“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 the National Crops Resources Research Institute (NaCRRI) advises.
Grafting involves joining a plant with desirable fruit characteristics to another one that has desirable disease resistance, but of the same species.
Kangire says if grafted, tomatoes can generate higher returns. He advises commercial farmers to always put to practise grafting to be in position to generate enough profits after harvesting.
He says the idea can help transform even the low quality tomatoes into high income yielding ones.
“Most of our farmers fail to grow tomatoes because their soils are infected with a disease called bacterial wilt, and many of them think that spraying continuously is the solution. This wilt is a devastating disease that affects the plant system. It does not only affect the quality of tomatoes but some even die suddenly.
“Sometime back, we carried out a survey and the soils 80% of the farmers whom we interviewed had bacteria wilt. So, we ventured into the grafting technique to try and resist this wilt since there is no chemical that can kill it,’’ Kangire says.
He adds: “When a farmer does grafting, they are killing two birds with one stone; you are growing a tomato where it used not to grow because of bacteria wilt, but also there is an 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 few farmers are unaware of the rightful procedure of doing it.
Kangire says it is important for any tomato farmer willing to start doing grafting to first seek advice and be guided on how it is done to avoid future losses.
Should grafted tomatoes only be planted in greenhouses?
Kangire says 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 minimise water loss, thereby enabling them to grow properly to the new plant grafted to it.
“If you grow them in an area like greenhouses as we do at 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 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 good and also the demand for them is good. The fruits as well are big and of good quality,” Kangire adds.
Unlike spraying of tomatoes that is at times harmful to both humans and the plants themselves, grafting according to Kangire, is clean and has no side effects since there is no use of chemical.
He says it is a cheap and simple technique that any farmer can apply themselves without need of hiring helpers.
“This technology is used in many European countries such as Italy and Germany, it is also common in America, so all these countries are using it, they no longer use our local mehotds of just planting.”
How is tomato grafting done?
Rebecca Akullo, a grafting technician at NaCRRI, says grafting of tomatoes involves three steps. These are raising of healthy tomato seedlings (pre-graft), cutting and merging of the tomato plant (grafting) and then caring for the grafted tomatoes (post-graft plant healing).
Akullo says tomatoes perform better and grow even quicker when farmers merge good fruiting characteristics with those that are resistant to diseases.
She says while grafting, one is required to cut a single tomato plant stem with a razorblade then join it on to another root stock. The resistant tomato plant should act as the root stock even if it is not a good yielder since it can help to fight the soil-borne diseases and then the high-yielding plant should be attached on to the root stock.
“Tie them together using a 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,” she says.
“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.,” Akullo adds.