Horticulture Final Exam

Define Soil Morphology

The study, observation, and description of the physical form and arrangement of soil components within the soil.

Define pedogenesis

How soil forms.

Define edaphology

How soil influences living organisms.

Label the following layers. What are the components of layer B?

A: Organic

A₁: Surface

B: Subsoil

C: Parent material

D: Bedrock

• Sand, silt, and clay

What is the biggest to smallest arrangement of silt, clay, and sand?

Biggest: Sand, silt, and clay :Smallest

Why is 100% clay not ideal for agriculture? Although it has the highest CEC, explain
your answer. First, explain what CEC is, and then explain why 100% clay is not suitable.

CEC is the cation exchange capacity of soil. 100% clay is not suitable because it holds too much water.

Fill in the table

Are organic fertilizers considered rapid-release or slow-release?

Slow release

What are the three ways you can incorporate organic fertilizers made from plant waste?
a. What are cover crops?

1. Straw

2. Green Manure

3. Compost

• Plants grown to benefit the soil rather than for harvest.

What is the origin of apple trees?

Kazakhstan

Who are the main producers of apples in the United States.

1. Washington

2. New York

3. Michigan

4. Pennsylvania

5. California

6. Oregon

7. Virginia

Explain the regular cold storage vs the controlled atmosphere (CA) storage, how these two methods allow apples to be available year-round. If you want fresh apples, when should you buy them?

• Regular cold storage: Marketing season can be extended through March, stored in a refrigerated warehouse where they ripen over time.

• Controlled atmosphere (CA): Marketing season may be extended through July, stored in a gas tight refrigerator where oxygen is low and apples enter “hibernation” state.

• If you want fresh apples you should by them late August through October.

What makes more money for growers, fresh apples or processed apples?

Fresh apples

Choosing a location for an apple orchard is very important. What are the three factors you would consider before deciding to plant apples? Regarding one of these factors, explain why the air is cold at the top of a mountain but also at the bottom.

1. Rolling or sloping land for air drainage

2. Areas with deep well-drained soil

3. Location close to a body of water for irrigation.

Cold air is at the top due to low atmospheric pressure and cold air is also at the bottom because cold air is more dense.

Which kind of soils test you should do before you start your apple orchard. Explain each one

• A soil fertility test: measures the essential nutrients in the soil (Nitrogen, Phosphorus, and Potassium)

• Organic matter test: measures carbon based components in soil

• Nematode survey: testing soil cores for nematodes

What is the importance of rootstocks? What do they mainly control?

The rootstock controls the size.

What is the importance of scions?

The scion depends on how you intend to market your fruit

Explain which cultivars (scions) growers should plant on a slope vs. at the bottom of a slope

Early blooming cultivars should be placed at the top of the slope and later blooming cultivars should be placed at the bottom of the slope.

What does “self-unfruitful” mean?

They can’t pollinate themselves

What should be taken into consideration apple cultivar that produce nonviable pollen?

You would need to plant a cultivar with viable pollen somewhere near the nonviable cultivar.

What are the pros and cons of planting different cultivars within the same row vs. in two different rows?

Planting the same cultivar in a row makes harvesting easier but could cause pollination issues.

Why are bees important in apple orchards?

To maximize fruit production.

What is the best pH for elements to be available to plants?

Between 4.5 and 5.5

Plants take up nitrogen as __________ and __________. Plants take up phosphorus as __________ and __________, and at which pH levels? Why is phosphorus so difficult to make available?

Ammonium and nitrate

H₂PO₄ and HPO₄

Phosphorus is very immobile in the soil and can become locked up with other compounds.

Which elements do growers use to increase and decrease soil pH, respectively?

Limestone is used to raise pH and sulfur is used to lower the pH.

How is nitrogen related to fire blight in apple production?
 Is fire blight caused by bacteria, fungi, or a virus?
 How does fire blight spread?

• Fire blight susceptibility may increase with excess nitrogen

• Caused by bacteria

• Spreads through bacterial ooze on pollinators and wind

What is the difference between sprinklers and drip irrigation? What are the pros and cons of each?

Pros of sprinklers

• full water coverage

• good for frost protection

Cons of sprinklers

• Initial investment is high

• Annual operating costs is high

Pros of drip irrigation

• Easily adapted for chemigation

Cons of drip irrigation

• only half of the orchard floor will be wet

• not suitable for frost protection

Why do you not want to grow peaches in soils previously used for soybean or alfalfa?
Which organisms transmit the virus?

