Grafting and Plant Density Influence Tomato Production in Organic Farming System

The tomato is a key crop cultivated worldwide for the fresh and processing markets. Only a small percentage of the tomatoes processed by industries were produced following the guidelines of the organic farming system. Potential reasons for the limited share of organic tomato production are probably related to the lower yield obtained in organic farming in comparison with conventional farming. In this study, the use of the cherry tomato genotype 'Tomito' as a rootstock and two different plant densities (2.5 and 1.25 plant m(-2)) were evaluated in order to improve the agronomic performances of the commercial processing tomato genotype 'H3402 & PRIME; cultivated in the organic farming system. Agronomic and quality parameters were assessed at harvest time. The plant density influenced the plant biometric parameters, mass and marketable yield, and fruit health and quality. The use of a rootstock improved the marketable yield per plant (more than 59%), with the quality of the fruit decreasing the number of sunburnt fruits (-27.7%). The use of the 'Tomito' as a rootstock and a plant density of 2.5 plant m(-2) are the better choices to achieve good performances in optimal environmental conditions. However, further studies are required to validate these results both in other environments and using different scions.