1: What region is dragon fruit (pitaya) indigenous to?
A: Southern Mexico, Guatemala, Costa Rica, and El Salvador
B: Southern United States and Mexico
C: Central Asia and India
D: North Africa and the Middle East
Correct Answer: A
Explanation: Dragon fruit is native to the region of southern Mexico and along the Pacific coasts of Guatemala, Costa Rica, and El Salvador.
2: What family do dragon fruit plants belong to?
A: Rosaceae
B: Solanaceae
C: Cactaceae
D: Rutaceae
Correct Answer: C
Explanation: Dragon fruit plants belong to the family Cactaceae.
3: Which country is the lead exporter of dragon fruit?
A: Thailand
B: Vietnam
C: Mexico
D: Brazil
Correct Answer: B
Explanation: Vietnam is the lead exporter of dragon fruit and often the fruit is designated as “Vietnamese dragon fruit.”
4: The most commonly seen dragon fruit with pink skin and white flesh belongs to which species?
A: Selenicereus costaricensis
B: Selenicereus megalanthus
C: Selenicereus undatus
D: Stenocereus griseus
Correct Answer: C
Explanation: Selenicereus undatus, also known as Hylocereus undatus, has pink-skinned fruit with white flesh and is the most commonly seen dragon fruit.
5: Which country’s indigenous people use the sour pitaya as an important food source?
A: Brazil
B: Mexico
C: Australia
D: India
Correct Answer: B
Explanation: The Seri people of northwestern Mexico harvest the sour pitaya (S. gummosus) as an important food source.
6: What is another common name for dragon fruit that relates to its appearance?
A: Kiwi
B: Cactus Fruit
C: Strawberry Pear
D: Spiky Melon
Correct Answer: C
Explanation: Dragon fruit is also commonly known as “strawberry pear” due to its appearance.
7: How many metric tons of dragon fruit can a hectare yield when in full commercial production?
A: 10-20 metric tons
B: 20-30 metric tons
C: 5-10 metric tons
D: 30-40 metric tons
Correct Answer: B
Explanation: A hectare of dragon fruit in full commercial production can yield 20 to 30 metric tons.
8: What kind of pollinators do dragon fruit flowers rely on?
A: Birds and bees
B: Butterflies
C: Nocturnal pollinators like bats or moths
D: Wind
Correct Answer: C
Explanation: Dragon fruit flowers rely on nocturnal pollinators like bats or moths for fertilization.
9: What are the small, black seeds found inside dragon fruit comparable to?
A: Kiwi seeds
B: Apple seeds
C: Watermelon seeds
D: Pumpkin seeds
Correct Answer: A
Explanation: The texture of dragon fruit seeds is likened to that of kiwifruit.
10: What key requirement is needed to grow dragon fruit plants successfully?
A: Full shade
B: Sandy soil
C: Climbing support
D: Continual frost
Correct Answer: C
Explanation: Dragon fruit plants are climbing cacti and need something to climb on, often putting down aerial roots from the branches.
11: Which pigment family gives red and purple dragon fruits their color?
A: Anthocyanins
B: Betacyanins
C: Carotenes
D: Chlorophyll
Correct Answer: B
Explanation: The red and purple colors of some dragon fruits are due to betacyanins, which include the pigment betanin.
12: What is the ideal USDA zone for dragon fruit cultivation?
A: 1-2
B: 7-8
C: 10-11
D: 12-13
Correct Answer: C
Explanation: Dragon fruit cacti thrive most in USDA zones 10–11.
13: Which fungus can cause brown spots on dragon fruit?
A: Aspergillus
B: Dothiorella
C: Penicillium
D: Rhizopus
Correct Answer: B
Explanation: The Dothiorella fungus can cause brown spots on the dragon fruit.
14: What is the approximate water content of dragon fruit per 100 grams?
A: 50 grams
B: 84 grams
C: 91 grams
D: 72 grams
Correct Answer: B
Explanation: The water content of dragon fruit is about 84 grams per 100 grams of the fruit.
15: What notable nutrient is present in the seed oil of dragon fruit?
A: Omega-3 fatty acids
B: Linoleic acid
C: Saturated fats
D: Phytosterols
Correct Answer: B
Explanation: Dragon fruit seed oil contains linoleic acid, a type of fatty acid.