• Because it may harbor stem pitting virus

• the dagger nematode

Do you need different cultivars (scions) to produce fruit? Explain your answer.

No you do not because all commercial variety peaches are self fertile.

Into which classes are peaches divided?

1. wild types

2. commercial cultivars

3. seedlings used for rootstocks

What is the genus name of pears?

Pyrus communis

Quince is the most used rootstock for pears; unfortunately, the drawback is
that ___________. How can this be remedied?

They are susceptible to fire blight. You can remedy this by measuring the nitrogen in your soil.

Old Home × Farmingdale (OHxF): the advantages are __________, __________, and
__________, but it performs poorly on unusually fine-textured clay soils.

• Resistant to fire blight

• dwarfing ability

• earlier bearing

Define fruit

Mature ripened ovary of a flowering plant that contains seeds.

Fruits can be classified based on the climate in which they grow. Name the three climate
categories and provide three examples of fruits for each.

• Tropical (Bananas, pineapples, and mangoes)

• Subtropical (Citrus fruits, avocados, and persimmons)

• Temperate (Apples, pears, and peaches)

What are the five most economically important fruits in the world today?

1. Bananas & Plantains

2. Citrus fruits

3. Melons

4. Pome fruits

5. Grapes

Which three countries have the highest production, export, and import levels in the world?

Production

1. China

2. India

3. Brazil

Export

1. Spain

2. Netherlands

3. USA

Import

1. USA

2. China

3. Germany

What does it mean when a country is the principal producer of fruits but not the leading exporter?

The country consumes most of what it produces, the country has a large domestic market, or lacks logistics to move large volumes of product.

What is the family of citrus fruits?

Rutaceae

What are the five main citrus varieties from which most of the citrus fruits we consume are derived?

1. Kumquat

2. Micrantha

3. Citrons

4. Mandarins

5. Pomelos

What are the two main producers of most citrus fruits in the United States?

California and Florida

Citrus production is declining, and this has been attributed to citrus greening. Citrus
greening originated in southern China and is spreading worldwide, causing significant
damage to the citrus industry. (Similarly, fire blight originated in the United States and
has also spread globally.) Explain what causes citrus greening, how it spreads, and what
symptoms it produces.

Caused by a bacteria, spreads by the asian citrus psyllid. Symptoms include leaf yellowing, fruit malformation, premature fruit drop, tree death.

Do oranges have rootstock and scion? What was the role of rootstock in the past?
Currently, what traits are growers focusing on improving in rootstocks (e.g., tolerance
to what conditions)?

Yes, oranges have a rootstock and scion. The role of rootstocks in the past was pathogen resistance and tree vigor. Growers are focusing on tolerance to HLB, drought resistance, and dwarfing traits.

What is the origin of oranges?

Southeast Asia

Who are the main producers of oranges?

1. Brazil

2. China

3. European Union

4. United States

5. Egypt

6. Mexico

7. Turkey

8. South Africa

9. Morocco

How are seedless oranges produced?

Making the orange species triploid

What is the origin of lemons and limes?

Northeast India and the Indo-China region

Who are the main producers of lemons and limes?

1. Mexico

2. European Union

3. Argentina

4. Turkey

5. U.S.

6. South Africa

7. Israel

What family does the avocado belong to?

Lauraceae

What is the origin of avocados?

Mesoamerica

What are the three species of avocado? Which one is most commonly used for consumption?

1. Persea americana

2. Persea shiedeana

3. Persea indica

Persea americana

What are the three avocado races that exist today? What are avocado cultivars?

1. Mexican

2. Guatemalan

3. West Indian

• Hass and Fuerte

What are the three ways to classify vegetables? Explain each one. Which method is the most useful?

1. Annuals

2. Perennials

3. Biennials

Annuals

What are the 10 plants you were asked to memorize and what are their conditions?

1. Beet

2. Cabbage

3. Chinese Cabbage

4. Collard

5. Endive

6. Kale

7. Lettuce

8. Mustard green

9. Green onion

10. Spinach

• Cool, leaf, annuals

What are the 10 most economically important vegetables in the world?

1. Potatoes

2. Tomatoes

3. Onions

4. Carrots

5. Lettuce

6. Bell peppers

7. Broccoli

8. Cucumbers

9. Salad mix

10. Celery

Where is the origin of tomatoes?

