Horticulture 201 TAMU Exam 2 Review - Modules 5 to 9

These flashcards cover key concepts from the lecture on plant hormones, their effects, and other physiological processes relevant to horticulture, focusing on preparation for the upcoming exam.

Gibberellins are primarily involved in the abscission of leaves and fruits.

True or False?

False.
(Gibberellins are primarily involved in the abscission of leaves and fruits)

Gibberellins are used to promote uniform germination in seeds.

True or False?

True.
(Gibberellins are used to promote uniform germination in seeds.)

Cytokinins are responsible for promoting cell elongation in stems.

True or False?

False.
(Cytokinins are responsible for promoting cell elongation in stems)

Abscisic acid regulates stomatal closure during water stress conditions.

True or False?

True.
(Abscisic acid regulates stomatal closure during water stress conditions. )

Ethylene is a gaseous hormone that facilitates fruit ripening.

True or False?

True.
(Ethylene is a gaseous hormone that facilitates fruit ripening.)

Ethylene is involved in the process of postharvest handling of climacteric fruits.

True or False?

True.
(Ethylene is involved in the process of postharvest handling of climacteric fruits.)

2,4-D is a synthetic herbicide that kills broadleaf weeds by mimicking the plant growth hormone auxin.

True or False?

True.

(2,4-D is a synthetic herbicide that kills broadleaf weeds by mimicking the plant growth hormone auxin.)

Cytokinins are used in horticulture to enhance fruit set and size in tomatoes.

True or False?

True
(Cytokinins are used in horticulture to enhance fruit set and size in tomatoes. )

The process of dormancy involves a plant's physiological response to warm temperatures.

True or False?

False.
(The process of dormancy involves a plant's physiological response to warm temperatures. )

The length of the chilling period does not influence the timing of flowering in vernalization-dependent crops.

True or False?

False.
(The length of the chilling period does not influence the timing of flowering in vernalization-dependent crops. )

Plants that are exposed to inadequate chilling hours might not experience full bud break.

True or False?

True.
(Plants that are exposed to inadequate chilling hours might not experience full bud break. )

A damage caused by low, non-freezing temperatures (32-45^{\circ}\text{F}) is called chilling injury.

True or False?

True.
(A damage caused by low, non-freezing temperatures (32-45^{\circ}\text{F}) is called chilling injury. )

Frequent and shallow watering during heatwaves is a common strategy to mitigate heat stress.

True or False?

True.
(Frequent and shallow watering during heatwaves is a common strategy to mitigate heat stress. )

Insufficient chilling hours can lead to delayed flowering and poor fruit set.

True or False?

True.
(Insufficient chilling hours can lead to delayed flowering and poor fruit set. )

Irrigation provides latent heat during freezing as water transitions to ice.

True or False?

True.
(Irrigation provides latent heat during freezing as water transitions to ice. )

Radiation freeze occurs on clear, calm nights when the ground loses heat rapidly, cooling the surface below freezing.

True or False?

True.
(Radiation freeze occurs on clear, calm nights when the ground loses heat rapidly, cooling the surface below freezing. )

Dormancy is a state of inactivity that protects plants from cold damage.

True or False?

True.
(Dormancy is a state of inactivity that protects plants from cold damage. )

Smudge pots were an old way to warm up the orchard/grove by burning oil.

True or False?

True.
(Smudge pots were an old way to warm up the orchard/grove by burning oil. )

Shading nets can help prevent excessive light stress on plants.

True or False?

True.
(Shading nets can help prevent excessive light stress on plants.)

Changes in leaf chlorophyll concentration represent a light acclimatization strategy.

True or False?

True.
(Changes in leaf chlorophyll concentration represent a light acclimatization strategy. )

Phytochromes are photoreceptor proteins that detect red and far-red light.

True or False?

True.
(Phytochromes are photoreceptor proteins that detect red and far-red light. )

Short-day plants flower when the nights are longer than a critical length.

True or False?

True.
(Short-day plants flower when the nights are longer than a critical length. )

Far-red light inhibits stem elongation and is unnecessary for most plants.

True or False?

False.
(Far-red light inhibits stem elongation and is unnecessary for most plants. )

Light acclimatization is the process by which plants adapt to changes in light intensity and quality.

True or False?

True.
(Light acclimatization is the process by which plants adapt to changes in light intensity and quality. )

Plants under low light conditions will often exhibit shorter stems and smaller leaves. True or False?

False.

Supplemental lighting is commonly used in greenhouses to compensate for low light during winter. True or False?

True.

Light quantity influences flowering, fruiting, and nutrient uptake. True or False?

True.

Poinsettias flower in the winter when the days are short and the nights are long. True or False?

True.

Tomato production benefits from high VPD conditions during the summer. True or False?

False.

