EFFECT OF TASSEL INJURIES ON THE GRAIN-YIELD AND QUALITY IN MAIZE

We have examined the role of mechanical stress (hail injury effect), heat and drought stress effect - by weather - commonly in the hybrid corn seedproduction, over three years. The role of weather as component of effects of physiological processes, and plant life processes - is very important - especially in the hybrid corn seed production. Our conclusions: The partial tassel injuries, do not cause big yield loss, in good years. The yield loss can be equal with the whole yield of poor years. The partial tassel injuries can cause 25-50% yield loss in average years. The stressing factors against the tassel caused huge damages in bad years. The result with heat, and drought weather stressing effects can be the worst. The partial tassel injuries in this case can cause eliminating the whole seed yield also. The breaking of the tassel branches (one of the treatments) had the most gentle damage effect. Treatment - removing of the tassel central spike - delays the starting of pollen shedding. Treatment - removing the tassel branches - can shorten the pollen anthesis. The effect of tassel injuries: poor fertilizated reduced biological value seeds. The ratio of roundish fractions grew. Because of the poor fertilization, the seeds maturity conditions are different. It depended on the seeds' position on the cob. The damage effect is growing after the harvesting, drying processes, and germination ability is deteriorating. These results are valid only to the concrete crossing combinations, place, and year. Because the parental lines compatibility, the synchronization, and floration weather can be different.