The vigor of water melon hybrid seeds declines fast in general. The germination percentage of fresh water melon seeds was 100% and vigor index 18 11. After storage for 12 months in open condition the germination percentage decreased to 10% and vigor index to 0 12 The lower the seed moisture content(MC) was

the higher seed vigor was.Under the same MC condition

the lower seed temperature was

the higher seed vigor was. The vigor was highest in room temperature and ultradry storage condition. The acid phosphatase activity of melon seeds emerged after imbibing for two hours. The catalase activity and peroxidase activity emerged after germinating for two days in melon seeds. There was good correlation between the emzyme activity and the seed vigor. The water melon seeds released large amount of volatile aldehyde compound (VAC) within lst day and 2nd day of imbibing and germinating. Significant negative correlation have been obtained between melon seed vigor and volatile aldehyde. By measuring the quantities of VAC

we can test melon seeds in different vigor levels.