Lecture 5 - Alfalfa History, Sub-species Management

Question 1

Scientific name of Alfalfa

Answer 1

Medicago sativa

Question 2

what is another name for alfalfa

Answer 2

the ‘Queen of the forages’

Question 3

______ ha of alfalfa was grown in the prairies in 2021

Answer 3

4 million

Question 4

alfalfa is the ______ most grown crop in the US

Answer 4

4th

Question 5

origin of alfalfa

Answer 5

ancient Iran

Question 6

who brought alfalfa to Texas, Arizona, New Mexico, and California

Answer 6

catholic missionaries

Question 7

who was Wendelin Grimm

Answer 7

brought strain of alfalfa that can survive harsh winters

Question 8

what is the most widely adapted forage species/agronomic crop

Answer 8

alfalfa

Question 9

adaptation of alfalfa

Answer 9

-genetic diversity (2 diff species and range of intermediate types)
-extreme stress tolerance/winter hardiness/easy to grow
-deep roots
- fall dormancy categories (1-11)

Question 10

limitation of alfalfa

Answer 10

cant tolerate acidic soil and poor soil draining

Question 11

what is fall dormancy ratings

Answer 11

plants responses to photoperiod (short day) and low air temp

Question 12

how does the alfalfa fall dormancy rating work

Answer 12

1-11
1=little to no growth in fall
11=rapid growth in fall

Question 13

what are the recommended cultivars/dormancy ratings in Western Canada

Answer 13

dormancy rating 1-3 because higher ratings are less winter hardy

Question 14

alfalfa sub species

Answer 14

Medicago sativa
Medicago falcata
Medicago media

Question 15

characteristics of Medicago sativa

Answer 15

Purple flower
shallow root crown
spiral seed pod (10-20seeds/pod)

Question 16

what is the ploidy of Medicago sativa

Answer 16

auto-tetraploid (AAAA)

Question 17

characteristics of Medicago falcata

Answer 17

yellow flower
deep-set crown
branched roots
sickle-shaped pod (10seed/pod)
small leaflets

Question 18

ploidy of Medicago falcata

Answer 18

diploid or tetraploid

Question 19

what are some benefits of medicago falcata

Answer 19

deep crown=more grazing resistant
slow regrowth=winter hardy and drought tolerant
very persistant

Question 20

example of medicago falcata cultivar

Answer 20

AC yellowhead alfalfa

Question 21

characteristics of Medicago media

Answer 21

various flower color (variegated)
intermediate type

Question 22

ploidy of Medicago media

Answer 22

tetraploid

Question 23

types of alfalfa root system

Answer 23

Tap rooted
branched rooted
creeping rooted

Question 24

tap rooted

Answer 24

limited branching

Question 25

branched rooted

Answer 25

deeper set crown, more winter hardy

Question 26

creeping rooted

Answer 26

rhizomatous type

Question 27

multi-foliate leaf alfalfa types

Answer 27

more than 3 leaflets

Question 28

forage quality of multi-foliate types compared to normal alfalfa

Answer 28

similar leaf to stem ratio to regular types (no added benefit)

Question 29

2 types of axillary buds that facilitate alfalfa growth

Answer 29

-develop from crown between a petiole of a leaf and the stem (leaf axil)

Question 30

fall harvest management of alfalfa

Answer 30

must have critical fall rest period from Aug 15-Oct 1 can have final harvest/grazing after killing frost

Question 31

what happens if you cut alfalfa during that critical fall rest period

Answer 31

depletes the organic reserve (CHO) winterkill affects following year yield

Question 32

when/where is 1 cut schedule used for alfalfa

Answer 32

early July southern SK

Question 33

when/where is 2 cut schedule used for alfalfa

Answer 33

Late June and Mid Aug Black soil zone

Question 34

when/where is 3 cut schedule used for alfalfa

Answer 34

late June + mid Aug + after Oct 1 Black soil zone or irrigation

Question 35

ideal conditions to establish alfalfa

Answer 35

control perennial weeds soil pH 6.5-7.0 well-drained site

Question 36

t/f: alfalfa is easy to establish

Answer 36

t

Question 37

what compound is responsible for alfalfa's autotoxicity

Answer 37

medicarpin

Question 38

ideal seeding depth for alfalfa

Answer 38

no deeper than 1.5cm

Question 39

when to cut hay for beef cattle

Answer 39

10-50% bloom

Question 40

when to cut hay for dairy (quality over quantity)

Answer 40

late bud to very early bloom at <5%

Question 41

does alfalfa cause ruminant bloat

Answer 41

yes

Question 42

what is grazing tolerant alfalfa

Answer 42

selected under continuous grazing has a wide-deep set crown

Question 43

Roundup ready alfalfa (GMO)

Answer 43

bacterial gene introduced for tolerance to herbicide roundup

Question 44

why is roundup ready alfalfa not allowed to be grown in western Canada

Answer 44

alfalfa is typically grown with grass, so it will kill grass if you spray

Question 45

low-lignin alfalfa (GE)

Answer 45

conventional breeding type that improved digestibility 10-20%