We are going to dedicate this article today to the wide world of herbicides. These chemical elements that help us eliminate weeds to allow and improve the growth of the plants that interest us. Today, in Gardenprue , we tell you a lot about herbicides.
THE MODERN USE OF HERBICIDES
More and more we can find different active ingredients to control weeds. The evolution of this type of product is to be as selective as possible to this type of plants and reduce, as far as possible, their ability to leave residues on the ground and contaminate future plantations.
Within the different types of herbicides , we can find different divisions. Some control broadleaf and other narrowleaf grasses, although there are also those that eliminate both.
On the other hand, we can also find pre-emergence herbicides and post-emergence herbicides . The difference is that the first is used to prevent the emergence of weeds, usually used together with germination, and the other, post-emergence, when we already find weeds visibly in the soil, growing little by little.
This would be a difference in the activity of herbicides according to the type of grass and its emergence.
DIFFERENT TYPES OF HERBICIDES ACCORDING TO THEIR ACTIVE MATTER
AMITROLE 24% + AMMONIUM THIOCYANATE 21%
Mixture of 2 active substances, amitrole and ammonium thiocyanate, with post-emergence herbicidal activity.
Controls resistant herbs characteristic of the olive grove such as Allium sp., Erodium sp, Conyza bonariensis, Diplotaxis sp., Conyza canadensis, Malva sp., Etc.
The dose varies between 4 and 6 L / ha for crops such as olive groves, citrus, hazelnut, vine or pome fruit trees.
Selective herbicide for broad-leaved weeds (the most common) dicotyledonous type, especially adapted to the cultivation of rice, vegetables such as peas or beans, alfalfa and potatoes.
The dose is between 1.5 and 2 L / ha in most crops.
DICAMBA + MCPA + 2,4-D
A triple mix of herbicides with different effects to enhance each other. This herbicide is used post-emergence (once the weeds have germinated) and is used to control broadleaf in crops such as cereals and lawns.
It is used in cereal crops such as oats, rye, wheat, barley, etc., at a dose of 0.8-1.5 L / ha
DIFLUFENICAN 50% P/V
Herbicidal active ingredient well known in agriculture, widely used in cereals and olive groves. It usually has great action against dicotyledons, applied at a dose of 0.5-0.7 L / ha against Conyza, Ecballium, Lactuca, Picris, etc.
Against vallico and other difficult-to-eliminate weeds, the dose is increased to 1 L / ha, having a great persistence in the soil.
- Application between October and November: 4-5 months in soil.
- Application between March and April: 3-3.5 months.
- Application between May and June: 2-2.5 months.
Diflufenican 50% is capable of controlling weeds such as Bl edo, Borage, Hand Opener, Chamomile, Edge Chamomile, Calendula, Ragwort, Dandelion, Cerraja, Dandelion, Veronica, Pinito, Altamisa, Malva, Nettle, Mujares, etc.
DIQUAT (BROMURO) 20% P / V
Non-selective herbicide but with the advantage that it is not residual , used in post-emergence control of weeds.
It is especially suitable for broad-leaved herbs applied to a large number of crops, such as corn, potato, garlic, onion, parsley, pepper, fruit trees, citrus, olive, etc. Its effect against herbs can be seen within a maximum period of 1 week.
A total volume of broth that varies between 300-400 L / ha is usually used, with a dose ranging between 1.5 and 2 L / ha.
FLUAZIFOP-P-BUTYL (ESTER) 12.5% P / V
In this case, this herbicidal active ingredient at 12.5% is selective in terms of eliminating weeds. Controls annual and perennial grasses with a wide spectrum of crops.
It is applied post-emergence (once we see that weeds are born). It prevents the formation of fatty acids and phospholipids by the plant, causing death in a short period of time.
This herbicide controls weeds such as Almorejo ( Setaria sp .), Vallico ( Lolium sp .), Avena loca ( Avena fatua ), Foxtail ( Alopecurus myosuroides ), Grama ( Cynodon dactylon ), Grama de Agua ( Paspalum distichum ) and Cañota ( Sorghum halepense ).
