w*w
2 楼
Black Spot is caused by the fungus Diplocarpon rosae. The disease can
cause almost complete defoliation of bushes by early fall. It produces a
weakened bush on which cane dieback, stem canker, and winter injury can
become severe.
Control: A preventive program for black spot should begin with a
thorough cleanup in the fall. Diseased leaves on the ground should be
raked and destroyed. All diseased canes should be pruned off by cutting
several inches into good wood. These precautions reduce overwintering
fungi.
A fungicide program should start in the summer just before leaves become
spotted. From then until frost, the leaves may require a protective
fungicide coating. When the leaves are growing rapidly or during rainy
weather, it may be necessary to spray the plants two times a week.
However, if growth is less rapid and rains are less frequent, spraying
at 7 to 10 day intervals is usually sufficient. Proper timing is as
important as the chemical spray. A preventive spray program can include
the chemicals listed in table 1.
http://www.extension.umn.edu/distribution/horticulture/dg1163.h
【在 l****z 的大作中提到】
: 今年玫瑰有很严重的黑斑，开完花后我已经剪点了所有的黑斑叶子。 还有什么好办法
: 吗？
: 多谢
cause almost complete defoliation of bushes by early fall. It produces a
weakened bush on which cane dieback, stem canker, and winter injury can
become severe.
Control: A preventive program for black spot should begin with a
thorough cleanup in the fall. Diseased leaves on the ground should be
raked and destroyed. All diseased canes should be pruned off by cutting
several inches into good wood. These precautions reduce overwintering
fungi.
A fungicide program should start in the summer just before leaves become
spotted. From then until frost, the leaves may require a protective
fungicide coating. When the leaves are growing rapidly or during rainy
weather, it may be necessary to spray the plants two times a week.
However, if growth is less rapid and rains are less frequent, spraying
at 7 to 10 day intervals is usually sufficient. Proper timing is as
important as the chemical spray. A preventive spray program can include
the chemicals listed in table 1.
http://www.extension.umn.edu/distribution/horticulture/dg1163.h
【在 l****z 的大作中提到】
: 今年玫瑰有很严重的黑斑，开完花后我已经剪点了所有的黑斑叶子。 还有什么好办法
: 吗？
: 多谢
l*z
3 楼
谢谢， 我也google过了，好像也没有特别有效的方法。
【在 w**w 的大作中提到】
: Black Spot is caused by the fungus Diplocarpon rosae. The disease can
: cause almost complete defoliation of bushes by early fall. It produces a
: weakened bush on which cane dieback, stem canker, and winter injury can
: become severe.
: Control: A preventive program for black spot should begin with a
: thorough cleanup in the fall. Diseased leaves on the ground should be
: raked and destroyed. All diseased canes should be pruned off by cutting
: several inches into good wood. These precautions reduce overwintering
: fungi.
: A fungicide program should start in the summer just before leaves become
【在 w**w 的大作中提到】
: Black Spot is caused by the fungus Diplocarpon rosae. The disease can
: cause almost complete defoliation of bushes by early fall. It produces a
: weakened bush on which cane dieback, stem canker, and winter injury can
: become severe.
: Control: A preventive program for black spot should begin with a
: thorough cleanup in the fall. Diseased leaves on the ground should be
: raked and destroyed. All diseased canes should be pruned off by cutting
: several inches into good wood. These precautions reduce overwintering
: fungi.
: A fungicide program should start in the summer just before leaves become
w*w
4 楼
既然是FUNGUS，还是fungicide。你们那里可能比较潮湿。
【在 l****z 的大作中提到】
: 谢谢， 我也google过了，好像也没有特别有效的方法。
【在 l****z 的大作中提到】
: 谢谢， 我也google过了，好像也没有特别有效的方法。
l*z
5 楼
北加，去年冬天雨水非常多。
【在 w**w 的大作中提到】
: 既然是FUNGUS，还是fungicide。你们那里可能比较潮湿。
【在 w**w 的大作中提到】
: 既然是FUNGUS，还是fungicide。你们那里可能比较潮湿。
z*7
6 楼
这就是我为什么一直对休斯顿种玫瑰信心不足。
z*n
7 楼
哈哈
【在 z******7 的大作中提到】
: 这就是我为什么一直对休斯顿种玫瑰信心不足。
【在 z******7 的大作中提到】
: 这就是我为什么一直对休斯顿种玫瑰信心不足。
z*7
8 楼
一直被阿美大斑竹所耻笑。捂捂。
【在 z*********n 的大作中提到】
: 哈哈
【在 z*********n 的大作中提到】
: 哈哈
f*h
9 楼
我这边也是春天雨水多，玫瑰都被我剥成光屁股。。。只有花，没有叶子，哈哈
后面买了点东西喷在土里，新叶子已经没问题。
好像没有什么好办法，就是春天的时候提前预防，喷药。
【在 l****z 的大作中提到】
: 谢谢， 我也google过了，好像也没有特别有效的方法。
后面买了点东西喷在土里，新叶子已经没问题。
好像没有什么好办法，就是春天的时候提前预防，喷药。
【在 l****z 的大作中提到】
: 谢谢， 我也google过了，好像也没有特别有效的方法。
c*g
10 楼
浇水时（或者喷水时）避免水直接碰到叶子； 另外浇水时间选在出太阳前1-2个小时（而不是晚上），会减少霉菌的生长
【在 l****z 的大作中提到】
: 今年玫瑰有很严重的黑斑，开完花后我已经剪点了所有的黑斑叶子。 还有什么好办法
: 吗？
: 多谢
【在 l****z 的大作中提到】
: 今年玫瑰有很严重的黑斑，开完花后我已经剪点了所有的黑斑叶子。 还有什么好办法
: 吗？
: 多谢
l*z
11 楼
谢谢。早上浇水有点难度。
（而不是晚上），会减少霉菌的生长
【在 c*****g 的大作中提到】
: 浇水时（或者喷水时）避免水直接碰到叶子； 另外浇水时间选在出太阳前1-2个小时（而不是晚上），会减少霉菌的生长
（而不是晚上），会减少霉菌的生长
【在 c*****g 的大作中提到】
: 浇水时（或者喷水时）避免水直接碰到叶子； 另外浇水时间选在出太阳前1-2个小时（而不是晚上），会减少霉菌的生长
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