Author is Robert M. [Bert] Hamilton (Compiler), posted over 8 years ago
Damage by cold water causes sunken cell wall collapse; water dripping from the roof in winter causes it. F85-8
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LEAVES: On Vandas Turn Yellow and Drop
Author is Robert M. [Bert] Hamilton (Compiler), posted over 8 years ago
Repot the plant in loose medium dampen it and place in a plastic bag in indirect light. A75-35
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LEAF BLIGHT: Also Known as Leaf Die-back, Tip Burn
Author is Robert M. [Bert] Hamilton (Compiler), posted over 8 years ago
Caused by fungus invasion; spreads gradually through leaf; cut it out before treating; infected areas show watery before drying; control with Benlate, or Anti-Damp, or Tersan. RMH
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LEAVES: Wilting Without Changing Color, Leading to Death of Plant
Author is Robert M. [Bert] Hamilton (Compiler), posted over 8 years ago
Too little light can cause it, or excessive wetness; check the roots for root aphids or fungus. A71-345
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LEAVES: Shrivelling on Cattleyas
Author is Robert M. [Bert] Hamilton (Compiler), posted over 8 years ago
Is caused by several things, such as dryness of culture, lack of high enough humidity, roots possibly dead from over-watering. A86-383
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LEAVES: Sunburned
Author is Robert M. [Bert] Hamilton (Compiler), posted over 8 years ago
The best treatment is to remove only the badly burned ones; partly burned ones are unsightly but still functional. A69-130; A75-906; A79-334
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LEAVES: White Patches
Author is Robert M. [Bert] Hamilton (Compiler), posted over 8 years ago
Check the Mg and Fe levels in the fertilizer and increase one or both. Au84-204
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LEAVES: White Patches on Phalaenopsis
Author is Robert M. [Bert] Hamilton (Compiler), posted over 8 years ago
Most likely this is caused by cold damage which results in sunken cell-wall collapse, likely on plants too near a cold wall or under a cold-water drip; always use water for watering which is warmer...
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ALGAE: On Plant Leaves
Author is Robert M. [Bert] Hamilton (Compiler), posted over 8 years ago
Caused probably by too little light; low intensity of fertilizer on leaves promotes growth; it can cut down on photosynthesis. F68-187
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PESTICIDES: Shelf Life
Author is Robert M. [Bert] Hamilton (Compiler), posted over 8 years ago
They should be purchased for short-term use; mark the date of purchase on the container; most keep their effectiveness for two or more years if stpred properly; signs of ineffectiveness in dusts an...
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