Abstract
Studies on the photoperiodism in "Nori-Asa" (glutinous-hemp), an amphidiploid crop raised between Abelmoschus esculentus and Abel. Manihot, were made in comparison with those of the parents. In a normal outdoor condition, the flowering times of esculentus and "Nori-Asa" were about the same, while in Manihot it was quite later. The flowering period was the longest in "Nori-Asa, " the medium in esculentus and the shortest in Manihot. The numbers of flowers and pods were the largest in Manihot, the medium in "Nori-Asa" and the smallest in esculentus. The set percentage of pods was the largest in esculentus, the medium in "Nori-Asa" and the smallest in Manihot. By shortening and lengthening the day length, the beginning of flowering of "Nori-Asa" was not changed, while those of the parents were changed. By shortening the day length, the duration of flowering periods of three crops were shortened and the numbers of flowers and pods be came smaller in most cases. By lengthening the same, the duration of flowering periods of esculentus and "Nori-Asa" was lengthened and the numbers of flowers and pods became larger, but those of Manihot were shortened and became smaller in number. The set percentage of pods of three crops showed in most cases a marked decrease by shortening and lengthening the day length. The plant height in a normal outdoor condition and also when lengthening the day length was the heighest in "Nori-Asa" the medium in Manihot and the lowest in esculentus. But in short day length, the highest was "Nori-Asa" the medium in esculentus and the lowest in Manihot.
