Crop Science Final Exam Knowledge Questions

What is the difference between a monoculture and crop rotation?

monoculture-you only plant one crop in the same field over and over again

crop rotation- you switch which crop is grown in which field every year

What are the three advantages of growing two different types of crops, for example corn with soybeans, in rotation to just growing one or the other every year?

restores nutrients in the soil, and if market crashed in one crop you still have the other one to sell

What are 3 reasons for using a monoculture system?

specialization, easier to manage, better yields because you are specialized

What are rotation cropping, double cropping, and intercropping?

rotation cropping- switching between two crops in the field every year

double cropping- plants two crops in the same field in the same year

intercropping- planting two different crops in the same field at the same time

What is the advantage of using growing degree days over the days to maturity system of determining corn maturity?

because the growth of the corn plant is directly related to the accumulation of heat over time rather than the number of calendar days from planting

What is lodging?

stems bend over because of weight of water collected on ripened seed heads making the crop difficult to harvest.

What are three major transgenic crops?

corn, soybean, cotton

What are the two major traits placed into transgenic crops?

herbicide and insect resistance

What is a risk of continually growing transgenic crops? Give an example of how good management can reduce the risk

the insects become intolerant to the traits

-only using chemicals when the crop actually needs it, and switching which chemicals you use

What are some problems when planting soil that is to wet? When soil is too dry?

wet-poor seed to soil contact or furrows reopen upon drying

dry-penetration problems with the Coulter, which allows planting to shallow and the seed slot to not close

What are the two main considerations when determining planting date in the temperate regions? In tropical and subtropical monsoon regions?

soil temps and moisture

Why would a newly germinated soybean field more likely have to be replanted after a late spring frost than a newly germinated corn field beside it?

the soybean plant is not as hardy to frost that corn is

What determine seeding rate of a crop?

plant population

What are the main determining factors in determining optimal plant population?

availability of water, nutrients, light and temps and soil conditions are conductive for growth

What is the rule of thumb for seed planting depth?

not to shallow where it doesn't have good soil-moisture contact but shallow enough that it allows rapid emergence

4-5 times the seed diameter

How do the following affect planting depth: seed size, soil texture, and soil temperature?

seed size- depends on how deep you plant

soil texture- soil to seed contact

soil temperature- seeds can't germinate if it is to cold

In what family do true cereal grain belong? Why are seeds from other families sometimes called cereal grains?

Poaceae, because their seeds are used similar to those of the grasses

Why are the cereal and "pseudo" cereal grains the principal source of food for humans?

because they are used for everything

List 5 genera of FABACEAE beans that are important to human nutrition, do not include soybeans.

broad bean, garbanzo, cowpea, pigeon pea, peanut

What are the differences among dent, flint, and flour corn?

dent- principal commercial feed type grown in the United States

flint- mostly hard starch

flour- has little hard starch also know as soft corn

What part of the sugar beet is harvested for its sugar content? What part of sugar cane is harvested?

sugar beet- root harvested for the sugar

sugar cane- sugar found in the stems

What are the four main classifications of wheat? Give a production area and culinary use for each type.

hard red spring- bread flour

hard red winter- bread flour

soft red winter- cake flour

durum- pasta flour

Why is unsaturated oil preferred for human diets over saturated oil?

less likely to cause high levels of cholesterol

Name the plant part that is the source for fiber in each of the following: cotton, flax, hemp, agave

cotton- lint

flax- stem fibers

hemp- whole stem

agave- lower leaves

what is forage?

total plant material available to be consumed by an animal

what types of species dominate forage fields and rangeland?

perennial plants

What is the typical range in the number of species in a forage crop or rangeland system?

5-50

What is the difference between grazing and a confinement system for raising livestock?

confinement the animals are on feed diets and not forages

grazing- livestock only on grass and forages

What is the most important objective of grazing?

getting all the nutrients the animal needs and to keep the forages growing and not die

What is stock rotation in a grazing system and what are the benefits?

moving the animals to different pastures so each pasture has time to grow back and not get short enough it dies

In the United States what species usually makes the best quality hay? What makes up the greatest quantity of hay?

alfalfa

In general, when is the best time to harvest hay?

just before the heading stage

Give two reasons why proper dehydration is necessary when preserving hay

to preserve quality and to prevent barn fires

what is silage

Product of acid fermentation of green forage crops that have been compressed and stored under anaerobic conditions.

describe the process that occurs in silos to make silage

the anaerobic bacteria multiplies and act on the carbohydrates in the plant tissues to form lactic acid, which ferments the plant material

what is the primary factor affecting forage quality?

maturity

What are the different types of fiber found in forage and what is the digestibility of each?

