A guide to
Why grow dryland cotton? 4
1. Better gross margins - the analysis
2. A rotational plan to control weeds and disease
3. There’s more choice with Cotton Choices™
Biotechnology has transformed the cotton industry 9
Cotton - the agronomic pros and cons 10
What is required to grow dryland cotton? 11
The 8 stages of successful dryland cotton growing 12
Selecting a dryland cotton variety 16
Cotton marketing 17
Plan for refuge crops 19
Post crop management 20
Control of volunteer and ratoon Roundup Ready Flex and Bollgard II cotton
Herbicide resistance 23
For more information 23
Why grow dryland cotton?
It’s time to take another look at growing cotton. With
the introduction of biotechnology, cotton production
has changed dramatically and the benefits are
hard to ignore.
Dryland Cotton in particular has had some major
advances of late, with improvements in managing
insects and weeds, making it a viable summer
cropping option. With Monsanto’s revolutionary traits
you can now use less insecticide sprays to manage
pests, which means reduced labour, less costs and
a more manageable cash flow. What’s more, CSD in
partnership with the CSIRO Cotton Breeding program
have developed a new suite of high yielding and
high quality varieties, such as Sicot 71BRF, which are
highly adaptable for dryland production, giving you
the opportunity to maximise returns whilst minimising
Planting row configuration effects on dryland
risks. And with the introduction of Cotton Choices™
cotton gross margin
you have more flexibility for your operation.
The vigorous tap root of the cotton plant allows for
wider exploration of the soil profile for moisture and
1. Better gross margins – the analysis
nutrients, particularly when compared with fibrous
Improvements in variety performance and root type crops. This characteristic has led to the use
technology traits have simplified the process of wide row configurations that increase the total
of growing dryland cotton, making this crop a amount of soil moisture available to the plants. This
more reliable and consistent performer within extends the time before in-crop rainfall is required
the rotational mix. It is well documented that and therefore makes the crop less reliant on in-crop
growers with cotton in their rotation program are rainfall particularly in the first 2-3 months of its life.
achieving higher returns over the cropping cycle Narrower row configurations such as single skip are
when compared to growers with soley grain based more popular in higher rainfall eastern areas while
rotations. The relative profitability of any dryland the wider row configurations such as super single are
crop will fluctuate with commodity prices and yields. used in the lower rainfall western areas.
This is not different for dryland cotton, however the
The wide row spacings provide greater surety in yield
use of different planting row configurations helps
and maintenance of base grade fibre quality. There
manage yield potential, fibre quality and production
is a strong relationship between row configuration
costs - all of which influence your gross margin.
and fibre quality, especially for fibre length. In row
configuration trials, fibre quality improved with wider
row configurations. Therefore the row configuration
chosen in combination with the seasonal conditions
experienced will have an influence on the likelihood
of quality discounts being incurred on delivery of the
Savings in variable costs of inputs such as planting
seed, insecticides, defoliants and the picking
operation are likely with wider row configurations.
Taking this into account, a lower yielding wider row
configuration crop can at times give a better gross
margin than a higher yielding crop on a closer
configuration. In many ways growing dryland cotton
really emphasises that gross margin is not just a
function of the yield produced, but very much a
combination of yield and costs associated with the
row configuration chosen.
Dryland cotton gross margin (GM per ha) sensitivity analysis
Single Skip Bale and post ginning seed price combined
Yield (b/ha) $400 $450 $500
2.75 $265 $402 $540
3.25 $433 $596 $758
3.75 $602 $789 $977
Double Skip Bale and post ginning seed price combined
Yield (B/Ha) $400 $450 $500
2.5 $259 $384 $509
3.0 $427 $577 $727
3.5 $595 $771 $946
Super Single Bale and post ginning seed price combined
Yield (B/Ha) $400 $450 $500
2.0 $173 $273 $373
2.5 $341 $467 $592
3.0 $510 $660 $810
How does the planting row configuration affect
Dryland cotton has a couple of big ticket items
which make up the majority of the growing costs,
these being picking and technology licence fees.
In wide row configurations, efficiencies in picking
can be made through not trafficking every pass,
with some contractors charging on a green hectare
The technology licence fee (see section in booklet)
can either be based on a green hectare rate or on
an end point royalty scheme where the licence fee
paid is related to the yield achieved. This not only
works as a risk management tool but also in wider
planting row configurations where the green hectare
rate and yield potential is lower, it is also a cost
management tool because the grower pays less.
