Seed Production Technology of
Cucurbits Varieties

Requirement of seed production

The basic requirement of seed production is availability of improved varieties/hybrids and their demand among the farmers. Preferably the variety should be realsed and notified for certified seed production, however, any kind/variety can be multiplied for Truthfully Labeled Seed (TFL). The status of available varieties are given in table 2 and table 3.

Isolation requirements

The cucurbits are cross pollinated in nature and honeybees are major pollinator, thus for pure seed production an isolation distance all around seed field is necessaryto separate it from fields of other varieties, fields of the same variety not confirming to varietal purity requirement. The isolation distance of 400 m for C.S. and 800 m for F.S. and at least 1000 m isolation is required for breeder seed production.
It is important to mention that muskmelon, longmelon and snapemelon (phoot) can cross with each other. Similarly, species of genus Cucurbita have the risk of crossability among them. The cucumber can cross easily with its wild relative Cucumis hardwickee found in wild form in sub-mountanious regions of Himalayas.

Choice of season and areas of seed production :

Seed crop should be raised in such a seasons which remain dry at the time of seed maturity and seed extraction. Rainy season is preferred over summer season for raising seed crop.
Locations are also important in seed production with reference to seed yield and quality of seed. To harness the advantage of climate, private sector seed companies are organizing their seed production in these areas. The Jalana (Aurangabad) in Maharashtra, Ranibenur and around Bangalore in Karnataka, Nandyal Vlley in A.P., are the main areas of seed production.

Major cucurbits seed production regions in India

Crop	Areas	Region
Muskmelon, Longmelon	Punjab & Haryana	Northern Region
Bittergourd	Eastern U.P., Faizabad and Jaunpur	Northern Region
Cucumber and Muskmelon	Azamgarh, Ballia and Gonda in U.P. Jalana (Maharashtra)	Northern Region Central Region
Pumpkin and Ridge gourd	West Bengal (South West)	Eastern Region
Sponge gourd, Watermelon, Cucumber	Telingana, Karool and Vijayawada (North A.P.) Ranibenur (Karnataka)	Southern Region Southern Region
Watermelon, Bottle gourd and Bitter gourd	Costal districts of A.P.	Southern Region

Roguing

Seed crop is to be monitored at various stages of crop growth for removal of off-type and obviously should be carried out before flowering to avoid natural cross-pollination. However, fruit set and complete fruit development stages are also important. The crop-wise main features described here under for effective roguing (George, 1985).
Muskmelon: Fruit shape, colour, rind colour, skin (netted/plain), flesh colour (orange/red), TSS and cavity size.
Watermelon: Fruit shape, colour, rind colour, flesh colour (red/yellow/white).
Longmelon: Fruit shape, colour, bitterness.
Cucumber: Fruit shape, colour, presence of spines, spines colour, colour of ripen fruit (green, yellow, white or orange)
Pumpkin (Squash, summer): Fruit shape, colour, flesh colour.
Gourds (Bottle gourd, Bitter gourd & Luffa etc.): Fruit shape, colour, stripe, neck etc.

Maturity of fruit:

Cucurbits takes fairly long time to attain harvestable maturity. The maximum period is required in crops like pumpkin (Cucurbita moschata), ashgourd and watermelon, however, muskmelon, round melon and bitter gourd take relatively lesstime. The maturity also influenced by the environmental factors and crop management (trailing etc.). The maturity period is shorter in summer season than rainy season.
Harvestable maturity in cucurbits in India

Crop	Variety	Period in days (seed to seed)
Bitter gourd	Priya, Pusa Vishesh	65 days
Snake gourd	TA-19	65 days
Bottle gourd	Arka Bahar, Pusa Naveen	75 days 80 days
Pumpkin	Ambali Pusa Vishwas/Vikas	90 days (Rainy season) 100 days
Ash gourd	Local	90 days
Cucumber	Mudikode Local	70 days
Watermelon	Sugar Baby	85 days
Muskmelon	Pusa Madhuras	80 days

Besides days to maturity, some other parameters like change in colour also used as crietaria of maturity index.
Cucumber and summer squash: Fruit turn pale yellow to golden yellow and attached with plant.
Pumpkin: Fruit reddena and seeds inside the shell breake readily from pulp.
Muskmelon: Full slip stage.
Watermelon: Fruits are ready for harvest when they reach edible maturity, fruit colour change from green/white to pale yellow of under side of the fruit.
Bitter gourd and snake gourd: Fruit turn to bright yellow.
Bottle gourd: At maturity fruit colour fade to starw freen or pale yellow.
Luffa: Complete drying/fruit turn to gray colour.

Seed Extraction

There are two method of seed extraction employed in cucurbits.
(a) Dry method: The dried fruits are cut from one side and the seeds comes out from the fruit e.g. sponge gourd, ridge gourd, snake gourd.
(b) Wet method: This method is employed for seeds extraction of cucumber, muskmelon, watermelon, ash gourd, bitter gourd, round melon and long melon. The fruit of cucumber and bitter gourd, summer squash and long melon are cut longitudianlly and seed is scooped out while fruit of muskmelon and pumpkin are cut into two piece and seed is scooped out from cavity. However, in case of watermelon and ash gourd whole central portion are manually scooped out and macerated to separate the seed from pulp. In wet method, the seed extraction done by three ways :
(i) Mechanical Extraction: In this method the fruits are cut into pieces and macerated by machine. The seeds are separated out from pulp by floating with water. This method is quick, less expensive and seeds retain good lusture, but require good amount of water. This method is applicable in bottlgourd, watermelon, roundmelon and ash gourd.
(ii) Natural Fermentation: The scooped material kept in wooden/plastic or steel vesel for 48 hours at room temperature and stired 2-3 times and then seed is washed throughly with water 2-3 times. The main problem with this method are discolouration and poor lusture of seed.
(iii) Chemical Extraction: 25-30 ml. of HCL or 8-10 ml. of commercial H2SO4 added per 5 kg of pulp and some quantity of water is mixed, stiring of pulp is done to enhance to separation and left for 30 minutes. The impurities will float and seed will sink. The seed should be washed throughly with clean water. This is quick method but accuracy of acid and time is important (Agarwal, 1980).

Seed Yield

Seed yield depends upon the crop, variety, location, season and management of the seed crops.
Seed attributes of selected cucurbits varieties of IARI

Crop	Variety	Seed Yield/ fruit (gm)		No of seed/ fruit (gm)	1000 Seed wt.(gm)
		Summer Season	Rainy Season
Bottle gourd	Pusa Naveen	63.00	73.33	634.93 and 654.69 in summer & rainy season	120-130 gm
Sponge gourd	P. Supriya P. Chikni	25.78 -	- 9.93	248.44 -	- -
Pumpkin	P. Vikas	52.83	-	270.00	200 gm
Bitter gourd	P. Vishesh	4.052	-	21.77	160-170 gm

Genetic Attributes
Hybrid seed production