Tomato plants (Lycopersicum esculentum Mill) grown under tropical field conditions were treated with an alkaline seaweed extract made from Ascophyllum nodosum (ASWE).
Two field experiments and one greenhouse experiment were conducted to evaluate methods of application, dosage of application, and the impact of each on plant growth parameters and on the quality and yield of fruit.
Field experiment 1 included 0.2 % ASWE spray, 0.2 % ASWE root drench, fungicide spray and combinations of the above. Plants foliar-sprayed with 0.2 % ASWE had significantly increased plant height (10 %) and plant fruit yield (51 %) when compared to control plants. Similar results were observed for ASWE spray alternated with fungicide or with ASWE root drench. Field experiment 2 included 0.5 % ASWE spray, fungicide spray and ASWE spray alternated with fungicide. The higher concentration of ASWE resulted in a significant increase in plant height (37 %) and plant fruit yield (63 %) compared to control plants. The third experiment under greenhouse conditions also showed that 0.5 % ASWE spray caused a significant increase in plant height (20 %) and plant fruit yield (54 %) compared to control plants.
In the greenhouse, ASWE-treated plants had larger root systems and increased concentrations of minerals in the shoots. Fruit from plants treated with ASWE showed significant increases in quality attributes including, size, colour, firmness, total soluble solids, ascorbic acid levels and mineral levels.
Overall, the use of ASWE resulted in clear improvements in tomato fruit yield and quality under tropical growing conditions.