Abstract:
This present study was conducted to evaluate the yield performance of lettuce under
led light spectrum. The experiment was comprised of two factors, viz., three light
spectrums [WhC - White Light (Control), Wr-Florescent Light (known as warn light),
Rb- R4:B1] and three lettuce varieties [BL1- BARI Lettuce-1, RL- Red Lettuce, IcB-
Ice Berg Lettuce] grown in deep water culture with a floating raft system using
hydroponics nutrient solutions. Plants were hydroponically cultured with a 16-h
photoperiod at 20/18 C (day/night), 75-80% relative humidity, and 100 mol m
photon flux density (PFD) under Rb LED, Warm (Wr) LED, and White (WhC) inside
growth chambers for 42 days. The marketable sensory characteristics (crispness,
sweetness, sourness, bitterness, and appearance) of fresh plants were also evaluated.
The shoot and root fresh and dry weights as well as the acceptance of the plants treated
with Rb were higher with IcB than those of plants treated with WhC and Wr light.
Anthocyanin and antioxidant% were significantly higher in plants grown under
WhCRL (9.99) and (60.54%) treatments, respectively, than in those grown under Rb
treatment, whereas 0brix and Vitamin C content were higher in plants grown under Wr
(6.70) and Rb (1.20) treatments, respectively, for Ice Berg Lettuce. RbIcB (0.16kg,
0.80kg, 47.35 ton) outperformed RbRL (0.14kg, 0.73kg, 43.23 ton) and WrBL1
(0.14kg, 0.73kg, 43.17 ton) in terms of fresh weight plant
ii
-1
(kg), yield pot
(kg), and
yield ha
-1
(ton). The treatment (RbIcB) Rb light and Ice berg varieties had the best
significant positive effect on growth, yield contributing parameters, and yield and
quality parameters of lettuce and resulted in the highest fresh weight plant
(0.16 kg)
and total yield (47.35 t ha
-1
) compared to all other treatments. Precise control of
irradiance and wavelength may hold promise for improving the economic efficiency,
-1
-1
−2
s
−1
quality, and nutritional potential of vegetables grown in controlled environments.
Description:
A Thesis
Submitted to the Faculty of Agriculture,
Sher-e-Bangla Agricultural University, Dhaka,
In partial fulfillment of the requirements
for the degree of
MASTER OF SCIENCE (MS)
IN
HORTICULTURE
