AU2021101419A4 - Composite herbicide for corn field under conservation tillage - Google Patents

Abstract

The present disclosure relates to a composite herbicide for corn fields under conservation tillage, where specific raw materials have the following weight percent: atrazine 10%-15%, bromoxynil 4%-6%, pendimethalin 12%-16%, thifensulfuron-methyl 2%-4%, methanol 20%-35%, pesticide emulsifier 1600# 5%-8%, glycerol 1%-4%, silicone oil 0.02%-0.06%, sodium alginate 0.5%0.8% and adding deionized water to 100%. The herbicide has the advantages of excellent weeding effect, broad weed control spectrum, harmlessness and safety to the corn fields under conservation tillage.

Description

COMPOSITE HERBICIDE FOR CORN FIELD UNDER CONSERVATION TILLAGE TECHNICAL FIELD The present disclosure relates to the technical field of pesticides, and in particular to a composite herbicide for corn fields under conservation tillage. BACKGROUND Conservation tillage has played an important role in improving agricultural efficiency and emancipating the agricultural labor force. With the expansion of the scale of conservation tillage and the continuation of time, some regional weeds have spread rapidly, and some weeds have become more and more serious. Compared with conventional tillage, the conservation tillage has eliminated the means of ploughing the weeds by the moldboard plough; moreover, the ground is covered with straw or straw stubble remains, so that there are more weeds in conservation tillage fields and consequently more harm is caused. This brings certain difficulties to conventional chemical, mechanical or hand weeding. There are a plurality of outstanding aspects as follows: 1. farmland weeds increase, development becomes uneven, and the degree of weed occurrence is aggravated; 2. no-tillage farming protects the growth environment of farmland weeds, resulting in high succeeding weed density and advanced weed age, and increasing the difficulty of control; 3. increase herbicide application has aggravated the degree of environmental pollution; and 4. reduced crop yields and commodity may occur on farmlands with serious weed occurrence under conservation tillage. Weed damage has become an important limiting factor for stable promotion of the conservation tillage. Corn is not only one of the main food crops in China, but also the main crop used in conservation tillage. Throughout the growth of corn, weeds compete with corn for sunlight, nutrients, moisture, and growth space due to unique growth competitiveness thereof, which seriously affects the normal growth of corn and reduces corn yield. At the same time, because weed growth hinders ventilation and light transmission, which is beneficial to breeding corn diseases and insect pests, corn quality is influenced. At present, there are many kinds of corn herbicides. During use, if the herbicides are used improperly, herbicide injury will occur. In severe cases, seed germination may be inhibited or abnormal plant growth may be caused. Therefore, the objective of this study is to explore and select a herbicide that can control corn weeds more effectively and ensure the normal growth and development of corn, so as to promote the application of corn production in fields under conservation tillage. Weeds in corn fields mainly include gramineous weeds (Digitariasanguinalis,Eleusine indica, Echinochloa crus-galli, Setaria viridis, Sorghum sudanense, and Commelina communis), broad leaved weeds (Portulaca oleracea, Amaranthus retroflexus, Acalypha australis, Chenopodium album, Polygonum sp., Abutilon theophrasti, Xanthium strumarium, and Hibiscus trionum), and sedge weeds (Cyperus rotundus). There are many types of corn field herbicides on the current market. 1. Types of single-agent corn field herbicides (1) Amide herbicides: These products are currently the most important class of herbicides for corn fields. These herbicides can be absorbed by weed buds, and the soil is sealed before weeds germinate, so that annual gramineous weeds and some annual broad-leaved weeds can be controlled effectively. There are a plurality of such herbicides, such as acetochlor, alachlor, butachlor, metolachlor, and propisochlor. (2) Triazine herbicides: These herbicides can effectively control annual broad-leaved weeds and annual gramineous weeds. These herbicides are mainly absorbed by the roots of the weeds, and can be absorbed by the stems and leaves of the weeds in small amounts. The representative products include atrazine, cyanazine, simazine, and prometryn. Among them, atrazine is widely used, which is safer to corn and has the highest activity; but atrazine should be mixed with acetochlor in an equal ratio to reduce the dosage and improve the weeding effect and the safety of the succeeding crops. (3) Phenoxy carboxylic acid herbicides: These herbicides are mainly used in corn to control broad-leaved weeds and C. rotundus after emergence. The representative products include MCPA sodium and 2,4-D butyl ester. Among them, MCPA sodium is widely used in corn fields to control C. rotundus, but when used improperly, it is susceptible to herbicide injury. (4) Sulfonylurea herbicides: Nicosulfuron and rimsulfuron can be used in corn fields to control gramineous weeds, sedge weeds and some broad-leaved weeds; thifensulfuron methyl can be used in corn fields to control annual broad-leaved weeds. (5) Other herbicides: Paraquat and glyphosate are sterilant herbicides, which can be sprayed directionally after the corn is 40 cm tall, effectively controlling a variety of weeds; Starane, Banvel, bromoxynil, and bentazon may be used to control broad-leaved weeds in corn fields. 