MSc

Cucumber is an annual cucurbitaceous crop. It is grown throughout the world
for its tender, crisp and immature fruits. It is mainly used as a salad crop. Parthenocarpic
cucumber has more consumer preference as they are seedless. KPCH 1 is a
parthenocarpic cucumber hybrid developed by Kerala Agricultural University.
Parthenocarpic cucumber varieties are preferred for cultivation under polyhouse, since
pollination is not required for fruit set.
Fertigation is a technique in which water-soluble fertilizers are supplied through
irrigation water. It is preferred over conventional fertilizer application methods due to
its high nutrient and water use efficiency. Different studies have shown that fertilizer
recommendation for cucumber varies drastically across India. At present, KAU has an
ad hoc recommendation for precision farming in vegetables. The optimum dose of
fertilizers has to be standardised for obtaining the highest yield and thereby increasing
the income of farmers. Hence the present investigation was conducted with the objective
of standardisation of fertigation schedule and evaluation of different levels of fertigation
on yield and quality of KPCH 1 grown under polyhouse.
The study was conducted at Department of Vegetable Science, College of
Agriculture, Vellanikkara during January to March, 2022. The experiment was
conducted in a randomised block design with seven levels of fertigation viz., 100%
RDF, 90% RDF, 80% RDF, 70% RDF, 60% RDF, 50% RDF and 70% RDF (100% P
+ 25% N + 25% K as basal). Fertigation was given at three days interval. Trichodermaenriched FYM was applied at the rate of 15 t/ha uniformly to all the treatments. Fifty
percent dose of recommended P was applied as basal in all the treatments except T7. In
T7 100% P, 25% N and 25% K were applied as basal. Hundred percent recommended
dose of fertilizers was 175:125:300 kg NPK/ha (30 splits). In the present study, only 20
splits of fertilizers were applied because the crop ended early, 70 days after sowing due
to high temperature. The actual quantity of fertilizer (20 splits) applied was at the rate
of 116.67:104.2:200 kg NPK/ha (100% RDF).
Findings of the study revealed that fertigation had significant effect on growth
and yield of cucumber. Hundred percent RDF recorded the highest vine length (2.88 m)
and it was statistically on par with 90% RDF, 80% RDF and T7. Fertigation had
significant effect on the number of days to first flower opening and parthenocarpic
expression. Hundred percent RDF recorded the highest parthenocarpic expression and
100% RDF along with T7 registered least number of days to first flower opening.
However, the number of flowers per node did not exhibit any significant difference
between treatments. The highest number of fruits per plant was observed in 100% RDF
and 90% RDF. Moreover, highest yield was recorded in 100% RDF (2.66 kg/plant) and
90% RDF (2.43 kg/plant). Average fruit length, average fruit girth and average fruit
weight did not show any marked difference with different levels of fertigation.
Similarly, number of harvests and days to first harvest were not influenced by nutrition
level. Fertigation had no significant effect on TSS of fruits.
Benefit-cost ratio was found to be highest for 100% RDF (2.18) and the second
highest B:C ratio was obtained for T7 (2.09). Incidence of pests like rodents, snails,
serpentine leaf miners, white flies, thrips and mites were observed during the study. The
crop was affected by diseases such as damping off, Rhizoctonia rot, melon yellow spot
virus, downy mildew and bacterial wilt. Physiological disorders like crooked fruits were
also observed during the study.
Thus, based on the present study it can be concluded that 100% RDF
(116.67:104.2:200 kg NPK/ha) is the best fertigation dosage for obtaining maximum
yield and B:C ratio for parthenocarpic cucumber KPCH 1 grown inside polyhouse.