16: In which type of soil do dragon fruit seeds grow best?
A: Sandy soil
B: Potting soil mix or compost
C: Clay soil
D: Peat soil
Correct Answer: B
Explanation: Dragon fruit seeds grow well in a compost or potting soil mix.
17: What is one of the main uses of dragon fruit aside from consuming it fresh?
A: Flavoring and coloring juices and alcoholic beverages
B: Producing essential oils
C: Making candles
D: Extracting latex
Correct Answer: A
Explanation: Dragon fruit is used to flavor and color juices and alcoholic beverages.
18: How often can dragon fruit plants flower in a year?
A: Once a year
B: Three to six times a year
C: Once every two years
D: Every month
Correct Answer: B
Explanation: Dragon fruit plants can flower between three and six times per year depending on growing conditions.
19: What happens to dragon fruit flowers by the evening?
A: They bear fruit
B: They wilt
C: They change color
D: They release seeds
Correct Answer: B
Explanation: Dragon fruit flowers usually bloom overnight and wilt by the evening.
20: What bacterial pathogen causes the stems of dragon fruit plants to rot?
A: Bacillus thuringiensis
B: Pseudomonas aeruginosa
C: Xanthomonas campestris
D: Corynebacterium diphtheriae
Correct Answer: C
Explanation: Xanthomonas campestris is the bacterium that causes the stems of dragon fruit plants to rot.
21: Which of the following is not a commonly recognized pitaya variety?
A: White-fleshed pitaya
B: Red-fleshed pitaya
C: Blue-fleshed pitaya
D: Yellow-fleshed pitaya
Correct Answer: C
Explanation: Common pitaya varieties include white-fleshed, red-fleshed, and yellow-fleshed pitayas, but not blue-fleshed.
22: Which factor is a concern for home growers of dragon fruit?
A: Underwatering
B: Overwatering
C: Lack of sunlight
D: Excessive fertilizer
Correct Answer: B
Explanation: Overwatering is a significant concern for home growers of dragon fruit plants.
23: How long after planting do dragon fruit seeds typically germinate?
A: 3-5 days
B: 6-10 days
C: 11-14 days
D: 15-20 days
Correct Answer: C
Explanation: Dragon fruit seeds usually germinate between 11 and 14 days after shallow planting.
24: Which nickname is sometimes used for dragon fruit flowers?
A: Night Bloomers
B: Morning Glory
C: Twilight Flowers
D: Moon Blossoms
Correct Answer: D
Explanation: Dragon fruit flowers are sometimes nicknamed “Moon Blossoms” because they bloom overnight.
25: Dragon fruit plants escape cultivation and become what in numerous regions?
A: Garden plants
B: Invasive weeds
C: Forest shrubs
D: Aquatic plants
Correct Answer: B
Explanation: In numerous regions, dragon fruit plants have escaped cultivation and become classified as invasive weeds.
26: What role does cross-pollination play in dragon fruit cultivation?
A: Reduces fruit set
B: Increases fruit set and quality
C: Has no effect
D: Stops flowering
Correct Answer: B
Explanation: Cross-pollination with a second, genetically distinct plant generally increases fruit set and quality.
27: How many calories does 100 grams of raw dragon fruit provide?
A: 57 kilocalories
B: 100 kilocalories
C: 75 kilocalories
D: 50 kilocalories
Correct Answer: A
Explanation: 100 grams of raw dragon fruit provides 57 kilocalories of food energy.
28: Which vitamin is particularly notable in raw dragon fruit?
A: Vitamin A
B: Vitamin C
C: Vitamin D
D: Vitamin B12
Correct Answer: B
Explanation: Raw dragon fruit contains 4.3 mg of Vitamin C per 100 grams, giving it notable Vitamin C content.
29: Selenicereus megalanthus is better known as which type of pitaya?
A: White-fleshed pitaya
B: Red-fleshed pitaya
C: Yellow-fleshed pitaya
D: Sour pitaya
Correct Answer: C
Explanation: Selenicereus megalanthus is also known as the yellow-fleshed pitaya.
30: In which season do dragon fruit cacti bloom most frequently?
A: Spring
B: Summer
C: Fall
D: Winter
Correct Answer: B
Explanation: Dragon fruit cacti bloom most frequently during the summer season.
