2011 Exam

Question 1

Name ways you could increase the humidity in a glasshouse or polyhouse

Answer 1

• fogging
• misting
• close ventilation
• wet flooring

Question 2

Name ways you could reduce the impact of frost in an orchard

Answer 2

• fans, helicopters, etc.
• shade cloth, shelter, etc.
• overhead irrigation
•  fires.

Question 3

Name ways you could improve the water-holding capacity of a sandy soil

Answer 3

• add organic matter, compost, humus
• add water-holding crystals
• mix in other soil types – clays or loams.

Question 4

Name ways you could reduce the acidity of a potting mix or soil

Answer 4

• add lime (calcium carbonate)

- add dolomite (calcium magnesium carbonate).

Question 5

Name ways you could reduce heat stress on sheep in a paddock

Answer 5

• provide shade in the paddock, shade trees, shelter belts, sheds
•  carefully time the shearing (not too bare but not too much heavy wool).

Question 6

Name ways you could improve the structure of compacted soil in a field

Answer 6

• deep ripping
• add organic matter
• add gypsum if the clay component is high
• reduce traffic (stock or machinery).

Question 7

Name ways you could increase the concentration of carbon dioxide (CO2) in a glasshouse or polyhouse

Answer 7

• recycle CO2 emissions from other farm activities
•  recycle CO2 emissions from off farm businesses (for example, power stations)
•  release CO2 from cylinders of compressed gas.

Question 8

Describe benefits of using a non-soil growing medium such as perlite, peatmoss, vermiculite, gravel, sand, clay pebbles, coconut bre and rockwool

Answer 8

•  there is less chance of disease; no soil-borne diseases or weed seeds
•  they are lighter; there is less mass for lifting or hanging pots, baskets, etc.  they are clean and attractive
•  they provide better control over water holding capacity, porosity, nutrient application, and pH.

Question 9

Explain the benefits associated with laser levelling for modifying farm topography.

Answer 9

better control over water management; allows for precision irrigation, collection and recycling of irrigated water; reduces water entering and raising the water table

Question 10

Explain the benefits associated with contouring for modifying farm topography.

Answer 10

reduced runoff; retains moisture in the soil; reduced likelihood of soil erosion; safer use of tractors and other vehicles

Question 11

Explain the benefits associated with terracing for modifying farm topography.

Answer 11

converts land that is too steep for cropping to land that can be cropped; increases the area available for crops; retains moisture; prevents the erosion of top soil

Question 12

Explain the benefits associated with raised beds for modifying farm topography.

Answer 12

improved drainage; less water-logging; reduced impact of compaction if vehicles always use hollows between beds

Question 13

Describe the effects of blackberry on business production

Answer 13

• competition with the crop/pasture for light, nutrients, moisture and/or growing space
•  reduced product quality of wool or meat due to thorns being present in these products
•  reduced availability of farming land due to this weed taking over the landscape/field
•  lost production, measured as reduced plant yield or lower livestock production, due to competitive effects
•  reduced biodiversity as these weeds may become the dominant species in a suitable environment/location

Question 14

Describe the effects of chilean needle grass on business production

Answer 14

• competition with the pasture for light, nutrients, moisture and/or growing space
•  reduced product quality of wool or meat due to weed seeds being present in these products
•  reduced availability of farming land due to this weed taking over the landscape/field
•  lost production, measured as reduced plant yield or lower livestock production, due to competitive effects
•  reduced biodiversity as these weeds may become the dominant species in a suitable environment/location

Question 15

Describe the effects of gorse/furse on business production

Answer 15

• competition with the pasture for light, nutrients, moisture and/or growing space
  - reduced product quality of wool or meat due to thorns being present in these products
  - reduced availability of farming land due to this weed forming dense thickets and taking over the
  landscape/field
  - lost production, measured as reduced plant yield or lower livestock production, due to competitive effects
  - reduced biodiversity as these weeds may become the dominant species in a suitable environment/location

Question 16

For Integrated Weed Management (IWM), what steps should be considered

Answer 16

• accurately identify the weed as being a problem
  - assess the scale of the problem (economic threshold)
  - prioritise the sequence for treating weedy areas
  - plan the IWM program
  - combine all available weed management options
  - when herbicides are used, repeated applications may be required for several years, until the weed populations
  are below the economic injury level
  - to avoid/delay the onset of herbicide resistance, herbicide products with different modes of activity must be used on a rotational basis to reduce weed populations
  - monitor and review the performance of all IWM practices, modify practices to achieve optimum weed
  management.