Approximate variable cost breakdown
Single Skip Double Skip Super Single
Consultant $35 $35 $35
Planting $70 $60 $50
Fallow $96 $96 $96
Weed Management In-Crop $45 $45 $45
Total $141 $141 $141
Insect Control $59 $50 $41
Defoliation $43 $37 $30
Harvest & Cartage $268 $210 $185
Post Crop Management $80 $80 $80
Technology Licence $261 $198 $130
Total $957 $811 $692
Dryland cotton is often referred to as being a capital Cost accumulation of single skip dryland
intensive crop to grow, requiring high capital and cotton and solid plant sorghum
inputs to establish and grow the crop. While it is
true that dryland cotton is more expensive to grow Sorghum
than other summer crop alternatives, a break Cotton
down of the cash flow associated with growing
this crop shows that it has a similar variable cost
accumulation to a comparable crop such as
sorghum throughout the entire season, up until
Picking and post-crop management operations
comprise approximately 40 to 50 percent of the
total variable costs with dryland cotton. Many of
these costs can be grouped as bale or yield related
costs, such as cartage and licence fees, where yield
determines the final cost incurred. Payment of some
of these is not required until following payments are
received from the merchants after ginning.
Cotton seed: the forgotten commodity
As well as the cotton lint produced, cotton seed is
also a tradable commodity. There is a ready market
for cotton seed meal or whole seed for livestock
feed and for the cotton seed oil for cooking. Price
fluctuations are dependant on the Australian supply
and demand, it varies on the size of the Australian
cotton crop. In recent years, growers have been
able to offset the cost of ginning as well as add
some extra to the bale price due to the strong
demand for cotton seed.
2. A rotational plan to control weeds and disease
Rotating away from a cereal based program with a broadleaf crop such as cotton allows the insertion of
a disease and weed break into the crop rotation plan. The added ability to apply glyphosate over the top
of cotton throughout the season allows for fields with a high weed burden to be easily managed.
Cotton’s fit into the rotation
There are countless ways of incorporating cotton into a dryland rotation. The below table shows some
examples of rotations that are currently being used by growers. The key to these rotations is FLEXIBILITY –
being able to adjust depending on moisture availability, disease risks and the likely returns for each crop.
Cotton Cereal Cereal Cotton Cereal
Cotton Cereal Cotton
Sorghum Cereal Chickpea Cereal Cereal
Cotton Cereal Chickpea Cereal Cotton
Millet* Millet* Cotton Millet* Millet*
Sorghum Cereal Cereal Cereal Cotton Cereal
YEAR 1 YEAR 2 YEAR 3 YEAR 4 YEAR 5
* Millet is a sacrificial crop grown for only 6 weeks and then sprayed out to provide ground cover which helps harvest rainfall
3. There’s more choice with Cotton Choices™
Monsanto has introduced Cotton Choices™ giving you greater flexibility and choice in managing cash
flow and production risks. By planting Bollgard II stacked with Roundup Ready Flex growers are eligible
to participate in the Cotton Choices™ program, where you select the best choice to suit your unique
Cotton Choices™ offers eligible growers the choice of a price discount on crop technology fees;
selecting the added value of Late Crop Removal (LCR); or paying a set End Point Royalty (EPR) fee per
bale, a system where you pay for your technology fee after you have ginned your cotton.
Pay your technology fee after you gin
The End Point Royalty choice has been specifically developed with potential dryland cotton growers in
mind. The majority of your insect control costs are pushed to the end of the season and you only pay for
what you pick – this makes it much easier to manage cash flow.
Cotton Choices™3 – End Point Royalty (EPR)
Product Price(excl GST)
Bollgard II stacked with Roundup Ready Flex $ 50 per bale of ginned lint
Roundup Ready Flex (unsprayed refuge) $ 50 per bale of ginned lint
Note: The EPR fee will be capped based on your Bollgard II stacked with Roundup
Ready Flex harvested area. The cap is set at the equivalent of $405/ha (green).
