Pragatiprava
Grafting is a technology that could be used to great advantage in combating bacterial and viral degeneration in plants and multiplying yields, while at the same time cutting down on production costs that hold back agri-entrepreneurs from investing liberally…
Thanks to grafting that maximises the amount of crop reaped that can be produced on a small piece of land or even in a cloistered urban environment. The technology has made crop production more efficient, according to a Bhubaneswar-based horticulturist GS Nayak.
Plant grafting is a process in which parts of different plants are joined so as to enable them to grow as one plant. A grafted plant is a composite of parts derived from two or more plants, he added.
“Plant grafting is a process in which parts of different plants are joined so as to enable them to grow as one plant. A grafted plant is a composite of parts derived from two or more plants,” said botanist Dr Santosh Kumar Nayak.
“It is an asexual propagation of horticultural and agricultural plants. In this horticultural technique, tissues of plants are joined so as to continue their growth together. Stem grafting is a common grafting method conducted in late winter and spring.
Even as the practice of grafting traces back to even beyond 2000 BC, when it was used by the Chinese for multiple purposes, with the advent of modern technologies it is being widely used as a means of disease control and for boosting the productivity of plants.
While in several developing countries, farmers reap the benefit of grafting to cut down on space, time and labour without affecting the quality of the produce by growing pomato plants, the plants are yet to gain popularity among the agri-entrepreneurs in Orissa. However, a few of them have come forward to avail of the technology for disease control in tomato plants.
Shishir Sarangi, an agricultural researcher and alumnus of OUAT, has used the technology by grafting tomato on wild brinjal (called ‘vegi baigana’ in Oriya).
He says grafting tomato on wild brinjal goes a long way in minimising problems caused by flooding, soil-borne diseases and root-knot nematode. As tomato is the most popular vegetable, and is sought after in every season, farmers suffer a heavy loss when they sow the crop in the rainy season because of the dampness and the resulting bacterial, fungal and viral infections in plants. Tomato plants are susceptible to these infections which cause wilting.
However, wild brinjal is immune to any such disease. So, grafting tomato on the wild brinjal rootstock is the best way of eliminating bacterial and fungal wilt.
After completing due training from the World Vegetable Centre in Ranchi, a team of four youths led by Shishir started producing grafted plants in July, 2015, with the assistance of three farmers. Describing the process, Shishir, the team leader of Shristi, an organisation working for capacity building of farmers in Keonjhar and Mayurbhanj districts, says the eggplant variety used for rootstock is known to be highly resistant to bacterial wilt and other soil-borne diseases. The hybrid tomato variety was used as the scion.
Shishir sowed seeds of wild brinjal for rootstock a week ahead of tomatoes. When the brinjal plants were 27 days old (around 7-10 cm high) the researchers slant-cut the stock and scion with a sterilised blade at 70 degree angles above the first two leaves. They used cycle valves for clipping and inserted the valve on the stock allowing the cut portion of the scion to set with the stock. Nowadays, special clips are available for grafting. When two plants are grafted, both should be of the same height and thickness. The grafted seedlings (which are placed on a plastic tray) are later placed inside the healing chamber (humidity chamber), says Shishir.
A healing chamber is covered (2 ft above the ground) in black polythene to ensure that sunlight doesn’t affect the saplings. Also, direct watering of the saplings is avoided. It takes at least four to seven days for the saplings to heal and set properly, after which the seedlings are transplanted in fields.
As part of their initial experiment, Shishir and his co-researchers grafted 1,180 plants, of which, 720 could be successfully grafted. This year too he, along with his team members, grafted tomato on wild brinjal to produce high-yielding seedlings, and the success rate is 80 per cent.
The process is very simple and cost-effective, but the success rate depends on skilled hands, says Shishir, adding that grafted tomatoes on wild brinjal yielded around 20 per cent higher than ordinary tomato seedlings.
Most plants cannot be grafted onto a plant of a different species. For instance, chilly cannot grow on a cucumber plant. Plants can be grafted onto related species belonging to the same family, he added.
According to Manoranjan Prusty, senior technical assistant at the Central Institute for Women in Agriculture in Bhubaneswar, grafting has been widely used in fruit plants, over and above vegetable plants, as grafted plants yield in a few years. They also require less area. Fruit orchards can be rejuvenated by using the technique of grafting.
Disease-resistant plants should be used as rootstock, while those with high-yielding capacity should be used as scions. In Orissa, particularly, mango and cashew nut orchards can be developed by using grafting. For more yield, grafted plants of good varieties of mangoes and cashew nuts should be planted. Grafting can be taken as the best solution for preventing diseases in plants keeping in view the health risks of chemicals and pesticides used in plants for disease control. In future, grafting will be practised in more and more crops. It will be useful in providing employment to rural and semi-urban youth and will contribute to boosting production and creating ornamental plants, Prusty adds.
According to horticulturist G Sahoo, even though the possibility of successful grafting is ensured among plants within the same family, inter-generic grafting is now widely practised in plant propagation to take advantage of disease-resistant rootstocks.
Composite grafting of eggplant and bottle gourd with tomato and watermelon is an example. While eggplant and tomato belong to the same family, Solanaceae, bottle gourd and watermelon belong to the family Cucurbitaceae, he adds.