Question 17

Describe how an Integrated Weed Management (IWM) approach may be used to manage a blackberry problem.

Answer 17

• introduce leaf rust, crown borer or leaf miner
•  buy certified seed
•  don’t buy hay/livestock from contaminated areas
•  the most vigorous growth is in the spring and it can grow up from root parts in the soil
•  graze heavily with goats
•  cut down, dig out and burn
•  during winter, burn then deep rip accessible areas to remove canes
•  sow perennial pasture
•  use crop/pasture rotation
•  repeat-spray emerging leaves
•  spot-spray with registered herbicides: Knock-down, Roundup (glyphosate)
•  selective: metsulfuron-methyl (Brushoff, Trounce) or triclopyr (Garlon) products

Question 18

Describe how an Integrated Weed Management (IWM) approach may be used to manage a chilean needle grass problem.

Answer 18

• good hygiene can be effective in preventing human-assisted spread of Chilean needle grass
•  cleaning vehicles, machinery, equipment and other material is very important in preventing further spread, as is controlling the movement of livestock from infested to clean areas, particularly along roadsides
•  feed stock in controlled areas to minimise the risk of seed spread and to limit the area requiring control
•  reduce the risk of this and other weeds by requesting a Weed Hygiene Declaration from suppliers confirming that the material and livestock brought onto the property are free of weed seed
•  avoid overgrazing and leaving pasture areas bare
•  aim to maintain competitive perennial pastures that provide good ground cover
•  burn, then spray the regrowth
•  spot-spray with registered herbicides: Knock-down, Roundup (glyphosate)

Question 19

Describe how an Integrated Weed Management (IWM) approach may be used to manage a Gorse/Furse problem.

Answer 19

• introduce gorse seed weevil, gorse thrips, gorse soft shoot moth
•  burn plants, spot-spray
•  bulldoze/rip/rotary hoe and/or plough infestations
•  follow-up with herbicide treatment
•  avoid overgrazing and leaving the pasture area bare
•  spot-spray with registered herbicides: Knock-down, Roundup (glyphosate)

Question 20

Frieda applies a selective herbicide to a 20 hectare oat crop. The following year she sows inoculated peas into half of the treated paddock as part of a crop rotation program. The other half of the paddock is sown for grass hay. After emerging from the ground the peas fail to thrive and grow poorly but the grass grows well. Explain a likely cause for the poor pea growth.

Answer 20

the herbicide residue on dicots and monocots responds to different herbicides. The herbicide would have been a ‘broad leaf’ herbicide that only kills dicot plants, hence the grass is not affected.

Question 21

Describe the responsibilities a farm owner has in relation to regionally controlled weeds

Answer 21

Regionally controlled weeds are declared noxious weeds that are widespread and established in a region (for example, blackberry and ragwort). Land owners must take reasonable steps to prevent the growth and spread on or in relation to their land (for example, at the adjacent roadside).

Question 22

Explain what a ‘withholding period’ is on the label of a pesticide

Answer 22

The withholding period is the period that must elapse between the last application of a chemical and the harvesting of plants, grazing or cutting for stock food or consumption by a human or an animal after post-harvest use.

Question 23

Explain how a withholding period relates to quality assurance of a farm product

Answer 23

If the withholding period is not observed, product quality may be compromised by excessive residue of the pesticide in the product. The pesticide may be toxic if ingested. In the case of antibiotic use, the likelihood of antibiotic-resistant bacteria may be increased.

Question 24

Suggest reasons why it is important to read the label for a pesticide (not including withholding period)

Answer 24

It is important to read the label for a pesticide to determine:

•  the correct application rate
•  the correct application method
•  how to avoid resistance to active ingredients
•  the correct pesticide for pest and/or mode of activity
•  the correct frequency and timing of application
•  health and safety considerations (for example, protective clothing)
•  the correct disposal of unused product or container.

Question 25

Explain how you would go about monitoring for Coccidiosis

Answer 25

• Problems are not common in chicks under three weeks of age because the parasites take time to build up.
•  Affected birds exhibit depression, loss of condition, paleness, ruffled feathers, drooping wings, pale and dry flanks, slight whitish soiling around the vent (only occasionally), diarrhoea and blood in the droppings.
•  Often a large percentage of the chickens are sick. Birds may die suddenly before the above symptoms are obvious.

