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

Ailments Orchid Doctor

by Robert M. [Bert] Hamilton (Compiler)

Originally published in The Orchid Doctor in 1980 and 1988

Posted by Sys Admin almost 8 years ago.

Article Blog   Article Index

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 repeat at 15 day intervals three times to eliminate it from the greenhouse; illus. AH23+

Share on Social Media:  
Log in to Add a Comment

More The Orchid Doctor Articles under the Heading Leaf-spot

Leaf-spot Comments
LEAF-SPOT: Cercospora angraeci Fungus found in Florida in 1964; tiny tan or light brown spots become dark purple-brown; may occur in a circular pattern or on a whole leaf; spray with benomyl 50WP at 1 ttpg. fortnightly three times and use a wetting agent; or, with Daconyl 2787; destroy leaves; space plants out. BU24 This has been reported on various angraecums, dendrobiums and odontoglossums. AH86-77 0
LEAF-SPOT: Cercospora dendrobii 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 plants; spray with benomyl 50WP at 1 ttpg. fortnightly, or with Ferbam, or Zineb. B21; BU20 0
LEAF-SPOT: Cercospora dendrobii and Others Control is a spray with benomyl or Benlate 20 at 1 ttpg. AH86-76 0
LEAF-SPOT: Cercospora epipactidis 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 out; spray with benomyl at 1 ttpg., or with Ferbam or Zineb. B18; BU19 0
LEAF-SPOT: Cercospora odontoglossi Control by spraying with benomyl (Benlate 50W) at 1 ttpg plus wetting agent, three times at 15 day intervals. AH86-80 0
LEAF-SPOT: Diplodia Laeliocatleyae 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 0
LEAF-SPOT NECROSIS: Control by Various Compost Techniques A build-up of undissolved solutes in water cause the leaves to die at the tip; it also causes punctate areas of necrosis of tender leaves of species such as stanhopeas, pescatoreas, lyxastes, etc.; good drainage and much leaching helps; the "wet growing" system is described, emphasizing use of Palco wool and plastic chips medium; refer to OD68-8 0
LEAF-SPOT: Phyllosticta pyriformis 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 50W) A86-814 0
LEAF-SPOT: Septoria selenophomoides 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 1 ttpg. three times fortnightly. AH86-69 0
LEAF-SPOT: Soft Spots Slowly Cover the Whole Leaf 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 0

New Topics

  1. Danielle Carbonneau asked question phalaenopsis, dendrochum and Odontoglossum in category Phalaenopsis
  2. Nicholas Filannino asked question Phalaenopsis William Kistler? in category General Discussion
  3. Mark Farran asked question How to open and read articles listed in category General Discussion
  4. Juliann Eckhard started topic Cattleya little susie in category Cattleya Alliance
  5. Shannon Gardea asked question NELLY ISLER in category General Discussion
Ask a Question

Start a Topic

New Comments

  1. Louis Wilson commented on member plant E. alata f. alba by Louis Wilson
  2. Julie Ellner commented on member plant Phal. amabilis var. formosanum by Vickie Seibert
  3. Julie Ellner commented on member plant Rlc. Green Dragoon 'Mendenhall' by Jeanne Uzar Hudson
  4. Danielle Carbonneau commented on member plant Ons. Catatante 'Los Roble' by Henry Shaw
  5. Barry J Silver commented on orchid Lyon. SunCoast Pink Passion
  6. Carol Holdren commented on topic "Phalaenopsis William Kistler?" by Nicholas Filannino
  7. Carol Holdren commented on orchid Colm. Eric Gabriel Heines
  8. Carol Holdren commented on topic "Cattleya little susie" by Juliann Eckhard
  9. Carol Holdren commented on member plant Bc. Morning Glory by Chris Siolo
  10. R .Benson commented on member plant Kir. New Hybrid (Fred Clarke) SVO9831 by R .Benson
  11. Carol Holdren commented on topic "Blooming Stenglottis Venus “jamboree “" by John Urey
  12. Jeanne Uzar Hudson commented on member plant Lc. Canhamiana var. coerulea 'Cobalt' by Jeanne Uzar Hudson
  13. Jeanne Uzar Hudson commented on member plant Sns. gemmata by Jeanne Uzar Hudson
  14. Stefan Neher commented on topic "Orchid roots .com site?" by Mary Lane
  15. Kevin Barry commented on member plant Bul. Tammie Sue Pernas by Tony Pernas
  16. Linda Hartman commented on member plant Ctt. Final Blue by Linda Hartman
  17. Kevin Bergeson commented on member plant Paph. rothschildianum by Kevin Bergeson
  18. Carol Holdren commented on topic "recently purchased orchid shows unstoppable roots " by David George
  19. Michael Makio commented on orchid V. Beatrice Makio
  20. Carol Holdren commented on topic "shorter stem with less vigorous blooms" by katherine mott