Author : Sebidos, Rodrigo F.

Summary : Vivipary or pre-mature germination of seeds while still attached to the mother plant is considered to be minor significance in the Philippines not until recently when temperate germplasm was introduced into the tropical germplasm that the malady has seriously affected the corn industry. It is believed that vivapary could be managed through genetic, environmental and nutritional manipulation. Two field experiments were established at the Central Experiment Station, UPLB from February to October 1994, to determine the effects of water stress, nitrogen fertilization, and maternal background on the expression of vivipary in corn. The study revealed that water stress at 45 days after planting raises the concentration of ABA in the seeds both in zero N and 120 kg N/ha significantly. P3274, a viviparous variety regardless of water stress treatment and nitrogen application gave significantly high germination. Viviparous varieties maintain significantly high fresh and dry seed weight. Varietal crosses having viviparous female parent failed to show significant maternal effects on germination and water loss. However progenies having viviparous male parent showed significantly high germination percentage both at 10 days after planting and one month after harvest. The effects of maternal background failed to indicate significant correlation between germination and phytohormones and between water loss and phytohormones in the expression of the vivipary among varietal cosses.