The document outlines a comprehensive weed control program that combines cultural, mechanical, and chemical methods to effectively manage weeds, emphasizing the importance of identifying weeds and understanding their growth characteristics. It discusses strategies for pre-planting weed reduction, the use of cover crops, and the significance of crop rotation to interrupt weed cycles and manage infestations. Additionally, it highlights the challenges of herbicide-resistant weeds and recommends practices to prevent resistance while maintaining soil health and agricultural productivity.

1. Weeds Control
Weeds Control
The weeds control program must take advantage of a combination of cultural
methods, mechanical, and chemical adapted to the situation. The effectiveness of
the methods of weed control depends on the weather conditions, the type of soil
and cropping history. Before adopting any corrective action, identify the weeds
present and learn about the characteristics of their growth. Pesticides are now
classified in eleven categories for the purposes of sale and use. Exceptions are
provided for agricultural uses (including the production of nursery plants). Once
the weeds are identified, it is to reduce to the minimum the infestations before the
plantations, to eliminate possible sources of infestation and prevent the
establishment of weeds.
Principles of weeds control
You can avoid a lot of infestations by using seed and plants free of weeds and
preventing weeds from setting seed. Monitor the growth of weeds in both the
culture and in the non-crop areas nearby. Increase the activity of soil organisms
(bacteria, fungi, earthworms, insects, etc.) is a good way of defense against weeds
since this increases the force of the culture and active the decomposition of weed
seeds in the soil. Cropping practices favoring the biological activity of the soil (e.g.
manure application or plant waste composted, use of cover crops) can reduce
weed problems.

2. Reduction of infestations before the plantations
use of cover crops to curb the growth of weeds when a field of a nursery is put out
of production, it must cultivate plants louvers or a green manure before putting it
back in production. Of cultures that are buried as rye, red clover, buckwheat, the
herbaceous sorghum, millet and oilseed radish are examples of cover crops.
These cultures limit the growth of weeds by competition and by allelopathy (in
exuding of chemicals that affect the germination of the seeds of weed). They also
have the effect of reducing the erosion due to the wind, and the residues that they
leave enrich the soil with organic matter. The soil is significantly more piece of
furniture in a culture that follows a culture of coverage.
Fight against perennial weeds
many perennial weeds are harmful to crops of nurseries, including quackgrass,
bindweed, vetch, wild vine, the perennial nightshade, the thistle, the ground ivy,
the glutton, horsetail, toadflax, milkweed, aster, the Souchet, fireweed, and
goldenrod. The following are points to consider:
• Always strive, in the year preceding the plantations, to reduce to a minimum (or
eliminate) the perennial weed.
• The need, apply a systemic herbicide such as Roundup, on perennial weeds the
year preceding the plantations. Respect the mode of employment specified on the
label and always use the recommended dose against the weed in question. To
ensure a long-term elimination, apply the herbicide in the good growth stage of the
weed (e.g. just before flowering in the case of most of the perennial species of
broad-leaved).
• It may be difficult to combat of perennial weed in established stands because of
the sensitivity of the culture to some herbicides and the impossibility of weeding to
bottom of nurseries established.
• A repeated weeding also gives good results against certain perennial weeds
such as bindweed. Rid the farmer of the debris of weeds before the use
of soils free of weeds.
• Use of non-selective herbicides (as Gramoxone and Roundup) before planting a
culture of green manure and before the Bury. The herbicides at low remanences,
such as 2,4-D, can be used in combination with green manure crops, tolerant.
However, we must avoid the use of herbicides which expose the following
plantings to residues in the soil.
Crop Rotation Crop
rotation is an important element of the strategy Long-term control of weeds. After
burying a culture of coverage, it is preferable to install of nursery stock different
from the previous culture. For example, do follow a culture of conifers by a culture
of hardwoods. This rotation leads to an alternation of the methods of work of
the soil, spacing, systems of crop and herbicides employees. The rotation

