MSc

Onion (Allium cepa L.) belonging to the family Alliaceae is one of the
oldest vegetables in world and has been cultivated for more than 5000 years. It is
an important and indispensable item in every kitchen as vegetable, spice and
condiment. It is used as salad and cooked in various ways. Besides fresh
consumption, onion provides a good raw material for processing industry as it can
be processed in the form of dehydrated powder, rings, shreds, onion vinegar etc.
The
present
experiment
entitled
“Evaluation
of
varieties
and
standardization of planting time in onion (Allium cepa L.)” was conducted at the
Department of Vegetable Science, College of Horticulture, Vellanikkara during
November-March, 2017-18. The major objectives of the study were to identify the
best variety and planting time in onion for the plains of Kerala, and to study the
effect of varieties, planting time and their interaction on the qualitative and
quantitative traits of onion. Five onion varieties were evaluated in four different
dates of planting with an interval of fifteen days which was commenced from 10 th
November to 25th December 2017 in a split plot design with four replications.
There were no variations among different dates of planting for qualitative
traits such as bulb shape, bulb skin colour, bulb flesh color, etc. Vegetative
characters such as plant height and leaf length were maximum in Arka Kalyan
(50.47 cm and 46.47 cm respectively), whereas number of leaves was highest in
Agrifound Dark Red (8.31). Leaf girth was maximum in Agrifound Light Red
(3.35 cm). Among different dates of planting, plant height (51.05 cm) and number
of leaves (8.50) were maximum in 10th December planting. Leaf length was
highest in 25th November planting (46.60 cm) while leaf girth was maximum in
10th November planting (3.49 cm).
Agrifound Dark Red recorded a minimum number of days (64.25) to reach
75% maturity. Among different planting dates, the plants in 10th December
planting took minimum days (63.4) to reach 75% maturity. In the interactions
between planting dates and varieties, Agrifound Dark Red planted on 10th
December took minimum number of days (60) to reach maturity. Plant stand
(39.63), neck thickness (4.16 cm) and bulbing percentage (70.76%) were highest
in the variety Arka Kalyan.
Average bulb weight varied significantly among different dates of
planting. Highest average bulb weight was obtained when the planting was done
on 25th November (66.2g). Average bulb weight ranged from 18g to 73.5g. There
was no significant difference in number of scales among varieties, planting time
and their interactions.
Total Soluble Solids was highest in the variety, Agrifound Light Red
(16.37°B). Among different planting dates, bulbs from 10th December planting
recorded the highest TSS (16.92°B). Among the interactions, highest TSS was
noted for Agrifound Light Red planted on 10th December (18.32°B). All the
varieties were having medium to high pungency except Agrifound White in all the
dates of planting.
Total yield and marketable yield per plot varied significantly among
different dates of planting. Among different dates of planting, marketable yield
was highest in 25th November planting (0.96kg/plot). Among the interactions
between varieties and planting dates, all the dates of planting except 25th Dec.
were found to be statistically on par with respect to marketable yield for the
varieties such as Arka Kalyan, Arka Pragati, Agrifound Dark Red and Agrifound
Light Red. Planting on 25th Nov. and 10th Dec. were found to be superior and on
par with respect to marketable yield in Agrifound White.
All the five varieties can be recommended for commercial cultivation as
they do not differ with each other with respect to marketable yield. Considering
the consumer preferences, we can recommend Arka Kalyan and Agrifound Dark
Red as they are having attractive dark red colour. The best time for transplantation
was found to be 25th November, which was statistically on par with 10th
November and 10th December. As a future line of work, more number of varieties
are to be evaluated, nursery and crop management practices need to be
standardised, and for conclusive results experiment has to be repeated.