Abstract:
Coconut water (CW) is one of the world‟s most versatile natural products rich in essential minerals
and growth hormones. Despite its potentials, large quantities of coconut water remain unutilized at
the industry and household levels as waste in the Sri Lankan context. Therefore, the present study
investigates the potential of coconut water as a liquid fertilizer for greenhouse tomato production. For
this purpose, different combinations of coconut water (CW) and Albert‟s solution (AS) were
evaluated under controlled environment conditions using tomato cv “Thilina” in grow bag culture.
The experiment was laid out in a Complete Randomized Design with five treatments replicated
thrice, viz., T1 (100% CW), T2 (100% AS + CW spray), T3 (75% CW + 25% AS), T4 (50% CW +
50% AS) and T5 (100% AS at recommended dosage) as the control. Growth and yield parameters
were measured at 45 and 60 days after transplanting (DAT). T4 and T5 (control) treated plants
recorded statistically similar values, which were significantly higher (p<0.05) than the others for
plant height (98.7±4.7; 95.3±2.4 cm), number of flower clusters/plant (16.3±1.8;16±1.2) and number
of flowers/plant (78±8.7;76.7±2.2) at 45 DAT, respectively. A similar pattern was observed at 60
DAT for plant height (139.3±8.1;138.7±0.7 cm), number of flower clusters/plant (23±1.5;21.7±1.5),
number of fruits/plant (76.3±6.4;77.7±4.3), average fruit weight (87.7±0.6;81.7±0.4 g) and total
yield/plant (1755.1±8.9;1753.4±14.1 g) in T4 and T5 respectively. There was a significant difference
(p<0.05) in pH and TSS (°Brix) among treatments. pH value ranged from 5.12 in T5 to 5.33 in T3.
The highest TSS (°Brix) value (5.67±0.33) was recorded by T4. Plants treated with 100% CW (T1)
showed a 13% total yield reduction per plant compared to the control, possibly due to low nitrogen
content. In conclusion, coconut water has a potential to be developed as a liquid fertilizer for
greenhouse tomatoes partially replacing the requirement of Albert‟s solution (AS) which is more cost
effective. Further studies are recommended to evaluate the possibility of using 100% coconut water
with supplementary organic sources of nitrogen.
Keywords: Albert‟s solution; Coconut water; Growth and yield; Tomato
