Preventive Management
Define EDRR
Early Detection and Rapid Response
Which crop is more competitive? Soybeans or onions?
Soybeans
The three overall ways that tillage kills weeds
Direct action, smothering effect, indirect effects
The two types of selective biological controls
Classical (Inoculative) and Inudative/Augmentative
Define management in terms of weeds
The process of reducing the impact of weed infestations (often by reducing them).
Quarantine vs Containment
Quarantine is the exclusion from a given area where containment is restriction to within a given area
Why is the planting date so important in regards to cultural/ecological control?
Timing weed emergence can allow for more vigor in the crop or weeds.
What is conservation tillage?
Any tillage system that reduces soil and/or water loss compared with conventional tillage either by leaving appreciable crop residues on the soil surface, leaving the surface rough and cloddy or ridged, or a combination of the two
The definition of biological weed control.
The deliberate use of natural enemies to reduce the density of a particular weed to a tolerable level
What is the conservation biological control approach?
Control agents already existing in field are maintained/increased by providing habitat.
What factors kill seeds in corn silage?
low pH, high organic acid content, and lack of oxygen
Name 2 direct effects of cover crops on weeds.
Competition for resources, allelopathy, altered microenvironment, physical suppression.
Name three disadvantages to tilling
Exposure of soils to wind and water erosion
Breakdown of soil aggregates and formation of compacted soil layers
Continued burial of weed seeds
Spread of weed seeds and vegetative reproductive structures to uninfested area
Damage to crop roots, especially with deep or late season cultivation
Give two examples of how biological agents control weeds.
seed predation, rosette feeders, herbicide action etc.
How did conventional tillage select for perennial and annual weed species?
Selected for perennials that rely on fragmentation and dispersal for successful regeneration
Selected for annual species that produce dormant seeds having a potentially long life span
The difference between a noxious weed and an invasive species
A noxious weed is a plant or plant product that can directly or indirectly injure or cause damage to crops, livestock, or other interests of agriculture, irrigation, navigation, natural resources, public health, or the environment while an invasive species is a : 1) non-native (or alien) to the ecosystem under consideration and 2) whose introduction causes or is likely to cause economic or environmental harm or harm to human health--- a noxious weed CAN be native
Name 4 ways to improve the competitive ability of a crop.
Transplant seedlings and establish size hierarchy, Fertilizer or irrigation placement close to crop, Select competitive crop cultivars (taller, larger leaves), Using larger crop seeds and increasing seeding rate, Delay planting in spring until soil warms, Shift to a less competitive weed community, Increase soil resources pool diversity
Primary tillage- moldboard plow
Secondary tillage- harrows, field cultivators, bed conditioners
cultivation/intertillage- rotary hoes, light harrows, cultivators
Give one example of a Biological Control Agent and it's related host.
ex) Control of Lythrum salicaria by Galerucella...answers may vary
Fill in the Blanks: (Blank) year’s seeding is worth (Blank) years weeding.
1, 7
List 5 Ways Preventive Weed Control at the Farm Level
1.Be able to identify weed species. Be aware of weeds in the regional species pool.
2.Perform additional control measures on isolated patches of new weed incursions.
3.Effective weed management in-crop.
4.Control late growing weeds and survivors (escapes) before seed set as appropriate.
5.Take care burying seed by cultivation. Record where long-lived seed is buried.
6.Use clean crop seed. (Contaminated seed is the most common method of introducing weed seeds to a given area).
7.Caution with livestock feed and movement: feed ensiled/cooked (killed), screenings, ferment (heat) manure, caution moving livestock out of infested areas.
8.Clean farm machinery.
9.Keep irrigation ditches and drainage channels free of weeds.
10.Control new species appearing on field edges, fencerows, buffer areas, roads, etc.
11.Use ecological/cultural management techniques.
12.Use integrated weed management approaches.
Which common cover crop did we learn during weed identification(common and scientific name).
Wild Radish (Raphanus raphanistrum)
The two processes of minimum tillage and a disadvantage to the process
1) plow-harrow-plant: can be achieved in 2 operations (plow-harrow followed by planting) eliminates disking after plowing and results in a less firm seed bed in between rows for weed seed germination (in contrast, rain will firm soil)
2) plow-plant: can be achieved in 1 or 2 operations, eliminates both disking and harrowing; poor contact between soil and weed seeds in between rows but press wheels of planter firm soil on row and results in early emergence of crop and weeds on row
The disadvantage to these methods is the presence of loose soil in between rows and depressions on rows where planting occurred. During heavy rainfall, herbicides can be leached into these depressions causing phytotoxicity
At which point in Sorghum's life cycle is Fusarium oxysporum applied?
It is a seed coating
You are a grower with a heavy infestation of perennial weeds. Combine all known strategies and recommend 2 management strategies for control.
tillage to break apart rhizomes, cover crops to reduce carbohydrate stores, etc.