Horticulture temp

Temperature

Key limiting factor for plant distribution.

Controlled environments

Greenhouses and high tunnels for plant growth.

Favorable tissue temperatures

Optimal growth occurs between 10-30 °C.

Growth cessation temperature

Growth slows at 0 °C (32 °F).

Protein denaturation temperature

Proteins denature at 50 °C (122 °F).

Day and night temperatures

Influence growth, development, and flowering.

Cold Hardiness Zones

13 zones based on minimum temperatures.

AHS Heat Zones

12 zones based on days above 86 °F.

Microclimates

Localized climate differing from surrounding area.

Air drainage

Cool air settles in low areas.

Frost pockets

Low-lying areas prone to frost.

Altitude effect

Temperature drops 9 °F per 1000 ft.

Water's heat capacity

Large bodies moderate surrounding temperatures.

Warm season plants

More prevalent in hotter locations.

Cool season plants

Thrive in cooler temperatures, e.g., C3 plants.

Respiration in plants

Chemical reactions increase with temperature.

ATP in plants

Energy carrier for growth and maintenance.

Optimum growth temperatures

Ideal temperatures vary by plant species.

Increasing temperatures

Speeds up plant growth in controlled settings.

Decreasing temperatures

Slows down plant growth in controlled settings.

Days to Maturity

Listed on seed packets, often misleading.

Growing Degree Days

Predicts crop timing based on temperature.

Minimum threshold temperature

5 °C for cool season, 10 °C for warm.

Maximum threshold temperature

Generally assumed at 50 °C (122 °F).

Temperature impact on maturity

Influences timing of harvest and pest control.

Greenhouses

Structures for growing plants in controlled climates.

High tunnels

Season extension structures for crops.

Favorable tissue temperatures

Optimal growth occurs between 10 to 30 °C.

Protein denaturation temperature

Proteins are destroyed at 50 °C (122 °F).

Heat Tolerance

Zones based on days above 86 °F annually.

Microclimates

Localized climate differing from surrounding areas.

Altitude effect on temperature

Temperature drops 9 °F per 1000 ft increase.

Warm season plants

Prefer warmer temperatures, e.g., C4 plants.

Respiration in plants

Chemical reactions increase with temperature rise.

Optimum growth

Achieved with ideal temperature conditions.

Minimum threshold temperature

Lowest temperature for plant growth.

Maximum threshold temperature

Highest temperature for plant growth.

Temperature's role in chemical reactions

Directly affects plant metabolic rates.

Plant propagation

Temperature influences seed germination and growth.

Plant dormancy

Temperature affects periods of inactivity.

Growing Degree Days

Heat accumulation used to predict plant growth.

Minimum threshold temperature

Lowest temperature for plant growth, 10 °C.

Maximum threshold temperature

Highest temperature for plant growth, 30 °C.

Threshold temperature

Critical temperatures for plant development.

Temperature accumulation

Sum of daily temperatures above minimum threshold.

Heat units

Measurement of heat accumulation for growth.

Growing Degree Day formula

[(Max temp + Min temp) / 2] - Base temp.

Base temperature

Temperature below which growth does not occur.

Degree Day calculation

Method to quantify heat for plant growth.

Temperature exceeding threshold

Indicates potential stress on plant growth.

Temperature below threshold

Indicates insufficient heat for plant growth.

Cumulative Degree Days

Total Growing Degree Days calculated over time.

Agricultural forecasting

Predicting crop development based on temperature data.

Maturity prediction

Estimating time to harvest based on heat units.

Crop development stages

Phases of growth influenced by temperature.

Environmental impact

Effect of temperature on crop yield and quality.

Predicting Maturity

Using temperature data to estimate crop readiness.

Extension service

Agency monitoring and publishing GDD data.

Water Use Management

Evaporation helps control plant tissue temperature.

Evaporation effects

Increased temperatures lead to increased water use.

Stomates

Plant openings that regulate water loss.

Fruits cooling

Fruits have fewer stomates, less cooling.

Sunburn in fruits

Fruits can scald even when well-watered.

Freeze damage

Ice crystals puncture cell membranes, causing death.

Acclimated plants

Plants adapted to withstand freezing temperatures.

Radiation frost

Short-term frost from radiated heat loss.

Protecting against radiation frost

Methods include sprinklers and wind machines.

Advective freeze

Long-duration cold from moving air masses.

Winter survival strategies

Focus on avoiding ice crystal formation.

Snow cover

Natural insulation against cold temperatures.

Cryopreservation

Preservation of cells at extremely low temperatures.

Freezing

Rapid freezing prevents ice crystal formation.

Temperature Stress

Occurs outside optimum temperature range.

Cold Acclimation

Plants prepare for cold through environmental factors.

Winter Hardiness

Plants survive winter using freeze tolerance or avoidance.

Freeze Tolerance

Ice forms between cells; cells dehydrate.

Freeze Avoidance

Supercooling prevents ice formation in cells.

Supercooling

Cooling below freezing without ice formation.

Nucleation

Process initiating ice crystal formation.

Winter Injury

Damage from temperature fluctuations during winter.

Sunscald Injury

Cells freeze after being warmed by the sun.

Frost Cracking

Longitudinal splits in trunks from freeze-thaw cycles.

Cold Hardiness Zones

Regions indicating plant survival in cold climates.

Provenance

Origin of plants affects their hardiness.

Heat Stress

Damage from excessive heat exposure.

Sunburn of Fruits

Fruit damage from intense sunlight.

Heat Tolerance

Ability to withstand high temperatures.

Heat Avoidance

Adaptations to minimize heat exposure.

Thick Bark

Provides protection against heat injury.

Temperature Fluctuations

Rapid temperature changes cause significant plant stress.

Chilling Injury

Damage without ice formation, occurs at 15°C.

Symptoms of Chilling Injury

Lesions, discoloration, and defoliation in plants.

Temperature and Pollination

Extreme temperatures hinder successful pollination.

Respiration in Plants

Continuous process vital for plant life.

Respiration Rate

Increases with higher temperatures in plants.

Photosynthesis vs Respiration

Balance affects plant growth and decline.

Sugar Storage

Short-term energy storage in plants.

Starch Storage

Long-term energy storage in plants.

Asparagus

Sweeter when harvested early in spring.

Brussels Sprouts

Best planted in summer for fall sweetness.