World�s first experimental plantation of grafted Assam Lemon raised at Kahikuchi

KAHIKUCHI, Dec 28 - In a significant breakthrough in horticultural research, the world�s first experimental plantation of grafted Assam Lemon raised at the Horticultural Research Station (HRS) at Kahikuchi in the outskirts of Guwahati has literally started bearing fruits.

The research on development of Assam Lemon by grafting its scion wood on rough lemon rootstock was started at the HRS under Assam Agricultural University (AAU) for the first time in 2016 with the objectives of getting a proper tree framework with mono-trunk, good canopy architecture and a vigorous root system for better anchorage, water and nutrient uptake.

The application for award of the GI tag for Assam Lemon has already been filed by AAU and the process is in the final stage.

Conventionally, Assam Lemon is propagated through stem cutting, leaf-bud cutting and air layering, but plants developed with these techniques form adventitious root system which is less efficient than the tap root system of Rough Lemon used as rootstock in the grafting process.

�In this technology, one-year-old seedling of Rough Lemon having pencil girth was used as rootstock on which the scion wood of Assam Lemon of the current season having equal thickness was grafted during the monsoon season under a protected environment. The grafted plant attained field plantable age in about a year,� Dr S Saikia, Chief Scientist, HRS, told The Assam Tribune.

The grafting technology was standardized by a team of HRS scientists comprising Dr S Saikia, Dr RK Das and Dr KK Deka.

According to Dr Saikia, the technology will open up avenues for lemon growers of the State to raise high-density plantation, better canopy management, effective water and nutrient management with micro-irrigation and fertigation, and also facilitate other cultural operations leading to establishment of Assam Lemon orchards with higher productivity and profitability. Fertigation is the injection of fertilizers, used for soil amendments, water amendments and other water-soluble products into an irrigation system.

The origin of Assam Lemon, a highly-sought-after commodity in the region both for table and processing purposes and a common horticultural entity in the homestead gardens of Assam, dates back to the post-independence period when the early citrus researchers SC Bhattacharyya, Horticultural Development Officer, Assam, and S Dutta, Officer-in-Charge, Government Citrus Fruit Research Station, Byrnihat, Assam collected a variety under the name China-kaghi from the Hahchora village during their survey in the 1940s in the then undivided Sivasagar district of Assam.

Using the seeds of China-kaghi fruit, an experimental progeny plantation was raised in the Government Citrus Fruit Research Station, Byrnihat in the then undivided Assam.

�During experimentation, a seedling plant was spotted by chance which was characteristically different from others and had seedless fruit. In order to preserve this unique quality of non-seediness, it was further propagated by vegetative means and developed as a clonal horticultural variety and named as Assam Lemon as documented by the workers concerned in their famous monograph Classification of Citrus Fruits of Assam published by the Indian Council of Agricultural Research in 1956,� Dr Saikia said.

Subsequently, in 1960-61, Assam Lemon found its route to the research farm at Kahikuchi when the Regional Fruit Research Station was shifted from Byrnihat to Kahikuchi under the Agriculture Department of the Government of Assam. The station was renamed as Horticultural Research Station in 1973 when it was handed over to AAU.

Subsequently, research works on Assam Lemon gained momentum resulting in the development and extension of a basket of technologies and planting materials of original Assam lemon.

�Today, Assam Lemon has acquired a prized status as the Second Citrus of Assam following Mandarin Orange with about 13 thousand hectares of cultivated area and an annual production of 1.12 lakh MT,� Dr Saikia said.

The results of the current experiment at HRS have demonstrated luxuriant plant growth, flowering and fruiting during both rainy as well as winter seasons, more particularly due to better ability of stion (a plant consisting of a stock and a scion) to draw moisture and nutrient from soil.

�The new technology will not only widen the scope for commercialization of Assam Lemon, both in domestic and international markets, but will also encourage processing ventures aimed at developing value-added products locally,� he said.

Steps are being taken to transfer this novel technology to accredited nursery houses of the State for larger generation of Assam Lemon grafts and also to citrus growers with a plan to cover the pockets under Assam Lemon Producers Organisation in Anandabazar area of Baksa district, Lemon Village at Arora, Nalbari, �Lemon District� Dhemaji and CRS � Nadihing Nemu Unnayan Samiti, Dirak, Tinsukia in the first phase.