A method for integrated control of canada goldenrod

Abstract

This invention discloses a method for controlling Canadian goldenrod, belonging to the field of biological control technology. The method includes: physical tilling combined with chemical spraying during the seedling stage; tilling followed by application of biological herbicides during the vegetative growth stage; spraying flower bud inhibitors to suppress seed formation during the flowering stage; and physical removal during the seed maturation stage. This invention employs a phased, multi-pronged, synergistic comprehensive control strategy, targeting the biological characteristics of Canadian goldenrod at different growth stages, and combining chemical, biological, and physical methods to achieve highly efficient, long-lasting, and environmentally friendly control effects. This significantly reduces problems such as herbicide resistance, high recurrence rates, and environmental pollution caused by single-method control.

Description

Technical Field

[0001] This invention belongs to the field of biological control technology, specifically relating to a comprehensive control method for Canadian goldenrod. Background Technology

[0002] Canadian goldenrod is a perennial herbaceous plant with stout stems, possessing perennial underground rhizomes and annual above-ground stems. It can reproduce through both sexual and asexual means, with both methods yielding highly viable offspring. Each plant can produce over 20,000 seeds annually through insect pollination, with a germination rate as high as 80%, allowing it to rapidly establish seedling populations in abandoned land or disturbed habitats. Therefore, suppressing its flowering to prevent seed production is a supplementary technical measure to control the spread and harm caused by Canadian goldenrod. Besides sexual reproduction, asexual reproduction also plays a significant role in the invasion of Canadian goldenrod. Underground rhizomes only 5cm in length can germinate and propagate, forming clones approximately 1m in diameter after one year of growth, making it the primary mode of invasion after establishment.

[0003] The ecological harm and economic losses caused by *Solidago canadensis* in its invasive areas cannot be ignored. These are mainly manifested in the following ways: *Solidago canadensis* has a strong competitive ability, secreting allelopathic substances that effectively inhibit the growth of its competitors. This leads to a significant reduction in species diversity in areas where *Solidago canadensis* is prevalent, sometimes even resulting in the absence of companion plants and the formation of monodominant communities. *Solidago canadensis* competes for and occupies the ecological niches of native species, depriving them of living space and reducing species diversity by forming large areas of highly pure monodominant communities. *Solidago canadensis* can also hybridize with other plants in the same genus. This gene exchange between invasive and native species may lead to the loss of unique genotypes in native species, altering their genetic diversity and integrity, and even causing extinction. More importantly, the invasion of *Solidago canadensis* causes direct economic losses to agriculture, forestry, and animal husbandry in my country. It can invade farmland and surrounding areas, causing a sharp decline in crop yield and quality. After *Solidago canadensis* invades orchards, the economic losses are at least 10% to 30%, and in severe cases, even total crop failure.

[0004] Currently, the main method for controlling Canadian goldenrod is chemical control, which involves spraying herbicides. Trials in various regions have shown that while herbicides such as glyphosate, dicamba, clopyralid, MCPA, and aminopyridine are effective against the above-ground parts of Canadian goldenrod, they are ineffective against its underground rhizomes, which will reproduce the following year. Furthermore, the heavy application of chemical herbicides reduces the number of susceptible plants and leads to the emergence of herbicide-resistant biotypes in weeds. The extensive use of chemical herbicides to control Canadian goldenrod is uneconomical, pollutes the environment, damages soil fertility, and inhibits the growth of soil microorganisms. In addition, the aforementioned herbicides effective against Canadian goldenrod are unsafe for most garden plants; therefore, selecting safe and effective chemical herbicides is a crucial technical aspect of control. Mechanical control has limitations in horticultural ecosystems. Simply using mechanical methods not only fails to effectively control Canadian goldenrod but can also promote its spread. This is because after being damaged by mechanical weeding, the plants employ stress-induced reproduction strategies, resulting in a far greater number of adventitious buds sprouting from the plant debris than the number of clones from a naturally occurring, intact plant. Biological control could involve introducing natural enemy insects from the native habitat or utilizing plant pathogenic fungi to effectively curb the spread of this noxious weed. Alternative control involves planting economic and ornamental plants in severely invasive habitats to create cover and prevent further invasion. Utilizing Canadian goldenrod as a beneficial resource is another control approach. Currently, technologies are being developed that use the stems as a substrate for cultivating edible fungi, which offer superior flavor compared to crop straw and are also greener and safer. Harvesting Canadian goldenrod as green fodder for goats is another experimental technology for turning a harmful plant into a beneficial one.

