Palmer amaranth, an annual weed, and Verticillium dahliae, a fungal pathogen, can substantially reduce chile pepper yield. On the basis of the results of this study, we clarified implementation strategies for a potential management tactic for Palmer amaranth and V. dahliae in chile pepper: mustard seed meal (MSM). The objectives were to (1) determine MSM effects on Palmer amaranth seedbanks under different moisture levels, (2) measure glucosinolate degradation in soil hydrated to saturation and field capacity, and (3) determine the effects of decreasing moisture availability on MSM control of Palmer amaranth and V. dahliae. To address objective 1, seedbanks with and without MSM were hydrated to levels expected to both inhibit and promote germination (flooded, saturated, −0.03, −0.6 MPa, respectively). For objective 2, soil columns with MSM were held at different moisture levels and sampled over time. For objective 3, Palmer amaranth seeds were incubated with and without MSM, and with polyethylene glycol (PEG) solutions comprising a range of water potentials (0, −0.03, −0.6, −1.0, and −2.0 MPa). These PEG solutions were also used to hydrate MSM in agar plates with plugs of V. dahliae. All experiments were performed in growth chambers with temperatures and light conditions conducive to Palmer amaranth germination and V. dahliae mycelial growth. MSM-induced mortality in Palmer amaranth seedbanks was greater in soil at field capacity than in saturated soil and flooded soil; however, rates of glucosinolate degradation were greatest in saturated soil. Decreasing water availability progressively decreased the efficacy of MSM on Palmer amaranth because MSM was ineffective on nongerminated seeds. When incubated with PEG solutions with water potentials of 0, −0.03, and −0.6 MPa, MSM stopped growth of V. dahliae; however, MSM-induced control of V. dahliae was reduced by water potentials of −1.0 and −2.0 MPa. The results of this study indicate soils hydrated to field capacity maximize MSM-induced control of Palmer amaranth and V. dahliae.

中文翻译：

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水分利用率影响芥菜粕对棕榈苋（Amaranthus palmeri）和黄萎病菌的抑制作用

苋菜，一年生杂草，和黄萎病菌，一种真菌病原体，可以大大降低辣椒的产量。在本研究结果的基础上，我们阐明了帕尔默苋菜潜在管理策略的实施策略和五、大丽花在智利辣椒中：芥末籽粉（MSM）。目标是 (1) 确定不同水分水平下 MSM 对 Palmer 苋菜种子库的影响，(2) 测量水合至饱和和田间容量的土壤中硫代葡萄糖苷的降解，以及 (3) 确定降低水分可用性对 Palmer 的 MSM 控制的影响苋菜和五、大丽花. 为了实现目标 1，将含有和不含有 MSM 的种子库水合到预期抑制和促进发芽的水平（分别淹没、饱和、-0.03、-0.6 MPa）。对于目标 2，具有 MSM 的土壤柱保持在不同的湿度水平，并随着时间的推移进行采样。对于目标 3，Palmer 苋菜种子在有和没有 MSM 的情况下孵育，并使用包含一系列水势（0、-0.03、-0.6、-1.0 和 -2.0 MPa）的聚乙二醇 (PEG) 溶液进行孵育。这些 PEG 溶液还用于在琼脂板中水合 MSM五、大丽花。所有实验均在有利于帕尔默苋菜萌发的温度和光照条件的生长室中进行，五、大丽花菌丝生长。在田间容量的土壤中，MSM 引起的 Palmer 苋菜种子库的死亡率高于饱和土壤和淹水土壤；然而，在饱和土壤中硫代葡萄糖苷的降解率最高。由于 MSM 对未发芽的种子无效，因此减少水的可用性会逐渐降低 MSM 对棕榈苋菜的功效。当与水势为 0、-0.03 和 -0.6 MPa 的 PEG 溶液一起孵育时，MSM 会停止生长五、大丽花; 然而，MSM 诱导的控制五、大丽花被-1.0和-2.0 MPa的水势降低。这项研究的结果表明，土壤水合到田间持水量最大化 MSM 诱导的对 Palmer 苋菜和五、大丽花.