Abstract:
Okra, Abelmoschus esculentus
(L.) Moench, is a multipurpose vegetable
crop grown in tropical and subtropical
regions of the world for its immature seed
pods and leaves. The crop seldom reaches its
yield potential in most of these areas,
primarily due to a decline in soil fertility. As
a result, a field experiment was carried out at
the Faculty of Renewable Natural Resources
Demonstration Farm, KNUST-Kumasi to
assess the effect of NPK (15:15:15) fertiliser
and Leucaena leucocephala leafy biomass
application on the growth and yield of okra.
The treatment combinations were laid out in
a 3 × 3 factorial randomised complete block
design with 9 treatments replicated 4 times
for a total of 36 experimental units.
Leucaena leafy biomass and NPK were
evaluated solely and in combinations at a
rate of 75 kgN/ha on a weight basis. The
treatment combinations were applied as
follows: T1 = Control; T2 = 0.14 kg NPK
(15:15:15); T3 = 0.07 kg NPK (15:15:15);
T4 = 0.5 kg L. leucocephala leafy biomass;
T5 = 0.25 kg L. leucocephala leafy biomass;
T6 = T2 + T4; T7 = T3 + T5; T8 = T2 + T5;
T9 = T3 + T4. The number of days from
planting to the first anthesis of okra differed
significantly (p ˂ 0.05). T3 showed the least
number of days to the first anthesis
observation (47 days), while T9 had the
highest number of days to the first anthesis
(49.3 days). On a weekly basis (starting with
5 weeks after planting, WAP), height was
not significantly different among the various
treatments. Stem diameter followed a
sequence similar to plant height, starting
from 5 to 10 WAP, where no significant
differences occurred between treatment
means. However, mean values revealed that
okra plants varied significantly in height; T9
had the tallest plants (27.2 cm), while T2 and
T8 had the shortest plants (21.2 and 21.2 cm,
respectively). There was a significant
difference between the treatment means and
stem diameter. In the same advanced line, T9
had the highest stem diameter (9.9 mm),
with T5 having the lowest stem diameter (6.9 mm). Fruit yield was also significantly
different, with T4 having the most fruit
(39,259 fruits per ha) and T8 having the least
(19,259 fruits per ha). The fruit dry weight
was significantly different, as the highest
weight was recorded in T7 (12.5 tonnes/ha)
and the lowest was recorded in T9 (5.3
tonnes/ha). The combination treatment T9
[0.07 kg NPK (15:15:15) fertiliser + 0.5 kg
L. leucocephala leafy biomass per plot] had
a significantly improved height and diameter
compared to the other treatments. The
highest fruit yield of okra was recorded in
T4 (0.5 kg L. leucocephala leafy biomass per
plot), and the highest dry weight of okra was
registered in T7 (0.07 kg NPK (15:15:15)
fertiliser + 0.25 kg L. leucocephala leafy
biomass per plot). Therefore, it is
recommended that sole L. leucocephala
leafy biomass (T4) and its combination with
NPK (15:15:15) fertiliser (T9) be adopted by
smallholder farmers to cultivate okra in the
tropics.