Question 26

Explain how you would go about monitoring for Aphids

Answer 26

• Monitor using a sticky trap and plant leaf checks. Decide on a threshold level for aphids in your crop, above which you must spray and below which you can safely withhold spraying.
•  Plan the layout of traps to identify hot spots and estimate overall aphid levels together with plant scouting. Place traps just above the plant tops. Do a weekly count of aphids on each trap and look for infected plants. Mark infected plants with tape for removal and replace sticky traps.
•  Note any aphid hot spots and check aphid numbers on nearby plants to find the size of hot spots. Check for biological control activity. Record trap and scouting details. Check numbers on marked plants one to two days after spraying to check the results.

Question 27

Explain how you would go about monitoring for Milk fever

Answer 27

• Jersey cows that are mature and fat and graze on lush, clover-dominant pasture before calving are most susceptible.
•  Regularly (at least twice daily) check cows that are close to calving and for about three days following calving.
•  In typical cases, cows show some initial excitement or agitation and a tremor in muscles of the head and limbs. Then they stagger and go down to a ‘sitting’ position, often with a ‘kink’ in the neck, and finally lie flat on their side before circulatory collapse, coma and death.
•  A dry muzzle, staring eyes, cold legs and ears, constipation and drowsiness are seen after going down. The heartbeat becomes weaker and faster. The body temperature falls below normal, especially in cold, wet, windy weather.

Question 28

Explain how you would go about monitoring for Sheep blowfly

Answer 28

• Monitoring climatic conditions can help to predict blowfly activity.
  - The risk of flystrike increases once the temperature is above 17 °C, wind speeds are moderate (< 30 km per hour) and sheep fleece remains moist from rainfall for a few
  days.
  - Monitor blowfly populations through trapping.
  - Inspect sheep for maggots.
  - Catch, clip and treat individual blowfly-struck sheep.

Question 29

What is important to mention in a question about monitoring pests and diseases?

Answer 29

A description of a well-planned strategy that includes timing of events.

Question 30

what should an outline of a farm biosecurity plan include?

Answer 30

• physical prevention activities (consider how the pest or disease could enter the property)
•  a plan for monitoring
•  a plan for preventative treatments
•  a consideration of management options that are available if needed.

Question 31

Describe a biosecurity plan for prevention of Coccidiosis from impacting on the sustainability of an agricultural/horticultural business.

Answer 31

Disease agents and pests can be introduced to a poultry farm by the movement of eggs, birds, people, vehicles and equipment between farms, and by clothing, footwear, aerosols, water, feed, litter, wild birds, biting insects and vermin.

Question 32

Describe a biosecurity plan for prevention of Aphids from impacting on the sustainability of an agricultural/horticultural business.

Answer 32

• Control weeds on field edges if scouting indicates that aphids are present, and control weeds within crops.
  - Destroy old crops immediately after the harvest has finished.
  - Use a fallow period, if possible, when no crop is grown to clear pest populations.
  - Do not plant new crops near or close to neighbouring infested weeds or old crops (greenhouse and open field).
  - Use seedlings that have been grown away from infested areas; that is, start with a clean crop.
  - Avoid moving aphids around the crop by staff moving from infested to clean areas.
  Do not work in old crops on windy days, especially when prevailing winds are blowing towards new plantings.
  - Mesh screening has been shown to effectively exclude aphids in covered/protected crops and the use of reflective plastic soil mulch can be beneficial in reducing aphid numbers. Rolls of yellow sticky tape may be useful in some greenhouse designs if placed near entry points and hot spots.
  - Monitor pest populations for early control. Use yellow cards to alert you of new infestations and scout plants by turning leaves to work out where they are. Control is simpler and less expensive when plants are young and spray coverage is not an issue.

Question 33

Describe a biosecurity plan for prevention of Milk fever from impacting on the sustainability of an agricultural/horticultural business.

