Adult Hessian Fly.
- 在种植小麦之前做出的决定对于有效地控制整个季节的病虫害至关重要.
- 品种选择应平衡满足整个种植制度目标所需的各种因素.
- 黑森州无蝇种植日期等文化因素仍然非常重要.
- Seed treatments provide additional protection in high pressure environments.
在种植小麦之前做出的决定对整个季节的病虫害管理计划的成功有很大的影响. 也许对任何作物来说，最重要的季前决定是品种选择. 小麦品种在产量潜力、农艺学和防御性状方面差异很大. 品种的选择必须考虑到种植制度的总体目标.g. 较早成熟的品种可能会降低最高产量，这种品种有利于双收大豆，并提供更好的抗病包装. By contrast, full-season top yielding varieties may compromise disease tolerance traits, requiring additional crop protection inputs.
Variety Selection
Obviously the first trait that you are looking for is yield. 你应该寻找的第二个特征是对枯萎病(FHB)的抗性。. 这是北美小麦生产系统中最具破坏性的疾病, 除了真菌毒素(脱氧雪腐镰刀菌醇- don)污染谷物外，还导致产量下降, requiring additional cleaning and potentially blending by elevators. 抗性小麦品种降低了小麦穗上的定植率和扩散程度，减少了DON污染. 这一点很重要，因为看起来健康的谷粒可能含有较高的DON，而且这些谷粒无法从高质量的谷物中去除. 最正规的赌博软件的现代小麦品种对赤霉病的抗性比5-10年前发布的小麦品种强得多. 此外，这些品种中的大多数不会像过去那样受到产量损失. Ratings can be found on company websites. Universities also publish uniform FHB trials, 哪些使用雾状托儿所来避免疾病逃逸并提供更准确的FHB抗性评级. These ratings can be easily accessed at the ScabSmart website: http://scabsmart.org/
其他可能没有那么严重但在小麦生产中更常见的疾病应该是你接下来要寻找的品种特征. These diseases include Septoria leaf blotch, Stagonospora leaf and glume blotch, 白粉病(特别是在高氮管理系统和施肥的田地)和条锈病和叶锈病. 如果它吹到小麦产区，并且天气仍然非常凉爽潮湿，那么条锈病通常会引起人们的关注. 记住你的品种有什么特点，这样你就可以确定在这个季节要注意什么疾病.
Planting Date
A second critical pre-season factor to consider is planting date. The Hessian fly is a small fragile gnat that appears in late September, lives for just a few days, and lays eggs in wheat, barley, rye, and other native grasses. Maggots hatch soon thereafter and feed on plant juices, which can lead to permanent stunting, chlorosis, and lodging. 在无蝇日期之后种植是有效的，因为小麦是在大多数成虫死亡和产卵期结束后出现的. 在中西部大部分小麦种植区，无蝇日期从9月下旬到10月中旬不等, so check with your local extension entomologist for more information. 黑森蝇现在在美国中西部的问题比历史上要小得多, due to the widespread cultural practice of planting after the fly-free date. Mild fall weather can push back the fly-free date by several days, because adults will remain active longer into the fall. 主要目标是在“无蝇日”后的10天到两周内将小麦播种.” As you go beyond this target, 增加多达30%的播种率，以弥补较少的秋季分蘖.
在无蝇日期之后种植是一种很好的栽培方法，还有几个原因:
- Early planting can lead to excessive fall growth, 哪些会增加对冬杀和某些叶面疾病的易感性. In some cases, 秋季感染可以让一些通常无法在冬天存活的疾病越冬, such as stripe rust.
- Late planting can result in poor tiller development and winter survival.
- 初秋较高的土壤温度增加了许多土壤传播疾病的活动, including seedling blights, 以及土壤传播的病毒，如土壤传播的小麦花叶病毒(SBWMV)和小麦纺锤条花叶病毒(WSSMV), vectored by the fungus-like organism, Polymyxa graminis).
- Modern varieties have been bred for resistance to Hessian fly, 但是新的黑森蝇生物类型正在进化，没有遗传抗性.
- Aphid populations are often higher in earlier planted wheat. 蚜虫直接降低小麦活力，并在秋季传播大麦黄矮病毒(BYDV).
- 早播增加小麦条纹花叶病毒(WSMV)感染的严重程度, 哪一种是小麦卷曲螨的载体，在高温下更活跃.
- Early planted fields may be targets for beetles that produce white grubs (i.e. June, Japanese beetles, masked chafer). 这些蛴螬可能会对随后在这些土地上种植的大豆和玉米造成问题, especially if three year grubs from June beetles establish.
Seed Treatments
种子处理也是高管理小麦项目的重要组成部分. 种子杀菌剂处理对土壤传播疾病(霉病)提供重要保护, Rhizoctonia, Fusarium, common bunt, and stinking smut), seed-borne diseases (loose smut), and even some early fall, foliar diseases (powdery mildew, rust, and Septoria). 请记住，这些持续大约3周左右，并且在春季不会有活动.
杀虫种子处理在虫害控制和产量响应方面不太一致, 但噻虫嗪和吡虫啉已被证明可以很好地预防黑森蝇, aphids, and below ground insects for a period of about 30 days after planting. In general, 如果你所在地区提前播种，考虑使用杀虫剂处理种子，以尽量减少这些害虫的问题. In the absence of insecticidal seed treatments, foliar insecticides can be used to manage aphids in the fall if warranted, but application timing is critical to effectively reduce damaging populations. Always refer to product labels for specific control recommendations.
Hessian fly larva and flax seed puparium
Symptoms of Barley Yellow Dwarf Virus in wheat