云杉针铸
害虫通用名称
- 疾病名称:云杉针状铸造
- 致病微生物:主要 Rhizosphaera kalkhoffii 在爱达荷州; Rhizosphaera扎, Lophodermium sp. 和 Lirula sp. can also produce similar symptomology among spruce, fir 和 pine species
- 蓝云杉(云杉pungens) -高度易感
- 恩格尔曼云杉(云杉engelmannii) -高度易感
- 防风林-易感性可变
- 苗木来源于苗木(vs .. 无性系繁殖品种)-易感性变
- 白杉(云杉glauca) -中等耐受性
- 铁杉(Tsuga heterophylla) -中等耐受性
- 许多松树种类(松果体 sp.) -中等耐受性
- 挪威云杉(挪威云杉) -高抗性
- Dwarf cultivars of blue spruce planted as l和scape ornamentals — often highly resistant
Spruce needle cast is a fungal disease that causes discoloration 和 eventual loss of needles. Initial symptoms of needle cast disease include a mild yellowing of current-season needles, 通常是先上后下, 拥挤的分支. Symptoms tend to progress outward from the inside 和 upward into previously healthy branches 和 often an entire tree will ultimately be impacted (Figure 1). Severely infected trees lose the ability to retain needles for their normal five- to six-year life span 和 only first-year needles are held at the ends of the branches. Continued cycles of infection will eventually kill the branches completely. Older trees may be partially or totally denuded of healthy, dark green needles. Young trees may die if weather favors the disease for several years in a row.
生物学
真菌病原体 Rhizosphaera kalkhoffii overwinters in the infected needles that remain on the tree or fall to the ground close by. 在春季48小时或更长时间的湿润期, rain-splashed spores may spread to current-season new growth. 在夏天, continued spread can occur during periods of sprinkler overspray or the activity imposed by pruning 和 shearing. Season-long spread can occur on trees that are irrigated with overhead sprinklers.
Needle cast disease requires two seasons to complete its cycle. Infection of new needles occurs in spring 和 early summer of the first year. The fungus penetrates the needles 和 creates a mild yellowing in these current-season needles. At this stage, the disease is difficult to diagnose correctly. 感染后的第二个季节是五月或六月, the fungus continues to develop in the needles 和 symptoms become more pronounced. 泛黄的进展, 真菌产生可见的子实体, 从夏末到初秋, 针变成深红褐色(图2). 到晚秋, 这些变色的针大多是从树上掉下来的, 留下相对光秃秃的树枝.
损害
- Diagnostic symptoms 和 signs of spruce needle cast include:
- Mottled yellowing of current-season needles (alone, this symptom is not diagnostic)
- 黑色子实体的发育, 直线可见, 沿针叶平行排列(从气孔中伸出). This is the most important diagnostic trait 和 typically becomes visible in the late spring after initial infection.
- Needles turn dark reddish-brown in the fall of the second year after spore dispersal
- Needles are cast from the tree in the late fall of the second season
- Only the current-season needles are retained through the second winter on infected branches. These needles are usually infected with the fungus 和 will express second-season symptoms the following season.
- 枝条枯死开始于下部, shaded branches 和 slowly spreads outward 和 upward; eventually affecting much of what was once a healthy tree (Figure 1)
控制
Management 和 control of all pathogens that cause needle cast dem和 similar protocols, thus allowing this guide to be applied across all such disease-causing pathogens.
物理
- Remove visibly infected trees to prevent spread to healthy neighbors
文化
- Prune only when foliage is dry (between trees, sterilize pruning equipment using 70% ethanol)
- 清除掉掉在树下的死针
- Select 和 plant Norway spruce or spruce, fir, or pine species that have resistance to needle cast
- 只使用无病原体的种植材料
- Plant only in sites with deep, rich, fertile soils that will support excellent tree health
- Space trees far enough apart to prevent overcrowding resulting high humidity within the canopy
- Manage to prevent drought 和 fertility stresses that make trees more susceptible to the disease
- Use irrigation equipment that provides adequate water without routinely wetting the foliage
化学
- Pesticide recommendations for control of spruce needle cast can be found at the 植物病害管理手册 网站.
农药的警告
总是 read 和 follow the instructions printed on the pesticide label. The pesticide recommendations in this University of Idaho webpage do not substitute for instructions on the label. Pesticide laws 和 labels change frequently 和 may have changed since this publication was written. Some pesticides may have been withdrawn or had certain uses prohibited. 小心使用农药. 不要使用农药，除非特定的植物, animal or other application site is specifically listed on the label. Store pesticides in their original containers 和 keep them out of the reach of children, 宠物和牲畜.
贸易名称 -为了简化信息，使用了商品名称. No endorsement of named products is intended nor is criticism implied of similar products not mentioned.
地下水 -保护地下水, 当有杀虫剂的选择时, 涂抹者应该使用最不容易浸出的产品.
- 图1 - 2. 史蒂夫·洛夫，bet365亚洲官网
Steve Love，作物科学教授
2023