This document outlines the process for producing cucurbit seed crops. It discusses climate and soil requirements, flower morphology, sex expression, planting, cultural practices, irrigation, field standards, rouging, pest and disease management, harvesting, seed maturity, extraction, drying, storage, yield, packaging, and standards. The key steps include selecting the proper climate and well-drained soil, applying plant growth regulators to control sex expression, maintaining isolation distances of 500-1000m for cross-pollinated species, rouging off-type plants, harvesting fruits at maturity, extracting seeds when fully developed, drying seeds to 6-7% moisture, and meeting certification standards for seed quality.

1. Presenter
Ashmita Bajagain
M. Sc. Ag (HRT)
Department of Horticulture
AFU, Rampur

2. Outline of the Presentation
 Introduction
 Climate and Soil
 Flower Morphology
 Sex Expression
 Planting
 General practices
 Irrigation
 Field standards
 Rouging
 Plant Protection
 Harvesting
 Seed maturity
 Seed extraction
 Drying and Storage
 Seed yield
 Seed packaging
 Seed standards
 Conclusion

3. Introduction
 Crops belonging to family Cucurbitaceae but genera may be different
 Family consists of a wide range of vegetables consumed as salad, for
cooking, as dessert fruits and as candied / preserved products (Singh
& Bhandari, 2015)
 Cucurbits are characterized by bitter principles, called Cucurbitacins
(Bose et al., 2002)
 Vast scope for increase in area and production in the state to make
available these to consumers as part of balanced diet and exploit their
export potential in new emerging markets

4. Introduction contd…
 Seed crop is not any way different from vegetable crops
 Instead of picking fruits at vegetable maturity, they are allowed to
mature in the plant itself
 Seeds are extracted in full maturity
 Cucumber, Bitter gourd, Sponge gourds, etc.: Fruits allowed to
ripen fully
 Bottle gourds, Sponge gourds, etc.: Even letting them dry
 Muskmelon, Watermelon, etc.: Seed maturity coincides with edible
maturity

5. Climate and Soil
 Warm season crop and do not tolerate even light frost
 Require a long growing season with average monthly temperature of
25-30°C
 Cucumber and squash prefer slightly lower temperature while
melons do well even at 35-40°C (Bose et al., 2002)
 Grow well on almost any soil, but mostly a well drained loamy soil
is preferable
 Most of the cucurbits germinate when day temperature is above
25°C
 Soil pH should be in the range of 5.6 to 6.8 (McCormack, 2005)

6. Flower Morphology
 Most cucurbit plants have five yellow
petals, although there are a few
exceptions (McGregor, 1976)
 Most of the cucurbits are monoecious
in nature except coccinea and pointed
gourd which are dioecious in nature
 Male flower opens at first in
monoecious cucurbits
 High temperatures, high light intensity,
and long days favor the production of
male flowers (McCormack, 2005)
Fig: Male (Left) and female
(Right) flower
Female flower ovary looks like
a miniature fruit

7. Sex Expression
 Knowledge of sex expression for any cultivar among cucurbit crops
is essential in planning the best methods for seed production (Nerson,
2007)
 Both PGR and nutrients at proper concentrations modify sex
 Application of the correct PGR at the appropriate time and
concentration is a cornerstone in modern cucurbit seed production
 A single application of AgNO3 (600 mg/ltr) before opening of flower
can induce maleness
 Etheral sprayed at 200-250 ppm at 2nd and 5th true leaf stage can
induce female flower (Bose et al., 2002)

8. Planting
 Land to be used for seed production should be free from volunteer
plants of the same or other crossable species
 Season of growing is mainly determined by the rainfall and
temperature conditions
 Preferable to avoid the fruits of cucurbits maturing during the spells
of rainy weather of heavy downpour
 Terai: Magh- Jestha
Mid hills: Falgun- Chaitra
High hills: Baisakh- Jestha (AICC, 2075)

