Irrigation
Eggplants, peppers, and tomatoes require regular, uniform watering during the growing season. Inconsistent water availability can cause several problems, including poor early vigor, inadequate leaf cover, flower drop, sunburn, blossom end rot, and fruit cracking. For this reason, drip irrigation is well suited for solanaceous plant production. Water deeply and infrequently to encourage deeper root growth. As temperatures increase and plants grow, irrigation rates should be increased to meet plant needs. A small decrease in water after fruits reach mature size is beneficial in that it can trigger fruit ripening. Monitor soil water status regularly to maintain consistent soil water. This is easily done with a resistance block such as the Irrometer Watermark sensor. Place sensors at various locations in the field and depths in the soil profile to get a more accurate measurement of soil water content. Sensors typically express soil water content as a tension reading (centibars) that defines the resistance in the plant to access available water. Soil texture (clay, loam, sand) influences the soil’s ability to hold water. Field capacity describes a soil at 100% available water-holding-capacity, after excess water has drained away. Start drip irrigation at 20%-25% depletion of available water holding capacity depending on your soil type (Table 12.2). Reference the Soil Moisture Monitoring: Low-Cost Tools and Methods fact sheet from Appropriate Technology Transfer for Rural Areas (ATTRA) Sustainable Agriculture.
Soil Tension Values for Different Soil Textures for use in Scheduling Drip Irrigation
| Soil Texture | 0% Depletion of Available Water Holding Capacity (Field Capacity) Soil Tension Values (in centibars) |
20-25% Depletion of Available Water Holding Capacity Soil Tension Values (in centibars) |
|---|---|---|
| Sand, loamy sand | 5-10 | 17-22 |
| Sandy loam | 10-20 | 22-27 |
| Loam, silt loam | 15-25 | 25-30 |
| Clay loam, clay | 20-40 | 35-45 |