Cucurbit Genetics Cooperative Report 2:22 (article 13) 1979
A Technique for Improving Fruit Set by Hand Pollination and Observations on Optimum Cultural Conditions for Fruit Set Under Greenhouse Conditions
J. A. Principe and J. D. McCreight
Imperial Valley Conservation Research Center, Brawley, CA
Melon pistillate flowers are often tied the afternoon before anthesis, after removal of anthers if they are present, to protect them from natural pollinators. They are revisited the next morning to affect pollination. This requires two visits and two sets of manipulation of each pistillate flower.
We regularly use pistillate flowers the day before anthesis for hand pollinations in the greenhouse. This results in a high percentage of successful pollinations and permits pollinations to be made throughout the afternoon. With a little experience, one can easily find flowers that will open the next morning. An unopened pistillate flower can be prepared for pollination by inserting the thumbnail into the corolla and tearing down to the base of the calyx. While holding the flower gently with the other hand, peel off the corolla and calyx by tearing around their bases at the top of the receptacle enclosing the ovary to expose the stigma. If the flower is andromonoecious, remove the anthers. There is no chance of self-pollination since they have not yet dehisced. If the stigma or ovary is damaged, try another flower; a damaged flower usually aborts. Apply pollen by gently, but somewhat firmly, rolling the anthers around the stigmas. The staminate flower, stripped of its petals and sepals, is held by its receptacle and pedicel for this maneuver.
With container-grown plants in a greenhouse, one should not attempt more pollinations than the particular plant can reasonably support. Pollinated flowers should be located on first nodes of secondary stems separated by two or more nodes on the main stem. Select the best flower or two and remove others nearby.
If pollinating insects are present, all subsequent pistillate flowers should be removed until each flower set from controlled pollination is well established. This may have to be done at 3-day intervals for at least two weeks.