Western South America

What is the species name of tomatoes

Lycopersicon esculentum

Which countries are the top producers of tomatoes?

1. China

2. India

3. Turkey

4. U.S.

5. Egypt

6. Italy

7. Iran

8. Spain

9. Mexico

10. Brazil

Who are the top producers of tomatoes in the U.S.

1. California

2. Florida

3. Indiana

4. Ohio

5. Michigan

6. Tennessee

7. South Carolina

8. New Jersey

9. North Carolina

10. Virginia

Plastic mulch helps with: __________.

Capturing heat, reducing weeds, conserve moisture and fertilizer.

Explain the difference between determinate and indeterminate tomatoes. Include:
a. Which type requires pruning?
b. Which is preferable for tomato sauce?
c. Which type is perennial in tropical zones?
d. What is the difference between heirloom varieties and hybrids?

a. Indeterminate

b. Determinate

c. Indeterminate

d. Heirloom are passed down from generation, hybrids are from crossing two varieties

Where did onions originate?

Central Asia

Who are the main producers of onions globally and in the U.S.

1. China

2. India

3. USA

4. Egypt

5. Iran

6. Turkey

7. Pakistan

8. Brazil

9. Russia

10. Republic of Korea

• California

• Texas

• Georgia

• Oregon

• Washington

Explain the difference between short-day, intermediate-day, and long-day varieties.
Which are grown in Pennsylvania?

Classified by the amount of daylight needed to trigger bulb formation

Long days are usually grown in PA

What are the four most commonly used greenhouse materials in the U.S.? Explain the
pros and cons of each

• Polyethylene Films (affordable, lightweight / needs replaced every few years, less durable)

• Glass (Most light transmission, longevity / expensive, fragile)

• Rigid Plastic (Good light transmission, longevity / combustible, expensive)

• Structured Polycarbonates (Good insulation, impact resistance / needs replaced every few years)

Who are the main producers of starchy crops?

• Asia

• Africa

• Europe

• America

What are the four most consumed starchy/root/tuber crops worldwide? (Note: bananas and plantains should be included and rank above the others.)

1. Bananas & plantains

2. Yuca

3. Potatoes

4. Sweet potatoes

What genetic combinations do bananas and plantains have? Which two species are involved (including chromosome information)?

AAA, AAB, ABB

Cavendish (AAA)

Plantains (AAB)

Where is the origin of bananas and plantains?

Southeast Asia

How are bananas and plantains propagated?

Using the suckers, corm pieces, or tissue culture.

What is a corm?

A short, vertical, swollen, and solid underground plant stem that stores nutrients

What is the species name for potatoes?

Solanum tuberosum

Are potatoes stem tubers or root tubers? Explain.

They are stem tubers because the stem is what becomes swollen.

Which countries produce and consume the most potatoes?

Produce

• China

• India

Consumption

• Belarus

• Ukraine

Where is the origin of potatoes?

America

How are potatoes propagated?

Planting “seed potatoes” that have at least two “eyes” making sure the eyes are facing upward.

What is the species name for sweet potatoes?

Ipomoea batatas

Are sweet potatoes stem or root tubers?

Root tubers because the roots are what swell.

What is the origin of sweet potatoes?

Central America

How are sweet potatoes propagated?

Planting a sweet potato till it grows “slips” which are then removed and planted.

What is the species name for cassava (yuca)

Manihot esculenta

Is cassava a stem or root tuber?

Root tubers

Where is the origin of sweet potatoes?

South America

How is cassava propagated?

Using stem cuttings with two or more nodes from mature plants and planting them vertically or at an angle.

How is cassava different from other starchy/root/tuber crops?

It requires specialized processing to remove cyanide.

What is the species name for yams?

Dioscorea sp.

Where is the origin of yams?

Africa, Asia, and South America.

What are the 7 steps in post harvest handling?

1. Harvesting

2. Sorting

3. Grading

4. Cleaning

5. Sorting

6. Packaging

7. Storage

What percentage of the world’s population relies on medicinal plants?

80%

Which regions or countries have the most knowledge and studies on medicinal plants?

China, India, and regions in Africa.

What are the challenges of using medicinal plants?

• Concentration

• Purification

• Overexploitation

What are four medicinal plants used in medicine?

• Poppy

• Foxglove

• Indian snakeroot

• Quinine

When did medicinal plants transition into pharmaceuticals?

The 19th century.