Category: Orchid Doctor

BLACK ROT: Two Kinds Are Prevalent

Author is Robert M. [Bert] Hamilton (Compiler), posted over 7 years ago One is a cool-weather rot, the other is a warm-weather type and both cause blackening of leaf tissue; both are contagious and can be spread by splashing water; keep plants dry, spray with Benlate; ... Read More

BLACK ROT: Water Mold Pythium Ultimum Is the Cause

Author is Robert M. [Bert] Hamilton (Compiler), posted over 7 years ago The special enemy of commumity pots of seedlings; damp-off; spray with Physan, Anti-Damp, or Natriphene once a month as preventive; on mature plants cut out rot; soak plant in good fungicide, dry, ... Read More

BLACK ROUND SPECKS (BALLS): On Leaves

Author is Robert M. [Bert] Hamilton (Compiler), posted over 7 years ago Likely spores of a common bark fungus Spaerobolus stellatus which may be shot two to three feet by the fungus; not harmful; drench mix with Physan; (may be fly excreta?) OD73-115 Read More

BLACK SHEATHS: Caused by Fungi Under Excessively Damp Conditions

Author is Robert M. [Bert] Hamilton (Compiler), posted over 7 years ago Prevent spread to buds within by cutting off tops of sheaths to let in air; spray with Physan or Tersan. A73-815 Read More

BLACK SHEATHS: Fungus Disease

Author is Robert M. [Bert] Hamilton (Compiler), posted over 7 years ago Occurs especially under humid conditions and when water stands at base of the sheaths; cut off sheath above buds and spray with Tersan, Zineb or Natriphene. N319; cut off just above buds. S203 Read More

BLACK TIPS: On New Shoots on Cattleyas

Author is Robert M. [Bert] Hamilton (Compiler), posted over 7 years ago If the blackening does not progress rapidly it is probably not due to disease but excessive use of fertilizer. A72-1100 Read More

BLACK TWIG BORER: Found in Hawaii in 1966

Author is Robert M. [Bert] Hamilton (Compiler), posted over 7 years ago Bores holes and galleries in orchid tissue; use malathion 2 tpg. as spray; or, use Sevin 1.5 ttpg. P69(l)13 Read More

BLACK-BALL: Type of Excrement

Author is Robert M. [Bert] Hamilton (Compiler), posted over 7 years ago Frequently found on plants is merely the sticky seed of Oxalis; looks like sticky poppy seed; control with DuPont Karmex DW (Diuron), spraying floors and elsewhere, except dicot plants. A80-850 Read More

BLEACH: As Virus Control

Author is Robert M. [Bert] Hamilton (Compiler), posted over 7 years ago A one-minute soak in two to four percent bleach (Clorox, 5.25 percent sodium hypochlorite) solution kills Cymbidium mosaic virus; a four percent bleach is prepared by adding three tablespoons of Cl... Read More

ACID OR ALKALINE: Changing the Values

Author is Robert M. [Bert] Hamilton (Compiler), posted over 7 years ago Various means can be used: tufa, a limestone form, can be added to paphiopedilums from limestone cliffs; bark composts acidify with age; peatmoss, pine needles, oak leaves in the mix produce acidit... Read More