Novel Biofungicide CE

Jan 14, 2024

Presented By Chengdu Newsun

Grey mold disease is a fungal disease caused by the infection of Botrytis cinerea, which is very harmful to agricultural crops and garden ornamental plants. It can infect more than 470 kinds of plants such as Solanaceae, Cucurbitaceae, and Rosaceae [1]. Once infected, the plant leaves drop seriously, fruits rot, and the quality of agricultural products will decline. For horticultural plants, such as roses, grey mold disease mainly infects their flowers. In severe cases, it will cause harm to young branches and leaves, causing petals to turn brown, rotted, wilted, until the whole plant becomes brown and wilted [2-3], thereby reducing the commercial values of the flowers. Tomato is one of the most widely cultivated and consumed vegetable crops in the China. After tomato is infected, grey-white or grey-brown mold will appear on the infected parts, and even cause rotten seedlings and fruits, so as to reduce the yield [4]. For strawberry, its nutritional values and the unique taste are preferred by the consumers, but it is very susceptible to the grey mold disease, which harms all the above ground parts of the strawberry plants, including fruits, flowers, fruit stalks, leaves, petioles, and etc., among which, the fruits are infected most serious [5].

Grey mold, as one of the main fungal diseases in plants, has brought huge economic losses to garden plants and agricultural crops. The annual global economic loss caused by this disease exceeds 10 billion U.S. dollars. For the grape wine industry, the annual reduction of wine production caused by grey mold can reach more than 20%. The post-harvest grapes are also damaged by grey mold during storage, and the losses can be as high as 50% in severe cases [7]. In China, the strawberry planting area is large, but due to the damage of grey mold, the yields are generally reduced by 20 – 30%, and in severe cases, by more than 50%, which has caused huge economic losses that cannot be ignored by the growers [6]. Grey mold is an important disease in tomato cultivation, which can cause a 20% to 30% reduction in yields, or even as high as 50%. Among garden ornamental plants, roses are also severely damaged during long-distance refrigerated transportation. According to the investigations, more than 70% of post-harvest losses can be caused under extreme conditions. So, the harms of grey mold disease to plants cannot be ignored.

Fig. 1: Grey mold on cucumber

In recent years, the chemical fungicides are mainly used to control grey mold. At present, there are two types of agrochemicals. One is curative fungicides, such as anilinopyrimidines (e.g. Pyrimethanil), dicarboximides (e.g. Procymidone, Iprodione) and N-phenylcarbamate (e.g. Carbendazim), the other one is protective fungicides, such as Chlorothalonil, Mancozeb, Captan, and etc., which only show a protective activity. [7-9].

As using agrochemicals will also inhibit the physiological activities of plants to a certain extent, the long-term use of agrochemicals will reduce their resist to pathogenic fungus, leading to great reduce of control effects. The large-scale use of agrochemicals will increase not only the cost, but also the hazards to the environment and human health. For example, the systemic fungicides Carbendazim and Benomyl, which were firstly used to prevent and control grey mold, have already had a serious resistance problem. In 2012 and 2013, the resistance rate of grey mold to Carbendazim in Hubei Province, China was 63.6% [10]. The resistance rate of grey mold to Carbendazim in Liaoning, Hebei, Beijing, Anhui and Sichuan provinces ranged from 53.6% to 99.0%, and the lowest resistance rate was 24.1% in Xinjiang province [11].

Therefore, to develop the new natural fungicides and use biocontrol are effective alternatives to control grey mold. With the rapid development of science and technology, through in-depth research on natural plant extraction and formulation technology, plant-based metabolites are more and more popular because of their good control efficacy, fast decompositon in nature, and less prone to drug resistance. Therefore, they are used for agricultural disease control more and more often. Essential oils are natural antimicrobials which are found in many plants to protect them from disease infection and have great potential in the food industry against foodborne pathogens and spoilage organisms. Plant essential oils such as oregano oil and thyme oil have broad-spectrum antibacterial properties. Generally, the essential oils are complex mixtures of different types of compounds, containing about 20 to 80 different moleculars. Phenols are the main antibacterial components in the plant essential oils, and their antifungal activity is determined by their concentrations and chemical composition. Plant essential oils can inhibit or delay the growth of bacteria, yeast and mold. Because of its broad-spectrum bioactivities, it has been favored by many natural medicine researchers around the world. It is a natural antifungal product that can replace chemical fungicides.

Oregano is a kind of medicinal and edible plant in China, which has high medicinal and edible values. The whole oregano plants can be used as medicine, which has anti-oxidation, antibacterial, anti-tumor effects, and etc. It is also used as biopesticides, insecticides, and antioxidants. At the same time, oregano is often used as a cooking flavor herb for baking and meat deodorization and refreshing. Carvacrol is the main component of oregano essential oil, which is reported to inhibit the growth of a variety of pathogenic microorganisms, including Gram-negative bacteria, Gram-positive bacteria, Fusarium and Alternaria [12-14]. It has been widely used in food, medicine and cosmetic industries.

