1 / 22

Effect of Preharvest Fungicide Applications on the Control of Postharvest Gray Mold

Effect of Preharvest Fungicide Applications on the Control of Postharvest Gray Mold. R.W. Blacharski, J.A. Bartz, D. Mitchell, S.A. Sargent and D.E. Legard. Disease. Major limiting factor to production Weekly fungicide applications

eben
Download Presentation

Effect of Preharvest Fungicide Applications on the Control of Postharvest Gray Mold

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Effect of Preharvest Fungicide Applications on the Control of Postharvest Gray Mold R.W. Blacharski, J.A. Bartz, D. Mitchell, S.A. Sargent and D.E. Legard

  2. Disease • Major limiting factor to production • Weekly fungicide applications • Receive more fungicide applications than any other vegetable crop in the state

  3. Disease • Gray Mold • Botrytis cinerea • Preharvest • Postharvest

  4. Disease Progress • Infects floral parts and remains latent during periods of wet weather • Ripe fruit in field • During shipping and storage

  5. Control • Preharvest fungicide sprays • Rapid cooling after harvest

  6. Objectives • To determine which treatment provides the best control of postharvest gray mold • To determine the importance of bloom sprays of Rovral • To determine if Thiram provides similar control as Captan

  7. Methods • Two year study 1997 to 1998 1998 to 1999 • GCREC-Dover • Strawberry produced using commercial standards

  8. Captan • Full rate (3.75 lbs/a) +/- Rovral • 2/3 rate (2.5 lbs/a) +/- Rovral • 1/2 rate (1.88 lbs/a) +/- Rovral

  9. Thiram • Rate 1 (1997-98) : 2.2 lbs/acre +/- Rovral • Rate 2 (1998-99) : 4 lbs/acre +/- Rovral

  10. Rovral • Bloom period only (2 lbs/a) • Applied weekly throughout the season

  11. Results

  12. 1997 to 1998 • Unique weather year (El Niño) • Wetter than average temp °C rainfall (cm) Dec 16.38 4.39 Jan 17.45 1.28 Feb 16.28 3.05 March 17.28 2.82 • Conditions favor Gray Mold

  13. Bloom Sprays: 1997 to 1998 at Day 7

  14. Thiram and Rovral Sprays for 1997 to 1998

  15. 1998 to 1999 • Another unique weather year (La Nina) • Drier than 1997-98 • temp (°C) rain (cm) • Dec 18.64 0.73 • Jan 17.09 0.09 • Feb 17.65 0.17 • March 18.12 0.25 • Conditions not favorable for Gray Mold

  16. Captan Sprays: 1998 to 1999

  17. Best Sprays

  18. Conclusions 1997 to 1998 • Captan +Rovral provides the best control of postharvest gray mold • Thiram at 2.2 lbs/a rate does not provide sufficient postharvest control • Bloom sprays improved postharvest control

  19. Conclusions 1998 to 1999 • Captan and Thiram at full rate provided the best postharvest control • Bloom sprays of Rovral did not improve postharvest control

  20. Conclusions • Control of postharvest disease begins with control in the field • Apply fungicides at full label rate • Apply additional fungicides during peak bloom periods and wet weather

More Related