Example 1 Example 2
Grower plants 50 ha of Bollgard II stacked with Roundup Grower plants 250 ha of cotton in a single skip
Ready Flex in a double skip configuration (50%) and configuration (66.67%) and yields 2.2ba/ha or 550 bales
yields 5ba/ha or 250 bales in total. in total.
EPR FEE PAYABLE 250 Bales x $50 = $12,500 EPR FEE PAYABLE 550 Bales x $50 = $27,500
AREA BASED CAP 50ha x 50% x $405 = $10,125 AREA BASED CAP 250ha x 66.67% x $405 = $67,503
GROWER PAYS $10,125 GROWER PAYS $27,500
Note: All examples are indicative only and growers should refer to the full terms and conditions before making a purchasing decision.
• There are no upfront fees applicable to the EPR under the 2010/11 program
• EPR will only apply to Bollgard II stacked with Roundup Ready Flex and any associated unsprayed
Roundup Ready Flex refuge equal to 10% of the Bollgard II area.
• The only cotton that can be planted on farms selecting the EPR option is Bollgard II stacked with
Roundup Ready Flex and associated unsprayed Roundup Ready Flex equal to 10% of the Bollgard II
• All cotton on a farm unit must be placed under the EPR program – this includes both dryland and
• Farms cannot be split into separate farm units. If growers have questions they should contact their
Monsanto Regional Business Manager to discuss.
Please refer to the 2010/11 Bollgard II with Roundup Ready Flex Technology User Agreement Terms and Conditions before you plant for full details on the
Cotton Choices program and on growing Monsanto’s cotton traits in the 2010/11 season.
Biotechnology has transformed the cotton industry
Cotton production has changed dramatically since the introduction of biotechnology. Advances in
managing insects and weeds have made dryland cotton much more attractive, with significantly
fewer insecticide sprays and labor required to manage pests. Budgets can now be determined and
this makes cash flow management much easier.
Simplified insect and weed control
Bollgard II and Roundup Ready Flex technologies provide Australian growers with simple tools
to effectively protect cotton yields. The Bollgard II trait is an important tool in the sustainable
management of Helicoverpa spp., one of the cotton industry’s most significant insect pests. Roundup
Ready Flex cotton is able to tolerate applications of Roundup Ready Herbicide with PLANTSHIELD in
its vegetative and reproductive stages. Therefore growers can apply Roundup Ready herbicide with
PLANTSHIELD in crop to weeds when and where they appear with full season tolerance.
Bollgard II reduces variability in planning and budgeting. Growers can expect significant savings in
time and money from reduced insecticide applications, savings in labour, equipment costs and
storage costs – due to reduced reliance on shielded spray equipment, cultivation and chipping
compared to conventional cotton systems.
Environmentally sustainable approach to growing cotton
Biotechnology has reduced the environmental impact of cotton production enabling
an overall decrease in the amount of pesticides used.
• Since the introduction of INGARD cotton in 1996, and the progression to Bollgard II,
cotton growers have been able to reduce pesticide usage by 90%.
• Roundup tolerant products have also helped growers reduce reliance on more
persistent herbicides, which have been attributed to the contamination of our
With Bollgard II, cotton growers can successfully implement Integrated Pest
Management (IPM), improving crop biodiversity.
Cotton – the agronomic pros and cons
Many growers include cotton in their dryland rotation system each year. Like any crop they use in their
system, it has its pluses and minuses. The following lists some benefits of both cotton and sorghum to a
rotation as told to us by growers who use both crops.
• Better gross margin in average and above-average yield situations
• Tap rooted crop:
- Vigorous forager/recycler of Nitrogen from depth. Often don’t need to apply additional fertiliser
- Can hold on for long periods in skip row situations
- Can open up country, removing compacted areas
• Longer maturity means larger window to capture and use in-crop rainfall
• Wide planting window – mid September to mid November
• Few lodging or standability problems
• Handles extended dry periods post planting better than sorghum
• Roundup Ready Flex option simplifies weed management and provides an opportunity to get on top of
• Provide a break from cereal diseases such as crown rot
• Pupae busting at the end of cotton provides an opportunity to level country and incorporate feedlot
manure or granular fertilisers as part of a no-till rotation
• Fewer final product handling issues than grains
• Relatively tolerant to weather damage around harvest
• A range of marketing opportunities
• High input costs BUT many of these are not incurred until late in the season
• Tap rooted crop may leave the soil profile very dry at the end of the season
• Minimal useful stubble at the end of the season
• Re-growth plants can be difficult to manage if root cutting or mulching has not been done correctly
• Roundup Ready Flex volunteers will require products other than glyphosate to control them in subsequent
fallow or crop
• Difficult to control some broadleaf weeds in crop – particularly fleabane and vines
• Susceptible to drift from broadleaf herbicides
What is required to grow dryland cotton?
