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Plant Science > Unit 4 12/5/22 > Flashcards

Unit 4 12/5/22 Flashcards

1
Q

Why is weed control important?

A
  • Livestock producer
  • Home
  • Medical
  • Recreational
  • Aesthetic
  • Hort/turf/agronomic
  • Preserving native species
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2
Q

Generally ______________ produce the most amount of seed in one year

A

Annuals

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3
Q

How do we
influence
weeds?

A
  • Annual weeds are adapted to growing in any
    soil with characteristics favorable for crop
    growth (most data indicates)
  • However, there are economically important
    weeds that are perennial
  • Dandelion, Canada thistle, curly dock,
    common milkweed, etc.
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4
Q

one plant can produce how many seeds

A

60-80 thousand

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5
Q

What are the tree main weed groups?

A

Annuals
Biannual
Perennials

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6
Q

What is the annual weed group?

A
  • Annuals (summer and winter) – Should be managed before they can produce seed
    for the following year
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7
Q

Biennials

A
  • Biennials – Reproduce by both vegetatively or by seed (seed not produced until the
    second year)
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8
Q

Perennials

A
  • Perennials – Survive for many years and produce seed. However, many primarily
    produce vegetatively by creeping stems (rhizomes and stolons). Hardest to control
    once established.
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9
Q

How are weeds dispersed?

A
  • Wind
  • Water
  • Animals
  • Humans
  • Equipment
  • Plant mechanisms (barbs, hooks,
    spines, awns, sticky secretion,
    cottony lint)
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10
Q

What is an example of a weed dispersed by animals?

A

Buckthorn, birds eat seeds and poop

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11
Q

What makes weeds so
successful?

A
  • Abundant seed production
  • Rapid population establishment
  • Seed dormancy
  • Long-time survival of buried seed
  • Adaption for seed dispersal
  • Vegetative reproductive structures
  • *Ability to thrive in disturbed soils
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12
Q

What do weeds compete

A

light
water,
nutrients
space

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13
Q

Would you expect more dormancy for weeds or crops

A

Weeds

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14
Q

What are the two vegetative structures

A

Stolons and rhizomes

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15
Q

What is GDD

A

Growing Degree Day

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16
Q

Why is understanding Weed Emergence Sequence important?

A

*improve weed management by determining when to scout fields

  • GDD = are heat units required to reach 10%
    emergence
  • For some species, the majority of emergence
    occurs in a short time period (2-3 weeks). Other
    plant species may emergence over a prolonged
    period (8-10 weeks)
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17
Q

Emergence date of group 0

A
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18
Q

Emergence date of group 1

A
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19
Q

Emergence date of group 2

A
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20
Q

Emergence date of group 3

A
21
Q

Emergence date of group 4

A
22
Q

Do weeds grow more when they are younger or older

A

Weeds will grow more as they get older

23
Q

How long can weed seeds survive?

A

5-10 years in soil

Weeds in your field (seed bank) can go up to 142 years

24
Q

Seed bank viability

A
  • 142-year-old experiment at Michigan State University
  • Moth Mullein
25
Q

How many weeds in the United States are Native?

A

40 percent of the weeds found in the United States are native

60 percent are considered exotic or imported.

26
Q

Cost of Invasive Plants in USA

A

Invasive species cost the United States an estimated $34.7 billion each year in control efforts and agricultural losses.

27
Q

Is their any utility for these weeds?

Can we produce another type of crop?

A

Agriculture has not found
another major food crop
since the soybean was
rediscovered in the
western world in the 20th
century.

28
Q

What foods provide about 60% of the human diet?

A

Wheat, rice, and corn

29
Q

What is the difference between summer and winter annual weeds

A
30
Q

What is the advantage for a weed to be a winter annual

A
31
Q

What was the latest major food crop added in agriculture

A

soybean

32
Q

What does soil do for plants?

A

Anchorage: root systems
Oxygen: the spaces among soil particles
contain air that provides oxygen
Water: the spaces among soil particles also
contain water
Temperature modification: soil insulates roots
from drastic fluctuations in temperature
Nutrients: soil supplies nutrients and hold the
nutrients that we add in the form of fertilizer

33
Q

Soil

A
  • Primary source of nutrients and physical support
    for plants
  • Comprised of minerals (inorganic compounds) and
    organic compounds
  • Soils vary in their texture: a ratio of sand, silt and
    clay
34
Q

What is organic?

A

plant material

35
Q

Water-holding capacity

A

soil’s ability to hold
water is called its water-holding capacity

36
Q

Cation exchange capacity (CEC

A

expression of the
soils ability to hold and exchange cations

37
Q

pH

A

is a description of the soil’s acid/alkaline
reaction

  • Soils generally range from pH 4.0 to pH 8.0
38
Q

pH

A
  • Northeastern forest soils can be very acid (pH 3.5)
  • Western soils can be very alkaline (pH 9)
  • Products can be added to soil to adjust pH
  • Example applying lime can increase soil pH for crop
    production
39
Q

Soil texture is defined as?

A

the percentage of sand, silt, and clay particles in a soil.

40
Q

Each plant has an optimal Ph range

A
41
Q

What are essential nutrience

A

needed to complete life cycle
macro and micro nut
macro

42
Q

essentrial nutrience

A

Macro - Nitrogen

Micro - iron

43
Q

what can a plant look like if it has a deficienty

A
  • Stunting
  • Chlorosis
  • Necrosis
  • Purpling
44
Q

Fertilizers

A

Most soils have at least some
residual nutrients (only a soil test
can assess this)
* Fertilizing without the results of a
soil test leads to a waste of
money and product
* Sometimes nutrients are present
but unavailable to plants because
of too high or too low pH

45
Q

Fertilizers
can be
banded

A
  • Vegetable gardens can be
    fertilized by banding or placing
    fertilizer alongside the crop row
46
Q

Compost

A
  • Compost is cheaper than
    traditional ingredients, holds
    water well, provides nutrients,
    and can be produced at home
  • Quality of compost will depend
    on the quality of the materials
    that were composted
  • Organic
47
Q

Why not use
garden soil?

A
  • Garden soils are too dense to
    allow good air and water
    movement when added to a
    container
  • Insects
  • Diseases
  • Weeds
48
Q

Fertilizing a
lawn

A
  • Determine the level of growth
    desired
  • If a low-maintenance lawn is
    desirable, no fertilizer may be
    needed
  • Slow-release fertilizers are
    preferred over soluble fast-
    release formulations
49
Q

How do you know what type of media to select?

A

listed on soil bags

Plant Science (8 decks)

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