crop science final

Plants that are managed in some manner or degree and are produced primarily for economic return are

Crop plants

Cultivation of crops started when people learned about seed collection.

true

Agricultural development anywhere is typically dependent on

Climatic and edaphic factors

Which of the following do not represent ways we can increase food production to meet future needs?

Do nothing because there is no need for action

Agronomic classification of crop plants is usually based on all of the following except

Leaf shape

Mr. Thomas Stewart in Waco, Texas raises beef cattle on one hundred acres of well managed land using a system of irrigated pastures. Which of the following best describes  his operation?

Intensive commercial agriculture

Mario Sanchez in Equatorial Guinea cultivates an acre piece of land for three years and abandons it for a new area and hopes to return to it in a few years after it regains its fertility. What kind of cultivation is he practicing?

Shifting cultivation

Forage harvested directly by livestock through grazing is called a

Pasture crop

Agronomically corn can be classified as each of the following except

Root crop

Which of the following statements is true?

Only 10% of our planet is economically suitable for field crop production

A seed that contains a viable embryo but does not germinate when exposed to favorable environmental conditions is?

Dormant

Water, oxygen, temperature and light are -------------------- factors affecting germination

Environmental

Which of the following does not need consideration when seeding a crop?

Cloud cover on the day of seeding

Seeding rate and row spacing determine the amount of space each plant will have and the pattern of the plants.

True

Seeding depth is usually decided based on which of the following?

Seed size and soil conditions

In small seeds, sensitivity to light occurs after the seed has imbibed water and is otherwise ready to germinate.

true

The minimum and maximum temperatures at which crop seeds will germinate are called the ---- temperatures of germination.

Cardinal

Seed shape is the form of the seed

True

A dry one-seeded fruit in which the ovary wall is united with the seed coat is called?

Caryopsis

The process by which a seed embryo develops into a seedling and subsequently a plant is?

Germination

The two most important families of crops are

Poaceae and Fabaceae

is the primary purpose of field crops

Seed production

Each seed contains an -------- which is a miniature plant with a stem, leaves and root.

embryo

Which of the following is not a way we can increase food production to meet future needs?

Do nothing because there is no need for action

Which of the following statements is true?

Only 10% of our planet is economically suitable for field crop production

A farmer planted soybeans and corn on two adjacent fields with the same moisture content on the same day.  Assuming that the seed quality for both crops was excellent, and all other biotic and abiotic factors as well as planting depth were optimal for germination. What will be the most plausible reason for poor germination on the soybean field?

Inadequate moisture as soybean requires more water for germination due to its protein content

Which of the following plants fixes CO₂ in two cell types during the process of photosynthesis?

Corn

Photosynthesis occurs in two steps namely the --------------- reactions and ----------------reactions. Select the word pair that applies

 

Light, dark

Which of the following are considered as factors affecting photosynthesis? 

Carbohydrate translocation and age of leaf

The radiant energy absorbed by chlorophyll that is used to drive photosynthesis is called 

Photosynthetically active radiation

During carbohydrate translocation in plants, the leaves serve as the ------------- while the roots or growing points serve as the -----------------. Select the correct word pair that applies.

Source, sink

This equation C₆H₁₂O₆ + 6O₂ + 40ADP + 40Pi  → 6CO₂ + 6H₂0 + 40ATP represents?

Aerobic respiration

Which of the following statements about photosynthesis is false?

It does not occur in two steps.

During photosynthesis the light reactions directly use radiant energy while the dark reactions do not.

True

Which of the following is a technically true statement about C₃ and C₄ plants?

C4 plants feed a four-carbon compound into the Calvin’s Cycle versus a three-carbon compound for C3 plants.

Plants absorb all the solar energy that strike the leaf

False

When the CO₂ fixed in photosynthesis equals the CO₂ released during respiration, the plant has reached the?

Compensation point

Which of the following statements about anaerobic respiration is true?

It produces 2 ATP molecules.

The form of respiration that uses light energy to drive respiration in much the same way that photosynthesis uses light energy is known as?