P Precision Disc Opener planter
P Spray boom
P Chisel plough or similar for pupae busting
P Experienced agronomist
P Cotton harvester
Simple steps for accessing Bollgard II and Roundup Ready
Flex cotton technology
Attend an accreditation course
• This training is part of Monsanto’s Bollgard II stewardship program.
• Stewardship is about ensuring the sustainability of Monsanto technologies and helping our
customers get long-term value from our products.
• You must be accredited to use Bollgard II and Roundup Ready Flex technologies.
• For details regarding accreditations please contact your local Monsanto representative by
calling 1800 069 569
Contact your local Technology Service Provider (TSP)
• Growers can access Monsanto’s cotton technology through TSPs
• TSPs will provide technical support, technology user agreements, Roundup Ready herbicide with
PLANTSHIELD and cotton planting seed.
• Contact your local TSP to help step you through this process.
• To find a list of accredited TSPs in your region please visit www.monsanto.com.au/cottontsps
Understand the stewardship requirements
• Resistance is the greatest danger to the continued availability and efficacy of agricultural
technologies. This is why the Australian cotton industry and Monsanto are committed to sustainable
agricultural practices and collectively have developed rigorous and robust stewardship practices
and management plans to ensure the longevity of Bollgard II and Roundup Ready cotton
• The requirements set out in the Management Plans are put in place to reduce the opportunities
for resistance to develop. These requirements are continually monitored for compliance by
regulators and expert scientific committees. They are also developed, improved and endorsed
through consultation with the cotton industry.
• Ensure you read through the general terms and conditions of the technology user agreement to
fully understand your obligations.
The 8 stages of successful dryland cotton growing
This is a basic checklist of production considerations that require some thought as you determine your
dryland cotton planting intentions
1. Pre planting
Like most aspects of farming prior planning can assist in minimizing potential problems and aggravations
during the growing of any crop. The following is a checklist which growers should consider before planting
Golden Rule - Engage an experienced cotton consultant to assist you in all aspects in the management
of your crop; even the most experienced cotton growers use consultants.
b. Field selection
i. Plant available water capacity
Golden Rule – Select suitable soil types – cotton will perform best in soils with a good plant available
water holding capacity.
Selecting soils which can hold in excess 180mm in the top 150cm of soil is a good rule of thumb. This is
particularly important in regions with lower potential for in-crop rainfall. There is also the opportunity to
match planting intentions with differing soil types and water holding capacities through variety selection
and planting row configuration, thus increasing the amount of soil moisture available to the plant.
ii. Ground cover
Golden Rule - Utilize stubble cover – the benefits of stubble to the farming system are many including:
improved infiltration rates, extended planting opportunities, protection for young seedlings, habitat for
beneficial insects etc.
c. Row configuration
Dryland cotton growers can use planting row configuration to manage their growing costs and maintain
yield and fibre quality.
Decisions on what row configuration to use in different scenarios are based on:
i. In-crop Rainfall
ii. Seasonal Outlook
iii. Soil type
iv. Commercial experience in your region
d. Contact your Technology Service Provider (TSP)
Ensure you are accredited and able to grow varieties containing Bollgard II and Roundup Ready Flex
Further information can be found in the “Simple Steps for Accessing Bollgard II and Roundup Ready Flex
Cotton Technology” section of this booklet.
e. Marketing options
Make contact with cotton merchants to discuss what marketing options they have available to dryland
If you are going to use contractors for some farming operations, start organizing them well before
g. Weed control strategy
Golden Rule - Have a plan for weeds – Don’t rely solely on Roundup Ready Flex technology.
