Abstract:
The Gliricidia [Gliricidia sepium (Jacq.) Walp] is used as a hedgerow tree species in alley
cropping system. However, studies on the impacts of Gliricidia on alley crops were
limited to the dry zone of Sri Lanka. This experiment was conducted at alley cropping
units of Department of Agronomy, Faculty of Agriculture, University of Jaffna, located
in dry zone of Sri Lanka to assess the effect of gliricidia hedgerows on growth and yield
performance of Tomato (Solanum lycopersicon L.), Radish (Raphanus sativus L.), and
Water spinach (Ipomea aquatic F.). Three treatments; (i) 5 m spaced hedgerows, (ii) 10
m spaced hedgerows, and (iii) no hedgerows as a control, were laidout in a Randomized
Complete Block Design (RCBD) with 3 replicates. Growth and yield parameters were
measured and expressed in two ways; (1) per plot and (2) distance from a hedgerow.
Light intensity was measured thrice a day. ANOVA with Duncan multiple range test was
done at α 0.05 using SAS 9.1 package. Results revealed that the average yield of Tomato
(1.29±0.22 t/ha) and Radish (7.15±1.85 t/ha) was significantly high in 10m alley. The
average yield of Water spinach was significantly high in control (9.07±1.42 t/ha). The
average yield of all crops was significantly low in 5 m alley. Light intensity was greater in
control by 35.14 % and 88.78 % compared to 10 m alley and 5m alley, respectively. Yield
with hedge row distance showed that significantly high yield was recorded in the middle
of alley (Tomato: 0.27±0.12 kg/plant, Radish: 0.561±0.28 kg/plant, Water spinach:
0.66±0.28 kg/plant) than closer to the hedgerow. Light intensity was greater (22.72 %)
in middle of the alley than closer distance to the hedgerows. Plant height of tomato
was significantly high in 5 m alley, but number of fruits and leaves was significantly
high in 10 m alley. For Water spinach, number of suckers and leaves was significantly
high in the control. For Radish, root length and circumference were significantly high in
10 m alley. The average yield was low compared to recommended yield however, crop
performance was comparable with alley cropping system. From this study, 10 m alley
can be recommended for Tomato and Radish for better yield whereas Water spinach
can be cultivated without hedgerows.