Week 4 control techniques

Question 1

Outline a range of physical control methods that might be used to control weeds

Answer 1

Tillage
Roguing
Mowing
Seed Collection

Question 2

Tillage - historical reasoning

Answer 2

Remove Veg
Prepare seed bed
Facilitate infiltration of water

Question 3

Types of tillage

Answer 3

Conventional
Direct Drill
Current cultivation

Question 4

Conventional Cutivation

Answer 4

Long fallow- stores water underneath but dust is an issue

Burried weeds

Question 5

Current cultivation

Answer 5

Use of disk faded out

can bury seeds but most are near surface
Encourages germination of annual Reygrass - Autumn Tickle

Question 6

Direct Drill

Answer 6

Varies from full soil disturbance to narrow slot
Decrease chance of weed germ and establishment
Pre-emergent herbicide less effective
Seed bed retains strength and allows timely application of weed control

Question 7

Roguing

Answer 7

Physical Removal

Effective but labour costly

Question 8

Mowing

Answer 8

Aims to reduce seed set

Depends on how indeterminate the species is

Question 9

Seed collection

Answer 9

Collection of concentrated seeds behind header

Harring seed destructor- pulverises seed

Question 10

Describe what is meant by cultural control methods

Answer 10

Manipulation of practices normally undertaken in a crop or pasture production system
Supress weed growth and seed production while promoting the desirable species

Question 11

Cultural control potential options

Answer 11

Seed cleaning
Delay sowing 
Fire
Crop Rotation
Crop Competition
Rotation to pasture
Grazing management

Question 12

Pros and cons of fire

Answer 12

Early summer burn - 99.9% effective

but leave soil exposed for months

Question 13

Why Delay sowing

Answer 13

allow for weeds to germ, then spray before sowing

Question 14

Crop rotation Pros and cons

Answer 14

Simple Rotation - limited opp to rotate herbicide groups
Forage legumes can be used instead of grain legumes - green manure
long fallow - skip season = more moisture

Question 15

Crop Comp p and c

Answer 15

Oats are most competitive
Aim for appropriate seed depth and seeding rate
Apply fert

Question 16

What pastures should be used in pasture phase

Answer 16

Perennials out compete weeds

Question 17

Outline the range of techniques for using herbicides in a IWM in crop

Answer 17

Herbicide Tolerant Crops
Weed seeker system
Pre-Harvest Application
Brown Manure crop

Question 18

Herbicide tolerant crops

Answer 18

TT- slower growth, conventionally bred

RR- GM

Question 19

Weed seeker system

Answer 19

Only sprays green weeds when sensed by the NDVI sensor

Question 20

Brown Manure crop

Answer 20

Sowing low input grain legume - peas/vetch
Sprayed with knockdown pre seed set
Controls weeds, Increase N, stores Water

Question 21

IWM Techniques Pastures

Answer 21

Winter cleaning 
Spray Topping
Spray Grazing
Wick wiping
Spot spraying

Question 22

Winter cleaning

Answer 22

Remover weed seedling from pasture 6-8 weeks after autumn break
Simazine

Question 23

Spray Grazing

Answer 23

Sublethal dose of hormone herbicide MCPA 2-4,D

Makes broadleaves stand up straighter and taste sweeter

Question 24

Spray Topping

Answer 24

Herbicides used to sterilise annual weed seed set in legume pasture
Apply at flowering - graze 4 weeks before hand
Glyohosate

Question 25

Wick Wiping

Answer 25

Round up to control weeds on the basis of height

Herbicide moves along ropes by capilary action