9. Cultural Practice
S.N. Common
Name
Seed Rate
(gm/ropani)
Spacing (m) Manures (kg/ropani)
Compost N P K
1 Cucumber 50- 100 0.75*0.75 1500 7 2 5
2 Bottle gourd 50-100 2.0*2.0 1500 2 1 1
3 Bitter gourd 100 1.5*1.0 1500 10 6 3
4 Sponge gourd 50-100 2-3*2-3 500 2 1 1
5 Watermelon 250plants/ropa
ni
2.0*1.0 500 3 2 2
6 Pumpkin 100 1-2*1-2 1500 12 9 3

10. Irrigation
 Appropriate water supply during the growing season is an
essential factor in cucurbit production
• Tendency to reduce irrigation as fruit maturation occurs in
order to increase fruit sweetness and shelf-life
When
grown for
fruits
• Crop has to be irrigated all the way to harvest
• Where the yield is harvest by multiple pickings (diffused
fruit set and development) the supply of water has to
continue even later, into the harvest period
• No eating-quality considerations are involved
When grown
for seeds
(Nerson, 2007)

11. Field Standards
a. Isolation Distance:
 Every doubling of isolation distance decreases the amount of cross-
pollination by a factor of four (McCormack, 2005)
C. moschata
C. pepoC. maxima
crosscross
Doesnot
cross
Muskmelon cross freely with
long melon / serpent melon
Minimum isolation
distance required is 500 m
and 1000m respectively for
certified seed and foundation
seed (Singh, 2016)

12. Contd..
 Cucurbits are cross pollinated in nature and honeybees are
major pollinating agent
b. Varietal purity:
Maximum off –type plant (%)
Foundation seed : 0.1 Certified seed : 0.2
Maximum diseased plant (%)
Foundation seed : 0.1 Certified seed : 0.2
Designated disease: Mosaic Virus

13. Roguing
 Field inspection is to be done
during critical stages of the crop
Off-type plant should be
removed as soon as noticed
Roguing should be based leaf
and vine characteristics, flower
size and its fruit
Roguing are plants, which differ
from normal plant population
Vegetative /
pre-
flowering
stage
Flowering
stage
Maturity
stage
Off-type
plants with
leaf and vine
character may
be observed
Off-type
flower size,
fruits may be
detected at
ovary stage
Plant with
off-type
fruits may be
observed
from the field

14. Plant protection
Insect pest
 Red pumpkin beetle (Aulocophora fovicollis)
Spray Malathion 50 EC @ 2 ml/litre of water or Metacid 50 EC @
1 ml/litre of water
 Pumpkin fruit fly (Dacus cucurbitae / D. dorsalis)
Spray Malathion 50 EC 1 ml + 10 g sugar/litre of water
Use of pheromone traps
 Epilachna beetle (Epilachna vigintioctopunctata )
Foliar application of malathion (0.05%), carbaryl (0.1%) and
lambda-cyhalothrin (0.004%)

15. Contd…Diseases
 Downey mildew (C.O: Pseudoperonospora cubensis)
Under humid conditions, starts to develop underside of leaf, which causes
on the underside forming the light yellowish lesions
Spray Dithane M-45 @ 2-3 g/litre of water or Blitox-50 @ 2.5 g/litre of
water
 Anthracnose (C.O: Colletotrichum orbiculare)
Seed treatment with Thiodan @ 2-3 g/kg of seed and spray Bavistin @ 1
g/litre of water
 Powdery mildew (C.O: Erysiphe cichoracearum)
Controlled by sprinkling solution prepared mixing one part of cow's or
buffalo's urine with 8-10 parts of water, 3-4 times at the interval of 4-5 days

16. Harvesting
 Cucurbit’s fruits mature faster i.e. immediately after fruit set
 Picking of fruits as the right edible maturity stage is dependent
upon individual kinds and cultivars (Bose et al., 2002)
 Harvested only when the majority of fruit are fully mature, as
generally indicated by yellowing of the fruit (Murray et al., n.d.)
 Seed quality may decline if harvest is delayed, particularly if
temperatures are high and the fruit are exposed to the sun
 If sunburn can occur, better to harvest the fruits from the vine at
maturity and place under cover where they can continue to after
ripen before extracting the seed (McCormack, 2005)

