Tomato- infecting single stranded begomoviruses (family Geminiviridae) causing Tomato yellow leaf curl diseases (TYLCD) are major limiting factors of tomato crop production in Oman. Two replicated experiments were performed with nine tomato genotypes that contained different combinations of genes conferring TYLCD resistance (Ty genes) to determine the effect of TYLCD on yield, height and chlorophyll content in open field grown tomato genotypes in Oman. Overall, genotypes containing Ty genes performed better than the susceptible control (genotype without Ty gene), with less disease infection (60–70%), and more chlorophyll content and fruit production after TYLCVD infection. Statistically, there was no significant difference among tomato genotypes for plant height at the Agricultural Experimental Station trial. However, in the Al-Suwiq trial there was a significant difference for tomato genotypes and the p-value was less than 0.001. Among both trials, T2a and T1a tomato genotypes performed best, exhibiting no symptoms, high chlorophyll contents and fruit production. The finding of this study is discussed in relation to the effect of TYLCD on the yield, height and chlorophyll contents and production of different tomato genotypes in Oman. © 2021, Society for Plant Research.