Apple Disease Update: Week of June 8, 2025
go.ncsu.edu/readext?1076985
en Español / em Português
El inglés es el idioma de control de esta página. En la medida en que haya algún conflicto entre la traducción al inglés y la traducción, el inglés prevalece.
Al hacer clic en el enlace de traducción se activa un servicio de traducción gratuito para convertir la página al español. Al igual que con cualquier traducción por Internet, la conversión no es sensible al contexto y puede que no traduzca el texto en su significado original. NC State Extension no garantiza la exactitud del texto traducido. Por favor, tenga en cuenta que algunas aplicaciones y/o servicios pueden no funcionar como se espera cuando se traducen.
Português
Inglês é o idioma de controle desta página. Na medida que haja algum conflito entre o texto original em Inglês e a tradução, o Inglês prevalece.
Ao clicar no link de tradução, um serviço gratuito de tradução será ativado para converter a página para o Português. Como em qualquer tradução pela internet, a conversão não é sensivel ao contexto e pode não ocorrer a tradução para o significado orginal. O serviço de Extensão da Carolina do Norte (NC State Extension) não garante a exatidão do texto traduzido. Por favor, observe que algumas funções ou serviços podem não funcionar como esperado após a tradução.
English
English is the controlling language of this page. To the extent there is any conflict between the English text and the translation, English controls.
Clicking on the translation link activates a free translation service to convert the page to Spanish. As with any Internet translation, the conversion is not context-sensitive and may not translate the text to its original meaning. NC State Extension does not guarantee the accuracy of the translated text. Please note that some applications and/or services may not function as expected when translated.
Collapse ▲The forecast is calling for rain this week which means extended leaf wetting events and a battle to keep fungicide residues on the tree. We completed our first rating in our Glomerella leaf spot/bitter rot trials last week to give you early insight into what’s working so far. In addition to Captan 80WDG (2.5 lb/A) and Merivon, Omega has performing excellent in our ‘Gala’ block with high inoculum pressure. On Thursday June 5th we observed 23.7% incidence of GLS in the untreated program (no fungicides applied this year); whereas in the program where Omega was applied weekly since petal fall, we observed 6.8% incidence of GLS. Since we’ve tested Aprovia for many years and it’s been effective, we are not screening it this year. Given rainy week ahead combined with the early results from our GLS fungicide trial, I’d consider the following:
- If you applied Aprovia, a strobilurin (FRAC 11), or Omega last week with captan, consider applying 2.5 lb/A Captan 80WDG. You may want to add Topsin (thiophanate-methyl) for some added activity against GLS, frogeye leaf spot, Bot rots, and flyspeck/sooty blotch.
- If you DID NOT include a strobilurin (FRAC 11), Aprovia, or Omega last week, I’d suggest adding one of the aforementioned options in tank mixture with Captan 80 WDG (2.5 lb/A). Remember! Only 4 applications max of any FRAC 11, or any combinations of FRAC 11 fungicides. Also, Aprovia is limited to 3 applications of the high rate (7 floz/A) per season.
In addition to GLS and bitter rot, this is the earliest I’ve ever seen Marssonina leaf blotch on apple in NC. While rating the GLS trial last week, we observed quite a bit of MLB on ‘Gala’. For those who need a refresher here are some old photos from our ‘Rome Beauty’ block at MHCREC:
As of last week, the majority of symptoms I’ve observed resemble the bottom two photos. Unless you’ve had MLB issues in the past, applications of Captan 80WDG should do the trick. Neither Aprovia nor the single-A.I. strobilurins have performed well in our field trials. In addition to Captan 80WDG, which has good but not excellent efficacy, some of the better products for MLB control include:
- Cevya 5 floz/A (has label for MLB control)
- Tesaris (4.5 floz/A)- this is the active ingredient in Merivon so be careful about exceeding annual application limits for fluxapyroxad
- Inspire Super (12 floz/A)
- Cevya (5 floz/A) rotated with Howler Evo (2.5 lb/A)
- *All fungicide applications should be mixed with Captan 80WDG (2.5 lb/A)*. Other captan formulations can be considered.
Since we are reaching the robotic stage for apple disease management (Captan 80WDG + ………) let’s try something new for the upcoming weeks! In the feedback section, post any apple disease management questions you may have and I’ll address them in upcoming posts! Comments are anonymous!