Heat Damage in Blueberries Practices to reduce crop loss

Size: px

Start display at page:

Download "Heat Damage in Blueberries Practices to reduce crop loss"

Georgiana Griffin
5 years ago
Views:

1 Heat Damage in Blueberries Practices to reduce crop loss David Bryla USDA-ARS, Corvallis, OR Co-PI: Julie Tarara, USDA-ARS, Prosser, WA PhD Student: Joy Yang, OSU

2 Fruit cooling Sprinkler irrigation reduces crop temperature by three different energy transfer processes <30 gpm/acre misted Current cranberry guidelines: Run sprinklers for at least 1 h and continue irrigating until temperature falls below 85 o F >40 gpm/acre continuous 2. Convective cooling 30 gpm/acre pulsed 1. Hydro-cooling (conductance) Requires a separate system for irrigation Soil evaporation 3. Evaporative cooling (latent heat) Effective at cooling but inefficient in water use Requires 25 40% extra water (irrigate at night)

3 Hydro- & Evaporative Cooling Fruit cooling by sprinklers

4 Convective Cooling Fruit cooling by misters

5 Fruit cooling in wine grapes Over-vine cooling system Under-vine cooling system Greenspan (2009)

6 Cooling questions: At what temperature(s) does heatrelated fruit damage occur in blueberry? What causes the damage sunlight, temperature, or both? Do sprinklers & misters really reduce the damage? How long and often should sprinklers & misters be run?

7 Cooling questions (cont.): What cultivars benefit the most from cooling? Does cooling cause problems with fruit splitting? Does cooling increase plant disease runoff/leaching flooding? Does cooling alter harvest date?

Objectives: Joy Yang PhD Student Identify the critical temperatures at which overhead cooling is needed Develop a model to predict berry temperature and determine the amount of water (rate, time,

8 Objectives: Joy Yang PhD Student Identify the critical temperatures at which overhead cooling is needed Develop a model to predict berry temperature and determine the amount of water (rate, time, frequency) required to cool the fruit Determine the effects of fruit cooling on fruit quality and harvest date Identify cultivars that benefit the most from fruit cooling Identify potential problems associated with cooling (disease, flooding, etc.) Investigate strategies for reducing heat damage without overhead cooling

9 Sun/heat damage The sunburned spot shrivel Excessive vegetative growth => more sun exposure

10 Sun/heat damage Damage during early stages of fruit development may result in poor coloration at ripening

11 Sun-exposed vs. shaded fruit Air temperature: 31.5 o C (89 o F) 110 o F 91 o F Sun-exposed fruit Shaded fruit Bluecrop Corvallis, OR 3:00 PM, July 11, 2013

12 Sun-exposed vs. shaded fruit Corvallis, OR Aug. 2-5, 2013 Fruit (sun-exposed) Temperature ( o C) Air Fruit (shaded) :00 12:00 0:00 12:00 0:00 12:00 0:00 12:00 0:00 Aug. 2 Aug. 3 Aug. 4 Aug. 5

13 Diurnal changes in fruit temperature Corvallis, OR July 9, Fruit (skin) Temperature ( o C) Air Fruit (pulp) :00 10:00 11:00 12:00 13:00 14:00 15:00 16:00 17:00 18:00 Time

East- vs. west-facing fruit 45 40 Corvallis, OR Aug.

14 East- vs. west-facing fruit Corvallis, OR Aug. 2-5, 2013 Eastfacing fruit Westfacing fruit 35 Temperature ( o C) Air :00 12:00 0:00 12:00 0:00 12:00 0:00 12:00 0:00 Aug. 2 Aug. 3 Aug. 4 Aug. 5

15 Sprinklers Drip Sprinklers Drip Elliott OSU Lewis-Brown Farm Corvallis, OR

16 Overhead cooling Fruit (drip) Corvallis, OR Aug. 5, 2013 Temperature ( o C) Evaporative cooling Air Fruit (sprinklers) Hydro-cooling 15 Sprinklers run (15 min) 10 8:00 AM 12:00 PM 4:00 PM 8:00 PM 12:00 AM Time

17 Agricultural weather stations

18 Number of days with high temperatures above the threshold for heat damage 60 days > 30 o C / 86 o F 14 days > 35 o C / 95 o F 1 day > 40 o C / 104 o F Location 30 o C/ 86 o F 35 o C/ 95 o F 40 o C/ 104 o F 30 o C/ 86 o F 35 o C/ 95 o F 40 o C/ 104 o F 30 o C/ 86 o F 35 o C/ 95 o F 40 o C/ 104 o F 30 o C/ 86 o F 35 o C/ 95 o F 40 o C/ 104 o F Hillsboro, OR Salem, OR Corvallis, OR Springfield, OR Hermiston, OR Lynden, WA Carnation, WA Mt Vernon, WA Vancouver, WA Prosser, WA NA NA NA

19 Number of times that average max. daily temperature increased by >10 o F or 15 o F from one week to the next Location ΔT > 10 o F ΔT > 15 o F ΔT > 10 o F ΔT > 15 o F ΔT > 10 o F ΔT > 15 o F ΔT > 10 o F ΔT > 15 o F Hillsboro, OR Salem, OR Corvallis, OR Springfield, OR Hermiston, OR Lynden, WA Carnation, WA Mt Vernon, WA Vancouver, WA Prosser, WA NA NA

20 Number of times that average max. daily temperature increased by >10 o F or 15 o F from one day to the next Location ΔT > 10 o F ΔT > 15 o F ΔT > 10 o F ΔT > 15 o F ΔT > 10 o F ΔT > 15 o F ΔT > 10 o F ΔT > 15 o F Hillsboro, OR Salem, OR Corvallis, OR Springfield, OR Hermiston, OR Lynden, WA Carnation, WA Mt Vernon, WA Vancouver, WA Prosser, WA NA NA *Only includes days where high temperatures were > 85 o F

21 Early findings: Fruit exposed to sunlight have much higher temperatures than shaded fruit Internal fruit temperature similar to skin temperature Damage can occur in both green and ripe fruit Sprinklers are very effective at reducing fruit temperature Critical threshold for heat damage is fairly low and dependent on temperatures prior to hot weather

22 Graduate student Joy Yang Co-investigator Julie Tarara Acknowledgements Technical support Benito Mendoza, Bill Sabo & Crew OSU undergrads Funding Washington Blueberry Commission Oregon Blueberry Commission

Frost Management. Recommended Practices

Frost Management. Recommended Practices Frost Management Cranberries, like many other temperate crops, are sensitive to below-freezing temperatures during the active growing season. This sensitivity is an important factor in cranberry management.