Lecture 10 Flashcards
how many elements are required for plant growth?
16
what elements are acquired from water & air?
C
H
O
how many elements are acquired from the soil?
13
what type of nutrients are required in large amounts?
macronutrients
what are the primary macronutrients?
N, P, K
what are the secondary macronutrients?
Ca, S, Mg
secondary nutrients are required in ________ amounts than primary macronutrients
smaller
what nutrients are required in relatively small amounts?
micronutrients
what are the micronutrients?
B - boron
Mn - Manganese
Zn - Zinc
Fe - iron
Mo - Molybdenum
Cu - copper
Cl - chlorine
Ni - nickel
how many micronutrients are there?
8
what nutrient do broccoli & onion plants require more of?
S
what is the result of a deficiency in an essential nutrient?
abnormal growth
failure to complete life cycle
or premature death
what are essential nutrients directly involved with?
plant growth or metabolism
describe the nutrient content in urban soils
unbalanced - deficient in some & excess in others
describe the movement of mobile nutrients
relocate from older tissues to new tissues
what are the mobile nutrients?
N, P, K, Mg
if a plant has a nutrient deficiency, where is it initially seen?
older tissues
where do less mobile nutrients reside?
older tissues
what nutrients have variable mobility?
S, Fe, Zn, Cu, Mo, Cl
what are the least mobile nutrients?
Ca, Mn, B
where would a plant initially display nutrient deficiency symptoms it is deficient in Ca, Mn or B?
younger tissues
acute nutrient deficiency
Deficiency is severe and plants no longer have sufficient nutrients to support rapid growth
chronic nutrient deficiency
Nutrient supply is limited and insufficient to support rapid growth
slow growth, plant stunting
chronic nutrient deficiency symptoms are ______ specific than acute nutrient deficiency
less
what factors affect nutrient availability?
soil moisture
aeration
pH
temperature
chlorosis
lack of chlorophyll leading to yellow or white leaf colour
necrosis
tissue death
branching
new shoots coming out of leaf axels
tillering
producing new branches from the base
what are the common symptoms of nutrient deficiency? (6)
chlorosis
purple colouring
necrosis
stunting
lack of branching or tillering
poorly shaped leaves
symptoms of nutrient deficiency may be similar to symptoms caused by what? (5)
lack of water
excess water
salts
insects
plant pathogens
what measures need to be taken to determine the cause of a plant’s symptoms?
Observe whole plant envr, location of symptoms & plant to plant variation
what is N critical for?
plant processes (ex: NAs, PROs)
what are the symptoms of a N deficency?
Uniform leaf chlorosis (yellowing) in older leaves first
Plant stunting or new leaves smaller
Spindly plants
what are the symptoms of excess N?
Excessive vegetative growth at expense of reproductive growth (tall but no fruits)
Reduce quality
Lodging (falling over)
phosphorus is absorbed as _________ ions
orthophosphate
what are the orthophosphate ions absorbed by plants?
H2PO4
HPO42-
what are the 3 molecules that P is found in?
PROs, DNA & RNA
what is the main role of P in plants?
E transfer in the plant (ATP & ADP)
what are the symptoms of P deficiency? (4)
Poor root growth and delayed maturity
stunting, short internodes
Dark blue, purple or red-purple coloration – appear first in older leaves
few flowers & poor fruit
what factors influence the availability of P?
Often bound to soil particles
optimum pH 5.5-7.0
Dry or cool soils reduce availability
what form is N absorbed by plants?
ammonium (NH4a+)
nitrate (NO3-)
what form is K absorbed by plants?
ionic form (K+)
what is the role of K?
catalyst for regulatory enzymes
Photosynthesis, translocation, PRO synthesis, starch storage, meristematic growth
what are the symptoms of K deficiency? (5)
poor growth
Yellow scorching or “firing” on leaf margins
weak stems
Delayed maturity, uneven ripening
Shriveled fruit
where is a k deficiency commonly found?
sandy or healthy leached soils
leached
lots of rainfall
what form is Ca absorbed by plants?
Ca2+ ions
what is the role of Ca?
cell growth & division
Cell wall formation
N accumulation
what are the symptoms of Ca deficiency? (6)
Defective terminal bud development
Improper leaf margin formation
chlorosis with brown or black scorching
Tip die-back
Blossom end rot
Poor root growth (short and thickened)
what form is S absorbed by plants?
SO42-
what is the role of S?
essential component of PROs & AAs
PRO & chlorophyll syn
unique flavours in some vegetables (ex: onions & cabbage)
what are the symptoms of S deficiency? (3)
chlorotic foliage
Weak, thin stems
Hard and woody
what form is Mg absorbed by plants?
Mg2+
what is the role of Mg?
central atom in chlorophyll structure
involved in fat & sugar formation
what are the symptoms of Mg deficiency? (5)
appear in older leaves first
Interveinal chlorotic mottling
leaf margins become yellow or reddish purple
Mottling of the older leaves
leaf may become stiff & brittle