2. Types of main herbicide mixtures (1) 1:1 Mixture of acetochlor and atrazine: Among such herbicide mixtures, the earliest ones are atrazine-acetochlor herbicide and atrazine-acetochlor suspension concentrate, which can be used to control annual gramineous weeds and broad-leaved weeds before emergence of sown corn and in early postemergence period of corn and are safe for corn and succeeding crops. Similar products include butachlor + acetochlor + atrazine, butachlor + atrazine, alachlor + acetochlor + atrazine, metolachlor + atrazine, and propisochlor + atrazine. (2) 2:3 Mixture of acetochlor and atrazine: Such herbicide mixture can be used to control annual gramineous weeds and broad-leaved weeds in corn fields before emergence of sown corn and in early postemergence period of corn and is safe for corn; products with similar performance include chlortoluron + acetochlor + atrazine mixture, but the mixture cannot be used after emergence of corn. (3) Mixture of prometryn and atrazine: The mixture can effectively control annual gramineous weeds and broad-leaved weeds in corn fields. When applied before emergence of sown corn, the mixture achieves a stable weeding effect and less affected by soil moisture, but when the rain is heavy, more leaching will reduce the weeding effect; when applied in the growth period of corn, the corn is susceptible to herbicide injury under adverse environmental conditions such as high temperature and drought. (4) Mixture of nicosulfuron and atrazine: The mixture is an ideal herbicide mixture, which can not only effectively control a variety of annual weeds, but also control perennial gramineous weeds and sedge weeds. The mixture is easy to apply and safe for corn and succeeding crops. However, the mixture cannot be mixed with organophosphorus insecticides before and after use, but can be mixed with pyrethroid insecticides. (5) Mixture of acetochlor, atrazine, and paraquat: The mixture has both sterilant and sealed weeding effects and can effectively control a variety of weeds in corn fields when applied in the growth period of corn. There are a plurality of similar products, and there are also herbicide mixtures that replace paraquat with glyphosate. The above prior art has more or less the following problems: 1. Use of a single herbicide tends to meet the removal effect of a certain type of weeds only, that is, the herbicide has an effect on either broad-leaved weeds or gramineous weeds, and there is no outstanding herbicide with a broad weed control spectrum. In areas where two types of weeds are serious, respective use of two targeted herbicides increases the cost and the dosage is difficult to grasp, even causing safety problems. 2. Some herbicides have been used for years, which have gradually caused resistance of weeds to these herbicides during evolution thereof. Therefore, the original weeding effect of these herbicides is decreasing or disappearing year by year, such as atrazine. 3. In spite of combinations of two or more herbicides in the prior art, these combinations are only intended to achieve a broader weed control spectrum, that is, a simple combination of herbicides that kill broad-leaved weeds and gramineous weeds. This does not consider the synergistic effects brought by mixing two or more herbicides, such as improved herbicidal efficiency, reduced herbicide dosage, and safety-related issues. 4. Some herbicides may cause herbicide injury to succeeding crops. Next, some herbicide ingredients used in the present disclosure will be introduced below. Atrazine is a systemic selective pre- and postemergent herbicide. Root absorption is dominated, but stem and leaf absorption is scare. Atrazine has the same herbicidal action and selectivity as simazine, is easy to be washed by the rainwater to deeper soil layer and also effective for some deep-rooted weeds, but it is susceptible to herbicide injury. The effective duration is also longer. Atrazine is applicable to controlling D. sanguinalis, E. crus-galli, S. viridis, Cyperus sp., Alopecurus aequalis, Polygonum sp., C. album, and cruciferous and leguminous weeds in corn, sorghum, and sugarcane fields, fruit-bearing forests, nurseries, and woodland, and there is a certain inhibitory effect on some perennial weeds. Bromoxynil is widely used outside of China as a contrast herbicide for selective postemergence stem and leaf treatment in the form of octoate, sodium salt, and potassium salt. Bromoxynil is mainly absorbed by leaves, and necroses tissues rapidly by inhibiting the various processes of photosynthesis. This agent is mainly used in the fields of wheat, barley, rye, corn, sorghum, flax and other crops to control broad-leaved weeds such as Tribulus terrestris, Amaranthus tricolor, Silene conoidea, Solanum nigrum, X. strumarium, Salsola collina, Lithospermum arvense, Convolvulus arvensis, and buckwheat vines. For wheat, the dosage is 22.5-35 g per mu (active ingredient); for sorghum and corn, the dosage is 18.7-30 g per mu; for flax, the dosage does not exceed 18.7 g per mu. Pendimethalin can remove annual gramineous weeds, some broad-leaved weeds, and Cyperus sp. For example: E. crus-galli, D. sanguinalis, S. viridis, Leptochloa chinensis, E. indica, P. oleracea, A. tricolor, C. album, A. theophrasti, S. nigrum, Cyperus iria, and Cyperus difformis are removed. Pendimethalin has better control effects on gramineous weeds than broad-leaved weeds, and has poor effects on perennial weeds. Thifensulfuron-methyl, a systemic conductive postemergent selective herbicide, is an inhibitor synthesized by branched-chain amino acids, which can inhibit the biosynthesis of valine, leucine, and isoleucine, prevent cell division, and stop the growth of sensitive crops. The herbicide is mainly used to control broad-leaved weeds in wheat, barley, oats, and corn fields, such as A. retroflexus, P. oleracea, Descurainiasophia, Capsella bursa-pastoris,S. collina, Galium spurium, Veronica polita, and Stellaria aquatica, but is ineffective against Cirsium arvense var. integrifolium, C. arvensis, and gramineous weeds. The related references of the prior art include: The Development of Cornfield Chemical Herbicidesand Its Application in China Control Effect ofMain Herbicide Varieties in Corn Field ofNortheastArea Residue Analysis ofMesotrione as a New Maize Herbicide in Soil by HPLC Studies on the Effect ofNew Types Maize Herbicide Effects ofDifferent Herbicides on ControllingWeeds in Corn Fields Studies on Safety ofSulfonylurea Herbicides to Maize and DegradationDynamics in Soil Efficacy Comparison ofFour PostemergenceHerbicidesin Weed Control in Corn Tolerance ofDifferent Corn Varieties to Three Herbicides Development and Use of Corn Field Herbicides

