Nutrition of Horticultural Crops Exam 3 (SOAP)

Question 1

What is a crop in Florida which is typically planted in September and harvested the following March?

Answer 1

calabaza squash
(Cucurbita moschata)

Question 2

Because the calabaza squash is only in the field six to seven months of the year, when would the field associated with it be fallow without cover crops being planted?

Answer 2

field would be fallow between April and August

Question 3

What is the risk associated with a field in Florida which is fallow between April and August?

Answer 3

heavy summer rains can erode large soil particles, leach nutrients or cause compaction

Question 4

What can arise in fallow fields which grow more readily than cash crops with scant nutrients and poor soil quality?

Answer 4

weeds

Question 5

What is a common genus of weeds in Florida which are commonly known as “nut-sedges”?

Answer 5

Cyperus

Question 6

What kinds of cover crops are typically planted as “nutrient catchers” for a fallow field?

Answer 6

cereals and grasses

Question 7

What kinds of cover crops are typically planted as “soil enrichers” for a fallow field?

Answer 7

legumes

Question 8

In the context of what kind of agro-systems are cover crops planted to control species at the ground level?

Answer 8

orchards and vineyards

Question 9

What is the common name for the legume cover crop in the species ‘Trifolium reflexum’ which grow well in the Southeastern United States?

Answer 9

buffalo clover

Question 10

What is the common name for the legume cover crop in the species ‘Medicago sativa’ which grow well in the Southeastern United States?

Answer 10

alfalfa

Question 11

What is the common name for the legume cover crop in the species ‘Coronilla varia’ which grow well in the Southeastern United States?

Answer 11

crown vetch

Question 12

What is the common name for the legume cover crop in the species ‘Vigna unguiculata’ which grow well in the Southeastern United States?

Answer 12

cowpea

Question 13

One issue with planting only legume cover crops is their slow establishment period, which can be corrected for by doing what?

Answer 13

pairing them with a cereal or grass that can suppress weeds

Question 14

What is the common name for the cereal cover crop ‘Sorghum × drummondii’, which is planted in association with slow-growing legume cover crops?

Answer 14

Sudan grass

Question 15

What is the common name for the cereal cover crop ‘Lolium multiflorum’, which is planted in association with slow-growing legume cover crops?

Answer 15

annual ryegrass

Question 16

What is the common name for the cereal cover crop ‘Secale cereale’, which is planted in association with slow-growing legume cover crops?

Answer 16

winter rye

Question 17

What is the common name for the cereal cover crop ‘Avena sativa’, which is planted in association with slow-growing legume cover crops?

Answer 17

common oat

Question 18

In regards to timing, cover crops should be planted soon after what occurs?

Answer 18

harvest of the cash crop

Question 19

Should the soil be tilled before the cover crop is planted? Why or why not?

Answer 19

soil should not be tilled for the cover crop to intercept the maximum amount of nutrients

Question 20

In regards to timing, cover crops should be terminated before they can do what?

Answer 20

cover crops should be terminated before they have the opportunity to set seeds

Question 21

Why should planters wait two weeks after terminating the cover crops to seed their fields with the cash crop?

Answer 21

cover crops may have allelopathic root exudates which can break down in the soil during the two-week interval

Question 22

What part of the legume cover crop has been shown to provide the cash crop with more nitrogen, the shoots or the roots?

Answer 22

legume cover crop shoots provide cash crops with more fixed nitrogen than the roots do (nitrogen-rich proteins are more concentrated in the shoots than the ligneous roots).

Question 23

What part of an amino acid always contains nitrogen?

Answer 23

amino group (–NH2)

Question 24

What part of an amino acid potentially contains nitrogen?

Answer 24

side chain (–R)

Question 25

What are the five atoms and two elements present in the porphyrin ring of a chlorophyll pigment?

Answer 25

four nitrogen atoms encircling a magnesium

Question 26

considering nitrogen has a central role in producing proteins and chlorophyll pigments, what are the two classic symptoms of its deficiency in many crops?

Answer 26

(1) stunted growth (2) general leaf yellowing

Question 27

What is a symptom of nitrogen deficiency demonstrated by tomato plants besides the two classic issues?

