Hand - Pollination in Cucurbits

Ever wondered how a plant forms fruits from flowers? Or how a tree spreads its dynasty and sprouts up young lings all over an area? That sorcery is ‘pollination’! Read more to learn about this.

What is pollination? It’s the transfer of the fertilizing powder or pollen formed in the anthers of flowers to the stigma. What then follows is fertilization, which is a boon of nature. Clearly, pollination forms an inseparable part of the process of fruit manufacturing.

Natural Pollination challenges:

However, you must have observed that at times a plant forms flowers that bloom fully and then simply falls off from the plant. Apart from the male flowers that do not form fruit, if you see female flowers also fall off this way, then it is cause for concern. Cramped spaces and balcony gardens in concrete jungles exhibit one thing in common: the lack of insect traffic that forms an intricate network in the process of pollination and the low density of crosswinds resulting in lack of pollinators. Pollinator decline and concentrated pollination needs of monoculture may also be other factors in pollination shortage.

Growing your Hydroponic vegetable garden inside can have its many perks .Not all vegetable plants produce dry pollen to be carried by wind to produce fruit , this type of pollination called Anemophily.instead so many vegetables like Cucurbits crops rely on attracting insects for pollination to produce fruit , when the pollination occurs by insects/animals is called Entomophily. When hydroponic gardens are moved inside they lose the ability to be pollinated, so you will have to do it by hand.

Before Going to hand pollination in Cucurbits , you should know the flower morphology and identification of flowers.

All gourds bear separate male and  female flowers.The male flowers generally appear first,followed in a weak or by female blossoms.it is easy to tell male from female flowers,as the female flowers have the small gourd shape below the bloom , while the male flower grows on a stem without the ball shape/bell shape below the flower . You can have a look at the pictures below ..!!


The Female flower with a small fruit attached to it needs to be pollinated to produce into a matured fruit.honeybees and insects help in pollinating the flowers . though you can find lots of unpollinated young female flowers withering away in indoor gardens due to lack of natural pollinators. To get mature fruit , Hand-Pollination is a good practise in cucurbits .before going for hand pollination process, everyone should know the floral biology :-

  1. Time of Anthesis (Flowering) in both Female and Male  - 5:30 to 7 am
  2. Anther Dehiscence - 5 to 6 am 
  3. Pollen fertility - 5 am to 2pm
  4. Stigma receptivity - 24 hours before to 24 hours after Anthesis.

After the opening of male flower , the anther dehiscence is between the temperature range of 20 - 30 degree celsius. Pollen fertility was considerable upto noon and by afternoon fertility was greatly reduced,and it was negligible by evening of the same day.In female flower , stigma becomes receptive 24 hours before anthesis and remains upto 24hours after anthesis.if pollination not done flowers remain open only for a few hours , after which the petals wither.if pollination done after 24hours the stigma loses its shine and becomes brownish and increases by about 3mm in length,showing the start of fruit formation.

Hand-Pollination in the Cucurbits:-

Identify the male flowers and female flowers on your cucurbit family plants .All cucurbits produce orange colored flowers except Bottle Gourd and Pumpkin which have white flowers.before going for pollination process

Method 1 :- The first thing to do is to find a male flower , cut it off of the plant and snip its petals.as you do this ,try not to touch the stamen as much as possible so pollen doesn’t transfer to your fingers.next you want to find a female flower on the plant that is blooming open with its petals pushed back . Touch the stamen to the stigma on the female flower , and gently roll it over the stigma .

Method 2 :-  The 2nd method of pollination requires a small paint brush or cotton swab .Find a male flower and brush the stamen to collect as much pollen as possible.next , find a female flower and brush the pollen you collected over the stigma of the female flower.

Repeat these methods , pollinating every female flower and get a matured fruit ..!!

The long day and High temperatures promotes only male flowers in cucurbits , to control over this problem some cultural practices we have to follow :-

  • The first vine that grows will have male flowers,but make it produce more female flowers by cutting the ends of the vine back .
  • Avoid heavy leaf pruning (Heavy leaf pruning leads to more Malne flowers in plants )
  • Growth Regulator application in cucurbits is done at 2 - 3 leaf stage .
  • To enhance the female flower production - Ethylene is used and to enhance the male flower production - GA3 used 
  • In commercial farms , the sex ratio in cucurbits should maintain : -  25 -30 : 1 or 15 : 1 ( Female : Male ) to get higher yields.


 Pollination is an important step to indoor vegetable gardening.Without it,flowers will not turn in to fruit.be sure to repeat the process several times over the period to make sure flowers are well pollinated.

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