SUMMARY An objective of the present disclosure is to provide a quaternary composite herbicide for corn fields under conservation tillage, where specific raw materials have the following weight percent: atrazine 10-15%, bromoxynil 4%- 6 % , pendimethalin 12%-16%, thifensulfuron-methyl 2%-4%, methanol 20%-35%, pesticide emulsifier 1600# 5%-8%, glycerol 1%-4%, silicone oil 0.02%-0.06%, sodium alginate 0.5%-0.8%, and adding deionized water to 100%; preferably: atrazine 12%, bromoxynil 5%, pendimethalin 14%, thifensulfuron-methyl 3%, methanol 25%, pesticide emulsifier 1600# 6%, glycerol 3%, silicone oil 0.04%, sodium alginate 0.6%, and adding deionized water to 100%. Another objective of the present disclosure is to provide a method for preparing the quaternary composite herbicide for corn fields under conservation tillage, including the steps of: mixing atrazine, bromoxynil, pendimethalin, thifensulfuron-methyl, methanol, and pesticide emulsifier 1600# in a weight ratio to dissolve into a uniform oil phase, mixing glycerol, silicone oil, sodium alginate, and deionized water in a weight ratio to form a uniform aqueous phase, adding the aqueous phase to the oil phase or the oil phase to the aqueous phase under high-speed stirring, and dispersing well to obtain a product. The product may be a product used at 3-to-5-leaf stage after emergence. The herbicide obtained by the present disclosure has the following advantages: 1. There is a more broad-spectrum weeding effect, and there are very significant control effects on gramineous weeds, broad-leaved weeds, and sedge weeds, with a long-lasting weeding effect.