[0005] According to the National Biosafety Law and its implementing regulations, Canadian goldenrod, a serious invasive alien weed, should be completely eradicated. Currently, Canadian goldenrod is distributed in all 13 prefecture-level cities in Jiangsu Province, affecting 67 counties (cities, districts) and 443 townships. Survey data shows that the problem is significantly more severe in southern Jiangsu than in central Jiangsu, and significantly more severe in central Jiangsu than in northern Jiangsu. For example, Suzhou in southern Jiangsu accounts for 30% of the affected area in the province, Nanjing accounts for 25%, and Taizhou in central Jiangsu accounts for 12.1%. In terms of east-west distribution, the problem is more severe in the east than in the west. Although its distribution is evident along roads, riverbanks, seawalls, and along the land acquisition directions of development zones, it has already affected areas surrounding farmland and continues to spread. Canadian goldenrod has caused serious impacts on agriculture, horticulture, and the ecosystem, especially severely damaging horticultural ecosystems. Therefore, scientific and effective integrated pest management of Canadian goldenrod is imperative. Summary of the Invention

[0006] To address the problems of incomplete control, easy recurrence, high environmental risk, and high cost in existing Canadian goldenrod control technologies, this invention provides a phased, multi-pronged integrated control method. Based on the biological characteristics and reproductive priorities of Canadian goldenrod at different growth stages, this method selectively combines physical, chemical, and biological control measures to achieve efficient eradication, long-lasting efficacy, reduced dependence on chemical agents, less environmental pressure, and lower control costs.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows: A comprehensive control method for Canadian goldenrod includes the following steps: Includes the following steps: S1. Spray the entire plant of Canadian goldenrod with chemical reagents during the seedling stage, and remove, mechanically cut, and till the soil to expose the underground rhizomes of Canadian goldenrod on the soil surface. S2. During the vegetative growth period, till the soil to expose the underground rhizomes of Canada goldenrod on the soil surface. Immediately after tilling, evenly spread the mixed biological herbicide solid substrate on the roots of Canada goldenrod. S3. During the flowering period, spray flower bud inhibitors on Canadian goldenrod that is in the bud stage before flowering; S4. During the seed maturity period, pull out, mechanically cut, and till the soil to expose the underground rhizomes of the Canadian goldenrod on the soil surface.

[0008] As an improvement of the present invention, the chemical reagents in step S1 are 41% glyphosate aqueous solution diluted 200 times and 20% clopyralid emulsifiable concentrate, wherein the volume ratio of glyphosate aqueous solution to clopyralid emulsifiable concentrate is 1:1.

[0009] As an improvement of the present invention, the solid substrate of the biological herbicide in step S2 is a solid fermentation herbicide of *Sclerotium sclerotiorum* strain SC64, with a dosage of 80 kg / 667 m³. 2 The effective ingredient content is 17 kg / ha.

[0010] As an improvement of the present invention, the flower bud inhibitor in step S3 is a biological regulator, which comprises glyphosate, water, nutrients, and an adhesive; the adhesive is selected from at least one of gum arabic, xanthan gum, gum arabic, dextrin, starch, and agar; the nutrients are selected from at least one of sucrose, urea, and ammonium bicarbonate; the weight ratio of the plant growth regulator to the nutrients is 490:0.5~300, and the weight ratio of the plant growth regulator to the adhesive is 490:1~150; the concentration of the nutrients in the plant growth inhibitor is 0.05%~30%, and the concentration of the adhesive in the plant growth inhibitor is 0.01%~15%.

[0011] As an improvement of the present invention, the seedling period is from March to May, the vegetative growth period is from June to August, the flowering period is from September to October, and the seed maturity period is from November to December.

[0012] The beneficial effects of this invention are as follows: This invention targets the core dispersal mechanism of Canadian goldenrod, employing the most targeted measures at each of its four key life stages (seedling stage, vegetative growth stage, flowering stage, and seed maturation stage). It kills seedlings, inhibits seed formation and germination, and achieves three-dimensional eradication of both above-ground and underground parts through biological herbicides infecting the rhizome system, combined with physical destruction, effectively blocking its reproductive chain and significantly reducing the recurrence rate.

[0013] This invention reduces the reliance on chemical herbicides by employing a synergistic approach combining chemical, biological, and physical methods. For example, low-dose compounded chemical agents are used for rapid kills during the seedling stage, biological herbicides are used to specifically target the rhizomes during the vegetative growth stage, and flower bud inhibitors are used during the flowering stage to reduce seed quantity at the source. This combined strategy improves overall control efficiency while reducing chemical residues and the risk of environmental pollution.

[0014] This invention provides precise intervention based on the physiological weaknesses of plants at different growth stages. Chemical control is highly efficient when plants are weak in the seedling stage; biological herbicides are effective when roots and stems are active during the vegetative growth stage; and flower bud inhibitors are applied before flowering to minimize seed yield. This staged and precise treatment avoids pesticide waste, improves resource utilization efficiency, and reduces the labor and material costs of long-term control.

