新西兰种植蔬菜遇到的嘛烦事
在新西兰
请教大家:我种的毛利瓜叶绿，瓜多。可这几天发现叶子上有像霜那样一层白色，不知为什么？
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缺水？
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有可能是霜霉病，喷一下fungicide的药试试
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我家的叶子也这样，我妈剪掉一些旁边没用的叶子，因为长太大了。
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那是因为你叶子太多了。
每次摘瓜的时候都要把边上一些多余的旺盛叶子剪掉。
毛利瓜根本不用担心。
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毛利瓜需要把过多的叶子剪掉，问下黄瓜收成很好一路长上去每节收一个瓜，下面收过瓜的一些叶子需要剪掉吗？觉得会不会太吸收营养了
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谢谢！我试试吧！
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我的黄瓜，南瓜都不摘叶子的。
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切除，不是摘掉。
切掉（剪掉）多余的叶子除了集中营养之外，还有最重要的是增加通风，避免潮气积聚在植株上，潮气积聚就给了真菌滋生的环境
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明天我也去剪！
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摘其实更容易造成更大的伤口，一般会撕裂附近的组织或者表皮，如果是扭着掰断，则会对断口造成压伤或者扭伤。这两类伤口都不容易干燥愈合。伤口的潮湿更容易给fungi 提供生长环境，渐而从伤口烂到整棵植株。
我们一般不会摘长成的枝或者叶，因为长成的纤维都很容易沿着生长方向撕裂下去。顶多就摘一些刚冒头的嫩芽之类的。当然，这也仅仅是图快捷省事。要安全种植，最好连嫩芽也用刀片切掉。
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我只的切也是把叶子在叶柄处切离主干
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嗯 我发现那个叶子张毛了 叶子把儿上也有毛 就连把也剪了
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Large leaf vegetable plants, like zucchini and yellow squash, may develop powdery mildew, a fungus infection that looks like white fuzzy spots. Left untreated, the spots will spread, killing the leaf and eventually killing the plant. It was the third week of June, while harvesting some zucchini from my own garden, that I first saw them. There were two to three dozen small white spots on eight leaves of one zucchini plant. The spots were all less than one-quart inch across. The largest leaves, which are also the oldest leaves, are often the first to display powdery mildew.
Causes and cures of powdery mildew
Powdery mildew is the result of several factors such as warm temperatures and high humidity or lack of full sun. The University of California's Agriculture and Natural Resources Department says, "Powdery mildews generally do not require moist conditions to establish and grow, and normally do well under warm conditions." When caught early, there is a good possibility of saving the zucchini through diligent use of a fungicide. I do not use harsh chemicals in my organic garden so I went in search of homemade fungicides.
Homemade fungicide recipes
I tried two different homemade recipes as a fungicidal treatment for powdery mildew. One recipe from Doug Green at Simple Gifts Farm used one part skim milk to nine parts water. The second recipe from John Dromgoole, the Natural Gardener, uses four teaspoons baking soda and one teaspoon liquid dish soap (he suggests Dawn or Ivory) mixed into one gallon of water. The frequency of application varied from daily to weekly; however, daily for an existing infection makes more sense. A weekly spritzing seems more reasonable as a preventive measure to keep powdery mildew from (re)appearing.
Setting up the homemade fungicide experiment
I prepared both mixtures and poured some into separate spray bottles (the cheap plastic spray bottles from the local dollar-type store). I chose a fence post as a marker to visually divide the infected leaves for an experiment to see which homemade product worked better. The milk solution would only be applied to Set A and the baking soda/detergent solution to Set B. The plan was to spray the mixtures on the appropriate set of leaves each morning.
The daily results
Day 1 and Day 2, there was no measurable change in the fungus condition of the test leaves. By Day 3, I noticed a difference in the powdery mildew on both sets of leaves'"one good, one bad. On Set A with the milk mixture, there were more mildew spots and older spots were now larger. On Set B with the baking soda/detergent mixture, the spots were still present, but appeared slightly gray like they were less dense. Day 4, Set A looked even worse. Large areas of the leaves were covered with mildew. Set B's spots were definitly less obvious. Not willing to sacrifice the plant for the milk fungicide experiment, I cut off the leaves with the most fungus and switched to using the baking soda/detergent mixture on the remaining leaves in Set A.
Day 5, Set B's spots are barely visible. Day 6, the mildew is almost gone. After Day 7's application of baking soda and dish detergent in water, the powdery mildew is gone.
Which worked better?
For my experiment, a combination of baking soda and mild dish detergent mixed in water proved to be more successful at killing powdery mildew than the milk mixture. If you only have a few plants, mix the fungicide in a half-gallon milk container, cutting the recipe in half. For larger vegetable gardens, use a pressure pump sprayer.
Prevention
The best way to prevent powdery mildew on vegetable plants is to purchase disease resistant varieties, plant in full sun, and set plants the designated distance apart for adeqate air circulation. I plan a weekly repeat of the homemade fungicide this season to prevent the return of powdery mildew.
More from this contributor:
3 Seldom Mentioned Critical Vegetable Garden Mistakes
Beneficial Flowers for a Vegetable Garden to Deter Pests
Dealing with Container Vegetable Garden Problems
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http://www.ehow.com/how_3035_detect-prevent-powdery.html
http://forums2.gardenweb.com/forums/load/cornucop/msg0719204827383.html
http://voices.yahoo.com/get-rid-white-fuzzy-spots-zucchini-plant-leaves-8762103.html