Abstract:
Sri Lanka, a leading global tea producer and a pioneer in organic tea cultivation, holds
strong potential for expanding the organic tea sector. Comprehensive scientific
validation through systematic assessment of organic and conventional tea management
systems can generate evidence to promote the expansion of organic tea in Sri Lanka.
Growth, yield, and quality attributes of tea (cultivar DN) were evaluated under organic
with zero inputs (T1) and conventional with chemical inputs (T2) at Queensberry
Estate, Nawalapitiya, Sri Lanka, using a Randomized Complete Block Design (RCBD) with
three replicates. Growth and yield parameters, soil and leaf nitrogen content, and leaf
chlorophyll content (measured with SPAD) were recorded. Additionally, the quality of
brewed tea was assessed through sensory evaluation by untrained panelists. Growth,
yield, and chemical parameters were analyzed using one-way ANOVA in R, while sensory
data were evaluated through the Friedman test in Minitab. Results revealed that soil
available nitrogen was significantly higher (p<0.05) in conventional treatment
(0.090%) compared to organic treatment with zero inputs (0.065%). Similarly, leaf total
nitrogen content in T2 (1.145 %) is significantly greater (p<0.05) than in T1 (0.898%).
Correspondingly, leaf area, shoot growth rates, and mean shoot length were significantly
(p<0.05) higher in T2 (6.60 cm) compared to T1 (4.23 cm). In contrast, the mean
number of shoots in 100g was significantly greater (p<0.05) in T1 than in T2. Leaf
chlorophyll content and yield were not significantly different (p>0.05), yet greater in T2
than in T1. Sensory evaluation showed no significant quality differences between T1 and
T2. In conclusion, conventionally managed tea has superior growth, yield, and quality
attributes compared to organically managed tea with zero inputs. A long-term
application of organic inputs is recommended to achieve better growth, yield, and
quality in organically managed tea.