[0015] This invention significantly reduces the single use of highly residual chemical herbicides by introducing biological and physical control methods. The biological herbicide, cyhalothrin, is relatively safe for the environment and non-target organisms, and the flower bud inhibitor, as a bioregulator, also poses a lower environmental risk than chemical herbicides. This method helps protect soil microbial flora and maintain ecological balance, making it more suitable for application in areas with high environmental safety requirements, such as around farmland, gardens, and ecological reserves. Attached Figure Description

[0016] Figure 1 The images show the effects of chemical control on the three treatment groups in Example 1. Figure 2 The images show the effects of biological control at different time points after Example 2 (15 days, 30 days, and 90 days). Figure 3 This is a diagram showing the flowering state of the control group in Example 3; Figure 4 This is a diagram showing the flowering status of the treatment group in Example 3; Figure 5 This is a comparison chart of the size of the fluff in Example 3; Figure 6 This is a statistical chart showing the number of florets, inflorescences, and seeds in Example 3; Figure 7 Comparison of the effects of flower bud inhibitor on seed germination control in Example 3 (1 week); Figure 8 Comparison of the effects of flower bud inhibitor on seed germination control in Example 3 (2 weeks); Figure 9 The images show the effects of physical control measures in Example 4 (15 days, 30 days, and 90 days). Figure 10 Images of the control group at different time periods. Detailed Implementation

[0017] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that the following specific embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention.

[0018] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0019] Unless otherwise specified, all materials and reagents used in the following examples are commercially available.

[0020] Among them, the solid fermentation herbicide of Sclerotium sclerotiorum strain SC64 was purchased from Nanjing Agricultural University. The composition of the herbicide is the same as that of the solid granule composition of the herbicide herbicide disclosed in Chinese Patent CN105076265B. The bioregulator was purchased from Nanjing Dengbo Ecological Technology Co., Ltd., and the composition of the bioregulator is the same as the plant growth and development inhibitor composition disclosed in Chinese Patent CN106259328B. The bioregulator inhibits the differentiation of male and female flower stamens during flower bud differentiation, reduces the division of microspore mother cells, and inhibits the development of megaspores and embryo sacs, resulting in the inability of pollen grains to form normally, deformed ovules, and failure of embryo sac differentiation, thus leading to inflorescence abortion and reducing or eliminating fruit production.

[0021] Table 1 Prevention and control measures at different growth stages

[0022] Example 1

[0023] During the seedling stage, Canadian goldenrod seedlings were sprayed with a chemical reagent consisting of a 200-fold dilution of 41% glyphosate aqueous solution and a 20% clopyralid emulsifiable concentrate. The control effect was as follows: Figure 1 As shown.

[0024] Efficacy calculation: Visually assess the degree of pesticide damage to the plant. The pesticide damage grading standards for the above-ground parts are as follows: Grade 0: No pesticide damage; Grade 1: Slight malformation or slight chlorotic spots on the leaves, and slight yellowing of the leaves; Grade 2: A large number of leaves turn yellow, less than 5% of the leaves wither or 5% of the leaves of the whole plant are malformed; Grade 3: 6%-50% of the leaves wither or are malformed and twisted, the growing point dies, and there are slight necrotic spots on the stem; Grade 4: 51% to more than 99% of the leaves wither, and a large number of necrotic spots appear on the stem; Grade 5: All leaves die.

[0025] Control efficiency (%) = [(Number of surviving plants before application - Number of surviving plants after application) / Number of surviving plants before application] × 100 (Note: Number of surviving plants after application = Number of surviving plants before application - Number of plants with level 5 pesticide damage).

[0026] The chemical control efficacy of sprayed chemical reagents is statistically shown in Table 1: Table 2 Statistics on the effectiveness of chemical control

[0027] According to the statistics on control effects, the control effect of chemical control on Canadian goldenrod is 88.77%.

[0028] Example 2 During the vegetative growth period, the soil of Canada goldenrod is tilled to expose the underground rhizomes on the soil surface. Immediately after tilling, a well-mixed biological herbicide solid substrate (carbendazim) is evenly applied to the roots of the Canada goldenrod.

[0029] Table 3 Dosage of Biological Control

[0030] Efficacy analysis: such as Figure 2 As shown, biological control of *Solidago canadensis* was applied to different experimental plots, and the control effects were observed after 15, 30, and 90 days. The statistical results showed that after biological control, the control effect of *Solidago canadensis* in woody, mixed, and herbaceous vegetation plots reached 81.74% after 15 days; 90.17% after 30 days; and as high as 97.65% after 90 days. Biological control is fast-acting and highly efficient.

[0031] Table 4. Imitation of biological control

[0032] Example 3

[0033] During the flowering period, Canadian goldenrod, which is in the bud stage before flowering, is sprayed with a flower bud inhibitor, which is a biological regulator.

