Tomato is a very important food crop, offering income and nutrition on a massive scale worldwide. Not surprisingly, increasing tomato fruit yield and quality under all conditions is critical. Crops face many types of stress and growers employ various tools and techniques to counteract them. The challenge in commercial production is to create conditions in which crops can thrive using an overall approach that is efficient, profitable and sustainable. Variety selection is key to any successful approach but with vegetable grafting, the power of genetics and the importance of variety selection are greatly magnified.
Grafting instantly combines the traits of a rootstock and scion variety in a form of ‘organ transplantation’: the stem and foliage of the scion variety is spliced to the roots of the rootstock variety. Why? Grafted plants often outperform (especially in terms of yield) ungrafted ones, especially when disease, fertility, moisture, salinity and/or temperature stress prevail. Maintaining scion variety performance under stressful conditions is a major goal of grafting. However, there is growing evidence that fruit taken from grafted plants may differ in their composition compared to fruit taken from ungrafted versions of the same scion variety. So, grafting may be instrumental in helping to achieve the twin goals of greater yield and quality. And, when used as an experimental tool, it may help scientists to unravel the workings of major crop plants like tomato.
A research team working in Spain (where vegetable grafting is very common) tested the impact of grafting on fruit quality. Flores and coworkers created grafted plants using multiple rootstock and scion varieties and exposed them and ungrafted control plants to different environmental conditions. Then, they analyzed the fruit that were produced. They discovered that fruit from grafted plants tended to be of a higher quality. This and related work opens the door to further discoveries regarding how fruit yield and quality are shaped during production.