What are the methods for selecting herbicides for nursery flowers and plants?
Nursery flowers and plants can do a good job of greening the environment and purifying the air. However, during the process of growing nursery flowers and plants, some weeds are inevitably going to appear. When selecting herbicides, in addition to considering the prevention of direct harm to flowers, nursery stock and lawns, it is also necessary to prevent some potential, possible and hidden harm, so as to avoid irreparable damage to the yield and quality of flowers, nursery stock and lawns as well as to the surrounding environment.
1. Post-emergence herbicides for controlling broadleaf weeds
Bentazone, dicamba, fluroxypyr, chlorimuron, clopyralid, halosulfuron, MCPA and others must not be used in nurseries, gardens or dichondra lawns.
2. Post-emergence herbicides for controlling grass weeds
Post-emergence herbicides for controlling grass weeds, such as haloxyfop-R-methyl, fluazifop-P-butyl, quizalofop-P-ethyl, sethoxydim, clethodim and fenoxaprop-P-ethyl, are not suitable for use on grass lawns; while controlling grass weeds, these herbicides will also harm the lawn.
3. Herbicides with a long residual life
Sulfonylurea herbicides such as chlorsulfuron, metsulfuron-methyl, bensulfuron-methyl, pyrazosulfuron-ethyl, chlorimuron-ethyl, tribenuron-methyl and nicosulfuron; imidazolinone herbicides such as imazethapyr; heterocyclic herbicides such as quinclorac and clomazone. These herbicides have too long a residual life in the soil. In nurseries where these herbicides have been used, flowers and nursery stock planted even 3 years later may be harmed. Metsulfuron-methyl can cause damage to tall fescue lawns when sprayed, causing tall fescue grass to turn yellow and die. Clomazone can cause lawn plants to become albino.
4. Herbicides with toxic effects on soil
Some herbicides of the amide, urea and triazine classes, as well as alachlor, acetochlor, fluometuron, metribuzin, simazine, atrazine, prometryn and monolinuron. If these herbicides are applied on lawns, under waterlogged conditions they will affect the root system of lawn plants and thereby affect the development of lawn plants; in places where they are applied continuously, they will cause deterioration and compaction of soil structure, affect the aeration of the soil around the roots of lawn plants, and then cause lawn plants to turn yellow.
5. Herbicides with high toxicity or carcinogenicity
Sodium pentachlorophenol and paraquat are highly toxic and are banned in nurseries and lawns. Nitrofen has been banned in many countries because of its carcinogenicity, and China has banned it since 2000. Alachlor has a carcinogenic effect on animals and is also unsuitable for use. Trifluralin has been banned in Europe because of its carcinogenicity.
6. Herbicides with drift pollution
Dicamba, molinate and similar products pose a relatively large drift pollution problem. Generally, there are flowers and nursery stock around lawns. Spraying dicamba, molinate and other herbicides prone to drift on lawns will affect the growth of the surrounding flowers and nursery stock.
7. Herbicides with an off-odor
For example, the odor of MCPA is irritating to people; after inhalation, it affects people's stomachs, and it also causes phytotoxicity to nursery stock, so it is unsuitable for use.
8. Non-selective herbicides
Such as glyphosate (Roundup), paraquat (Gramoxone) and others. Although some nursery stock has a certain tolerance to low doses of glyphosate, sometimes the harm of glyphosate to nursery stock is difficult to judge clearly by intuition, and sometimes this harm is slow; in addition, when spraying glyphosate, drift is unavoidable, which will cause harm to surrounding sensitive flowers and nursery stock.
In addition, during use, attention should be paid to selecting, according to different needs, varieties and periods, herbicides with a broad weed-killing spectrum, moderate efficacy duration, good eradication effect and no pollution. That is all for today's sharing on how to select herbicides when using herbicides on nursery flowers and plants.