[0034] Table 5 Dosage of Biological Inhibitors

[0035] Analysis of efficacy: (1) Comparison of flowering status: such as Figure 3 , 4 As shown, the flower spikes of Canada 1 Yellow Flower in the sample plot sprayed with flower bud inhibitor were significantly smaller than those in the untreated group. The flower spikes in the untreated group were between 40cm and 50cm in length and about 20cm and 30cm in width, while the flower spikes in the treated group were about 20cm and 30cm in length and about 20cm in width, with the flower spikes being significantly smaller.

[0036] (2) Number of seeds: such as Figure 5 , 6 As shown, flower spikes were collected from different treatment plots of *Solidago canadensis*, and the number of inflorescences, florets, and seeds was counted. In the treated plots, the number of inflorescences, florets, and seeds were 41, 1275, and 8253, respectively; in the untreated plots, the numbers were 55, 6427, and 65817, respectively. The results indicate that flower bud inhibitor treatment significantly reduces the number of seeds in *Solidago canadensis*, thus lowering the risk of seed dispersal.

[0037] Table 6. Seed Difference Statistics

[0038] (3) Seed germination rate: such as Figure 7 , 8As shown, the germination rate of *Solidago canadensis* seeds in different treatment plots was measured indoors. The results showed that the average germination rate of *Solidago canadensis* seeds treated with flower bud inhibitors was zero, while the germination rate of untreated *Solidago canadensis* seeds was as high as 93%. Therefore, flower bud inhibitors can significantly inhibit the germination of *Solidago canadensis* seeds, causing seed abortion, thereby blocking the seed dispersal pathway and ultimately slowing down the spread of *Solidago canadensis*.

[0039] Table 7 Seed germination rate

[0040] Example 4

[0041] During the seedling and seed maturation stages, Canadian goldenrod is removed manually or mechanically (using rotary tillers), and the soil is turned over to expose its underground rhizomes on the surface. Physical tillage achieves the following results: Figure 9 As shown.

[0042] Table 8. Effects of physical tillage on pest control

[0043] In conclusion, comprehensive control measures at different growth stages of Canadian goldenrod can effectively control the plant, reduce damage, and achieve significantly better overall control results than any single-stage control.

[0044] It should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. For those skilled in the art, several improvements and modifications can be made on the basis of the above embodiments without departing from the principle of the present invention, and all such improvements and modifications fall within the scope of protection of the claims of the present invention.

Claims

1. A comprehensive control method for Canadian goldenrod, characterized in that, Includes the following steps: S1. Spray the entire plant of Canadian goldenrod with chemical reagents during the seedling stage, and remove, mechanically cut, and till the soil to expose the underground rhizomes of Canadian goldenrod on the soil surface. S2. During the vegetative growth period, till the soil to expose the underground rhizomes of Canada goldenrod on the soil surface. Immediately after tilling, evenly spread the mixed biological herbicide solid substrate on the roots of Canada goldenrod. S3. During the flowering period, spray flower bud inhibitors on Canadian goldenrod that is in the bud stage before flowering; S4. During the seed maturity period, pull out, mechanically cut, and till the soil to expose the underground rhizomes of the Canadian goldenrod on the soil surface.

2. The integrated management method for Canadian goldenrod according to claim 1, characterized in that: The chemical reagents in step S1 are a 200-fold dilution of 41% glyphosate aqueous solution and 20% clopyralid emulsifiable concentrate, with a volume ratio of 1:1 between the glyphosate aqueous solution and the clopyralid emulsifiable concentrate.

3. The integrated management method for Canadian goldenrod according to claim 1, characterized in that: The solid substrate for the biological herbicide in step S2 is a solid fermentation herbicide of *Sclerotium sclerotiorum* strain SC64, at a dosage of 80 kg / 667 m³. 2 The effective ingredient content is 17 kg / ha.

4. The integrated management method for Canadian goldenrod according to claim 1, characterized in that: The flower bud inhibitor in step S3 is a biological regulator, comprising glyphosate, water, nutrients, and an adhesive; the adhesive is selected from at least one of gum arabic, xanthan gum, gum arabic, dextrin, starch, and agar; the nutrients are selected from at least one of sucrose, urea, and ammonium bicarbonate; the weight ratio of the plant growth regulator to the nutrients is 490:0.5~300, and the weight ratio of the plant growth regulator to the adhesive is 490:1~150; the concentration of the nutrients in the plant growth inhibitor is 0.05%~30%, and the concentration of the adhesive in the plant growth inhibitor is 0.01%~15%.

5. The integrated management method for Canadian goldenrod according to claim 1, characterized in that: The seedling stage is from March to May, the vegetative growth stage is from June to August, the flowering stage is from September to October, and the seed maturation stage is from November to December.

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