hemicellulose- moderate digestible

cellulose- poorly digestibility by nonruminants

lignin- indigestible

how do each of the following affect forage quality: species, leaf-to-stem ratio, and maturity?

species- affects amount of fiber and the chemical composition of that fiber

leaf-to-stem ratio- stems have higher fiber amounts than leaves

maturity- as forages mature yield increases but quality declines

list three things that are considered to be antiquity factors in forage

leaf saponins, ergot, nitrates, high protein, natural estrogens

what symbiotic relationship do endophytes have with plants? How does this affect forage quality? Since 2001, how has this problem been reduced?

it increases production, persistence, insect resistance, and drought/heat tolerance but it is toxic to livestock

yes

what are tillers, stolons, and rhizomes?

tillers- a grass clump

stolons- specialized stems fo grasses, legumes and forms

rhizomes- similar to stolons but are underground

Why does overgrazing reduce pasture growth rate? Why can under grazing sometimes be detrimental to pasture growth and quality?

because overgrazing causes grassland to have less mass which reduces productivity and lessons leaf area which lessons photosynthesis

under grazing has high mass, which could led to yield loss since leaves are to big

Give two characteristics of vegetable farms and industries

help to maintain open rural or green spaces

provide homes for wildlife

what is the most common approach to vegetable farming?

operate as managed ecosystems

what is the advantage of using high tunnels for vegetable production?

no weather disruptions, no pests

Has the demand for organic foods increased or decreased?

increased because more people want no chemicals and it is technically better for the environment

what are the three factors that drive consumer demand for vegetables?

availability, convenience, and diversity

what's the reason for solarizing soil?

to kill the weeds and pests

why are many vegetables that are botanically fruits or seeds still considered to be vegetables?

to favor our dietary concept

what is the difference between pole and bush type beans?

pole- grown on supports-indeterminate

bush- grown unsupported- determinate

Why are cucumbers with predominantly pistillate flowers desirable?

they produce more than one fruit at a time

how does maturity influence the color of many pepper fruit?

green-immature

yellow- near maturity

red- fully mature

What are Scoville units?

is a measurement of pungency of chili peppers and other substances

what is the difference in harvest maturity of summer squash compared to winter squash and pumpkins?

winter squash and pumpkins- they are harvested after they have developed hard rinds and well-developed seed

summer squash- harvested at an immature stage when the rind is still soft and the seeds are underdeveloped

what is the harvest maturity difference between sweet corn and field corn?

sweet corn- harvested before sugars turn to starch

field corn- harvested when kernels are starch

how does harvesting differ between processing and fresh market tomatoes?

processing- harvested mechanically

fresh market tomatoes- harvested by hand

what are the main Cole crops? what time or times of the year are they harvested?

broccoli- harvested when still immature

brussel sprouts- when mature

cabbage- harvested before stem elongation

cauliflower- when mature

kohlrabi- when enlarged stem is between 5-7.6 cm

describe crisped, butterhead, romaine, and leaf types of lettuce.

crisped- brittled textured foliage

butterhead- soft and less dense

romaine- elongated coarse textured leaves

Why is a short day length important in spinach production?

because it could cause the plant to bolt and flower which is deteremental

What plant can be used as a substitute for spinach?

swiss chard

What is the difference between wild carrots and domestic carrots?

wild carrots- annuals

domestic carrots- biennale

What environmental factor is the primary signal for bulbing to start in onions?

day length

How are most potato plants started?

started from "seed" potatoes

How are sweet potatoes plants started?

they are perennial vines that grow prostate on the ground

What are the three factors that influence the transition from vegetative to reproductive status in a plant?

pollination, fertilization, maturation

What will likely happen to fruit production the following spring if trees are fertilized heavily with nitrogen before winter?

makes the branches and leaves grow so much that the fruit begins to fail

What is meant by "rest" period in regard to deciduous fruit plants? What is the advantage to plants to have a rest period?

it means the plant does not open even if the conditions are favorable to open

What happens if a deciduous fruit does not receive enough chilling during the dormant period?

some flower buds may drop beforehand reducing production

What is a fruiting spur, bourse shoot, primocane, floricane, and crown?

fruiting spur- short shoots composed of floral, vegetative or mixed buds separated by internodes

bourse shoot- a new shoot

primocane- a first year cane

floricane- a second year cane

crown- a stem with severely shortened internodes

What are the drawbacks to producing can fruits in a two year cropping cycle?

reductions of berry size and quality

What makes high bush and rabbit eye blue berries particularly well suited for organic production?

they are more resistant to weeds and insects and they are deeply mulched which discourages weed growth

Give three characteristics that grafted rootstocks can influence in fruit trees

adaptation response, response to growing system, size at maturity, flowering and fruiting characteristics