GLIFOSATO 36% P/V
This herbicide, well known to all, is used for post-emergence and localized application on monocotyledonous and dicotyledonous weeds.
The dose varies between 3-6 L / Ha for control of low height grasses and between 5-10 L / ha for large grasses.
The broth used depends on the machinery, counting an expenditure of between 300-400 L / ha for application through hydraulic machinery, with a maximum dose in any case of 10 L / ha.
15% GLUFOSINATE AMMONIUM
Contact herbicide with a small systemic action with the positive effect (for certain crops) that it does not offer any activity when the plants emerge after applying the active material.
It can be used both in woody and non-woody crops, to control grasses and dicots, or to suppress regrowth or children, applied to the base of the trunk (citrus, olive, fruit trees, etc.)
In any case, you can consult this link to find out first-hand which herbicides are authorized according to the crop.
OXIFLUORFEN 24% P / V
This active material is well known and used as a herbicide for dicots and grasses, both pre-emergence and post-emergence.
It has a dose of between 1-2 L / ha, depending on the height of the plant to a wide range of crops (garlic, artichoke, cotton, citrus, cruciferous, fruit, horticultural, olive, vine, etc.
By combining Oxifluorfen and Diflufenican , the control range is increased in both broad leaf and narrow leaf, playing at a dose of 2 L / ha in application for olive groves and citrus fruits.
TRIASULFURON 20% P/P
Specific herbicide used in cereal crops, which offers control against annual and broad-leaved weeds.
This product is registered in crops such as wheat or barley, at a dose that ranges between 20 and 40 grams per hectare.
DICAMBA 50% + PROSULFURON 5%
Sum of 2 active ingredients to stimulate and enhance the herbicidal effect. This herbicide is designed to control weeds in cereal crops.
It is used only in post-emergence (when the grass has already emerged), at a dose of between 0.3-0.4 kg / ha, with only 1 application per authorized campaign.
Controls the bad hierbas dicotiledóneas added to cereal as Abutilon theophrasti, Amaranthus blitoides, Amaranthus retroflexus, Chenopodium album, Datura stramonium, Diplotaxis erucoides, Mercurialis annua, Polygonum aviculare, Polygonum convolvulus, Polygonum Persicaria, Raphanus raphanistrum, Salsola kali, Solanum nigrum, PERENNIAL SOW THISTLE y Xanthium strumarium.
MESOTRIONA 10% P / V
It offers good control as a herbicide against broadleaf herbs ( Abutilon theophrastis, Amaranthus sp, Chenopodium album, Convolvulus sp, Datura stramonium, Solanum sp, Sonchus sp, Xanthium sp) in corn, at a dose of 0.75-1.5 L / ha.
Systemic herbicide with activity against weeds in crops such as barley, rye and wheat. Controls annual broadleaf herbs, with a treatment dose of 3 L / ha, both pre-emergence and post-emergence.
Selective herbicide widely used in agriculture. Controls annual broad-leaved weeds (which are found in greater numbers) in pre-emergence.
It is usually used in a wide range of crops and acts by inhibiting photosynthetic activity. The dose to be used varies between 1.5 and 2.5 L / ha.
The active ingredient Metribuzin 70% is a selective herbicide to control annual weeds of grasses and dicotyledons, both pre-emergence and post-emergence.
It is used in a wide range of crops (potato, tomato, asparagus, wheat, barley, alfalfa, etc.). A dose of 0.5-0.7 kg / ha is used, expending a broth of 400 L / ha.
Pinoxaden 5% is used as a herbicide against grasses in cereal crops in post-emergence (after the emergence of the weeds).
It controls typical cereal crop weeds such as crazy oats ( Avena sp .), Vallico ( Lolium sp .), Birdseed ( Phalaris sp. ) And foxtail ( Alopecurus myosuroides).
The dosage of this herbicidal active material is 0.5-1 L / ha, using the highest dose for the most difficult weeds to eliminate, such as vallico ( Lolium sp. )
BE VERY CAREFUL WITH THE DRIFT OF THE HERBICIDES USED
One of the biggest problems with herbicides and a current headache is the dispersion of chemical elements in plants that we are not interested in treating.