17. Seed maturity
 Seeds mature within a moist fruit and are often held at high moisture
content for several weeks before seed harvest (Welbaum, 1999)
 Cucurbit seed maturity occurs over a large range of days after
pollination (DAP), depending primarily on temperatures during
development
 Precocious germination in the cucurbit fruit is mostly prevented by
the osmotic pressure of the fruit juice, by germination inhibitor
metabolites (Botha & Grobbelaar, 1981)

18. Seed extraction
Seeds not mixed with pulp
 In the case of dry fruits like bottle gourd, sponge and
ridge gourd seeds are extracted when fruits dry and
seeds rattle inside the shell
 Shells have to be broken to extract the seeds and clean
them

19. Seeds mixed with pulp/placentae
 Direct extraction (seeds can be washed after they are
rubbed with sand or ash to remove pulp)
 Fermentation (seeds can be allowed to ferment for 48
hours then the pulp can be easily separated)
 Acid treatment (25-30 ml of HCL for 5 kg of
pulp/about 8 to 10 ml of H2SO4 & left 20-30 min)
 Alkali treatment (Sodium Bicarbonate)

20. Contd…
 Muskmelon
 In watermelon, the seeds are removed
from flesh and seed is washed in
water to float off flesh, and dried in
shade (Singh, 2016)
 Chethan et al., (2013) found seed
extraction by fermentation resulted in
higher seed quality seeds namely
higher germination, mean seedling
length, seedling dry weight, vigor
index I, vigor index II and field
emergence on Cucumber
Cut into half and the seed is
scooped out of the fruit
Placed in non-corrosive metallic
trough, earthen pot, wooden barrel
or plastic bag, allow fermentation
Fermentation is completed in 1-2
days, the seed mixture is washed
with water to float off the placental
debris
Muskmelon

21. Drying and Storage
 When the seed is extracted from the fruits, its moisture content is
very high
 Critical so that moisture and temperature be measure frequently
during drying operation to prevent under- or over- drying (Murray et
al., n.d.)
 Seed should be spread in a thin layer, either on the drying floor or
on screen - bottom trays, directly exposed to the sun
 Seed should be dried to a moisture content of 6-7 % for storage
 Carefully dried and properly stored seed in a cool, dry and well
ventilated place can retain its viability for 3-4 years

22. Seed yield
 Seed yield per unit area is a product of the multiplication of three
components; the number of fruits per unit area, the number of seeds per
fruit and the mean weight of the individual seed
Cucumber 110-130 kg/ha
Other cucurbits 200-500 kg/ha
 Maximal seed yield in cucurbits is positively correlated with fruit
number per unit area; more fruits of smaller size produce more seeds
than fewer fruits of larger size (Nerson, 2002)
 Plant population density was found to be a main factor determining seed
yield in all cucurbit crops (Edelstien & Nerson, 2002)

23. Seed packaging
 Packed in cotton, jute and paper bags
 These materials offer no protection against high relative humidity
 Under high humidity locations with inadequate seed storage
conditions, vapor proof containers can be used
 Polythene bags have been regarded as suitable looking to its cost
and easy handling

24. Seed standards
Components Standards for each class
Foundation seed Certified seed
Pure seed (min.) 98% 98%
Germination (min.) 65% 65%
Moisture (max.) 9% 9%

25. Conclusion
 Seed production is not any different from cultivation practice for
vegetable consuming
 Being cross pollinated crop isolation distance of 500-1000 m is
essential
 Agronomic principles from site selection to harvesting are
involved in maintaining the quality of the crop for seed production
 Seed extraction varies whether seeds are present with pulp or
without pulp
 Seed standards are also meant to be fulfilled for quality seed

26. THANK YOU