What is winter hardiness?

the ability to withstand severe midwinter temperatures

What factors does a producer use to judge fruit quality? What does a consumer value in fruit quality?

no bruise marks, mature, good shape, good color

all of the above

Why is it recommended to purchase certified virus- or disease-free nursery stock rather than from existing plantings?

they could have been previously infected with pathogens

Why is wet peat moss often placed into the planting holes of blueberries?

to help germinate the seed

When is it the best time to prune most dormant fruit trees and canes?

winter while the plants are dormant

Give two reasons for pruning fruit trees

encourage new growth on the plant, improve air supply throughout plant with lessons the possibility for disease

Why is annual light pruning preferable to a heavy running every few years?

because it could onset of bearing

What benefit is there to fruit thinning?

it can fully develop the fruits versus developing a lot but smaller fruits

Why is it said that optimal harvest maturity depends on the use of the fruit?

because different maturities of the fruit are used for different things

How is ethylene used in fruit ripening? What is a fruit that is not affected by ethylene?

ripens the fruit quicker, strawberries

sugar beet- taxonomic family, where it is grown, what part of plant is used, one unique thing

beta vulgaris, Minnestota, roots, is one of two sources for sucrose

sunflowers -taxonomic family, where it is grown, what part of plant is used, one unique thing

Asteraceae, Ukraine and Russia, all of the plant, the head turns towards the sunlight during the day

cotton- taxonomic family, where it is grown, what part of plant is used, one unique thing

mallows, Southern US, fiber, cotton is stronger when it is wet

cucumber- taxonomic family, where it is grown, what part of plant is used, one unique thing

Cucumis sativus, Michigan, seeds, can be turned into pickles

lettuce- taxonomic family, where it is grown, what part of plant is used, one unique thing

Asteraceae, california, flowers leaves or stems, has a water content of 95%

carrot- taxonomic family, where it is grown, what part of plant is used, one unique thing

Apiaceae, california, underground parts, they have seeds

________ is the term for the change from a vegetative growing point to into flowering parts.

Select one:

A. Initiation

B. Floralization

C. Commencement

D. De-vegetation

A

Pollenizers are:

Select one:

A. humans who cross pollinate orchard plants by hand.

B. trees of one cultivar that provide pollen for another cultivar in an orchard.

C. bees kept in hives in an orchard.

D. flowers that produce pollen.

B

Organic fruit production:

Select one:

A. is impractical so organic fruit is not grown.

B. may be best suited to blueberries.

C. requires heavy use of nitrogen rich composts and mulches.

D. can be described as benign neglect.

B

Which of the following is true?

Select one:

A. It is wrong to irrigate newly planted fruit plants right away because the roots will rot if watered then.

B. It is OK to prune heavily in the early summer because it acts as a growth regulator the rest of the season.

C. Training and pruning are different procedures, though training can include pruning.

D. There is no need to buy certified disease-free fruit tree stock because the trees are naturally resistant to most diseases.

C

Bilateral cordon, vertical shoot position, and Geneva double curtain are all examples of:

Select one:

A. grape training systems.

B. windbreaks.

C. orchard irrigation systems.

D. strawberry planting systems.

A

Vegetable farms:

Select one:

A. are usually just a few acres near metropolitan areas.

B. are operated as managed ecosystems.

C. require less management than other types of farms.

D. contribute little to the economy.

B

What happens when sweet corn is harvested too late?

Select one:

A. It becomes starchy.

B. It becomes sour.

C. Nothing - sweet corn has an exceptionally long life on the stalk.

D. It becomes soft and mushy.

A

Which of the following is NOT true about greenhouse vegetable production?

Select one:

A. Nutrition is less important than for outdoor crops.

B. Systems are highly mechanized.

C. Hydroponics is one type of greenhouse vegetable production system.

D. Artificial lighting is used to supplement solar energy.

A

Which one of the following is NOT true about cole crops?

Select one:

A. the harvested parts are not the same for each crop

B. have flowers with 4 petals arranged like a cross

C. members of the Brassicaceae family

D. they are mostly warm season crops

D

Parsnips, rutabagas, and salsify are all:

Select one:

A. old fashioned and no longer grown.

B. warm-season biennials.

C. grown for their rhizomes.

D. cool-season biennial root crops.

D

________ are the animals that can break down forage fiber (cellulose) during digestion.

Select one:

A. Ruminants

B. Camelids

C. Digastrics

D. Monogastrics

A

Grasslands usually are populated:

Select one:

A. predominately by Poaceae with other families mixed in.

B. only by dicotyledonous plants with blade-like leaves.

C. only by members of the Poaceae family.

D. predominately by blade-like dicotyledonous plants and a few Poaceae.

D