|Last year I planted Heatwave, Brandywine, Delicious, and Rutgers. The last three were hit by every bug and virus known to man. Yields and plant growth were way down with more than 50% crop loss. The Heatwaves were unscathed and yield was normal. Are the heirloom types not as disease resistant? I have never had this type of problem in any other year.
|Disease resistance in tomatoes is done through genetic manipulation, so yes, many of the newer hybrid varieties have more disease resistance than the heirloom types. But, you should have reasonable success with any of the varieties you planted. Try againnext year, making sure the plants get full sunshine, even moisture, and a side dressing of 5-10-10 about mid-season (or add a two-inch layer of compost to each plant). Mulch them well to deter soil-borne pathogens. You might want to plant them in a different garden spot next year, just to make sure none of the insects or diseases are lurking in the soil.