Although the Roundup Ready Flex system offers good in crop weed control growers still need to practice
integrated weed management. Through this they should plan for the control of problem weeds or weeds
not on the Roundup Ready herbicide with PLANTSHIELD label such as fleabane. Furthermore, a plan for
the control of ratoon and volunteer cotton plants after the crop should also be developed.
h. Plan for refuge crops
An area of refuge crop to produce susceptible moths is a vital tool within the Resistance Management
Plan of the cotton industry. It is important to understand the reasoning behind the refuge crop and how
it may impact on the farming operations. For further information and options available to dryland cotton
growers please refer to the Refuge Crop section (page 19) within this booklet.
a. Full moisture profile
Golden Rule - Plant on a full profile – Cotton is not the most vigorous of seedlings and is quite susceptible
to adverse conditions at emergence.
Avoid planting if surface moisture is marginal, unless you are set up to move dry soil and plant deep into
moisture. Adequate soil moisture reserves will allow the crop, once established, to grow for 2-3 months
b. Variety selection
Golden Rule – Use an appropriate variety, refer to the CSD Variety Guide for specific variety information.
However, ideal characteristics of a dryland cotton variety are:
ii. Reliable Yield Potential
iii. Inherently Good Fibre Quality Characteristics
For further information see the ‘Selecting a dryland cotton variety’ section in this booklet.
c. Even plant stand
Golden Rule – Aim to establish an even, gap-free plant stand of 6-8 plants per linear metre.
Planting rate may need to be adjusted to suit the planting conditions. An even plant stand is desirable to
generate a uniform crop which is easy to manage for the whole season.
3. Weed control
By using skip row planting configurations there is a lot of area without a crop cover. The capability to
spray Roundup Ready herbicide with PLANTSHIELD over the top of the Roundup Ready Flex cotton crop
has simplified weed control. However, this should not leave the impression that weed control is easy.
Herbicide applications should be targeted at the appropriate weed growth stage and size to ensure
4. Squaring to cut out
The cotton crop grows rapidly and daily water use increases dramatically. Good crop agronomy and
available moisture during this phase will increase yield potential. Your consultant will be monitoring the
i. Soil Moisture Status
ii. Fruit Numbers and Retention
iii. Crop Growth Rate
iv. Nodes Above White Flower
v. Insect Activity
5. Crop cut out to defoliation
Growth of the cotton crop is starting to slow and daily water use has decreased.
Boll numbers are set and the plant concentrates on boll fill. During this phase your
consultant will be monitoring the crop for:
i. Soil Moisture Status
ii. Maturity and Percentage of pen bolls
iii. Insect Activity
This is a critical time and the culminating task in growing the crop. Effective
defoliation is reliant on available soil moisture, crop maturity, good product selection
including: rate, timing and spray coverage. Most crops require two passes to
achieve an adequate leaf drop and boll opening.
7. Picking and ginning
Due to the requirement of specialized equipment most dryland cotton is contract
harvested. Some issues you may need to consider:
a. Harvesting and cartage contractors need to be aware of crop time lines to
ensure the picking operation is done efficiently.
b. Once cotton is within a covered module it is weather proof and can be stored
for extended periods. Locate module pads in areas which are free from debris and
where surface water will not pond, and where there is ample semi trailer access.
c. Contamination Free – Australian cotton has a reputation for being very
clean and debris free. Ensure that rubbish and other foreign materials
are kept away from cotton modules.
8. Post crop management
Effective removal of plant residues post picking is critical. Re-
grown and volunteer cotton plants can be persistent weeds within
the cropping rotation. It is also a legal requirement to cultivate
Bollgard II cotton fields. refer to the “Post Crop Management”
section within this booklet for further information
Selecting a dryland cotton variety
Some cotton varieties are much more suited to dryland conditions than others so it is
important that a lot of thought is put into variety selection. Typically those varieties well suited
to dryland condition;
• Are vigorous in growth so they can respond quickly when moisture is available
• Have inherently good fibre quality - particularly staple length
• Have a history of good performance in a region
Siokra 24BRF Sicala 340BRF
A vigorous, long season okra- A premium fibre quality full
leafed variety suited to the season normal leaf variety suited
central, northern and western to central and northern regions.
regions. Avoid in the southern NEW for 2010.
and far eastern regions,
particularly if planting late. NEW
Sicot 71BRF Sicot 74BRF Sicot 80BRF
A high yielding full season variety A high yielding full season variety A vigorous, long season variety
suited to central and northern who’s performance in dryland suited to the central, northern
regions. It has a more compact is still under evaluation. NEW for and western regions. Avoid in the
growth habit and has performed 2010. southern and far eastern regions,
best in seasons with rainfall early particularly if planting late.
in the season.
