Evaluation of sugarcane for animal feed in the Baixada Fluminense – RJ

ABSTRACT The edaphoclimatic adaptation of sugarcane varieties and clones can ensure higher forage productivity for animal feed. An experiment was conducted at the Seropédica campus of the Federal Rural University of Rio de Janeiro for the evaluation of two varieties (RB867515 and RB969017) and two clones (RB058046 and RB098022) of sugarcane under a randomized block design with seven replications. Biometric variables, tillers m-1, leaf area index (LAI), Brix degree, maturation index (MI), as well as forage and total yields, were evaluated during the cultivation of the sugarcane-plant cycle. Sugarcanes were planted on 10/08/2018 and harvested on 09/13/2019, totaling 323 days after planting (DAP). The data were analyzed using the R software, under randomized blocks and repeated measurements in time for biometric variables, tillers m-1, LAI, Brix Degree and MI. Means were compared using the Tukey test (p < 0.10). Clone RB098022 presented 20.2% more tillers m-1 than both the other varieties. At 296 DAP, both clones and the variety RB969017 presented MI higher than 0.85, indicating them as an earlier cycle than the variety RB867515 (MI = 0.91 to 323 DAP). Higher and similar forage and total yields were obtained with clone RB098022 and variety RB867515 (means 141.6 and 151.2 Mg ha-1, respectively). All sugarcanes adapted to edaphoclimatic conditions during plant cane cultivation, and it is recommended to use the clone RB098022 and the variety RB867515 for animal feed in the Baixada Fluminense region.

摘要
本研究探讨甘蔗品种与无性系的土壤气候适应性（edaphoclimatic adaptation）对动物饲用饲草生产力的保障作用。试验于里约热内卢联邦农村大学塞罗佩迪卡校区（Seropédica campus of the Federal Rural University of Rio de Janeiro）开展，采用随机区组设计，设置7次重复，对2个甘蔗品种（RB867515、RB969017）与2个甘蔗无性系（RB058046、RB098022）进行评价。试验在新植蔗栽培周期内测定了多项生物统计性状：每米分蘖数（tillers m⁻¹）、叶面积指数（leaf area index, LAI）、白利度（Brix degree）、成熟指数（maturation index, MI）以及饲草产量与总产。供试甘蔗于2018年10月8日定植，2019年9月13日收获，全生育期为种植后323天（days after planting, DAP）。
数据分析采用R软件（R software），针对每米分蘖数、LAI、白利度、MI等生物统计性状，采用随机区组结合时间重复测量模型进行统计分析，组间均值比较采用图基检验（Tukey test），显著性水平设定为p<0.10。
结果显示：无性系RB098022的每米分蘖数较其余两个供试品种高出20.2%；在种植后296天时，两个无性系与品种RB969017的MI值均高于0.85，表明其生育期早于品种RB867515（后者在种植后323天时MI值为0.91）；无性系RB098022与品种RB867515的饲草产量与总产更高且相近，分别为141.6 Mg·ha⁻¹与151.2 Mg·ha⁻¹。所有供试甘蔗在新植蔗栽培期间均适应了试验地的土壤气候条件，建议在弗鲁米嫩塞低地（Baixada Fluminense region）推广使用无性系RB098022与品种RB867515作为动物饲料原料。