较粗根出现软腐，根系缩小，植株长势或固定能力受影响。上述表现并非该病独有。
Soft rot of larger roots can reduce root-system size, crop vigour and anchorage. These effects are not unique to Pachymetra.
中英文字幕 · 每部约2分钟 · 无配音 / No narration。GAKI 会员登录即可观看；下载需要至少1贡献值。 / Sign in to watch; downloads require at least one contribution point.
症状与危害
DAMAGE AND SYMPTOMS
较粗根出现软腐，根系缩小，植株长势或固定能力受影响。上述表现并非该病独有。
Soft rot of larger roots can reduce root-system size, crop vigour and anchorage. These effects are not unique to Pachymetra.
来源与传播
ORIGIN AND SPREAD
土壤中的持存病原及附土移动是重点。机械或蔗材携带的土可造成田间转移；本片按澳大利亚资料讨论，不推断其他地区已发生本病。
Persistent inoculum in soil and movement of contaminated soil are central concerns. Soil carried on machinery or cane can transfer the pathogen. This Australian account does not establish its presence elsewhere.
生活史与机理
LIFE CYCLE AND BIOLOGY
Pachymetra chaunorhiza是卵菌，卵孢子可在土中持存。微图简化表现根部侵染与腐烂；不把孢子画成昆虫卵。
Pachymetra chaunorhiza is an oomycete with persistent soil oospores. A schematic can explain infection and root decay; oospores must not be depicted as insect eggs.
检查与确认
HOW TO INSPECT AND CONFIRM
观察粗根，结合土样与根样检测，排查线虫等原因。按当地实验室协议分区多点采样，并用种植状态和品种信息解释结果。
Examine thick roots and investigate alternative causes, including nematodes. Sample soil by the local laboratory protocol and interpret results with crop and cultivar information.
预防、治理与复查
PREVENTION, MANAGEMENT AND FOLLOW-UP
采用适宜抗性品种，减少附土转移，并长期跟踪。短休耕和晒土不足以保证清除；轮作虽可能改善土壤健康，也不应写成直接根除方案。
Use suitable resistant cultivars, limit soil movement and monitor over time. Short fallows and sun exposure do not guarantee elimination. Rotation may benefit soil health without directly eradicating this pathogen.
观察细节 / Look closely
图片为AI教学重建，非实拍标本或显微照片，不按比例；不能单凭图像确诊。 / AI teaching reconstructions, not authenticated specimens or microscopy; not to scale.
参考资料 / References
- Sugar Research Australia — Pachymetra root rot, Information Sheet IS13005 (2013)
- Sugar Research Australia — Diseases of Australian Sugarcane Field Guide
科普教学资料，专家审核尚未完成。管理措施需结合本地诊断和技术指导。 / Educational material; expert review pending. Use local diagnosis and agronomic advice.