2017 ASHS Annual Conference

Plant growth and development is dependent on several factors including essential nutrients especially their concentrations. [RR(1] Exploring the effect of nitrogen concentration in soilless container grown cherry tomato is critical due to nutrient and water demand for indeterminate fruit production. To investigate the effect of nitrogen concentration on the shoot and root response in cherry tomato (Solanum lycopersicum var. cerasiform), plants were supplied with four nitrogen rates[RR(2] (3.5, 7.1, 14.2 and 21.4 mM). The plants were grown in a 13.9 liter black plastic containers with a peatlite substrate mix. Plants were fertilized twice or three times [RR(3] daily (morning/afternoon/evening) with a water soluble fertilizer (20N-4.4P-16.6K) depending on the weather. Shoot, root and fruit mass and plant growth parameters were measured periodically. The shoot dry mass of plants grown at 3.5 mM N supply was the lowest (141 g) compared to plants grown at 7.1 (201 g), 14.2 (263 g) and 21.4 (254 g) mM N supply. The 3.5 mM nitrogen supplied plants had lowest leaf area (203 cm²), spad value-chlorophyll concentration (43) and the fruit cumulative mass (996 g) than the rest of nitrogen supplied treatments. However, the visual scoring index of root health decreased with an increased from 7.1 to 21.4 mM nitrogen supply. The water uptake was lowest (174 ml/hr) at highest N supply of 21.4 mM. However, the water uptake decreased with an increased in electrical conductivity i.e. with an increase in nitrogen concentration. Sub or supra-optimal supply of nitrogen affected the plant growth and fruit yield in container grown cherry tomato plants.