This occurs when we apply these products in non-optimal conditions, such as windy days, use of nozzles that are not suitable, not having a drift protection head, etc.
Many times it happens that, unfortunately, when applying the herbicide it spreads to other sensitive crops, the application tank or backpack is not washed well and we cause phytotoxicity in production plants.
Therefore, special care must be taken when applying herbicides , doing it at a prudent distance from the ground, washing the treatment equipment well or using it only for the application of this type of product, etc.
ARE THERE ORGANIC HERBICIDES?
This is, perhaps, a question asked by all those who develop sustainable and ecological agriculture. Until now, the best way to remove weeds was manual weeding, a technique that requires a lot of sacrifice if we have large areas but ideal for small gardens.
In the market, until recently, we could find some fertilizer bases (EC fertilizer) used as a herbicide, although it is not well expressed on the label because it is a fertilizer.
It is an example of highly hygroscopic forms of phosphorus (hydroxy phosphate) (ability to absorb moisture) that, at high doses (very high!), Are able to dry out weeds. Be careful, bad and good herbs, horticulturals, etc. It is not selective .
The dose varies between 8% and 12.5% (80-125 ml / L of broth). Very high doses but with an organic certificate that was valid until 2015.
The fact that it currently does not have an ecological certificate does not mean that it is not positive to replace it with respect to other herbicides and, at least, that it does not affect the soil as much as other active materials of recognized importance.
In our opinion, for small orchards or plantations , manual weeding with a hoe or other tools will always be better for the soil, as we will eliminate weeds, incorporate them into the soil for their decomposition and improve the aeration and turning capacity of the soil.
HOW TO CHOOSE THE BEST HERBICIDE?
Distinguish between broadleaf weeds and narrowleaf weeds.
NARROW-LEAVED WEEDS (MONOCOTS)
The narrow-leaved grasses are usually grasses and monocots, using non-selective herbicides that end up drying the leaf from the root and preventing its subsequent emergence.
Some examples of weeds of this type and, with this, knowing how to choose the perfect herbicides to use:
- Horsetail, Almorejo, Pega Ropa, etc. ( Setaria sp. )
- Crazy oats ( Avena spp. )
- Alpiste ( Phalaris spp. )
- Foxtail ( Alopecurus myosuroides )
- Grama (Cynodon dactylon (L.) Pers.)
- Juncia (Cyperus esculentus L.)
- Mijo (Panicum miliaceum L.)
- Mijera ( Echinochloa sp )
- Vallic ( Poa rigid )
These weeds correspond to dicotyledons (the leaves that come out of the seed have 2 cotyledons) and are found in greater numbers than narrow-leaved weeds, which we know as monocots.
This is a summary list of some broadleaf plants that we can find, in order to identify it and be able to use the best possible herbicide. More effective and less residual.
- Abrepuños (Ranunculus arvensis L.)
- Poppy ( Papaver roheas )
- The hinge cundida ( Cirsium arvense (L.) Scop. )
- Cenizo blanco (Chenopodium album L.)
- Cerraja (Sonchus arvensis L. )
- Horsetail ( Equisetum arvense L. )
- Conyza (Conyza canadensis)
- Dandelion ( Taraxacum officinale Weber )
- Spruce ( Spergula arvensis L. )
- Geranio ( Geranium L. )
- Ragwort ( Senecio vulgaris L. )
- Yellow dandelion ( Sinapis arvensis )
- Lechecino (Sonchus oleraceus L.)
- Malva enana ( Malva neglecta Wallr. )
- Manzanilla borde (Anthemis arvensis L.)
- Mostacilla ( Thlaspi arvense L. )
- Nettle ( Urtica dioica L. )
- Verbena ( Verbena officinalis L. )
- Purslane ( Portulaca oleracea L. )
- Link ( Vicia sativa L. )
- Shepherd’s staff ( Capsella bursa-pastoris (L.) Medik. )