Growth of Reed Canarygrass (Phalaris arundinacea L.) as Affected by Environment and Cutting : I. The influence of cutting height on the regrowth processes

[摘要] Reed canarygrass plants propagated from a clone were cut at ground level (A) and at 10 cm stubble height (B) and their regrowth in terms of dry matter and nitrogen and carbohydrate accumulations in plant parts were measured weekly until 5 weeks after cutting. The aboveground dry weight of plot A couldn't reach that of B during the five week regrowth period. However, some merits were demonstrated by cutting at ground level. Firstly, the number of vigorous tillers emerged from the axils of underground and ground surface nodes was increased at the middle period of regrowth, and these tillers newly produced their own roots which actively absorbed nutrients (nitrogen), thus raising the net assimilating rates. Secondly, the assimilates were dominantly distributed to new leaf formation, increasing the ratio of leaf-blade to stem plus leaf-sheath and the leaf area ratio. Thus, the RGR of plot A was greater than that of plot B. In contrast, the plants in plot B produced many tillers from the axils at high nodes near the cutting surface, which did not produce their own roots and depended on the old roots of their mother tillers for nutrient and water absorption, thus being very small and weak in regrowth. Further, the number of vigrous tillers such as extensively emerged in plot A was very small in plot B. These different patterns of regrowth by different cutting heights are peculiar as compared with other cool season grasses which are sensitive to lower cutting heights. Therefore, reed canarygrass may be safely cut closer to the ground surface to get herbages of higher palatability and digestibility.

[学科分类] 农业科学（综合）