MSc.

Ash gourd [Benincasa hispida (Thunb.) Cogn.] is a member of the family
Cucurbitaceae which is mainly grown for its fruits. Vaidyakumbalam or
neikumbalam is a specific ecotype of ashgourd in Kerala with hard pulp, long
keeping quality and size slightly larger than a cricket ball. It is the principal
ingredient used in the preparation of the Ayurvedic medicine “Kooshmanda
rasayanam” and “poosanilehyam”, a similar preparation made by the Siddha
medicine physicians. The availability of this special type of ash gourd is scarce at
present. And, not much is known about the morphology and biochemistry of
neikumbalam. The present study has been undertaken in this context.
The study entitled “Evaluation of neikumbalam (Benincasa hispida Thunb.)
collections for yield and quality” was carried out in the Department of Plantation
Crops and Spices during September 2016 to January 2017. Sixteen types of
neikumbalam (medicinal ash gourd) were collected from different locations in
Southern, Central and Northern Kerala. These were evaluated along with a vegetable
ash gourd variety ‘Indu’ used as check, for various morphological, yield, fruit, seed
and biochemical characters.
Morphological characters were recorded at four growth stages, viz. pre-
flowering, flowering, fruiting and harvest. Medicinal ash gourd accessions were less
vigorous in growth, producing lower number of branches and leaves and smaller
leaves when compared to the vegetable ash gourd variety ‘Indu’. Among the
neikumbalam types, highest vine length was recorded in BH 11 at all the four
growth stages (172.85 cm, 212.55 cm, 245.84 cm and 289.46 cm respectively). The
leaf area among the accessions ranged from 67.16 cm2 to 158.8 cm2.
With respect to flowering, a few of the neikumbalam accessions recorded
early opening of both male and female flowers. The accessions BH 13, BH 14, BH
15 and BH 16 were early in female flower opening and also produced female
flowers at lower nodes than other accessions. The first female flower was produced
at a lower node (4.75) in the accession BH 13. Also, all neikumbalam accessions had

a sex ratio lesser than the check variety ‘Indu’ (9.37). The lowest sex ratio was
recorded in BH 2 (3.5).
With respect to yield characters, the medicinal ash gourd accession BH 7
produced highest number of fruits per plant than other accessions and the check
variety ‘Indu’. However, due to low single fruit weight (1250 g in BH 7), the yield
per plant was less in medicinal ash gourd than ‘Indu’ in which the individual fruit
weight was significantly high (2380 g). There was variation in the number of days
taken for fruit maturity and crop duration among the medicinal ash gourd
accessions. The crop duration ranged from 102.66 days to 153 days.
Variability was observed in all the qualitative fruit characters studied.
Oblong, spherical and conical shaped fruits were observed. The check variety ‘Indu’
also produced oblong fruits. The intensity of hairiness and waxiness varied among
the accessions and they were categorized as low, medium and high. There was
variation in rind colour also among the accessions, viz. dark green, bright green,
yellowish green and light green. The keeping quality of fruits ranged from 6 weeks
to 11 weeks under ambient conditions.
Fruit size exhibited variation among the accessions. The fruits of medicinal
ash gourd were significantly smaller in size and lesser in weight (349 to 1250 g)
than vegetable ash gourd fruits. Rind thickness was significantly lower in the
medicinal ash gourd accessions than the check variety ‘Indu’. The neikumbalam
fruits also recorded significantly less flesh thickness and major part of the fruit
volume was occupied by seeds.
Seeds of neikumbalam were small compared to Indu, the check. However,
most of the neikumbalam accessions recorded more number of seeds per fruit (739
seeds in BH 7) than ‘Indu’ (523 seeds). Weight of seed coat, seed kernel and
hundred seed weight were significantly less in neikumbalam accessions. Seeds of all
accessions and the check variety ‘Indu’ recorded more than 96 % viability after two
months.

Fully mature fruits were screened for various phytochemicals after which
they were subjected to biochemical estimation. Most of the biochemical characters
showed variation among the accessions. Acidity in fruits of neikumbalam was
significantly higher than the vegetable ash gourd. Protein content and total sugar
content in the neikumbalam accessions were significantly lower than that in the
check variety ‘Indu’. But, the neikumbalam collections recorded high amount of free
amino acids which is an indication of the rejuvenating property of the fruits. Total
phenol content and tannin content showed significant variation among the
accessions. But a definite pattern could not be drawn between the neikumbalam
accessions and the check ‘Indu’. The ethanolic extract of neikumbalam fruits
exhibited significantly high antioxidant activity (1.315 to 2.595) than the check
variety ‘Indu’ (1.109) as indicated by the IC 50 value.
Results of the present study indicate that this unique type of ash gourd is
morphologically different from the vegetable type ash gourd in growth pattern,
flowering nature, fruiting and yield characters. Neikumbalam which is considered as
a medhya (rejuvenating) drug contained higher amount of free amino acids and had
high antioxidant activity. This might be one of the factors responsible for its
reported medicinal properties.