Siokra V-18BRF Sicala 60BRF
A quicker maturing okra-leafed A quicker maturing variety suited
variety suited to the eastern to the eastern regions. Ideal for
regions. Ideal for later planted later planted situations.
For further information on these varieties and others, please see the 2010 CSD variety guide
or visit www.csd.net.au
Marketing of cotton in Australia is slightly different to that of other agricultural commodities as there is no
domestic consumptive industry. As a consequence the international price, or export parity, fluctuates
on a daily basis rather than being impacted by domestic factors. Domestic and international cotton
merchants based in Australia distribute prices daily. These merchants use a combination of Cotton
Futures, Basis and Foreign Exchange to calculate the ex gin prices offered to producers. Once purchased
merchants will hedge (offset) their risk through the futures and foreign exchange markets. Merchants
make prices up to three years in advance and have field representatives available to discuss individual
Cotton futures are traded on the ICE (Intercontinental Exchange) in USc/lb. This exchange is utilized by
merchants, consumers, producers and speculators alike to offset their market risk. This market trades for 18
hours per weekday opening late morning AEST.
This is the physical component of the cash price. It is the difference between the value of the underlying
futures contract and the actual physical price at the gin.
Cotton futures are traded in USc/lb. To convert this to Australian Dollars per bale the merchant is required
to sell US Dollars and buy Australian Dollars. This is an inter bank market and trades weekdays 24 hours per
The Australian cotton industry offers some unique advantages over larger
Northern Hemisphere producers that will ensure it remains relevant despite
only representing around 2% of world production. Domestically we produce
consistently the best upland quality in the world and a contamination free
product. Geographically we are well located to service Asian markets and
product is available counter seasonal to the Northern Hemisphere. The
size of the domestic crop has little to no influence over the international
futures market due to our relatively small production although we remain a
significant player in the high grade export market.
Merchants offer a suite of marketing options to producers. These vary in their
complexity and give rise to different levels of liability and price security.
Fixed Bale – A contract to deliver a fixed quantity of bales at an agreed price
within a nominated valley and/or gin yard. This is a deliverable contract and
Force Majeure does not apply.
Fixed Area - A contract to deliver 100% of production from a specified area
at an agreed price. Production risk is assumed by the buyer.
Balance of Crop – A contract to deliver the production from a specified area
less nominated bales. The withheld bales must be nominated at the point of
contracting. Production risk is assumed by the buyer.
Pools – A contract where the producer nominates an area to be committed
and the merchant manages the price risk over a specified period of time.
Merchants will offer an indicative price or range. The final return to the grower
will be determined by the merchant’s ability to manage the production and
price risk over the life of the pool.
Cotton quality and classing
Australian cotton is classed against the USDA standard. The majority of parameters are measured by a HVI
(High Volume Instrument) but the colour and trash content are determined by a qualified classer (subjectively).
Growers can agree to have the merchant (buyer) classify their cotton or pay for their product to be classed by
a qualified independent classer. This is subject to negotiation with the buyer at the point of contracting.
In Australia the base grade parameters for cotton are:
Australian Base Grade
Colour Australian Middling (31)
Trash 3 leaf
Length 1-1/8”, 36, 1.125 inches
Strength 28 grams/tex
Micronaire 3.5 – 4.9 (G5)
Premium and discount schedules
The price that is negotiated against a forward or pool contract is subject to alteration depending on
the actual quality of the individual bales delivered. The majority of merchants will provide a schedule
of premiums and discounts (P&D) that they will use to adjust the agreed base price. Australian cotton is
generally of high quality and as a consequence the Base Grade (31-3-36 G5) is towards the top end of
the quality spectrum. As a consequence the penalties (discounts) can be significant should one or more
of the fibre parameters not meet the minimum requirements. Discounts are levied in USc/lb and are
converted to Australian Dollars per bale either using the spot Australian Dollar at the time of contracting
or on the same day as the cotton is classed depending on the policy of the contracting merchant. It is
important that the grower understands the potential impact of quality penalties and it is recommended
that a P&D be agreed upon with the merchant at the point of contracting.
