Weed Physiology and Morphology Flashcards
It is the reproduction of seeds without fertilization as of ferns.
Apomixis
It is the change in weed population that depicts the growth if weeds within a certain area or habitat.
Weed population Dynamics
The three parameters that determine weed infestation within a field.
- Number of Species present
- Density of each Species
- Distribution of Species Across the Field
The term used to describe a weed population which a negative crop yield response is detected.
Damage threshold
It is the weed population at which the cost of control is equal to the crop value increase from control to the present.
Economic Threshold
This implies that there are times during the crop cycle that weeds are more or less damaging than others.
Period threshold
It is the point at which some control action is initiated.
Action Threshold
This environmental factor has a primary influence on seed dormancy and germination.
Soil temperature
Oxygen concentration in soil air does not fall below __%.
19%
It is the process limiting infestation of weed plants so that crops can be grown profitably.
Weed Control
It is the prevention, eradication, and control by regulated use preventing complete destruction.
Weed Management
It includes every possible method to prevent the introduction, establishment, and spread of weeds.
Preventive Weed Control
The complete removal of weed propagative parts or seeds within the given area.
Eradication
These are the practices that aim to limit, reduce, and inhibit the growth and distribution of weeds within a certain area.
Control
This summer practice aims to break soil clods so that growing weeds and their roots will be exposed to the sun, letting them wither and die.
Summer Tillage
This type of weed are the best targets for biological control.
Introduced weeds
This moth controls Cyperus rotundus.
Bactra verutana
Lantana camara is controlled by this moth. It usually bores in the flowers, stems, and eat its fruits and flowers.
Crocidosema lantana
A liquid suspension of fungal spores of Phytophthora palmivora causes root rot. It is a strangle vine (Morrenia odorata) in citrus.
Devine
A wettable powder containing fungal spores of Colletotrichum gloeosporoides that causes stem and leaf blight. It targets Joint vetch (Aeschyomone virginica) in rice, soybean.
Collego
A suspension of fungal spores of Bipolaris sorghicola. It targets Jhonson grass (Sorghum halepense).
Bipolaris
A microbial toxin produced as fermentation product of Steptomyces hygroscopicus. It targets non-specific, general vegetation.
Biolophos