2. There is a synergistic effect among various active ingredients, and the weeding effect is significantly better than that of a certain herbicide alone; moreover, the dosage may be reduced accordingly, thereby reducing the possible negative effects caused by the use of chemicals. 3. The herbicide solves the problem of chemical toxicity caused by application of large dose of a certain herbicide alone. The herbicide is safe to use and has no detrimental effect on corn growth. 4. All raw materials used are relatively inexpensive materials commonly used in the art; after the creative compounding of the present application, the same effects as expensive chemical herbicides may be achieved, and thus, the cost may be reduced accordingly. 5. The herbicide of the present disclosure is an emulsion in water, and has advantages over wettable powders and other formulations in terms of ease of preparation and rapid exertion of the herbicidal effect. DETAILED DESCRIPTION Raw materials were prepared according to the following weight percent (%): Atrazin Bromoxyn Pendimethal Thifensulfuro Methan Pesticide Glycer Silicon Sodiu Deionize e il in n-methyl ol emulsifi ol e oil m d water er 1600# alginat e Exampl 10 6 12 4 28 5 2 0.02 0.55 Balance el Exampl 12 4.5 13 3.8 20 6.5 1 0.03 0.5 Balance e2 Exampl 15 4 14.5 3.1 30 8 2.5 0.035 0.65 Balance e3 Exampl 14 5.5 15 2.2 35 7.5 4 0.05 0.8 Balance e4 Exampl 13 4.8 16 2 32 7 3.5 0.06 0.7 Balance e5 Exampl 12 5 14 3 25 6 3 0.04 0.6 Balance e6 1

Atrazine, bromoxynil, pendimethalin, thifensulfuron-methyl, methanol, and pesticide emulsifier 1600# were mixed in a weight ratio to dissolve into a uniform oil phase; glycerol, silicone oil, sodium alginate, and deionized water were mixed in a weight ratio to form a uniform aqueous phase; the aqueous phase was added to the oil phase or the oil phase to the aqueous phase under high speed stirring, and dispersed well to obtain a product. Example 7, comparative experiment of control effect Control effect (%) = Fresh weed weight of fresh water control group - Fresh weed weight of treatment group X 100% Fresh weed weight of fresh water control group

Control agents (all commercially available): Control 1: 50% atrazine wettable powder Control 2: 40% bromoxynil emulsifiable concentrate Control 3: 33% pendimethalin emulsifiable concentrate Control 4: 75% thifensulfuron-methyl suspension concentrate Before the experiment, all the preparations were sprayed after mixing with 40 kg of water per mu, and the related weeds were classified and counted 30 days after application.

