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Explora: Environment
and Resource Low-cost hydroponic for chili production

stature. While this represented a limitation compared to
Set II, the compact growth habit may be advantageous
for indoor and vertical farming, where space is restricted.
Compact plants that maintain high productivity are
desirable in such contexts. Therefore, the establishment
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of this low-cost hydroponic system using recycled plastic
bottles (Set I) represents a promising alternative production
strategy for space-constrained urban farming. It supports
decentralized food production and urban nutritional
security initiatives and can be implemented with minimal
infrastructure investment.
Figure 9. Heatmap of Kendall’s tau correlation between oxidative stress Concerning the fruit and yield characteristics, soil-
markers (H O , MDA), antioxidant enzymes (SOD, CAT), fruit yield, and
2
2
nutritional quality traits (vitamin C, capsaicin content). The scale on the grown plants (Set III) exhibited significantly poorer
right indicates correlation values, with 1 representing a perfect positive performance compared to plants cultivated under soilless
correlation, −1 a perfect negative correlation, and 0 no correlation. All conditions with hydronic nutrient solutions (Sets I and II).
values are significant at p<0.05. This may be attributed to the lower moisture content and
Abbreviations: CAT: Catalase; H O : Hydrogen peroxide; MDA: reduced water-holding capacity of soil, which limited
2
2
Malondialdehyde; SOD: Superoxide dismutase.
nutrient availability in desiccated conditions and ultimately
compromised productivity. In contrast, the production
41
of heavier fruits and higher yields in both hydroponic
systems underscores the important role of efficient water
and nutrient delivery. The balanced availability of
42
essential nutrients also promoted increased biosynthesis
of capsaicin in mature C. annuum fruits, consistent with
earlier reports. 43
The compromised growth and yield in soil-grown
plants may be explained by the higher levels of stress
experienced under soil conditions. Elevated peroxide and
MDA levels indicated severe oxidative stress, leading to
cellular damage. This was further reflected in the rapid
44
depletion of antioxidant enzymes such as SOD and CAT,
which play a crucial role in mitigating oxidative damage.
Figure 10. Participant responses (1–5 scale) regarding accessibility, Their significantly reduced activities in soil-grown plants
technical difficulty, and cost-effectiveness of the low-cost hydroponic further confirm this mechanism. The fruits of C. annuum
45
system using plastic bottles
are highly demanded worldwide and widely used in daily
C. annuum while reducing the stress typically experienced cooking. The present study demonstrates that the use of
by plants grown in soil. Coco peat proved to be a superior repurposed bottles or other household containers for
hydroponics does not compromise either yield (quantitative
germination medium in comparison to soil, most likely due aspect) or nutritional value (qualitative aspect). Therefore,
to its higher water-holding capacity. This result is consistent this approach can be considered a viable and sustainable
with previous reports, which highlighted the advantages of option for household-level indoor cultivation, as well as for
coco peat—including high porosity, water retention, and large-scale applications under net or polyhouse conditions.
moisture content—over soil-based plantation systems. 37
The present study also underscores the pivotal role of
In terms of vegetative growth, plants in the conventional oxidative stress and antioxidant defense in shaping both
hydroponic system (Set II) exhibited the greatest plant yield and nutritional quality. Yield showed strong
performance. This outcome can be attributed to the aeration positive correlations with the antioxidant enzymes SOD
pump, which enhanced dissolved oxygen availability in and CAT, indicating that enhanced enzymatic activity
the nutrient solution and promoted robust root activity, supports greater productivity, likely through the mitigation
thereby supporting improved plant stature. 38,39 By contrast, of oxidative damage. In contrast, the significant negative
plants in the low-cost bottle-based hydroponic system correlation with MDA highlights the detrimental effects
(Set I) and soil-grown plants (Set III) exhibited shorter of lipid peroxidation on yield. Although the negative

Volume 2 Issue 3 (2025) 7 doi: 10.36922/EER025250050