1. Which of the following is the primary factor influencing the fruiting of biennial plants?
a) Light intensity
b) Temperature
c) Pruning
d) Fertilization
Answer: b) Temperature
Explanation: Biennial plants require a period of cold (vernalization) to initiate flowering and fruiting. Temperature plays a crucial role in this process.
2. In grafting, what is the main purpose of the scion?
a) To provide the root system
b) To provide the vascular tissue for growth
c) To provide the fruiting characteristics
d) To provide the bark for the union
Answer: c) To provide the fruiting characteristics
Explanation: The scion is the upper part of the graft, which contributes the desired fruiting variety. The rootstock provides root development and disease resistance.
3. Which of the following methods is most commonly used for propagation of citrus plants?
a) Grafting
b) Seed propagation
c) Layering
d) Cuttings
Answer: a) Grafting
Explanation: Grafting is the most common method of propagating citrus, as it allows the combination of disease-resistant rootstock with high-quality scion varieties.
4. The process of removing the apical bud to encourage lateral branching is known as:
a) Pollarding
b) Pruning
c) Pinching
d) Girdling
Answer: c) Pinching
Explanation: Pinching involves removing the tip of the stem or shoot to stimulate the growth of lateral buds and encourage bushier plant growth.
5. Which of the following plant hormones is primarily responsible for promoting cell elongation and fruit growth?
a) Auxins
b) Gibberellins
c) Cytokinins
d) Abscisic acid
Answer: b) Gibberellins
Explanation: Gibberellins are hormones that promote cell elongation, stem growth, and fruit enlargement, and they play a significant role in the development of fruits and flowers.
6. Which of the following is an example of a monocarpic plant?
a) Oak tree
b) Wheat plant
c) Tomato plant
d) Banana plant
Answer: d) Banana plant
Explanation: Monocarpic plants flower, fruit, and die after a single reproductive cycle. Banana plants are monocarpic as they die after fruiting once.
7. What is the primary advantage of hydroponics in horticulture?
a) Increased soil fertility
b) Reduced need for pesticides
c) Efficient use of water and nutrients
d) Improved fruiting rates
Answer: c) Efficient use of water and nutrients
Explanation: Hydroponics allows for the direct delivery of water and nutrients to plant roots, leading to more efficient use and less waste compared to traditional soil-based methods.
8. Which of the following is a key characteristic of “cold-hardy” horticultural crops?
a) High resistance to waterlogging
b) Ability to tolerate freezing temperatures during dormancy
c) Preference for acidic soil pH
d) High tolerance to drought conditions
Answer: b) Ability to tolerate freezing temperatures during dormancy
Explanation: Cold-hardy crops are able to withstand freezing temperatures during their dormancy phase, which is crucial for their survival in temperate climates.
9. Which of the following is the correct term for a graft union between two genetically distinct species?
a) Incompatibility
b) Cross-breeding
c) Intergeneric grafting
d) Intraspecific grafting
Answer: c) Intergeneric grafting
Explanation: Intergeneric grafting occurs when grafts are made between plants from different genera, while intraspecific grafting involves plants from the same species.
10. Which of the following plant diseases is most commonly spread through the use of contaminated pruning tools?
a) Powdery mildew
b) Phytophthora blight
c) Bacterial wilt
d) Black spot fungus
Answer: c) Bacterial wilt
Explanation: Bacterial wilt can be spread when pruning tools come into contact with infected plant material and then move the bacteria to healthy plants.
11. Which type of soil is best suited for most horticultural crops due to its structure and drainage properties?
a) Sandy soil
b) Clay soil
c) Loamy soil
d) Peaty soil
Answer: c) Loamy soil
Explanation: Loamy soil, which has a balanced mixture of sand, silt, and clay, offers excellent drainage, nutrient content, and structure for most horticultural crops.
12. What is the term used to describe the process of fruit formation without fertilization, often observed in certain species of plants such as bananas and oranges?
a) Parthenocarpy
b) Apomixis
c) Cross-pollination
d) Gametogenesis
Answer: a) Parthenocarpy
Explanation: Parthenocarpy refers to the formation of fruit without fertilization, leading to seedless fruits.
13. Which of the following is NOT a method of asexual plant propagation?
a) Layering
b) Grafting
c) Seed sowing
d) Cuttings
Answer: c) Seed sowing
Explanation: Seed sowing is a form of sexual reproduction, whereas layering, grafting, and cuttings are all methods of asexual propagation.
14. The process by which a plant goes from a juvenile stage to a mature, flowering stage is known as:
a) Vernalization
b) Senescence
c) Ripening
d) Juvenility
Answer: a) Vernalization
Explanation: Vernalization is the process of cold treatment that some plants require to transition from a juvenile to a mature flowering state.
15. Which of the following plant diseases is primarily transmitted through soilborne pathogens?
a) Downy mildew
b) Fusarium wilt
c) Leaf spot
d) Aphid-transmitted mosaic
Answer: b) Fusarium wilt
Explanation: Fusarium wilt is a soilborne disease caused by the fungus Fusarium oxysporum, which affects the vascular system of plants.