Dragon fruit can be now cultivated out of season – using light bulbs!

Highlights:

• Scientists from Chattogram Agricultural Research Centre invent the method after four years of hard labour
• They succeed cultivating dragon fruit during winter using 100-watt tungsten filament bulbs as alternative to daylight
• Fruits can be cultivated throughout the year, instead of the usual April-October season 
• The method will be spread at the field level through Department of Agricultural Extension

Dragon fruit can now be grown all round the year! A group of scientists from Khulshi Agricultural Research Centre in Chattogram have successfully grown the exotic fruit, which is a summer fruit, in winter.

Usually, dragon fruit is cultivated from April to October, considered the season for its cultivation, when daytime is longer.

But, the fruit can be cultivated throughout the year now using electric bulbs as an alternative to daylight. It took the Khulshi researchers four years of field-level research to get the results.

Chief Scientific Officer of the Agricultural Research Centre ASM Harunor Rashid told The Business Standard, "The days are shorter in winter, from November to March. Usually, dragon fruit is not cultivated at that time. But we cultivated the fruit during winter using 100-watt tungsten filament bulbs set up in the garden.

"We put the lights on for six hours after evening. The bulbs were hung on poles in such a way that the light can reach the surrounding plants. Thus, after four years of research and field testing, meeting the demand for daylight from electric bulbs, the fruits came in winter."

According to officials at the research centre, dragon fruit is cultivated in this way in different countries like Thailand and Vietnam. However, there are differences in environment and nature.

Chief Scientific Officer of the Khulshi research centre ASM Harunor Rashid and two of his colleagues – Md Golam Azam and SM Kamul Hasan Chowdhury – started the research in 2017. They used five types of lights including flash lights and LED lights in the beginning for BARI Dragon Fruit-1, a variety invented by the Bangladesh Agricultural Research Institute.

"About 200 dragon plants were planted on a 300 square feet land. Bulbs were hung on 49 poles. At first different types of lights – LED lights of 20, 25, 30, 35 watts – were used. Finally, in 2019, we got the expected result using 100-watt tungsten filament bulbs," Golam Azam said.

"After keeping the lights on for six hours from the evening for 20-30 days, the plants flowered. After another 20-25 days, the fruits appeared," he added.

The scientist said, "We are going to teach the method to dragon farming entrepreneurs. Some interested people have already contacted us. We are now training them. Besides, the method will be spread at the field level through the Department of Agricultural Extension."

Harunor Rashid said, "This tropical fruit is not usually available during off-season except in some super malls where it is sold for Tk1,000 per kilogram. During its season, the price is as low as Tk250-300 per kg. If cultivated following our method, the fruit will be easily available throughout the year – which will ultimately decrease its price."

Harunor Rashid said 12-14kg of fruits can be yielded during off-season from every four plants, which can produce 20kg fruits when it is in season.

"Interestingly, the off-season fruit is larger in size," he said.

The scientist said, "We have also calculated the cost and benefit factors. Spending Tk100, a farmer can get Tk241 – which is very profitable. Those who cultivate dragon fruit on a small scale – on rooftops, for example – can also be benefited using this method."