EXAM 2 Flashcards
What type of root system do cereal plants have?
fibrous
What are cereal plants mainly used for?
Starch
What are the top cultivated cereal plants?
Corn, wheat, rice, barley, sorghum, oat, rye
Are cereal plants monocots or dicots?
monocots
Are almost cereals monocots or dicots
dicots
What are some examples of almost cerals?
Amaranth, quinoa, buckwheat, chia
What are the three sisters?
corn, beans, squash
Why were corn, beans and squash planted together?
the beans provided nitrogen, the corn supported the climbing bean and the squash acted as a cover crop
What is monocropping?
cultivating one crop in an area at a time
What is intercropping?
cultivating two or more crops in the same area at the same time
Why are legumes part of intercropping?
because of their nitrogen fixing
What are the down sides of intercropping?
- seeding is more difficult
- reduced herbicide options
- seed separation required
- harvest time is challenging
What are the up sides of intercropping?
- good weed control and less use of nitrogen
- diversity of commodities
Why do poorer countries rely on pearl millet?
- its a source of income and it is very nutritious
What are the characteristics of cassava
- very starchy, large ones can contain a lot of cyanide
- less cyanide=less starch
called poor mans food because it ensures theres something to eat even in drought
Is sweet potato tolerant to cold temperatures?
yes
Which variety of cassava has more cyanide?
the bitter variety
What is an example of intercropping in Africa?
cassava-maize-plaintain
What is an example of intercropping in Africa?
cassava-maize-plaintain
What is the rhizoplane?
the surface of the roots
What is the rhizosphere?
the soil volume surrounding the rhizoplane affected by root activity
What is the key element for plant growth?
nitrogen
Why cant plants fix nitrogen in the atmosphere?
because of nitrogens triple bond, its too strong
what does nitrogenase do?
converts N2 gas into ammonia
does nitrogenase work in oxygenated areas?
no, only works in low oxygen areas
how do legumes fix nitrogen?
create root nodules which creates a low oxygen environment
how can root nodules create a low oxygen environment ?
through the bacteriod membrane which is an oxygen barrier
What protein maintains low oxygen
Leghaemoglobin
which legume has the biggest nitrogen fixation capacity?
Faba bean
What is mycorrhizae?
a fungal root that forms a symbiotic relationship with the plant it attaches to, enhances drought resisttance, improve soil aggregates and reduces soil reosion
What is ectomycorrhizae?
does not go deep into the plant, a type of symbiotic relationship between plants and ectomycorrhizae
What is endomycorrhizae?
goes deep into the plant, a type of symbiotic relationship
