Yield and quality of corn variety Arjuna in the wet season

An experiment was done to study corn yield and quality of variety Arjuna was undertaken during the 1989/1990 wet season at Bogor Research Institute for Food Crops. The corn planting was started at January 10, 1989. Seven harvest times were done, beginning at the half maturity stage, followed by on weekly period at harvest. The half maturity stage was identified by the visual appearance of 50 percent number of green husk cobs which was found at 97 days after planting. The 2nd, 3th, 4th, 5th, 6th, 7th harvests were done one ages of 104, 111, 118, 125, 133 and 140 days after planting, respectively. Each harvest area was 100 m2 with three replications. Drying of the cobbed corn, shelled corn, and sorted seed corn were done by sun drying. The highest total shelled corn yield and quality, and sorted seed, were found from the third harvest, at its physiological maturity stage. There were no significant differences among yield and quality of the first, the 2nd and the 3th harvest. The total yield of shelled corn yield was 44.0 kg/100 m2 at 14 percent grain moisture content. The highest sorted corn seed yield was 43,3 kg/100 m2, under 1.6 percent sortation losses. The average germination percentage of the first, 2nd and 3th harvest seeds was 99 percent, and their field emergence percentage was 98 percent, after seed processing and sortation. After 9 month of storage under airtight package at room temperature, the seed germination percentage was 95 percent, and the seed field emergence was 90 percent. The seeds from the harvest later than the third decreased their quality and yield rapidly, especially the seed viability. The sortation losses increased rapidly, reached 40,8 percent in seeds of the 7th harvest. This was due to the increase of number of seeds germinated in the field before harvest. The wet season is possible for good seed production, germination, vigor and viability for corn variety Arjuna. The harvest must be at physiological maturity stage or not more than 2 weeks before, but not later harvest.