Some Ecological Characters and Application of Joint-to-Joint Analysis in Sorgo Plant

[摘要] Some ecological characters of yield of sorgo were examined and it was found that the joint-to-joint analysis is recommended as a method for ecological studies in this crop just as in sugar cane. The results obtained in this experiment are summarized as follows: 1. April (early) planting may be recommendable for twice-reaping system when sorgo is used as a forage crop, though it is not suitable for grain sorgo because it may be seriously damaged by birds. A moderate planting season for using it as both green and grain sorgo seemed to be in June (late planting), when the advance of the date of heading may be brought about. 2. Varieties suitable for early planting may surely be distinguished from those for late planting by deciding the relative position of the heaviest internode which is determined by joint-to-joint analysis of the stem; the variety whose heaviest internode locates at a low positoin in a standing stem is adapted for early planting, and the one with the heaviest node at a high position for late planting. 3. Rind harness is remarkably high at the lowest intermode and it gradually decreases upwards along the stem. 4. An even transition of brix throughout the successive internodes from the base to the top can be observed at flowering time, but later, brix begins to increase, as grains mature, in the middle and uper portions of the stem, leaving brix in the lower portion almost as it is. The course of maturing as mentioned above may greatly be affected by yield of grains and mechanical damages in green leaves. The maximum mean brix is expected at full maturing stage of grains, and the persistence of high brix varies with either variety or planting season. 5. Windbreakage of the stem caused by stem borers, deterioration of the content of internode tissue and damages in grains by birds all vary widely with the plant variety as well as season.

[学科分类] 农业科学（综合）