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Talking Tomatoes

Monday, May 30th, 2011

Community Contributed by Glenn Teves, UH County Extension Agent

Tomato has more than its share of pests – starting with leaf miners, they are small fly maggots that feed between the upper and lower layer of the leaf, making meandering lines that are more cosmetic than damaging. Predacious wasps will control it, but spraying with a broad spectrum pesticide will kill the good guys and flare up the leaf miners to the point where they can knock out most of the lower leaves.  

Russet mites are microscopic and look like a teardrop. They cause a bronzing of the stem and will slowly progress up the stem, turning the lower leaves yellow. At first indication, spraying with sulfur can easily control it. Sulfur will also control red spider mites which can be especially troublesome in wind protected areas. They cause a cupping of the leaf, and yellow specks on the leaves, and occur on the undersides of leaves.

The corn earworm, also called the tomato fruit worm, can cause major damage by making large holes in fruits, especially if corn is grown nearby. Spraying with Dipel and other compounds containing Bacillus thurengiensis, a naturally occurring fungus, at the first sign of them will control them.

The tomato pinworm will lay its eggs at the base of the calyx attached to the stem end of the fruit, and will burrow into the fruit, rotting them. It is difficult to control, even with pesticides, and tomato producers use pheromone twisters placed near plants. These twisters contain hormones synthesized from the female pinworm, and will overwhelm the male pinworm to the point where they can’t find the female pinworm, disrupting mating activities.

Female fruit flies, especially the melon fly, are a major problem because they lay their eggs in the fruit, which rot fruits. The use of GF120, a natural occurring pesticide created from a fungus, Spinosad, mixed with a yeast-based attractant will control fruit flies. Sprayed on nearby trap crops/windbreaks such as in concentrated spots, fruit flies are attracted to the yeast compounds and killed when they come in contact with this toxin. All of these pest control methods are considered organic and low impact on the environment and non-target organisms.

In choosing the right variety of tomato to grow, find one with at least resistance to root-knot nematodes, including large-fruited bush types Celebrity, Anahu, Healani, Kewalo, Empire, Sanibel, First Blush, Quali-T23, Mountain Fresh Plus, and others. For romas, Puebla, Sunoma, Yaqui, Huichol, Hybrid 882, Cordova, Super Marzano, and Hybrid 46 are resistant. Resistant grape and cherries include Sweet Chelsea, Sweet Million, Sweet Quartz, Small Fry, Apero, Favorita, Red Grape, Golden Sweet, Sugary, Jolly, and Chiquita. Bush types are more wind tolerant and a good choice for the home garden, but it’s also good to have a few indeterminate cherry or grape types growing in the corner of your garden for a steady supply of little tomatoes.  

To order seed packets of UH varieties Healani, Anahu, and Kewalo and other vegetable seed, you can download an order form from UH at www.ctahr.hawaii.edu/seed/