• In general, the crop harvested at harvestable maturity will have the greater seed yield.
    • In crops the maturation will not be always be uniform but there will be mingling of matured, immatured and over matured based on the time of anthesis and fertilization.
    • Hence optimum time of harvest for a given seed crop is necessary as beyond the point losses will be greater than the potential seed yield.
    • Hot dry weather conditions greatly accelerate the rate of natural seed drying on the plant.
    • Seed moisture can form the most important indication of a crop’s fitness for harvesting.
    • Vegetable seed crops are divided in to three groups depending on the state of seed at harvest time.
    a. Dry seed
    • The seed is usually dried on the plant before harvesting
    • e.g. okra,brassicas, lettuce, peas, beans, beet and onion.
    b. Fleshy fruits
    • The ripened fruits are picked from the plants and dried first.
    • The dried fruits are then opened later to remove the dried seeds.
    • e.g. chillies, ribbed gourds and bottle gourd.
    c. Wet fleshy fruits
    • In fruits containing a high level of moisture, the seed has a gelatinous or mucilaginous coating adhering to it.
    • This has to be removed after seed extraction by a fermentation process or treatment with dilute acids.
    • Such fruits are harvested when they mature and ripen
    • e.g. tomato ,brinjal. cucumbers and pumpkins.


    Maturity indices


    Dried Seeds
    Amaranthus yellowish browning of inflorescence Prone to shattering
    Onion Seeds become black on ripening in silver colored capsules.10% heads exposed black seeds. Prone to shattering
    Carrot Second and 3rd order head turn brown Shattering on delayed harvest
    Radish Pods become brown and parchment like Do not shatter easily
    Turnip Plants turn to brown parchment colour Prone to shattering
    Coriander Plants turn to light yellow or brown in colour Prone to shattering
    Peas Pods become parchment like Do not shatter easily
    Beans Earliest pods dry & parchment like and remaining have turned yellow Over maturity leads to shattering and cotyledon cracking
    Wet fleshly fruits
    Brinjal Fruit turn to straw yellow colour Wet seed extraction (fermentation, acid, alkali)
    Tomato Skin colour turn to red and the fruits are softened
    Cucumber Fruit become yellowish brown in colour, and stalk adjacent to the fruit withers for confirming actual seed maturity. Seed extraction -scooping, (acid, alkali, fermentation))
    Watermelon Tendrils wither on fruit bearing shoot. Skin colour of the fruit resting on the soil is pale yellow and gives dull sound on thumping.
    Rind becomes hard & its colour changes from green to yellow/ orange or golden yellow to straw colour
    True potato seed (TPS) Berries of potato becomes green to straw coloured and soft
    Bitter gourd Fruit pulp and seed becomes red and light brown respectively Seeds are separated manually and washed
    Fruits dried before extraction
    Chillies Green colour changes to red or yellow Dry method of seed extraction
    Bottle and Sponge gourd Rind becomes hard and colour changes to light brown or yellow
    Vegetatively propagated materials
    Colacasia Drying and dieing of petiole and leaves Skin becomes tough, uproot
    Zinger Drying and falling down of pseudo-stem turning brown Select healthy, disease free rhizomes
    Turmeric Drying and falling down of stem turning brown Select healthy, disease free rhizomes
    Garlic The stem get dry and change in colour from green to brown
    Seed potato Haulms get dry, droop down turn dark brown in colour Delay leads to spoilage of seed tubes.

Last modified: Wednesday, 20 June 2012, 6:44 AM