Inefficacy of methanol as a growth promoter in selected vegetable crops

Nonomura and Benson (1992) reported that foliar applications of dilute solutions of methanol caused growth and yield increases and reduced water use in several crops. The request from commercial growers for explicit information regarding this report prompted our experiments using the same procedures. Growth of cantaloupe, pepper, cabbage, cauliflower and onion seedlings and mature plants were evaluated in the laboratory and greenhouse in 1993 and in the field in 1993 and 1994. Treatments of 0%, 10%, 20%, 30%, or 40% methanol (v/v water) with 0.1% surfactant generally did not cause significant growth differences. Stem diameters or lengths, shoot fresh and dry weights, or root fresh and dry weights of seedlings were unaffected as a result of methanol treatment. In the field, cabbage head weight was slightly higher after methanol application only in 1993, whereas cantaloupe fruit weight and number were significantly lower in 1993, but not in 1994.