Answer 27

less branches arise on nitrogen-deficient tomatoes

Question 28

What do some crops do in response to a nitrogen deficiency which is not noticeable without either a rhizo-box or by extracting the crop from the soil?

Answer 28

growth of longer root systems

Question 29

Because nitrogen is a plant-mobile nutrient, what can be an early indicator that it is deficient in crops?

Answer 29

evidence of yellowing in older leaves which is not yet apparent in the newer foliage

Question 30

What kind of enzymes do plants rely upon when the nitrogen concentration in the soil is high?

Answer 30

low affinity transporters (LATs -- incorporate nitrogen in line with the concentration gradient)

Question 31

What kind of enzymes do plants rely upon when the nitrogen concentration in the soil is low?

Answer 31

high affinity transporters (HATs -- incorporate nitrogen against the concentration gradient by consuming ATP)

Question 32

Plant uptake rates for (1)___________ rise as the plant is actively growing and peak once it is (2)____________. Once that occurs, the rate of uptake (3)__________, which is compensated by an increased rate of (4)_______________ within the crop.

Answer 32

(1) nitrogen (2) in bloom (3) declines (4) remobilization

Question 33

At any point in a crop's development (dormancy ~ bloom ~ young/mid/mature fruit) the majority of nitrogen (typically measured in milligrams) is retained in what organ?

Answer 33

roots

Question 34

When do root and shoot systems typically see the highest concentrations of nitrogen? Why is this the case?

Answer 34

roots and shoots have the highest concentrations of nitrogen during the dormancy period, which is because there are no flowers or fruits to divert the nitrogen

Question 35

What ecological principle states growth is limited to the least present nutrient?

Answer 35

law of the minimum

Question 36

What are the three components referenced by the SOAP initialism?

Answer 36

(1) subjective assessment (2) objective assessment (3) action plan

Question 37

What is the first step in the objective assessment of the SOAP method?

Answer 37

determining where the symptoms of nutrient deficiency are visible (i.e., old tissues vs. new tissues; all across the plant vs. in one section of the plant)

Question 38

What should we do once we have determined the symptomatic tissues in a crop?

Answer 38

determine which can be tested analytically

Question 39

Nutrient deficiency tests of the plant sap have proven especially useful for what kinds of crops?

Answer 39

greenhouse-grown fruits (cucumbers, tomatoes, etc.)

Question 40

The critical values for nutrient deficiency in the leaves in many crops will be different before and after what thing occurs to the host plant?

Answer 40

production of flowers

Question 41

Before blossoming, the critical concentrations of nitrogen in the leaves are ______________ than after blossoming.

Answer 41

higher

Question 42

What are the six plant-mobile nutrients?

Answer 42

(1) nitrogen (2) phosphorus (3) potassium (4) magnesium (5) molybdenum (6) zinc

Question 43

What are the six plant-IMmobile nutrients?

Answer 43

(1) calcium (2) sulfur (3) iron (4) boron (5) copper (6) manganese

Question 44

There is no clear relationship between inter-plant nutrient mobility and what?

Answer 44

mobility of the nutrient in the soil

Question 45

Appropriate plant tissue sampling requires (1)___________ from various parts and the avoidance of tissues which are (2)____________________ by things like mechanical equipment or (3)________________ from things like pesticide or fertilizer.

Answer 45

(1) replication (2) physically damaged (3) contaminated

Question 46

Which are more difficult to diagnose, macronutrient deficiencies or micronutrient deficiencies?

Answer 46

micronutrient deficiencies are more difficult to diagnose

Question 47

In what order should we consider factors to correct a nutrient deficiency in our action plan?

Answer 47

(1) biological factors (2) cultural factors (3) chemical factors

Question 48

What is an example of a biologically-minded correction one could make to correct a nitrogen deficiency?

Answer 48

planting a leguminous inter-crop with the cash crop

Question 49

What is an example of a culturally-minded correction one could make to correct a nitrogen deficiency?

Answer 49

spacing out the timing of a fertilizer so that it corresponds better with the rates of seedling growth

Question 50

What is an example of a chemically-minded correction one could make to correct a nitrogen deficiency?

Answer 50

increasing the overall amount of fertilizer applied to the soil