M Sc

The experiment entitled “Micro irrigation and mulching for yield optimization of
bhindi in rain shelter” was conducted at the Instructional Farm, College of Agriculture,
Vellayani, Thiruvananthapuram, during the period 2019-2021, with the objective to
evaluate the efficacy of micro irrigation and mulching on the growth and yield of
bhindi in rain shelter.
The field experiment was conducted using the variety Varsha Uphar, during
February to May, 2021. The experiment was laid out in split plot design with four
replications. The treatments consisted of five main plot treatments (i1: Surface drip
irrigation, i2: Rain hose irrigation, i3: Sub surface drip irrigation at 10 cm, i4: Sub surface
drip irrigation at 15 cm, i5: Sub surface drip irrigation at 20 cm) and two sub plot
treatments (m1: No mulch, m2: Organic mulch). Dry banana leaves available in the
area was used as organic mulch @ 10 t ha-1
and were laid as per the treatment.
Results of the experiment revealed that types of irrigation and mulching had
significant influence on growth characters, yield attributes, water productivity and
water use efficiency of okra.
Plant height at 30, 60, 90 days after transplanting, and at harvest were higher
in sub surface drip irrigation at 10 cm depth. The number of branches at final harvest
(4.00) and root shoot ratio (0.21) were observed to be the highest in sub surface drip
irrigation at 10 cm depth. Types of irrigation and mulching had no significant
influence on leaf area index at 50 per cent flowering stage. Dry matter production
(5273 kg ha-1
) was higher in sub surface drip irrigation at 10 cm depth, which was on
par with sub surface drip irrigation at 15 cm depth and that at 20 cm depth.
Considering the interaction, higher dry matter production was recorded by sub surface
drip irrigation at 10 cm depth (i3) with organic mulch (m2) (5328 kg ha-1
) and was on par
with i3m1 and i4m2. Between organic mulch and no mulch, organic mulching recorded
significantly higher growth attributes than without mulch.
The highest root depth was recorded in sub surface drip irrigation at 20 cm
depth (40.1 cm), whereas, higher root volume (35.26 cm3
) was recorded by sub surface
drip irrigation at 10 cm depth and was comparable with sub surface drip irrigation at 15
cm depth (30.72 cm3
). Organic mulching resulted in significantly higher root depth and
root volume than no mulch treatment.
Yield attributes like number of fruits plant per plant (28), length of fruit (15.53
cm), fruit yield per plant (411.19 g), and total fruit yield m-2
(2.29 kg) were found to be
higher in sub surface drip irrigation at 10 cm depth. Organic mulching resulted in
higher yield attributes compared to no mulch. Considering the interaction, sub
surface drip irrigation at 10 cm depth (i3) along with organic mulching (m2) was
found to be superior compared to all other treatment combinations with respect to
fruit yield per plant and total fruit yield m-2
.
The higher uptake of N (61.06 kg ha-1
), P (19.55 kg ha-1
) and K (19.55 kg ha-1
)
were observed in sub surface drip irrigation at 10 cm depth. Organic mulching recorded
higher NPK uptake. Available NPK after the experiment were not influenced by the types
of irrigation. Organic mulching recorded higher N (233.66 kg ha-1
) and P (45.32 kg ha-1
)
content than the no mulch treatment.
The highest water productivity (4.49 kg m-3
) was recorded by sub surface drip
irrigation at 10 cm depth. Water use efficiency (6.48 kg m-3
) was higher in sub surface
drip irrigation at 10 cm depth and remained statistically on par with sub surface drip
irrigation at 15 cm depth (6.11 kg m-3
). Organic mulching recorded significantly higher
water productivity and water use efficiency compared to no mulch. Among the
interactions, sub surface drip irrigation at 10 cm depth along with organic mulching was
found to be superior in terms of water productivity and water use efficiency compared to
the other treatment combinations.
The economics of cultivation in terms of net returns (₹ 5.31 lakhs ha-1
) and B: C
ratio (2.39) were observed to be the highest in sub surface drip irrigation at 10 cm depth,
which was on par with sub surface drip irrigation at 15 cm depth. Organic mulching
recorded significantly higher net returns and B: C ratio compared to no mulch.
Considering the interactions, higher net returns (₹ 5.47 lakhs ha-1
) and B: C ratio (2.43),
was recorded by sub surface drip irrigation at 10 cm with organic mulch.
Based on the findings of this study, it can be concluded that sub surface drip
irrigation at a depth of 10 cm combined with organic mulch (dry banana leaves) @ 10 t ha-1
can be recommended for bhindi cultivation for obtaining higher yield, water use
efficiency and economics.