Pollination Problems in cucurbits
The Vegetable crops in general and cucurbits in particular are important for Bangladesh economy as a whole and for the poor in particular. Many rural households are engaged in vegetable production as farmers and laborers. Further attention holds the promise of wider benefits. Vegetables are excellent sources of vitamins A, E and C, fiber, folic acid and potassium.
The major vegetables are classified into nine families including: 1.Cucurbitaceae, 2. Brassicaceae, 3.Compositae 4. Chenopodiaceae 5. Solanceae 6.Fabaceae 7.Umbelliferae
8. Amaryllidaceae and 9. Poaceae
Pollination is the process by which pollen is transferred from the anther to the stigma of the plant, thereby enabling fertilization and reproduction. This takes place in the flowering plants. Pollination is a key stone process in both human managed and natural ecosystems. It is critical for food production and human livelihoods. The vast majority of flowing plant species only produce seeds if pollinators move pollen from the anthers to the stigmas .Without this service, many species and processes within an ecosystem would collapse.
Recognizing the dimensions of a pollination crisis and its links to biodiversity and human livelihoods, the Convention on Biological Diversity has made the conservation and sustainable use of pollinators a priority. At the Fifth Conference of Parties (Cop7) in 2000, an International Initiative for the conservation and sustainable use of Pollinators, known as International Pollinator Initiative (IPI) was established.
Cucurbits are of tremendous economic importance as food plants, next to cereals and pulses.They are also important sources of medicines and fibers.
The Cultivated cucurbits of Bangladesh include: 1. Pumpkin ( Cucurbita maxima), 2. ash gourd (Benincasa hispida), 3. bottle gourd (Lagenneria siceraia) ,4. snake gourd (Trichosanthes cucumerina), 5. ridge gourd (Luffa acutangula) ,6. pointed gourd (Trichosanthes diocia) ,7. cucumber (Cucumis sativus), 8. Large bitter gourd (Momordica charantia) 9. small bitter gourd (M.muricata) 10. sweet gourd (Cucurbita moschata) 11.water melon ( Citrullus lunatus) 12. muskmelon (Cucumis melo), and 13. sponge gourd ( Luffa cylindrica). Most of the cucurbits are monoecious plants. There are separate male and female blossoms on the same plant. The male flowers open first, followed by the female flowers. It is only when both the male and female flowers open then pollination can occur. Cucurbits need cross pollination prom male to female flowers. But this requires a little more of nature. The insects, mainly bees, flies, wasps, beetles, butterflies and moths pollinate cucurbits. If insects are not present for some reason such as broad spectrum pesticides are sprayed then fruit either does not appear or it appears small and shriveled.
In a recent field visit to Kaliganj, Jhenaidah district during 10-12 August, 2014, I observed many farmers were hand pollinating pointed gourd flowers.
The farmers were pollinating the flowers early in the morning in the field near the Chitra river bank. Habibur Rahman, a farmer shared that he needs 2-3 hours to pollinate the flowers of pointed gourd in a plot of 50 decimals. He also mentioned that he needed to finish the pollination before the sun rise every morning.
Habibur Rahman recalled his past experience of crop cultivation.The introductions of cultivation of high yielding varieties and hybrids of rice as accompanied with pesticides, killed bees, butter flies and other insects, those were pollinating the flowers. These insects are not seen any more. Now, the farmers have to do everything for crop production including pollination.The sad thing is that in most of the time the cost of crop production is higher than the market price of the produce. Thus, the net return is a negative figure leading to pauperization of the farmers.