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Flashcards in Plant Growth Factors 2 Deck (41):
1

what makes up the physical soil texture?

the percentage of sand, silt and clay in soil

2

what is loam ?

an equal mixture of all 3 soil types

3

t or f loam is naturally occurring in nature

false

4

how many essential chemical element are there?

16

5

what 3 are obtained from air and water?

carbon oxygen and hydrogen

6

what are the 3 macronutrients?

nitrogen(n)
phosphorus(p)
potassium (k)

7

what are the secondary nutrients?

calcium (c)
magnesium(m)
sulfur (s)

8

what are 4 chemical properties?

1. fertlity
2. mineral nutrition
3. pH
4. cation exchange capacity

9

what is the cation exchange capacity

- index of soil fertility
-plant nutrients carry positive charge
-soil particle with large surface area are - charged
increases CEC = increase nutrients available for plants

10

chlorosis of older leaves is a symptom to what deficiency?

magnesium

11

chlorosis of young leaves indicate deficiency of?

iron

12

weak stems, roots and leaves indicate deficiency of?

nitrogen

13

imperfect cell development and delayed growth indicates deficiency of?

phosphorus

14

stunted growth indicates a deficiency of

calcium

15

what are the 5 observable symptoms of deficiencies ?

1. chlorosis
2. necrosis
3. accumulation of anthocyanin = purple colour
4. lack of new growth
5. stunted growing

16

mobile deficiencies present of what age of leaves? what nutrients ?

-older leaves --> nutrients moved to newer tissues
-N, P, K, Mg, Cl, Zn

17

immobile deficiencies show on what type of leaves? What nutrients?

- younger leaves
-S, Fe, Cu, Mn, B, Ca

18

what is the chemical formula for a chlorophyll molecule?

C55H72O5N4Mg

19

on a chlorophyll molecule , Mg is ____ and Fe is ___. Mg shortage results in ___. Fe shortage results in ____.

mobile, immobile
-chlorotic older leaves
-chlorotic new growth

20

too much N can result in

-fast growth, long thin weak shoots, dark leaves and lack of flowering

21

what is phosphorus important for?

-root establishment, flowering

22

what is potassium important for ? symptoms of potassium deficiency?

- general health; chlorophyll formation, disease resistance
- small fruit, yellowing of older blooms, sickly

23

nutrient availability is affected by what 3 things?

1. moisture
2. temperature (slow colder temps)
3. pH (acid <7, alklaine >7)

24

how can you increase soil acidity? Decrease?

limestone, gypsum
sulfur, nitrogen

25

how do you improve soil fertility?

1. adjust pH
2. adjust organic matter
3. fertilizers

26

what is optimum germination temperature?

18-21C

27

at what temp do roots stop growing?

5C or less

28

true or false; sandy soils warm faster than clay

true

29

typical mineral soil is comprised of what % air?

25%

30

what is the water table?

- upper surface of ground level below which the soil is saturated with water

31

how to you prevent a perched water table?

1. well draining media
2. porous soil
3. drainage holes

32

what are the 3 components of the disease triangle?

1. susceptible host
2. favourable env't
3. pathogen

33

what do plant roost exude that get eaten by pests?

cho, proteins

34

what is the building block of amino acids?

nitrogen

35

in what forms does N get taken in by plant?

NH4( ammonium) and NO3 (nitrate)

36

t or f forests have a high population of fungi in their soils

true

37

t or f lower pH soils are dominated by bacteria

false; dominated by bacteria
-low pH soils dominated by fungi

38

perennials, trees and shrubs prefer what type of soil?

-fungally dominated, low pH (N in NH4 form)

39

annuals prefer what type of soil?

-bacterially dominated; n in NO3 form

40

bacteria is dependent on what? Role?

-moisture
-primary decomposer (easy material)
-release enzymes
-pathogen

41

what role of fungi

-decompose tough material
-mycorrihizae (95%)
-pathogen