High relative humidity (RH) increases plant transpiration rates. True or False?

False.

Precipitation is the only factor that affects soil water content. True or False?

False.

Loam is the ideal soil type for horticulture due to its balanced properties. True or False?

True.

Either water-logging and drought stress can lead to poor yield. True or False?

True.

Precipitation includes only rain and snow. True or False?

False.

The wilting point is the minimum soil moisture required for a plant to prevent wilting. True or False?

True.

Waterlogging can lead to oxygen deficiency in roots and increase disease risk. True or False?

True.

Saturation occurs when all the soil pores are filled with air. True or False?

False.

Any form of water, liquid or solid, falling from the atmosphere to the ground is called precipitation. True or False?

True.

Water potential is the potential energy of water in a system. True or False?

True.

Gravitational potential is the water potential due to the pull of gravity on water. True or False?

True.

ET is critical for determining when and how much to irrigate. True or False?

True.

Furrow irrigation is a type of surface irrigation. True or False?

True.

Surface irrigation efficiency can reach up to 95%. True or False?

False.

Water potential is the measure of the potential energy of water in a system, determining the direction in which water will move. True or False?

True.

Cavitation refers to the formation of air bubbles in xylem vessels, disrupting water flow. True or False?

True.

Cavitation only occurs in the xylem during extreme drought conditions. True or False?

True.

All irrigation systems are equally effective for every crop and soil type True or False?

False.

If the irrigation system efficiency is 80% and the tomato crop requires 8,146 gallons per day, how much water must be applied to meet the requirement?

10,182.5 \text{ gallons/day}.

Plant hormones are also known as phytohormones. True or False?

True.

Major Plant Hormones are:

-Auxins

-Gibberellins

-Cytokinins

-Abscisic Acid

-Ethylene.

True or False?

True.

Plant hormones are chemical messengers that regulate plant growth, development, and responses to stimuli. True or False?

True.

Abscisic acid improves fruit quality in grapes by regulating sugar accumulation. True or False?

True.

Temperature is a critical environmental factor affecting plant growth and development. True or False?

True.

Cold stress causes membrane damage, reduced photosynthesis, and yield loss. True or False?

True.

Chilling hours accumulate when the temperature is consistently below freezing. True or False?

False.

Fruit trees exposed to insufficient chilling hours may produce more fruit. True or False?

False.

Insufficient chilling hours can lead to delayed flowering and poor fruit set. True or False?

True.

A damage caused by low, non-freezing temperatures (32–45°F) is called chilling injury. True or False?

True.

Heat stress reduces pollen viability and fruit set. True or False?

True.

Plants requiring chilling hours will flower later if they experience too many chilling hours. True or False?

False.

Low-chill cultivars are often bred for areas with warmer climates. True or False?

True.

It has been estimated that because of stress resulting from climatic and soil conditions (abiotic factors) that are suboptimal, the yield of field-grown crops in the United States is only 22% of the genetic potential yield. True or False?

True.

Lettuce farming in vertical systems relies on manipulating the light spectrum. True or False?

True.

Photoperiod manipulation is commonly used to control flowering in horticultural crops. True or False?

True.

Chrysanthemums flower in response to shorter nights. True or False?

False.

Light quantity is measured in terms of PAR and expressed as PPFD or DLI. True or False?

True.

Seasonality does not influence the quality of light plants receive. True or False?

False.

Photoperiodism refers to a plant's ability to respond to changes in temperature. True or False?

False.

A high VPD indicates reduced transpiration and less water stress on plants. True or False?

False.

Clay soils have a high water holding capacity but drain slowly. True or False?

True.

Field capacity refers to the amount of water remaining in the soil after it has drained of excess water. True or False?

True.

Low RH can lead to increased water loss from plants. True or False?

True.

VPD represents the “pressure” that air puts on the plant to transpire and move air from the roots through the plant and out the stomata in their leaves. True or False?

True.

RH is the percentage of water vapor relative to the air’

True.

Water moves through plants via cohesion and adhesion in xylem vessels. True or False?

True.

Advances in irrigation technology, such as AI, help predict water needs more accurately. True or False?

True.

Sprinkler irrigation can be affected by wind, causing uneven distribution. True or False?

True.

In dry environments, plants close their stomata to conserve water. True or False?

True.

Osmosis is the movement of water from an area of high solute concentration to low solute concentration. True or False?

True.

Stomata are involved in both gas exchange and water loss from the plant. True or False?

True.

Soil water potential becomes less negative as water content decreases in soil. True or False?

False.

Sap flow is constant in all plants, regardless of environmental conditions. True or False?

False.

During the peak water use period, the ET0 is 0.3 inches/day, and the Kc for tomatoes is 1.2. Calculate the daily ET.

0.36 \text{ inches/day}.