31: What is the main threat to dragon fruit plants from excessive rainfall?
A: Enhanced growth
B: Rotting of flowers and fruit
C: Better fruit quality
D: Nutrient deficiency
Correct Answer: B
Explanation: Excessive rainfall can cause the flowers to drop and the fruit to rot.
32: What is the USDA FoodData Central?
A: A recipe website
B: A database that publishes nutritional content
C: A soil improvement organization
D: A plant registry
Correct Answer: B
Explanation: The USDA FoodData Central is a database that provides nutritional information on various foods, including dragon fruit.
33: Which acid is not a component of the fatty acid composition in dragon fruit seed oil?
A: Myristic acid
B: Palmitic acid
C: Stearic acid
D: Boric acid
Correct Answer: D
Explanation: Boric acid is not a component of the fatty acid composition in dragon fruit seed oil.
34: What type of appearance does the skin of a dragon fruit have?
A: Smooth and glossy
B: Leather-like with scaly spikes
C: Rough and knobbly
D: Soft and fuzzy
Correct Answer: B
Explanation: The skin of a dragon fruit is leather-like with prominent scaly spikes.
35: How does the name “dragon fruit” originate?
A: From its dragon-like texture and appearance
B: Named after the scientist who discovered it
C: Comes from the region it grows in
D: Named after a mythical dragon’s egg
Correct Answer: A
Explanation: The name “dragon fruit” originates from its dragon-like, leather-like skin and scaly spikes.
36: What is a primary culinary use for dragon fruit seeds?
A: Making sauces
B: Grilling
C: Seed oil extraction
D: Baking cakes
Correct Answer: C
Explanation: Dragon fruit seeds can be used for extracting seed oil, which contains several fatty acids.
37: Which cactus species is important for the indigenous Seri people’s diet?
A: Selenicereus undatus
B: Selenicereus costaricensis
C: Stenocereus gummosus
D: Selenicereus megalanthus
Correct Answer: C
Explanation: Stenocereus gummosus, known as sour pitaya, is important for the Seri people’s diet.
38: How are dragon fruit seeds prepared for cultivation after extraction from the fruit?
A: Directly planted in rock bed
B: Cleaned and dried before planting
C: Planted in water garden
D: Stripped and charred
Correct Answer: B
Explanation: Dragon fruit seeds are cleaned and dried after extraction before planting.
39: At what weight can a dragon fruit plant begin to flower?
A: 1 kilogram (2.2 pounds)
B: 2.5 kilograms (5.5 pounds)
C: 3 kilograms (6.6 pounds)
D: 4.5 kilograms (10 pounds)
Correct Answer: D
Explanation: A dragon fruit plant may flower when it reaches a mature weight of 4.5 kilograms (10 pounds).
40: Which tropical region can dragon fruit cultivation not thrive in?
A: Zones 9a or 9b
B: Zones 10-11
C: Zones 1a-3b
D: Zones 5a-6b
Correct Answer: A
Explanation: Dragon fruit can survive outdoors in USDA zones 9a or 9b, but not necessarily thrive in colder climates.
41: What is the ideal temperature range for dragon fruit plant survival?
A: 10-15 °C (50-59 °F)
B: 20-25 °C (68-77 °F)
C: Up to 40 °C (104 °F)
D: Below 0 °C (32 °F)
Correct Answer: C
Explanation: Dragon fruit plants can endure temperatures up to 40 °C (104 °F) but not prolonged freezing temperatures.
42: Which vitamin in dragon fruit contributes to its bio-functionality?
A: Vitamin D
B: Vitamin B12
C: Vitamin K
D: Vitamin E
Correct Answer: C
Explanation: Vitamin K, present in dragon fruit, contributes to its bio-functionality.
43: Over how many months can commercially planted dragon fruits take to reach full production?
A: 12 months
B: 24 months
C: 60 months
D: 36 months
Correct Answer: C
Explanation: Dragon fruit plants can take up to 60 months to reach full commercial production.
44: Dragon fruit flowers are an example of which type of plant flowering behavior?
A: Diurnal
B: Annual
C: Vernal
D: Nocturnal
Correct Answer: D
Explanation: Dragon fruit flowers bloom nocturnally and wilt by the evening.
45: What is the scientific name for yellow-skinned dragon fruit with white flesh?
