Extra caution is needed when using herbicides on nursery flowers
When choosing herbicides, note that many herbicides are not suitable for use in gardens, flower nurseries and lawns.
1. Post-emergence herbicides for controlling broadleaf weeds——bentazone, dicamba, fluroxypyr, chlorimuron-ethyl, 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 damage 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; and heterocyclic herbicides such as thiobencarb and clomazone. These herbicides have too long a residual life in the soil. In nurseries where these herbicides have been used, flower seedlings planted even 3 years later may be damaged. Metsulfuron-methyl will cause spray damage to tall fescue lawns, causing tall fescue grass to turn yellow and die. Clomazone will cause lawn plants to become albino.
4. Herbicides with toxic effects on the soil——some herbicides of the amide, urea and triazine classes, as well as alachlor, acetochlor, fluometuron, metribuzin, simazine, atrazine, prometryn and flumetsulam. If these herbicides are applied to lawns and waterlogging occurs, they will affect the root system of lawn plants and thereby affect the development of lawn plants; 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. Highly toxic or carcinogenic herbicides——sodium pentachlorophenol and paraquat are highly toxic and are absolutely prohibited 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 others pose a relatively serious drift pollution problem. Generally, flowers and seedlings surround lawns; spraying dicamba, molinate and other easily drifting herbicides on lawns will affect the growth of the surrounding flowers and seedlings.
7. Herbicides with an odour——for example, the smell of MCPA is irritating to people; after inhalation, it affects the human stomach and also causes phytotoxicity to seedlings, so it is unsuitable for use.
8. Non-selective herbicides——such as glyphosate (Roundup) and paraquat (Gramoxone). Although some seedlings have a certain tolerance to low doses of glyphosate, sometimes the damage glyphosate causes to seedlings is difficult to judge clearly by visual inspection, and sometimes this damage is slow; in addition, drift is unavoidable when spraying glyphosate, which will cause damage to surrounding sensitive flowers and seedlings.
In short, when choosing herbicides, in addition to considering the prevention of direct damage to flowers, seedlings and lawns, it is also necessary to prevent some potential, possible and hidden damage, so as not to cause irreparable damage to the yield and quality of flowers, seedlings and lawns and to the surrounding environment. In use, herbicides with a broad weed-killing spectrum, moderate efficacy period, good eradication effect and no pollution should be selected according to different needs, varieties and periods.