M.Sc.

Oriental pickling melon ( is an important
vegetable crop cultivated in Kerala. This short duration crop has the potential to
produce high yields with low input requirements, so often referred as unique
vegetable of Kerala. Quality seed production in melon is affected due to the
occurrence of vivipary.
A study in oriental pickling melon varieties, Saubhagya and Mudicode was
conducted in the Department of Seed Science and Technology, College of
Horticulture, Vellanikkara, Thrissur, during 2017-2019 to elucidate the effect of
potassium nutrition on vivipary and seed quality. The objective of the study was to
assess the effect of time of planting and potassium application on vivipary and their
effect on seed quality.
The effect of time of planting on vivipary was assessed with three different
time of planting i.e., December, January and February following a factorial
randomized design with four replications. The fruit and seed yield attributes were
found to be significantly influenced by varieties, time of planting and their
interaction. Variety Mudicode was superior in parameters like fruit weight, fruit
yield and female flower emergence was early in the crop sown in December.
However, the presence of viviparous seeds and chaffy seed percentage were
observed to be high in December planted crop. The potassium content in fruit flesh
and placenta was found to be highest in the crop sown during February with
minimum percentage of viviparous and chaffy seeds. The results point out that
December planting is advantageous for fruit yield while February planting is
advantageous for seed production in variety Mudicode. The interaction between
varieties and time of planting on seed quality indices pointed out that it is
advantageous to go for February time of planting for variety Mudicode for seed
production.
In order to study the effect of potassium on vivipary a crop was raised in
February 2018 following a factorial randomised design with six treatments and
three replications. During the experiment, fruit and seed quality parameters were
found to be significantly influenced by varieties, fertilizer levels and their
interaction. Variety Mudicode exhibited high fruit yield attributes, fresh and dry
weight of seeds and 100 seed weight whereas seeds per fruit, seed yield was
superior in Saubhagya with low percentage of viviparous seeds. Irrespective of
varieties, treatments with additional potassium application i.e., POP + 25% K, POP
+ 50% K, and POP + foliar spray recorded high fruit and seed yield. Organic
nutrient management also resulted in seed yield of 7.48 kg ha-1. High potassium
content in fruit placenta and fruit flesh was found in treatments which exhibit least
percentage of viviparous and chaffy seeds i.e., POP + foliar spray and POP + 50%
K. Additional potassium application was found to be advantageous for reducing the
occurrence of viviparous seeds by increasing the K content in fruit placenta and
flesh. The interaction between varieties and fertilizer levels on fruit and seed
parameters pointed out that additional potassium nutrition was advantageous for
fruit and seed yield production of Mudicode whereas fruit weight, seeds per fruit,
seed yield and occurrence of viviparous seeds and chaffy seed percentage was the
least among the treatment combination of variety Saubhagya with POP + foliar
spray.
The seed quality during storage was evaluated following a factorial
completely randomized design with the seeds collected from Experiment-II (six
treatments and two replications). The seeds were dried to less than 8 per cent
moisture and packed in polyethylene covers of 700G and stored under ambient
conditions for a period of six months. The seed quality parameters were recorded
at monthly intervals. The seed moisture and seed micro flora per cent were recorded
at the start and end of the storage. Seed longevity was found to be significantly vary
between varieties, fertilizer levels, and their interaction throughout the storage
period. Germination, vigour indices I and II, decreased progressively over the
storage period. However, towards the end of storage period, there was an increase
in mean time to germination, time taken for 50 per cent germination, electrical
conductivity of seed leachate, seed micro flora per cent. Irrespective of the varieties,
fertilizer levels and their interaction, germination percentage of 60 per cent was
retained even after six months. The study revealed that that the seeds can be stored
for 6 months under the ambient conditions.