Several fruits and vegetables that Indians consume as staples today, trace their origin to foreign shores. However, over centuries, their relevance to the country’s cuisine has become indispensable. Take the case of tomatoes, potatoes, brinjals, capsicum or chillies. These are essential ingredients in any Indian kitchen, and feature in a range of recipes.
Careful experimentation and work in agriculture technologies overtime, have ensured a steady supply of homegrown tasty and nutritious vegetables and fruits. Now jumping many strides forward, following constant experiments over decades, scientists worldwide have found a unique way of growing at least two vegetables in a single plant.
This ‘interspecific grafting’ has emerged as a promising means to enhance productivity of vegetables. Grafting is an approach where two or more diverse living plant tissues are joined together to develop a new composite plant. Grafting technology is not new.
One of the oldest grafting techniques originated in China during 500 CE, when farmers grafted two plants of the same species to get a bigger crop of gourd. Presently, grafting technology for commercial production is being used in many countries across Europe, West Asia, North Africa, Central America, and Asia.
“Meanwhile, this dual or multiple grafting is a new technological option, wherein two or more scions of the same family are grafted together to harvest more than one vegetable from a single plant,” says Yashwant L Jagdale, Project In-charge at India’s first Indo-Dutch project -- Centre of Excellence for Vegetables, Krishi Vigyan Kendra, Pune.
Explaining the grafting process, Jagdale says that regular seedlings from seeds to ready seedlings require 25-30 days for transplantation in the field, but grafted vegetable seedlings require 40-45 days for transplanting in the main field. Pomato and Brimato At present, brinjal, capsicum, chilli, potato, and tomato plants are being grafted through this interspecific grafting process.
Already, scientists have successfully developed ‘Pomato’, a combination of potato and tomato, wherein in a single plant, one can derive tomatoes at the shoot and potatoes at the root. Motivated by this breakthrough, scientists have also developed ‘Brimato’, where brinjal and tomato are both grown at the shoot.
The above and other grafting trials by the KVK Pune were conducted at their demonstration farm, with technology from the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, and the Indian Institute of Vegetables Research (IIVR) in Varanasi. They also used grafted brinjal and capsicum plants in their trials, while also conducting demo trials on a local irrigated farmland, composed of medium black soil.
These demo trials were carried out during the Kharif season last year on farmers’ fields also. The trials were done in the Baramati region of Pune, which sees frequent incidence of low rainfall, water scarcity, soil-borne diseases and pest infestations. Farmers take up capsicum farming using drip irrigation, mulching paper, and raised beds, but production remains suboptimal, says a study by KVK Baramati.
“Trials here aimed to address these issues and enhance capsicum yield. After introducing grafted seedlings, using the same practices, a promising solution was achieved,” says Jagdale. According to him, 358 quintals per hectare of produce was yielded on the farm, whereas 465 quintals per hectare at their campus in capscicum. Through this approach, there are many advantages for farmers too, in the form reduced soil-borne diseases and yield increase by over 30%.
The diseases include fusarium wilt in cucumber, melons and bacterial wilt in tomato, peppers, and other vegetables. “Grafting is an effective approach to improve vegetable or fruit quality under both optimal growth conditions and salinity,” he informs. Explaining the nutritional aspect of the vegetables, Jagdale says there is no major difference between the vegetables grown through grafting and the normal way.
However, the vegetables grown through grafted seedlings are tastier that their normal counterparts. Interestingly, these grafted seedlings can be grown in any type of soil -- red or black or or any type of problematic soils by using suitable wild rootstock for it. They can be grown on a large scale, helping farmers by reducing the cost of production, and increasing the net benefits per acre of their farm.
It will also increase tolerance to biotic stresses (due to bacteria, fungus, etc.) and abiotic stresses (drought, heat, cold, etc.) on plants. Stressing on disadvantages, Jagdale says, “The only limitation is the lack of availability of grafted seedlings and different types of rootstocks.” In the coming years, this technology could be geared towards tackling shrinking agricultural lands, since it aims to get more yield over a minimum area through low-cost production.
“We have produced over 7.5 lakh vegetable grafted seedlings and supplied them to farmers across Maharashtra,” says Jagdale. At present, scientists continue to work on this technology in the Netherlands and at IIVR in Varanasi, and prepare it for the future. More on Grafting According to the University of Missouri, some cultivars of plants do not come true from seeds. Others are difficult or impossible to reproduce from cuttings or other propagation techniques.
Grafting is a way to change a large tree from an old to a new variety. It is also a method of using a root system better adapted to soil or climate than that produced naturally by a non-grafted plant. Meanwhile, the National Library of Medicine explains interspecific grafting as a method wherein the shoot part of a plant (scion) is grafted onto a root part of another plant (rootstock) often with distinct genetic constitution (different species or genera).