3. contributes to interrupt the cycle of weeds and reduce their proliferation. Short
rotations using several cultures allow increasing yields and the profitability of each
of the cultures. Choose a culture that opposes a strong competition to weeds
identified.
Technique of false seedlings
the technique of false seedlings is to prepare the seedbed at the very beginning of
the season of growth. It leaves the weeds to germinate. It kills a few weeks later
with the help of glyphosate or paraquat. Once the weeds destroyed, it sows or
Spade’s culture in the bed of plantation in ensuring to stir the ground the least
possible.
Preparation of beds intended to receive containers
Prepare the area intended to receive containers in y extending a layer of gravel or
by covering the ground with a film of black plastic or a geotextile membrane
opaque. It is important that the material used intercepts the light rays in order to
stop any germination. These materials can be reused for a number of years before
having to be replaced. Keep the bed of containers and the aisles free of weeds in
y tearing the seedlings or by chemically destroying.Remove and discard all weeds
pulled away from the area of culture so that the seed can be scattered in the
neighboring containers. Rid the containers of weeds existing before that they do
not flower.
Once plant flowers, it risk of disseminating hundreds of catapultées seeds or
washed away by the wind. A good number of species of weeds infesting the
containers are of annual who rely on several generations of seedlings per year
given that their seeds have not need to overwinter before germinating. In the
fall, well remove weeds in full growth of containers because the greenhouses
plastics are covered. This will avoid that weeds do not overwinter with success in
the sheltered that offers the plastic greenhouse. Be sure to remove the rosettes of
winter annual, as the bourse-to-Pasteur and the Canada fleabane, as well as
established plants and seedlings of chickweed and chickweed. Otherwise,
these plants will bloom in May or even before.
Control of Sources of infestation
reduce to a minimum the sources of infestation by resorting to methods of
mechanical weeding, cultural chemical or below:
• the use of mechanical or chemical methods to kill weeds that have escaped the
treatments before they do rise in a seed.
• Prevent weeds to mount in seed in the surrounding areas not cultivated.
• Mow at regular intervals to prevent weeds to flourish.

4. • Use a mower to nylon yarn to some places, particularly along fences.
• Search the Sources of weeds, such as the popular, willows, the fireweed and
Canada fleabane, which infest cultivation areas in full field or in containers.
• Combat weeds around the basins of irrigation in order to avoid that very small
weed seeds are not paid in the containers at each watering.
• Keep a canopy of dense grasses around the basins of irrigation to ensure the
stabilization of the shoreline and to avoid infestations of weeds.
• Install a filter in the irrigation network in order to delete the weed seeds in
the irrigationwater.
Mechanical Methods of Weed Control
It is possible to reduce weeds and the homes of infestation by mechanical
methods. Ensure that the seedlings and transplants are free of weeds before
transplanting. Before moving on to another field, rid the hardware of the debris of
weeds. Work in last infested fields.
Rotary Hoe
the teeth of the rotary hoe raise malaxate and the land, uprooting as well the weed
seedlings. The rotary hoes usually cause less damage to crops that the harrows.
They also allow to break the soil crust and to incorporate the herbicides applied in
the surface, which activates their chemical action and improves the destruction of
weeds.
Use the rotary hoe at the end of the before-noon or the afternoon when the heat
of the sun makes fade the uprooted weeds. In addition, the plants are grown more
flexible during these periods of the day, and Damage is thus reduced. To obtain
good results, maintain a sufficient speed, usually 10 to 20 km/h. A forward speed
too slow does not generate a force sufficient to raise the weeds out of the soil and
the risk of further damage to crops. On light soils or furniture, it is necessary that
the work of the rotary hoe is superficial.
Weeding hoeing or of the between-rank
the superficial job between the ranks of cultures in lines and uprooted weeds
Young and cut the most developed. Various types of equipment may be used.
When it was a use of bridles, there must be 50% overlap to obtain a complete
weed control. Use caches to avoid to bury the small cultures. The first hoeing is,
without doubt, the most important, because the weeds that escape them will reach
usually their full maturity. The complete weeding a marvelous herbicide treatment.
A superficial weeding (2.5 to 5.0 cm) prevents harm to the action of the herbicide
applied (the maintenance of the layer of herbicide will prevent the
weed seedlings to lift and to establish themselves in the soil).

