Category: Orchid Doctor

LEAF-SPOT: Cercospora dendrobii

Author is Robert M. [Bert] Hamilton (Compiler), posted almost 8 years ago Infects dendrobiums as light yellow area under leaves; circular enlargement; spots become sunken, purple-black, yellow margined; corresponding yellow-green areas follow on top; spreads to other pla... Read More

LEAF-SPOT: Cercospora dendrobii and Others

Author is Robert M. [Bert] Hamilton (Compiler), posted almost 8 years ago Control is a spray with benomyl or Benlate 20 at 1 ttpg. AH86-76 Read More

LEAF-SPOT: Cercospora dendrobii, C. epipactis, C. peristeriae Plus Six Other Cercospora Sp.

Author is Robert M. [Bert] Hamilton (Compiler), posted almost 8 years ago Usually shows as yellowish or brown spots on underside of leaves; sometimes join together to form larger spots; all are controlled by spraying with Benlate at 1 ttpg. with a wetting agent, and repe... Read More

LEAF-SPOT: Cercospora epipactidis

Author is Robert M. [Bert] Hamilton (Compiler), posted almost 8 years ago On Phaius grandifolius, etc.; tiny sunken, yellow spots under leaves, later on top also; enlarge in a few days and become sunken, purple-black; about 1/2 inch or larger; on old lesions center falls... Read More

LEAF-SPOT: Cercospora odontoglossi

Author is Robert M. [Bert] Hamilton (Compiler), posted almost 8 years ago Control by spraying with benomyl (Benlate 50W) at 1 ttpg plus wetting agent, three times at 15 day intervals. AH86-80 Read More

LEAF-SPOT: Diplodia Laeliocatleyae

Author is Robert M. [Bert] Hamilton (Compiler), posted almost 8 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-SPOT: Phyllosticta pyriformis

Author is Robert M. [Bert] Hamilton (Compiler), posted almost 8 years ago It is infrequent in Florida; it blemishes the leaves; starts as tiny slightly yellow spots, sunken, which enlarge and turn tan to dark brown or red with black margins; control with benomyl (Benlate... Read More

LEAF-SPOT: Septoria selenophomoides

Author is Robert M. [Bert] Hamilton (Compiler), posted almost 8 years ago Usually found on imported plants; starts as tiny yellow lesions, enlarges and turns dark, the spots coalesce; leaves soon fall and promote more infective spores; spray with benomyl (Benlate 50W) at... Read More

LEAF-SPOT: Soft Spots Slowly Cover the Whole Leaf

Author is Robert M. [Bert] Hamilton (Compiler), posted almost 8 years ago The condition should be treated early with Truban, 1 to 1.5 tpg. thoroughly even to the point of drenching, after removing the blackening leaves; if Truban is unavailable use Lesan (Dexon). A81-688 Read More

ACID OR ALKALINE: Changing the Values

Author is Robert M. [Bert] Hamilton (Compiler), posted almost 8 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