Applying control measures when carbohydrate levels are low can decrease the likelihood of plant survival, but little is known about the carbohydrate cycles of dewberry (Rubus spp.), a problematic weed group on cranberry (Vaccinium macrocarpon Aiton) farms. Weedy Rubus plants were collected from areas adjacent to production beds on commercial cranberry farms in Massachusetts, two locations per year for 2 yr. For each site and year, four entire plants were collected at five phenological stages: budbreak, full leaf expansion, flowering, fruit maturity, and after onset of dormancy. Root sections were analyzed for total nonstructural carbohydrates (TNC; starch, sucrose, fructose, and glucose). Overall trends for all sites and years showed TNC were lowest at full leaf expansion or flowering; when sampled at dormancy, TNC concentrations were greater than or equal to those measured at budbreak. Starch, a carbohydrate form associated with long-term storage, had low levels at budbreak, leaf expansion, and/or flowering with a significant increase at fruit maturity and the onset of dormancy, ending at levels higher than those found at budbreak. The concentration of soluble sugars, carbohydrate forms readily usable by plants, was highest at budbreak compared with the other four phenological samplings. Overall, our findings supported the hypothesis that TNC levels within the roots of weedy Rubus plants can be predicted based on different phenological growth stages in Massachusetts. However, recommendations for timing management practices cannot be based on TNC cycles alone; other factors such as temporal proximity to dormancy may also impact Rubus plants recovery, and further research is warranted. Late-season damage should allow less time for plants to replenish carbohydrate reserves (before the onset of dormancy), thereby likely enhancing the effectiveness of weed management tactics over time. Future studies should consider tracking the relationship between environmental conditions, phenological stages, and carbohydrate trends.

中文翻译：

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露莓（悬钩子属）根中的季节性非结构碳水化合物模式

当碳水化合物水平低时采取控制措施可以降低植物存活的可能性，但对露莓的碳水化合物循环知之甚少。悬钩子spp.），蔓越莓上的一个有问题的杂草组（越橘艾顿）农场。杂草丛生悬钩子植物是从马萨诸塞州商业蔓越莓农场生产床附近的区域收集的，每年两个地点，为期 2 年。对于每个地点和年份，在五个物候阶段收集了四株完整的植物：萌芽、全叶展开、开花、果实成熟和休眠开始后。分析根切片的总非结构碳水化合物（TNC；淀粉、蔗糖、果糖和葡萄糖）。所有地点和年份的总体趋势显示 TNC 在全叶展开或开花时最低；当在休眠时取样时，TNC 浓度大于或等于在萌芽时测量的浓度。淀粉是一种与长期储存相关的碳水化合物形式，在萌芽、叶片扩张和/或开花时含量较低，而在果实成熟和休眠开始时含量显着增加，以高于萌芽时的水平结束。与其他四个物候取样相比，植物易于使用的可溶性糖（即碳水化合物形式）的浓度在萌芽时最高。总体而言，我们的研究结果支持了 TNC 水平在杂草根部的假设。悬钩子可以根据马萨诸塞州不同的物候生长阶段来预测植物。然而，时序管理实践的建议不能仅基于 TNC 周期；其他因素，如时间上接近休眠状态也可能影响悬钩子植物恢复，有待进一步研究。晚季的损害应该让植物有更少的时间来补充碳水化合物储备（在休眠开始之前），从而随着时间的推移可能会提高杂草管理策略的有效性。未来的研究应考虑跟踪环境条件、物候阶段和碳水化合物趋势之间的关系。