Light
What are the three characteristics of light that affect plant growth?
Quantity, quality, and duration
What is the term for the difference between daytime and nighttime temperatures?
Thermoperiod
What percentage of a plant’s weight is made up of water?
About 90%
Which nutrient promotes leafy growth in plants?
Nitrogen
What is the main cause of most plant problems?
Environmental stress
Which type of light promotes vegetative (leaf) growth?
Blue light
What happens to plant processes such as photosynthesis and respiration as temperature increases (up to an optimal point)?
They increase
What is transpiration?
The evaporation of water from plant leaves
What deficiency symptom is caused by a lack of potassium?
Leaf scorching or browning on the edges
Which environmental stressor is most likely to cause wilting?
Water deficiency
What is the term for the amount of time a plant is exposed to light and darkness?
Photoperiod
What temperature range is optimal for germination of warm-season crops like tomatoes?
65–75°F
What happens to transpiration on a hot, dry, and windy day?
It increases
Which nutrient is essential for root development and flower production?
Phosphorus
What happens to plants when they "bolt"?
They flower prematurely due to high temperatures.
Name one way gardeners can manipulate light conditions for plant growth.
Use reflective materials, supplemental lights, or shading
Why is a proper thermoperiod important for plant growth?
It optimizes photosynthesis during the day and reduces respiration at night.
What controls the opening and closing of stomata?
Water pressure within the plant
Name one macronutrient and one micronutrient plants need.
Macronutrient: Nitrogen, Phosphorus, Potassium, etc.; Micronutrient: Iron, Zinc, Copper, etc.)
How can growers reduce the risk of winter injury in plants?
Ensure plants are well-watered before winter and protect against rapid temperature drops
Which photoperiodic category do tomatoes belong to?
Day-neutral plant
What type of injury can occur when a hardy plant breaks dormancy due to unseasonably warm weather and is then exposed to frost?
Frost damage or tissue damage
How does high humidity affect a plant’s transpiration rate?
It slows down transpiration
What is blossom-end rot, and which nutrient deficiency causes it?
It is a condition in fruits where the bottom rots, caused by calcium deficiency.
Name one plant adaptation that helps it survive environmental stress.
Deep roots for water access or reduced leaf size to conserve water