Fourteen-day-old plants of a photosensitive winter variety of rice, cv. BAM-3, were subjected to photoinductive cycles of 8-hr light and 16-hr darkness for 1, 2, 3, 4, 5 weeks, or until anthesis. Short-day treatment for 1 and 2 weeks caused vacuolation in the cytoplasm of a few of the sporocytes. Exposure for 3 weeks caused such a high degree of vacuolation in the cytoplasm of some of the sporocytes that such sporocytes showed no further meiotic divisions. The treatment for 4 weeks caused lagging of chromosomes in 10% of the sporocytes. Formation of binucleate abnormal pollen was noticed with a frequency of 20% as against 1.5% in control plants. Treatment for 5 weeks or until anthesis caused considerable contraction of the nucleus in the sporocytes, which did not divide further. In addition, this treatment caused loose pairing of chromosomes at the pachytene stage with a frequency of 20% and univalents at metaphase I with a frequency of 5%.