18 Cotton Marketing section compiled with assistance from ICM Moree
These are Helicoverpa spp. host crops planted to produce Bt susceptible moths in sufficient numbers to
ensure that there is a high probability of the susceptible moths mating with any Bt resistant moths from
Bollgard II crops. This has the aim of keeping resistant insects rare in the population. A dryland refuge crop
must be planed within the 2 weeks period prior to the first day of planting Bollgard ll cotton to ensure there
s enough moisture for the refuge to establish.
What is the purpose of a refuge?
The aim of a refuge is to generate significant numbers of Helicoverpa spp. moths which have not been
exposed to selection pressure from either of the Bt proteins. Moths produced in the refuge crops will
disperse to form part of the local mating population where they may mate with moths emerging from
any Bollgard II crops. This reduces the chance that resistant moths will meet and mate.
Different refuge options for dryland Bollgard II
For dryland Bollgard II crops the only dryland refuge options available are sprayed or unsprayed cotton.
The reason for this is that the other refuge option available in irrigated Bollgard II (irrigated unsprayed
pigeon pea) may need to be planted after the cotton. This limitation reflects the uncertainties of
establishing crops in dryland where planting opportunities from rainfall cannot be guaranteed.
Refuges for dryland Bollgard ll crops must be planted in the same row configuration as the Bollgard ll
• Sprayed Cotton Refuge - an area of dryland or irrigated conventional cotton, equal to 100% of the
area of dryland Bollgard II planted on the farm.
• Unsprayed Cotton Refuge - an area of dryland or irrigated conventional cotton equal to 10% of the
dryland Bollgard II area planted on the farm.
• An area of irrigated pigeon pea, equal to 5% of the Bollgard II planted on the farm.
Post crop management
Growers of Bollgard ll and Roundup Ready Flex are required to practice preventative resistance
management. Compliance with the Resistance Management Plan (RMP) for Bollgard ll and Crop
Management Plan (CMP) for Roundup ready Flex is required under the terms and conditions of the User
Agreement and under the conditions of registration (Agricultural and Veterinary Chemicals Act 1994).
All new growers must take the time to understand their responsibility to effectively carry out key
management practices outlined in the Roundup Ready Flex Crop Management Plan and the Bollgard
II Resistance Management Plan. This will ensure that growers continue to receive the benefits from the
technology while minimising the likelihood of resistance development in weeds or insects.
Fallow, in crop, and post crop weed control is very important for successful cotton production
Growers adopting Roundup Ready crops are encouraged to review their weed management systems to
ensure that this technology is being used as part of an overall Integrated Weed Management (IWM) plan.
The following principles are important considerations in an IWM plan with a more complete description of
tactics included in Figure 1, which was developed by Graham Charles (Industry & Innovation NSW) for use
in cotton production systems.
• Keep accurate paddock records
• Scout fields before and after herbicide or weed control operations
• Start with a clean field by practicing good fallow and whole farm management
• Use the right herbicide product at the right time at the right rate
• Use multiple herbicide modes of action in the weed control system
• Control weeds when they are small
• Control escapes: Prevention of weed seed set is vitally important to stop resistance developing
• Ensure good farm hygiene. Clean equipment before moving from field to field
• Use non-herbicide farming practices such as strategic cultivation and crop rotation
• As a standard part of the weed management system
• Use competitive crops and maintain robust planting rates
AUTHOR: GRAHAM CHARLES (I&I NSW)
Figure 1 Integrated Weed Management System
Control of volunteer and re-growth Roundup Ready Flex and
Bollgard II cotton
Cotton volunteers can;
• Compete for water and nutrients
• Act as a host for pests and diseases
• Increase the risks associated with Bollgard II cotton resistance
• Reduce seed purity
• Interfere with disease management strategies
All reasonable efforts should be made to remove ratoon plants, as
soon as possible after they emerge from all fields, including fallow
areas. Slashing alone will not prevent significant regrowth but used in
combination with an effective root-cutting operation, will greatly reduce
the problem. Mechanical disturbance and/or herbicide application may
be required to further eliminate ratoon cotton, e.g. centre buster with
Control volunteers early, small cotton plants, around 4-6 leaves or less than 25cm
high, are easier to control than larger ones.
