Abstract
The difference in the growth response to soil moisture content was investigated between two sugarcane cultivars, NCo310 and Ni1, differing in regional adaptability. An optimum curvilinear relationship was found between the soil moisture content and dry weight of the plant. No difference in the optimum soil moisture content (fopt) was found between the two cultivars. The soil moisture content at which growth stops (f0) was lower in NCo310. The early growth of sugarcanes was extremely inhibited under a soil submerging condition in both cultivars, but in NCo310 such an inhibition was removed gradually with the passage of time. Although the plant weight in fopt tended to be heavier in NCo310 than in Ni1, the latter was not inferior to the former in the stalk weight under optimum to sub-optimum soil moisture conditions because the percentage of stem to total dry weight (SP) was higher in the latter. On the other hand, the stalk weight of Ni1 dropped largely both under submerging and arid conditions because of larger decreases both in plant weight and SP. The characteristics such as lower f0, faster adaptation to soil submerging condition and relatively high stability of SP were judged to support the wide regional adaptability of NCo310.