Experimental results are as follows No. Dosage Digitaria Echinochloa Portulaca Polygonum Cyperus sanguinalis crus-galli oleracea sp. rotundus 1 Example 1 60 g/mu 94.2 93.7 94.9 91.3 93.7 2 Example 1 100 g/mu 99.2 99.1 99.4 97.8 98.1 3 Example 2 60 g/mu 94.9 92.3 94.5 93.2 94.5 4 Example 2 100 g/mu 99.5 99.6 99.1 97.9 98.4 5 Example 3 60 g/mu 94.6 93.6 94.8 93.0 94.4 6 Example 3 100 g/mu 98.9 99.5 99.2 98.4 97.9 7 Example 4 60 g/mu 93.9 93.4 95.1 93.0 94.6 8 Example 4 100 g/mu 99.2 99.4 99.1 97.9 97.7 9 Example 5 60 g/mu 95.1 93.7 94.8 92.9 94.1 10 Example 5 100 g/mu 98.8 99.4 99.3 96.7 98.3 11 Example 6 60 g/mu 95.5 94.8 95.5 93.2 94.7 12 Example 6 100 g/mu 100 100 99.8 98.6 98.6 13 Control 1 60 g/mu 79.1 81.3 73.5 67.9 9.2 14 Control 1 100 g/mu 82.3 82.6 78.9 72.6 11.0 15 Control 2 60 g/mu 0 0 79.7 80.6 34.6 16 Control 2 100 g/mu 0 0 84.5 83.7 38.1 17 Control 3 60 g/mu 82.5 81.2 78.3 77.4 38.9 18 Control 3 100 g/mu 85.6 84.4 80.9 82.3 40.5 19 Control 4 60 g/mu 0 0 83.6 79.8 82.4 20 Control 4 100 g/mu 0 0 86.5 83.4 85.6

It can be seen from the comparison of the control effect experiment that the composite herbicide of the present disclosure has a significant effect difference compared to the four main herbicide components used alone, and has very good broad-spectrum weeding effects on gramineous weeds, broad-leaved weeds, and Cyperus sp. Example 8, safety test of the herbicide of the present disclosure It was tested whether the herbicide of the present disclosure had an effect on corn growth (the number is consistent with the meaning in the above table). Plant height after 8 days (cm) Plant height after 15 days (cm) Fresh plant weight after 15 No. 1 51.4 57.9 6.8 2 51.3 58.1 6.9 3 51.0 58.2 6.9 4 51.1 58.4 6.9 5 49.8 58.3 7.0 6 50.4 58.3 7.0 7 50.8 58.6 6.8 8 51.2 58.5 6.9 9 50.7 58.5 6.9 10 51.0 58.3 7.0 11 51.5 58.5 7.0 12 51.6 58.7 7.1 Fresh water blank 51.3 58.6 6.9

It can be seen from the above table that there is no significant difference in each indicator of corn growth between the herbicide of the present disclosure and the control, and it can be seen that the herbicide of the present disclosure is safe for corns in fields under conservation tillage.

Claims (3)

1. What is claimed is: 1. A composite herbicide for corn fields under conservation tillage, wherein specific raw materials have the following weight percent: atrazine 10%-15%, bromoxynil 4%-6%, pendimethalin 12%-16%, thifensulfuron-methyl 2%-4%, methanol 20%-35%, pesticide emulsifier 1600# 5%-8%, glycerol 1%-4%, silicone oil 0.02%-0.06%, sodium alginate 0.5%-0.8%, and adding deionized water to 100%.
2. 2. The composite herbicide for corn fields under conservation tillage according to claim 1, wherein the weight percent is: atrazine 12%, bromoxynil 5%, pendimethalin 14%, thifensulfuron-methyl 3%, methanol 25%, pesticide emulsifier 1600# 6%, glycerol 3%, silicone oil 0.04%, and sodium alginate 0.6%.
3. 3. A method for preparing the composite herbicide for corn fields under conservation tillage according to claim 1 or 2, comprising the steps of: mixing atrazine, bromoxynil, pendimethalin, thifensulfuron-methyl, methanol, and pesticide emulsifier 1600# in a weight ratio to dissolve into a uniform oil phase, mixing glycerol, silicone oil, sodium alginate, and deionized water in a weight ratio to form a uniform aqueous phase, adding the aqueous phase to the oil phase or the oil phase to the aqueous phase under high-speed stirring, and dispersing well to obtain a product.