Photorespiration

A regular recurrence succession of different crops on the same land is known as

Crop Rotation

Which of the following is a correct criterion for crop rotation?

The most profitable crop or crops should be given as large an area as possible.

The practice of growing only one crop year after year on the same field is called?

Continuous cropping

In a fallow system, the proportion of precipitation that is stored in the soil for use by the subsequent crop is called?

Fallow efficiency

In organic farming, the use of manufactured agrichemicals including all pesticides, fertilizers, growth regulators and livestock feed additives are

Severely restricted

Photosynthesis and respiration are often seen as opposite to each other.

True

Water supply does not influence the opening and closing of the stomata.

False

Which of the following is by far the largest sink for photosynthesis?

Developing seeds

Which of the following C₃ crops is least likely to light saturate?

Alfalfa

Which of the following will be the most serious considerations for practicing double cropping in the U.S.?

State laws

 

Moisture availability and the length of the growing season

Which of the following is not a cultural practice in crop production?

The number of days with overcast during the growing season

Soil has ----- components.

4

The process by which plant nutrients are released for new crop growth through decomposition is called?

Mineralization

All the following are methods of nutrient uptake except?

Leaching

An 80-lb bag of fertilizer has an analysis of 20-5-10. How many pounds of P does this bag contain? Note that P₂O₅ is 44% P.

1.76 lbs

Tillage operation must return more in crop yield or improved soil conditions than the costs for it to be economically feasible

True

Soil compaction can be reduced by all the following except

Increasing the number of tillage operations

All the following are demerits of conservation tillage except

It provides maximum soil conservation

The two categories of tillage implements are stirring and sub-surface implements

True

Mr. Wiley Jones applied fertilizer at the same time he planted his field corn this year.  The fertilizer is applied is called

Starter fertilizer

Nutrients used by plants in large quantities are called

Macronutrients

A post-emergent fertilization method that involves the application of fertilizer through irrigation systems is called?

Fertigation

What percentage of the fertilizer 18-46-0 contains plant nutrients?

64%

The actual values of climatic variables in a given area is known as

weather

A plant that flowers in response to day length is described as

Photoperiodic

Plants that flower when the light period exceeds a critical length are called

Long day plants

The Köppen system of classification of climate combines ---------- conditions.

Temperature and moisture

Pests and diseases are more likely to be problematic for irrigated crops in dry climates compared to wet climates

False

Why is the Salinas Valley more favorable for temperate vegetable production than the San Joaquin Valley though both are in California?

The Salinas Valley is 10oC cooler than the San Joaquin Valley in the summer

Knowledge of frost days is useful because it can help farmers

Plan their crop production activities

If a day's maximum temperature is 84° F and the minimum is 52° F, how many GDDs will a crop accumulate within 24 hours under these conditions. Assume the base temperature is 50^oF.

18

Plant species that contain an introduced gene they did not originally have are technically best described as

Transgenic plants

Introducing a gene to a species that does not have that gene is called

Genetic engineering

Genetically engineered plants are tested to be sure they carry the desired gene by inserting

A marker gene

Seeds of known genetic identity and purity which are available in large quantities for farmers to purchase for general crop production are called

Certified seeds

Which of the following makes the least contribution to the volume of vegetables consumed?

The clearness of the day

Vegetables can be cultivated in the open field or under controlled climate conditions in greenhouses.

True

Which of the following should not be a major consideration during site selection for vegetable production?

The number of plant species in the area that are not endangered

Which of the following activities tend to lead to drier climates?  Select the most suitable answer

Clearing forest

If a homozygous cultivar cross-pollinates with other cultivars or species, the plants used to produce the seeds must be separated from other plants. Why?

To prevent pollen contamination and loss of genetic purity

In general, crop farms are operated as managed ecosystems called

Agroecosystems

Which of the following best describes shade avoidance response in plants?

Stem and petiole elongation to outgrow neighboring plants to access sunlight

Which of the following processes is directly influenced by photomorphogenesis in plants?

Chlorophyll production in response to light