A: Stenocereus gummosus
B: Selenicereus megalanthus
C: Selenicereus undatus
D: Selenicereus costaricensis
Correct Answer: B
Explanation: Selenicereus megalanthus is the scientific name for yellow-skinned dragon fruit with white flesh.
46: Which plant hormone is essential for dragon fruit flowering?
A: Gibberellins
B: Auxins
C: Cytokinins
D: Ethylene
Correct Answer: D
Explanation: Ethylene is a plant hormone known to promote flowering and fruit set in dragon fruits.
47: What percentage of a 100-gram serving of dried dragon fruit is carbohydrates?
A: 20%
B: 50%
C: 82%
D: 95%
Correct Answer: C
Explanation: 82% of a 100-gram serving of dried dragon fruit consists of carbohydrates.
48: What is the botanical genus name for the majority of sweet pitayas?
A: Selenicereus
B: Stenocereus
C: Opuntia
D: Echinopsis
Correct Answer: A
Explanation: The majority of sweet pitayas belong to the genus Selenicereus.
49: How much dietary fiber does 100 grams of raw dragon fruit provide?
A: 2 grams
B: 4 grams
C: 3.1 grams
D: 5 grams
Correct Answer: C
Explanation: 100 grams of raw dragon fruit provide 3.1 grams of dietary fiber.
50: How many times may dragon fruit plants flower under ideal conditions yearly?
A: Only once
B: Twice
C: Three to six times
D: Continuously
Correct Answer: C
Explanation: Under ideal growing conditions, dragon fruit plants can flower three to six times yearly.
51: Which acid is major in the seed oil composition in white-fleshed and red-fleshed pitayas?
A: Myristic acid
B: Oleic acid
C: Palmitic acid
D: Linoleic acid
Correct Answer: D
Explanation: Linoleic acid constitutes about 50% of the seed oil in both white-fleshed (Selenicereus undatus) and red-fleshed (Selenicereus costaricensis) pitayas.
52: What fraction of dragon fruit’s weight is typically made up of water?
A: 50%
B: 67%
C: 84%
D: 95%
Correct Answer: C
Explanation: Water makes up about 84% of the weight of dragon fruit.
53: What is the effect of self-pollination on some dragon fruit species?
A: Produces larger fruits
B: Does not produce fruit
C: Increases flowering period
D: Enhances seed quality
Correct Answer: B
Explanation: Self-pollination will not produce fruit in some dragon fruit species.
54: What benefit does cross-pollinating dragon fruit plants of the same species have?
A: Reduces plant height
B: Increases pest resistance
C: Improves fruit set and quality
D: Extends shelf life
Correct Answer: C
Explanation: Cross-pollinating with a genetically distinct plant of the same species generally increases fruit set and quality.
55: What happens during overwatering of dragon fruit plants?
A: Improved growth rate
B: Leaf proliferation
C: Flowers drop and fruit rot
D: Enhanced flower scent
Correct Answer: C
Explanation: Overwatering can cause the flowers to drop and the fruit to rot.
56: Which mineral is relatively high in dragon fruit, enhancing its nutritious nature?
A: Sodium
B: Potassium
C: Lead
D: Zinc
Correct Answer: B
Explanation: Dragon fruit contains a significant amount of potassium, a crucial mineral for overall health.
57: Which dragon fruit species has red flesh and red-skinned fruit?
A: Selenicereus undatus
B: Selenicereus costaricensis
C: Stenocereus griseus
D: Stenocereus gummosus
Correct Answer: B
Explanation: Selenicereus costaricensis has red-skinned fruit with red flesh.
58: What phenomenon is observed due to dragon fruit’s nocturnal blooming?
A: Day-long fruit ripening
B: Morning shading
C: Evening wilting
D: Midday seeding
Correct Answer: C
Explanation: Dragon fruit flowers wilt by the evening after blooming overnight.
59: In what form is dragon fruit commonly exported from Vietnam?
A: Dried powder
B: Fresh
C: Juice concentrate
D: Frozen pulp
Correct Answer: B
Explanation: Vietnam is the lead exporter of fresh dragon fruit.
60: What significant feature allows dragon fruit plants to thrive in USDA zones 10–11?
A: High water requirement
B: Flower scent attraction
C: Heat tolerance and moderate frost resistance
D