Temperature & Respiration

1. Temperature & Respiration A/H 100G J.G. Mexal

2. HORT Humor

3. Take Home Quiz(due Monday 2/27/06) What will be the impact of global climate change to: • Natural ecosystems • Agriculture in the southwest • Urban landscapes, esp. golf courses • Discuss these in terms of near-term consequences (10-20 years) and long-term (> 30 years)

4. What is ‘Respiration’? • The conversion of stored energy (sugar) into metabolic energy (ATP) • Occurs in mitochondria • Requires sugar • Generates ATP + CO2

5. The parts of a cell

6. Photosynthesis Occurs only in green cells Occurs in chloroplasts Occurs only in light Requires light, CO2, H2O Produces O2 and sugar ATP produced by photophosphorylation (used to make sugar) Results in biomass gain Respiration Occurs in all living cells Occurs in mitochondria Occurs 24/7 Requires O2 and sugar Produces CO2, H2O ATP produced by oxidative phosphorylation (‘burning’ sugar to make other products) Results in biomass loss Ps & Rs Comparison

7. Temperature Effects on Ps & Rs Relative Response (%) Temperature (C)

8. Temperature Effects on Ps & Rs Relative Response (%) Net Ps Temperature (C)

9. Terms • Cool season crops • Warm season crops • Cold-hardiness • Dormancy • Endo- • Eco- • Para- • Chilling requirement • Growing degree day GDD) • Stratification • Scarification • Vernalization • Heat-zone map • Hardiness zone map

10. Cool season crops • Prefers air temperatures: 20-25oC • Soil temperatures: 15-22oC • Crops: • Lettuce − Kentucky bluegrass • Cole crops − Christmas trees • Carrots − Wheat • Spinach − Barley

11. Warm season crops • Prefers air temperatures: 25-35oC • Soil temperatures: 20-28oC • Crops: • Tomato − Bermuda grass • Sorghum − Corn • Soybean − Chile • Afghan pine − Pineapple

12. Cold-hardiness • Definition: ability to survive temperatures below 0oC. • Function of tissue, season, growth stage • Shoots <-40oC − Roots ~ -10oC • N.B. Chilling injury is injury to tropical fruits caused by temperatures between 0-5oC

13. Spring Buds = -3o Cambium = -4o Roots = -4o Seedling = -3o Germinant = -2o Winter Buds = -25o Cambium = -50o Roots = -10o Seedling = -30o Basic Plant BiologyFactors Affecting Acclimation-Size

14. Tolerant Pinus pinea Shoots = -40oC Roots = -10oC Intolerant Eucalyptus camaldulensis Shoots = -10oC Roots = -3oC Basic Plant BiologyFactors Affecting Acclimation- Genetics

15. Basic PlantBiology Mesquite/ April 2003

16. Dormancy & Cold-hardinessCold - Hardiness of Apple Blooms LT50 (oC) Approximate Calendar Date

17. 1000 2000 3000 4000 5000 6000 7000 0 Tight Cluster -2 12mm Green -4 LT50 (oC) Full Bloom -6 Full Pink Green Tip -8 -10 Dormant -12 Photos by: Silver Tip -14 Growing Degree Hours (oC) Basic Plant BiologyCold - Hardiness of Apple Blooms

18. Basic PlantBiologyHow a Tree Grows • Dormancy-lack of visible growth • Ecodormancy- environmental stress induced- • Growth resumes when stress removed • Endodormancy- requires chilling • Growth resumes after chilling requirement met (h between 0-10oC), and sufficient GDD accumulate • Paradormancy- regulated by other buds • Remove the controlling bud and ‘whalaa’

19. Dormancy & Cold-hardinessDormancy of Apple Blooms Growth Units Chilling Units 20 1.0 0.5 15 10 0 -0.5 5 -1.0 0 0 5 10 15 20 25 30 Temperature (oC)

20. Growing degree days (GDD) • Growing degree days (GDD) is a measure of temperature requirements for plants and can be used to estimate growth and development. • The basic concept of growing degree days is that plant development will occur when temperatures exceed a base temperature.

21. Growing degree days (GDD) • Corn: the maximum temperature plus the minimum temperature in a day divided by 2 minus 50. • Fifty is selected as the constant because corn grows little at 50°F or below. • 86°F is the maximum temperature

22. Growing degree days (GDD) • Example: If a low temperature was 60°F and the high was 90°F, the GDD would be 60 + 86 = 146 divided by 2 = 73 – 50 = 23 GDD.

23. National Climate Zone MapE Gregory McPherson <egmcpherson@ucdavis.edu>

25. Plant Hardiness Zone Map

26. USDA Hardiness Zone Map

27. Plant Heat Zone Map

28. Days/yr> 86F 7-14 14-30 30-45 45-60 60-90 90-120 120-150 Zone 9 Nursery IndustryHeat-Zone Map/ AmHortSoc

29. Days/yr> 86F 7-14 14-30 30-45 45-60 60-90 90-120 120-150 Zone 9 New Mexico Maps

30. Seed Dormancy • Stratification • Overcoming physiological dormancy by exposure to cold temperatures (wet or dry) • Scarification • Overcoming physical dormancy by mechanical abrasion • Mechanical • Chemical (acid) • Thermal (hot water) • Percussion (certain species)

31. Vernalization • Chilling to induce transition from vegetative growth to reproductive growth • Examples: • Winter wheat • Onions (biennial) • Bulbs (daffodil, tulip)

32. Things to know: • Cool season crops (T & e.g.) • Warm season crops (T & e.g.) • Cold-hardiness (definition, LT50) • Dormancy • Endo- • Eco- • Para- • Chilling requirement • Growing degree day GDD)

33. Things to know: • Stratification (e.g.) • Scarification (e.g.) • Vernalization (e.g.) • Heat-zone map (what it means) • Hardiness zone map (what it means)

34. Temperature (oF) Military Time (hr) Infrared Surface Temperature Influenced by Surface Cover