Category: Ailments

INSECTICIDES: Wettable Powders (w.p.)

Author is Robert M. [Bert] Hamilton (Compiler), posted over 7 years ago Contact sprays with W.P. are often safer to use because less easily absorbed by both humans and plants; they are effective where they are carried by water droplets so a sticker/ spreader/wetting ag... Read More

LADY BUGS: Lady Bugs

Author is Robert M. [Bert] Hamilton (Compiler), posted over 7 years ago As insects for mite control in greenhouses, they are effective for biological control to such an extent that extra mites have to be put in the greenhouse so the voracious lady bugs do not starve to... Read More

LEAF BURN: Caused by Sun

Author is Robert M. [Bert] Hamilton (Compiler), posted over 7 years ago Too much sunlight causes temperatures of leaves to rise above 105 deg.F to 110 deg.F.; depending on air temperature and the leaf aspect to the sun; tops of leaves have less water and burn easier. A... Read More

LEAF ROT: Erwinia and Sp. of Pseudomonas

Author is Robert M. [Bert] Hamilton (Compiler), posted over 7 years ago Stimulated by warm, damp weather; areas are yellowish or brownish and watery; the bacteria spread quickly; cut off whole leaf; soak the plant in Anti-Damp or Natriphene. A73-815 Read More

LEAF TIP BLACKENING: On Main Leaflet of Cattleyas

Author is Robert M. [Bert] Hamilton (Compiler), posted over 7 years ago Caused by Phytophora or Pythium diseases; best controlled by Truban (ethazole) at 1 tpg.; avoid syringing with water at adverse times. A79-1112 Read More

LEAF-SPOT: Diplodia Laeliocatleyae

Author is Robert M. [Bert] Hamilton (Compiler), posted over 7 years ago Small yellow areas on top and bottom of leaf turn brown, become black and greasy; spray with fungicide such as Fore/ Dithane; Benlate is not effective in this case. AH86-70 Read More

LEAF-TIP NECROSIS: Causes

Author is Robert M. [Bert] Hamilton (Compiler), posted over 7 years ago It is a nutritional and compost problem and is not caused by fungal attacks as is commonly supposed; an unhealthy root system is likely at the base of it. AU84-199; it can be caused by a mix which ... Read More

LEAVES: On Cattleyas Become Yellowed

Author is Robert M. [Bert] Hamilton (Compiler), posted over 7 years ago If some have black splotches it may be caused by excessive soluble salts, or by toxic salts. A78-495 Read More

LEAVES: On Cattleyas Go Limp

Author is Robert M. [Bert] Hamilton (Compiler), posted over 7 years ago Too much nitrogen fertilizer, with too low light supply can cause it; poor root condition, such as too wet may be the fault. A72-686 Read More

LEAVES: On Cattleyas Stay Long and Narrow

Author is Robert M. [Bert] Hamilton (Compiler), posted over 7 years ago If they fail to spread open it is possibly because they lack sufficient light. A77-995 Read More