If chemical control is used the choice of herbicides is important and should include rotation of modes of
action, consideration of plant back periods for rotation crops, what other weeds are to be controlled and
the size of weeds to be controlled. It is important to remember that any Roundup Ready Flex volunteers
will not be controlled by glyphosate.Planning for volunteer control should be integrated into crop
For effective in-crop cotton volunteer control planning, three main factors need to be considered:
1. Type of potential volunteers present
2. Type of crop to be established
3. Method to be used for crop establishment
There are at least 5 registered herbicide options for controlling small Roundup Ready technology cotton
• Paraquat/Diquat – (Revolver®)
• Bromoxynil – (Bromicide 200®)
• Carfentrazone – (Hammer®)
• Flumioxazin – (Pledge 500WG®)
• Paraquat/ Amitrole- (Alliance®)
Other products may give supplementary control however they may not be registered. Please refer
to relevant product labels. Cultivation is a viable option.
Why should growers destroy pupae?
Once mature, Helicoverpa spp. larvae burrow into the soil and pupate as part of their developmental
cycle prior to emerging as a moth. From early autumn, pupae can enter into a stage of diapause, which
is a resting phase to survive over long periods and harsh conditions. In this state they are able to exist for
several months and not emerge until spring when the soil temperatures and day lengths have increased.
This makes the end of the growing season, once the crop has been harvested; the ideal opportunity to
target any surviving Helicoverpa spp. Cultivation destroys the pupae’s escape tunnel before moths can
emerge. The disturbance can also expose the emergence tunnel – leaving the pupae vulnerable to
predators. Either way the pupae are killed ensuring that they will not pass on any resistant characteristics.
Pupae destruction is the mechanical cultivation of soil aimed at destroying over wintering
pupae. The destruction of pupae is an important tool used to help combat the development
of resistance to the Bt proteins expressed in Bollgard II. Effective pupae destruction is a key part
of the Bollgard II Resistance Management Plan (RMP) and is compulsory for all Bollgard II fields.
It is particularly important to ensure the completion of effective pupae destruction before
planting a winter crop.
What are the requirements for managing Helicoverpa post-harvest?
Post harvest crop destruction:
As soon as practical after harvest, Bollgard II cotton crops must be destroyed by cultivation or herbicide
so that they do not continue to act as hosts for Helicoverpa spp. Unsprayed refuges should be left
uncultivated for two weeks after harvest to allow emergence of any pupating Helicoverpa spp.
In Bollgard ll cotton fields:
• Bollgard ll crops should be slashed and mulched and fields cultivated for pupae control within 4 weeks
of harvesting. All pupae busting must be completed by July 31.
• Research has shown that full soil disturbance of the whole soil surface to a depth of 10cm is required to
achieve effective pupae destruction.
In Refuge crops:
• All unsprayed refuges should preferably be left uncultivated until the following October.
Glyphosate is a key herbicide used widely in Australia and around the world and is a valued component
of modern agricultural farming systems. Glyphosate resistance however poses a serious threat to the long
term viability of Australian farming systems. Farmers using Roundup Ready Flex cotton need to implement
integrated weed management strategies to ensure that glyphosate continues to be an effective weed
control strategy for the whole farming system.
For more information
To find out more information about dryland cotton contact your local CSD or Monsanto representative,
visit www.csd.net.au or www.monsanto.com.au
Cotton Seed Distributors Monsanto Australia
‘Shenstone’ 12/600 St Kilda Rd
2952 Culgoora Road Melbourne VIC 3004
Wee Waa, NSW 2388 Phone 1800 069 569
Phone (02) 6795 0000 Fax (03) 9522 6122
Fax (02) 6795 4966
Roundup Ready, Roundup Ready Flex and Bollgard II are registered trademarks of Monsanto Technologies LLC, used under licence by Monsanto Australia Ltd.
Cotton Choices™ is a trademark of Monsanto Technology LLC used under license by Monsanto Australia Ltd.
Sicot, Sicala, Siokra and Sipima cotton varieties are a result of a research program conducted by CSIRO. Supported by the Cotton Research & Development
Corporation up until 2006
Please refer to the 2010/11 Bollgard II with Roundup Ready Flex Technology User Agreement Terms and Conditions and the Roundup Ready Herbicide with
PLANTSHIELD label before you plant for full details on the Cotton Choices program and on growing Monsanto’s cotton traits in the 2010/11 season.