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Tomato
First-Aid
It's tomato harvest season. It's time to pick the bright red fruit off the vine and savor the first luscious bite that sends juice dribbling down your chin. Perhaps your tomatoes are blemished or your vines are showing unwelcome scars, pests, or diseases? Here are a few of the most common disorders that affect our homegrown tomatoes. Poor tomato fruit set. Don't be alarmed if the first blossoms fall off. It is normal for blossoms to drop if they are not pollinated. Temperature is the main cause of poor pollination. In early spring night temperatures are too low. As the nights become warmer and temperatures remain above 55°F, fruit set improves. When day temperatures range above 100° F, fruit set also decreases. A sudden hot spell will interfere with fruit set for 7-10 days after the temperature has returned to normal. Failure to set fruit also may be caused by lack of moisture, poor soil fertility, or too much shade. Blossom end rot. This is a physiological disorder related to calcium nutrition brought on by poor watering practices. A tan discoloration appears at the blossom end of the green fruit. The discoloration enlarges, darkens, and becomes sunken and leathery. The remainder of the fruit ripens and can be used if there is no other decay. Because water stress within the plant brings on the problem, check the soil moisture. In most cases, the cure is more thorough, or more frequent, irrigation. Curling of tomato leaves. Curling of mature tomato leaves is very common and more prevalent in some varieties. It is most noticeable when plants are about 1 foot in height. The leaves on the sunny side of staked plants often may curl while those on the shady side do not. Wilt diseases - Verticillium and Fusarium. When purchasing tomato seed or plants, choose ones that bear VF on the label as these will be resistant to the two main wilt diseases, verticillium and fusarium. So prevalent are these fungi that plant breeders established resistance to these diseases many years ago. In both diseases the fungi infect the plant through the roots, then enter and plug the water-conducting elements in the stem. This eventually leads to wilting symptoms. The first evidence of plant infection is a slight yellowing of the older leaves for Verticillium which seldom kills tomato plants. Fusarium infected plants turn bright yellow. Initially the yellow leaves may be only on one side of the plant but soon the whole plant becomes affected. Fusarium usually renders a tomato plant useless. Tomato russet mites. Tomato mites are too small to be seen and therefore are seldom detected until serious damage has occurred. Lower leaves are killed, causing many dried leaves at the base of the plants. Some leaves are bronzed; others may have a glazed appearance. New growth at tips of branches appears normal. Stems are a greasy, bronzed color and the surface is glazed as if it were shellacked. To control mites, dust the plants thoroughly with dusting sulfur at monthly intervals starting in June. Tomato and tobacco hornworms. Hornworms are large, green worms with diagonal white stripes on the sides and a sharp spine at the tail. Because of their extensive feeding on the upper leaves of the plant, damage is obvious. But because of their protective coloration, the worms are very difficult to find. A few hornworms can be controlled by hand removal from the plants. Other foliage and fruit worms are armyworms, corn ear-worms, and pin worms. If worms are a big problem then treat with Bacillus thuringiensis. Stink bugs. Light-colored cloudy spots with pithy or corky areas in the tissue of the fruit just below the skin are caused by the feeding punctures of the stink bug. Stink bugs are green or brownish grey, shield-shaped and just under ½ inch in length. It is usually sufficient to hand pick the bugs and destroy them. There are no effective insecticides available for the home gardener. Storing tomatoes. Whether store-bought or home grown, tomatoes ripen best at temperatures between 55-65° F. If you are refrigerating your tomatoes, you are not allowing them to ripen and are actually ruining their tomato flavor. Eat tomatoes. Tomatoes are naturally low in sodium and
an excellent source of Vitamins C and A. Tomatoes also contain
the antioxidant lycopene, which is related to beta carotene. A
study conducted in Italy showed that consuming seven or more servings
of tomatoes a week reduced the risk of developing colon, rectal
and stomach cancer by sixty percent!
June 26, 2003 |