as the Irrometer® Watermark sensor. Place sensors at various locations in the field and at several depths in the soil profile to get an accurate measure of soil water content. Sensors typically express soil water content as a tension reading (centibars) that defines effort required to access available water. Soil water monitoring helps determine when to irrigate next. Field capacity describes a soil at 100% available water holding capacity after excess water has drained away. Start irrigation for the cucurbits at 25-30% depletion when irrigating by drip systems and at 40-50% depletion of available water holding capacity with furrow or sprinkler systems.
Melons
Melons require regular, uniform watering during the growing season. Water shortages early in the season can limit seed germination, transplant establishment, and vine growth. Inconsistent watering around fruit set can cause misshapen fruits and induce blossom end rot, and affect fruit sizing, flavor, and color development. Over-watering encourages root rots, belly rot on fruits, and can cause cracking. Furrow and drip irrigation is well-suited for melon production and some growers use sprinkler irrigation to aid in stand establishment. Later in the growth of melons, sprinkler irrigation (solid set, wheel lines, and center pivots) can contribute to foliar diseases and may interfere with bee activity, thus reducing fruit set, shape, or size. A small decrease in water after fruits reach mature size can improve fruit quality and flavor.
Soil water status should be monitored regularly to maintain consistent soil water. Soil moisture monitoring is easily done with a resistance block such as the Irrometer© Watermark sensor. Place sensors at various locations in the field and at several depths in the soil profile to get accurate measurements. Sensors typically express soil water content as a tension reading (centibars) that defines effort required to access available water. Soil texture (clay, loam, sand) influences the soil’s ability to hold water. Soil water monitoring is useful in helping to determine when to irrigate. Field capacity describes a soil at 100% available water-holding capacity after excess water has drained away. Start irrigation for melons at 20- 25% when irrigating with drip systems and at 40-50% with furrow or sprinkler systems. Note that irrigation depends on soil type.
Soil Tension Values for Different Soil Textures
| Soil Texture | 0% |
20-25% |
35-45% |
|---|---|---|---|
| Soil Tension Values (centibars) | |||
| Sand, loamy sand | 5-10 | 17-22 | 25-30 |
| Sandy loam | 10-20 | 22-27 | 33-40 |
| Loam, silt loam | 15-25 | 25-30 | 40-50 |
| Clay loam, clay | 20-40 | 35-45 | 55-65 |