| Abstract: | Abstract The effects of subirrigation and cylical (surface) irrigation on shoot growth and water stress of tomato grown in peat‐lite amended with 0, 4, 8, 12, and 16 kg Hydrogel/m were examined. While shoot growth showed a quadratic response to increasing Hydrogel rate with maximal growth occurring at the manufacturer's recommended rate (8 kg/m3), growth was greater with cyclical irrigation than with subirrigation. Subirrigation generally resulted in greater plant water stress than cyclical irrigation, but with ≤ 8 kg Hydrogel/m3 this differential irrigation effect diminished temporally. Initially, each kg Hydrogel/m3 increased peat‐lite water content by 9 percent but after 31 days, this value had increased to 27 percent and 16 percent with subirrigation and cyclical irrigation, respectively. The continued hydration resulted in a bulk volume increase sufficiently large with subirrigation to cause the Hydrogel‐amended peat‐lite to overflow the pots. |
