How to use herbicides in woody flower nursery
The control of weeds in nursery has always been a difficult problem in production. At present, most of the control methods of weeds are manual pulling, tillage, plastic film mulching and so on. In fact, the most simple and effective method in woody flower nursery is to use herbicides.
For annual and biennial seedlings, herbicides with high safety to seedlings can be used before weed germination. For example, using 2.5% herbicide wettable powder 400-600 grams per mu, mixed with sifted dry fine soil 40 kg per mu, can control 1-year-old Compositae and Gramineae weeds, with a validity period of up to 1 month. In addition, some herbicides can also be used for stem and leaf treatment during the peak period of weed growth, such as using 12.5% Gai Cao Neng EC 40-80 ml per mu, adding 40 kg of water, and spraying into a liquid spray, which can effectively control a variety of annual Gramineae weeds. For example, when there are many dicotyledonous weeds in the nursery, 10.8% high-efficiency Gancao Neng EC and 3.5% Guole EC can also be mixed with 1 ∶ 1 to carry out leaf treatment between the rows of seedlings, which can effectively control annual monocotyledonous and dicotyledonous weeds and has no adverse effect on seedling growth.
For more than two-year-old seedlings, you can choose herbicide or 50% prometryne wettable powder 100-200 grams per mu, mixed with 40 kg of fine soil to control weeds such as Niangmai, Kentucky bluegrass, Qianjin, shepherd's purse, barnyard barnyard, horse tang and other weeds. For large seedlings and young trees with high trunk and secondary transplanting, you can use 10% glyphosate water agent 750 ml per mu and 40% atrazine suspension 150-250 ml per mu to spray on the soil surface.
Drugs can be used according to the morphological differences of stems and leaves. Some broad-leaved seedlings, such as camellia, Michelia, Magnolia, privet, etc., can also use glyphosate directional spray for stem and leaf treatment; other broad-leaved seedlings, such as Albizia, Bauhinia, hibiscus, etc., cannot use glyphosate, but before sprouting, you can use 24% Guole EC 10-15ml per mu, mixed with dry fine soil, and then wash the seedlings with clean water to control annual monocotyledon and dicotyledonous weeds. In general, coniferous flowers have stronger drug resistance than broad-leaved flowers. For Pinus elliottii, pine and cypress, Platycladus orientalis, etc., we can use 10% glyphosate water agent 750 ml per mu and add water to directly treat the stems and leaves, which can effectively kill perennial weeds such as thatch, thorn and bitter vegetables, and is relatively safe for seedlings.
For the sake of safety, we should be extra cautious about the use of drugs in some rare precious flowers, such as rhododendron, tea plum and so on. When the weeds are about 15 cm, 0.3% w / 0.4% solution of glyphosate can be applied to the stems and leaves of weeds, so as to avoid the drug damage caused by touching the seedlings, and 400-600 grams per mu of wettable powder of 25% herbicide can be used to sprinkle the medicinal soil on the seedling bed before the weeds sprout, and then sweep the medicinal soil that falls on the seedlings. In addition, 48% trifluralin EC can be sprayed on the bed with 48% trifluralin EC 80-100 ml per mu, adding 50 liters of water before the weeds sprout, then wash the seedlings with clean water, wait for the seedlings to dry, and then cover them with an appropriate amount of fine soil, so as not to affect the efficacy of trifluralin volatilization and photolysis.
For the leathery leaves, Michelia mollissima with waxy layer on the surface, camellia, privet, magnolia, etc., and the pine and cypress flowers with aromatic grease in stems and leaves, because of their strong drug resistance, herbicides with poor selectivity such as glyphosate were sprayed on the stems and leaves of weeds in sunny and windless weather. For flowers and trees with thin leaves and less wax, French holly and hibiscus, hemp leaf hydrangea and other flowers and trees, because of their poor drug resistance, we can only use this selective and safe herbicide for stem and leaf treatment.
There are some precautions when using herbicides. 65% glyphosate soluble powder is used in the nursery, and micro-ultra-low volume spray is generally not used to prevent drug damage to seedlings due to liquid drift. 10.5% efficient Gengcao EC and 23.5% Guoer EC can be mixed or used alternately, which is beneficial to the control of monocotyledonous and dicotyledonous weeds in the nursery.