Answer 33

• There is no infective agent, so normal biosecurity measures do not apply.
•  Milk fever is a disorder mainly of dairy cows close to calving. It is a metabolic disease caused by a low blood calcium level (hypocalcaemia). Between 3% and 10% of cows in dairying districts are affected each year, with much higher percentages occurring on some properties. Jersey cows that are mature and fat and graze lush, clover-dominant pasture before calving are most susceptible.
•  About 80% of cases occur within one day of calving because milk and colostrum production drain calcium (and other substances) from the blood, and some cows are unable to replace the calcium quickly enough. High producers are more susceptible because the fall in their blood calcium level is greater. Selecting cows for high production may, therefore, increase the problem with milk fever. Some individual cow families or breeds (for example, jerseys) are more susceptible than others.
•  Age is important. Heifers are rarely affected. Old cows increase in susceptibility up to the fifth or six calving because they produce more milk and are less able to replace blood calcium quickly.
•  The feeding management of dry cows in the two weeks before calving is very important, because it affects both the amount of calcium available to replace blood calcium and the efficiency with which the available calcium can be used.
•  When the amount of calcium in the diet is greater than is needed, the efficiency of absorbing calcium from the intestine and the efficiency of transferring calcium from the skeleton both become very sluggish and the chance of milk fever is greatly increased.
•  Also, grazing pastures in southern Australia in winter and spring results in alkaline blood which creates unfavourable conditions for the availability of calcium in the body and predisposes the cow to milk fever. Feeding hay prior to calving and restricting access to green feed results in acidic blood which favours calcium mobilisation from bone and improves calcium absorption from the intestines, both of which are important factors in preventing the occurrence of milk fever.
•  Fat cows are at a greater risk than thin cows. This is partly because their feed and calcium intake has been higher and partly because fat cows produce more milk at calving time.
•  Some cows get milk fever several days or even weeks before or after calving. This is usually due to the feed, especially the dietary calcium, being insufficient to meet the heavy demand due to the rapidly growing foetus or milk production in early lactation.
•  In early lactation, cows should receive as much calcium as possible, and clover- dominant pasture is therefore desirable. They will help to prevent both milk fever and grass tetany.

Question 34

Describe a biosecurity plan for prevention of Sheep blowfly from impacting on the sustainability of an agricultural/horticultural business.

Answer 34

• Any flystrike prevention program must be aimed mainly at Lucilia cuprina. As this fly breeds almost exclusively on susceptible living sheep, prevention of flystrike will reduce the numbers of this fly. This in turn reduces the pressure on any sheep that do become susceptible to flystrike.
  Small flystrikes early in the season provide the means for numbers of Lucilia cuprina to build up from the relatively few maggots that survive the winter. These can be greatly reduced by:
  1. correct tail docking
  2. mulesing of sheep kept for wool (surgical mulesing ceased in 2010, but non-surgical alternatives are under development)
  3. preventing scouring by using a good worm control program o breeding breech-strike resistant sheep
  4. selectionawayfromharsh-woolled,wrinklysheep.
• Destruction of flystruck crutchings kills many maggots that would otherwise survive. Jetting should not be used as a substitute for other management practices, but can be a valuable aid.
  Trapping
  - The LuciTrap system consists of a specifically designed trap with a patented blend
  of chemicals to attract and capture the Australian sheep blowfly (Lucilia cuprina).
  - It is designed to reduce blowfly numbers and fly strike.
  - The LuciTrap system is an adjunct to other blowfly control procedures and must be combined with them in an IPM program to minimise pesticide use and residues on wool.

Question 35

Roundup Ready Canola is a variety of Canola that is genetically modi ed to be resistant to the herbicide, glyphosate (RoundupTM). Growers can spray Roundup Ready Canola as a non-selective, post-emergent herbicide over the crop, killing weeds and leaving the crop unharmed. Describe advantages and disadvantages of using this type of biotechnology

Answer 35

Advantages of using this type of biotechnology (genetically modified Roundup Ready Canola) include:

•  time saving
•  simpler spray equipment and regime
•  crop not contaminated with weeds
•  crop not harmed
•  no, or less, tillage and fewer herbicide applications
•  higher yielding genetically modified varieties
•  earlier sowing
•  reduced traffic, resulting in less compaction
•  reduced fuel, labour and machinery
•  use of cheaper, broad-spectrum herbicides.

Disadvantages of using this type of biotechnology (genetically modified Roundup Ready Canola) include:

•  higher volumes of spray used
•  not allowed to save seeds
•  drift to other areas
•  safety risks with greater use of herbicide
•  potential for cross species pollination
•  escaped canola may be a problem elsewhere (for example, for neighbours)
•  higher seed prices
•  need for buffer zones
•  threat to organic growers
•  diminished gene pool
•  weed resistance to herbicide may be increased  may reduce the saleability of the product.

Question 36

Suggest risks that genetically modi ed organisms pose to organic growers or to the natural environment.

Answer 36

- risks of spray drift causing damage to the environment, neighbouring crops/pastures, people, fauna, flora and
or soil/water
- cross pollination with neighbouring crops or related wild species resulting in herbicide resistance.