ENZA ZADENS graft tomatoes uganda
Dr Kangire tips Uganda to Graft tomatoes for better yields. File Photo

Dr Kangire tips Uganda to Graft tomatoes for better yields

As a practice that was introduced three years ago, to increase quality and also control some pests and diseases, graft tomatoes involves joining a plant with desirable fruit characteristics to another one that has desirable disease resistance but of the same species.

Tomatoes are not conventionally among the crops known to be propagated through grafting however, Dr Kangire says that commercial farmers must start doing it if they hope to generate enough profits after harvesting since it can help transform even the low-quality tomatoes into a high income yielding ones.

“With grafting, a tomato farmer can reduce pests and soil-borne diseases and also increase yields by 50% without spraying,” Dr Africano Kangire, a Plant Pathologist at National Crops Resources Research Institute (NaCRRI) advises farmers on how to plant tomatoes for sale.

According to Dr Kangire, farmers in most parts of Uganda fail to grow tomatoes because their farm soils are infected with a disease called ‘Bacterial Wilt’ and very many of them think that spraying continuously is the solution.

Bacterial wilt is a devastating disease that affects the plant system. It does not only affect the quality of tomatoes but some even die suddenly.

‘’We carried out a survey and 80% of the farmers whom we interviewed, the soils in their farms had bacteria wilt so we ventured into the grafting technique to try and resist the bacteria wilt since there is no chemical that can kill it,’’ Dr Kangire says.

He adds,

‘’When a farmer does grafting, you are killing two birds with one stone, you are growing a tomato where it used not to grow because of bacterial wilt but also there is another increase in yield by 50%.’’

Grafting of plants as a practice may not be new to many Ugandans, however, when it comes to tomatoes it is rare since many farmers are unaware of the rightful procedure of doing it. Dr Kangire says that it is important for any tomato farmer doing grafting to first seek advice and be guided to avoid future losses.

Should Grafted Tomatoes Only Be Planted in Green Houses?

Dr.Kangire says that farmers can still grow the tomatoes normally in their open gardens however, they must ensure that they have a Humidity Chamber in their farms.

A humidity Chamber is an enclosed place where the tomatoes are kept just after grafting for a period close to one week to minimize water loss thereby enabling them to grow properly to the new plant grafted to it.

‘’If u grow them in an area like in our greenhouses here in our Research Institute in Namulonge where you do not get pests and diseases, it is good but you can also grow them as organic tomatoes but also you can grow them in normal fields like you grow other plants and do grafting on them,’’ he says.

‘’We have been growing them normally in our farm in Mityana and the progress is doing good and also the demand for them is good and fruits as well are big and do not change the quality,’’ Kangire adds.

Unlike spraying of tomatoes that is at times harmful to both humans and the plants themselves, grafting according to Dr Kangire is very clean and has no side effects since there is no use of chemicals.

He says that it is a cheap and simple technique any local farmer in the village can do themselves without the need of hiring someone.

‘’It is a technology used in many European countries like Italy and Germany, it is also common in America, so all these countries are using it, they no longer use our local ways of just planting.’’

Over the years, a number of ignorant tomato farmers here in Uganda, have heavily relied on using different spraying chemicals to help fight soil-borne diseases and on various occasions.

Many have ended up losing all their plants to death however Dr Kangire insists that they are looking forward to acquiring more funding from various donors to support them in educating farmers countrywide about the technique and its future benefits.

He also thanks the few collaborators they are already working with, in particular, their main donors, the Ministry Of Foreign Affairs of the Kingdom of Netherlands through (The Netherlands Organization for Scientific Research- NWO).

ENZA ZADENS (Netherlands Seed Company) and House of Seeds (Netherlands Seed Company in Uganda) who also offer them with disease resistance seeds as well other collaborators, SOLIDARIDAD; East and Central Africa and Makerere University.

How is Tomato Grafting done?

According to Rebecca Akullo, a grafting technician at National Crops Resources Research Institute (NaCRRI), grafting of tomatoes involves three steps namely, raising of the healthy tomato seedlings (pre-graft), cutting and merging of the tomato plant (Grafting) and then caring for the grafted tomatoes (Post-graft plant healing).

Ms Akullo says that tomatoes perform better and grow even quicker when farmers merge good fruiting characteristics with those that are resistant to diseases but warns that each of the above steps is important to ensure the final success of the graft.

She adds that while doing grafting, you cut a single tomato plant stem with a razor blade then join it on to another rootstock.

The resistant tomato plant should act as the rootstock even if it is not a good yielder since it can help to fight the soil-borne diseases like bacteria wilt and then the high yielding plant should be attached on to the rootstock.

Tie them together using white polythene to avoid entry of water then after, store them in a Humid Chamber for seven days. For the first three days, do not open the Chamber. It should be kept closed for air not to go through since the plants require enough temperature to grow.

After three days, you can open the Chamber for 30 minutes and pour water there to try and reduce the humidity but ensure you do not pour water on the plant as it not yet intact properly.

From the Chamber, the tomato plant is left in small cans for another one week to continue with its growth before finally being transferred to the main garden or farm to start bearing fruits.

By Dalton Kigozi