Weed control

Question 1

mechanical control

Answer 1

• burial (annual weeds)
• cultivation (shallow cultivation to separate weed roots but has disadvantages)
• mowing (tall growing annuals, not effective for short growing plants or perennials)

Question 2

crop competition

Answer 2

• one of the cheapest and effective methods
• need optimal conditions
• factors that will affect the competitive advantage are:
• planting date
• row spacing
• seeding rate
• planting depth
• soil moisture
• soil pH

Question 3

crop rotation

Answer 3

• reduce the population of specific weed which was tolerant to the previous crop
• rotating grasses due to effective herbicide rotation

Question 4

biological control

Answer 4

bacteria and fungi, as well as some caterpillars and/or insects, can be used

Question 5

fire

Answer 5

scheduled burning especially prior to planting will help reduce some persistent weeds

Question 6

chemical control

Answer 6

• can be administered pre-plant
• pre-emergence and post-emergence
• the application of chemical control:
• broadcast (most effective)
• band applications (with cultivation, direct applications - late in the season)
• spot treatment (isolated areas)

Question 7

herbicides

Answer 7

• classified according to where and how they are applied and their action on plants
• may be either foliage applied of soil-applied
• consists of contact or systematic materials that are translocated throughout the plant
• can be selective or non-selective
• those registered for pasture are aimed at the control of broad leaf weeds, although young grass seedlings may also be sensitive
• registered for grass pastures are all post-emergence contact killers with hormonal effect
• registered for Lucerne and other legumes are usually pre-emergence, and the herbicide must be worked into a seed bed