Overwintering Ability and Dry Matter Production of Sugarcane Hybrids and Relatives in the Kanto Region of Japan

Many kinds of sugarcane hybrids and relatives were planted in two sites, Tsukuba and Nasushiobara, in the northern Kanto region of Japan to evaluate their overwintering ability and biomass production. JW49 (Saccharum spontaneum L.), US56-15-2 (S. spontaneum L.) and Ponape Hurukimura (Saccharum barberi Jeswiet) were able to overwinter in the field experiment conducted in Tsukuba, but not in Nasushiobara. In the field experiment conducted in Nasushiobara, only two lines, JW599 (Saccharum spontaneum L.) and JW630 (Erianthus spp.), overwintered. JW630 also showed good ratooning ability in Tsukuba, even though the results were obtained from the experiment without replication. The newly planted JW599 and JW630 were small in the first year, but from the second year the biomass production of the ratoon plants became huge. The dry matter yields of JW599 and JW630 in the first year were 0.07 and 0.13 kg per hill, respectively, and the average dry matter yields of JW599 and JW630 during three years of ratoon cultivation were 1.46 and 2.63 kg per hill per year, respectively. Assuming that they are planted at 1.5-m inter-row intervals and 0.3 m inter-hill intervals, and each hill can accumulate the same dry matter yield, the dry matter production of the ratoon plant of JW599 and JW630 is estimated to be 32.5 and 58.4 t/ha, respectively.