Hormone Spraying on Tomato Plants and Fruition of Tomatoes

The experiment was made in the Field of Yamagucti University in 1953, in order to study on the effect of 2.4-D, Tomato-tone and Vitamin B_1 on the tomato (Kumamoto No. 10). The results of the experiment are summarized as follws : ― 1. 2.4-D Area showed 94―100% of fruit-bearing ratio, Tomato-tone Area showed 89―92%, Combination of 2.4-D & Vitamin B1 Area 95―97%, and Vitamin Ba Area 57―72%. This 14―51% was excellent in result in contrast with 43% of Control Area. 2. In all areas, except Vitamin Bi Area, very much more bursting fruit was shown than in the Control Area which showed a minority. Bursting fruit in 5ppm Area was actually not harmed. 3. At the Control Area the growth and ripening of fruit was quickened, which increased fruit production. Also the ripening period was hastened by 2―5 days. By revising the spraying method and taking care so that the hormone chemical be not an injury to the stems and leaves, the ripening period can further more be hastened. The growth of fruit in Vitamin B_1 Area is almost the same as it'is in Control Area. 4. As to the gross weight of crop, in all those areaes, 2.4-D 5ppm Area, Tomatotone forty times Area, Vitamin Bi lppm Area, and 2.4-D 5ppm & Vitamin B_1 O.O5ppm Area, the gross weight was increased double as much as it was in Control Area. The other areas also increased. However, 2.4-D Area and Tomato-tone Area of high degree of dilution showed decrease caused by the chemical injuries and prevention of growth to a lrage degree. 5. 2.4-D Area and the Tomato-tone Area resulted in a large amount of seedless type fruit. In contrast, the standard seeded fruits in those areas were slightly larger. In seedless fruit, cavities resulted and so it was not marketable. 6. If the hormone spray contacts the stems and leaves, virose-like symptom results, so the revising of the method of spraying is neccessary. 7. Vitamin Bi is most effective against falling fruit and also against bursting fruit. In connection with Vitamin B_1, a field experiment is to be further continued. 8. Spraying hormones during rain is no adverse. However, after the rain, the hormones flow down the stems combined with rain and injure stems and leaves. Therefore, spraying must be done during fine weather.