5. Haying
Haying or mowing helps to reduce weed populations. The best time for
Mowing perennialweeds is at the stage of the floral button, before their roots
accumulate reserves and that the stalks rise in a seed. If a herbicide application is
planned for later in the season, it must let elapse enough time for the bad grass
regrowth after mowing.
Management of Herbicide Resistant Weeds
There are more than 120 species of herbicide-resistant weeds a little everywhere
in the world. Refer to the OMAFRA Factsheet, weed resistance to pesticides, to
obtain the list of weeds resistant observed in Ontario. The herbicides must be used
reasonably.
Delaying Herbicide Resistance
The resistance to a herbicide is the result of repeated applications of this herbicide.
The speed with which appears a resistance to different types of herbicides is
extremely variable of a weed species to another and from one stand to the other.
Here is a series of measures that contribute to reducing to a minimum the number
of weeds resistant:
Identification and vigilance.
Nothing distingue appearance the weeds resistant, if this is that they do not
undergo the destruction and damage observed in plants of the same stand. It is
known that it is frequent that weeds” escape ” to chemical treatments. We do note
sometimes the appearance of a resistance that when 10 to 30 percent of weeds
are insensitive to the treatment. It is, therefore, necessary to inspect the fields
regularly and use of diagnostic methods to detect a problem before it gets worse.
Prevention of the spread of weeds.
Out of a field, clean the equipment. Do not allow the rise in a seed of weeds
resistant.
Use the mechanical weeding.
To the extent possible, make a mechanical weeding with the help in particular of
the rotary hoe or the farmer.
Crop rotation and herbicides.

6. Do not use the same herbicides year after year after year. Practice crop rotation
and spray on the new culture of herbicides with modes of action or sites of action
different. Use of tank mixes or commercial mixtures registered containing multiple
active ingredients and that can fight a same bad grass in different ways.
Keeping of registers.
Keep accurate records of crop rotations practiced and herbicides used in each of
the fields. Well kept records facilitate the planning of long-term strategies for the
fight against weeds. Communication. Inquire with associations of producers,
universities, extension specialists, agri-businesses, friends and neighbors about
resistance problems which they are witnesses. Inform the provincial inspector of
weeds or the representatives of the manufacturers of plant protection products of
cases of resistance observed so that appropriate measures can be taken to
prevent the spread of resistant strains.
Diagnosis
The appearance of a resistance is not the only reason that can explain the
ineffectiveness of a herbicide. It is important to eliminate the other causes of the
inefficiency of a treatment, including errors in the application, the adverse weather
conditions, a treatment carried out at the wrong time and outbreaks of growth of
weed after the application of a herbicide without residual effect. If, after analysis, it
still retains the possibility of a resistance, make the checks that follow:
• The treatment has it been effective against other weeds listed on the label of the
product? In the event of the emergence of resistance, it is very likely that it would
develop in a field that in a single species of weed. Accordingly, if it remains many
weeds are normally susceptible to treatment, it must move to again review the
other possible causes of the failure of the treatment.
• A-T-we noticed the previous year to a same place in the field the same herbicide
or herbicides belonging to the same chemical group and having the same mode of
action have been ineffective?
• Was there year after year after year in the field an intensive use of the
same herbicide or herbicides belonging to the same group?
If you answered yes to one or the other of the foregoing questions, it is possible
that the weeds are resistant to the herbicide. Use a herbicide belonging to a
different group or to resort to a method of the fight other than chemical. Prevent
weed to mount in the seed. Communicate with the provincial inspector of weeds
as well as with the supplier of herbicides and the manufacturer of pest control
products