Excerpt from Tomato Production in California Fusarium Wilt - This disease is caused by a fungus living in the soil, which enters the plant through the roots. When the disease once gets into a field, it spreads rapidly in succeeding years. The disease is said to occur in many parts of the state. It usually appears a few weeks after the beginning of hot weather, the lower leaves of aflected plants turn yellow and dry up (fig. The stems, if split open reveal dark brown streaks in the woody portion. The disease advances rapidly and kills the entire plant, or sometimes only one of the main branches. There is no true wilting of the plant, in the ordinary sense of the word, connected with this disease. The control is to grow resistant varieties, of which the Norton seems best at present, though Marvel, an early variety, and Norduke, a late shipping sort, may be desirable under some conditions. These varieties were recently developed by the U. S. Department of Agri culture. Snmmer Blight (western Blight). - This trouble/ occurs very generally in the state and is known by several names. The cause is unknown. The disease usually appears about mid-summer and may gradually involve many plants during the season. Affected plants stop growing, the margins of the leaves roll upward, and the under sides become purplish. The leaves and tips of the stem gradually dry up, and eventually the whole plant dies. No satisfactory control measure can yet be recommended. Root-knot. - This trouble is caused by nematodes - microscopic worms which infest the soil and which enter the roots of tomatoes and many other plants, causing the characteristic swelling of the roots. Affected plants appear stunted and yellowed, and die slowly. The trouble can always be recognized by pulling up the plants and inspecting the roots. Extreme caution should be exercised by growers to prevent the introduction of the disease on vegetable plants or seed potatoes shipped from other sections. When once introduced into the soil, nematodes are very. Difficult to eradicate. Flooding the land for two or three months, thorough drying out of the soil over' summer, summer fallow, and growing resistant crops for two years are prac tices that have been recommended. The small grains, the Iron variety of cowpea, and the velvet bean are some of the crops resistant to nematodes. One Should always be sure that the soil used for plant beds is free from nematodes, for infected beds are often responsible for infecting a field and spreading the trouble. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.