Oregano essential oil is a light yellow clear oily liquid extracted from the stems and leaves of oregano plants. It is highly volatile and difficult to preserve. The phenolic compounds and terpenes in oregano essential oil have strong antibacterial and antioxidant activities. The key indicators to evaluate the antibacterial activities and effects of oregano essential oil are the contents and ratios of carvacrol and thymol. Carvacrol can impact the bacterial biofilm, inhibit the fungus film-forming process, reduce the membrane potential and proton movement force, and at the same time increase the permeability of the cell membrane, which can quickly penetrate the cell membrane of pathogenic microorganisms and promote a large amount of water accumulation in the cell so as to cause cell expansion, resulting in rupture of the cell membrane and death of the bacteria [15].

Carvacrol is an aromatic compound that is a volatile, light yellow transparent oily liquid with characteristic fragrance. Carvacrol exists in oregano plant, Comanthosphace ningpoensis (Hemsl.) Hand.-Mazz., Rabdosia amethystoides (Benth.) Hara, and etc. The content of carvacrol in these plants will be different according to the growing areas, plant parts, extraction methods, and etc. Carvacrol has not only small molecule, low toxicity and low polarity, but also antibacterial and anti-oxidant properties. It also stimulates appetite, promotes absorption and etc., with a big commercial development value. Carvacrol is the main component in oregano (60%-74%) and thyme (45%). The World Health Organization issued a statement in 2012 that when the carvacrol content in food is less than or equal to 50mg/kg, it will not cause harm to human health and can be used in fruit preservation. The carvacrol-rich essential oils have been reported to have significant antibacterial activity. Dai Ran et al. (2015) found that oregano essential oil has an excellent effect on resisting intestinal diseases caused by bacteria in rabbits. When the concentration of oregano essential oil is 1.2cfu/mL, it can effectively inhibit the growth of Gram-positive bacteria and Gram-negative bacteria, and the oregano essential oil has higher antioxidant activity than other commonly used natural antioxidants. Cleff et al. (2010) found that the oregano essential oil has high antifungal activity against Candida, of which the minimum concentrations to inhibit and kill fungi are 2-5 mL/L. Hu Yanfen et al. (2010) found that carvacrol also has a strong inhibitory effect on Escherichia coli, Staphylococcus aureus and Salmonella choleraesuis, and can prevent and treat infections in the gastrointestinal tract of animals. Vatavali et al. (2013) studied the effect of oregano essential oil on the shelf life of red sea bream and found that the shelf life of the control group was 11 days, while the shelf life of treatment with oregano essential oil was 16 days. Liu Meng et al. (2011) found that carvacrol has anti-microbial growth and anti-oxidation effects, and can prevent feed deterioration, with advantages of no residue, no pollution, no resistance to microorganisms, and good compatibility with antibiotics.

With the supports of the rich resources of medicinal plants and a long history of using medicinal plants in China, Chengdu Newsun Crop Science Co., Ltd., focusing on the innovation, research and development of green agricultural biotechnology, with years of research and development, successfully adopted the innovative biotechnology of the plant essential oil carvacrol in the agricultural disease control, and made outstanding contributions to the global organic and green agricultural industry.

Fig. 2: Botrytis spores under electron microscopic inspection

For Botrytis spores, 0.5% CE carvacrol AS can force the shape of the spores become droplet shape, and break and rupture at the tip to cause cytosol leakage. For the grey mold on plant leaves, 0.5% CE carvacrol AS can destroy the spores to the greatest extent and prevent the expansion and spread of the lesion spots.

Carvacrol 10% technical grade has a richer extracted components, and a variety of the fungistatic and fungicidal active ingredients in oregano and thyme are extracted, saving costs of energy and solvents, and the components synergize with each other to get the better efficacy. The carvacrol technical is extracted by the patented technology from Chinese medicinal plants oregano and thyme, containing a variety of fungistatic and fungicidal compounds, which has good affinity with plants, a wide control spectrum and safe to use.

Fig.3: Various active ingredients in 0.5% CE carvacrol AS

According to the laboratory tests, it was found that 0.5% CE carvacrol AS had a strong inhibitory effect on grey mold caused by Botrytis cinerea, and the inhibition rate of 0.5% CE carvacrol AS diluted 500 times was higher than 80%.

In order to solve the problems of the use of botanical biopesticides and give full play to their advantages, Chengdu Newsun has established the active prevention and control system of "prevention-preventive treatment-treatment" of biopesticides, that is, before and at the early stage of occurrence of plant diseases, use biopesticide alone or with chemical pesticides to inhibit the disease infection to the greatest extent, so as to reduce disease infection index and the use of chemical pesticides.

0.5% CE carvacrol AS for the prevention and control of grape grey mold. Before occurrence of grey mold, use 0.5% CE carvacrol AS for 3 times with 7 days interval. The efficacy of using 0.5% CE carvacrol AS alone reached more than 80% ofthe chemical fungicide (40% Iprodione SC).

In the middle and late stages of disease occurrence, that is, the outbreak period of disease, use "botanical pesticide + chemical pesticide" as core technology, under the premise of improving the effectiveness of prevention and control, to reduce the use amount of chemical pesticide, the resistance, and chemical pesticide residues, improve the quality of agricultural products and eco-environment, and maintain the biodiversity and alleviate environmental pressure.

A large number of field test results show that after mixing with chemical fungicide such as Pyrimethanil, Iprodione and etc., 0.5% CE carvacrol AS can reduce the use of chemical pesticides by 20-30%, increase the field control efficacy by more than 30%, and be more environmentally friendly.

Fig.04

The treatment from left to right as below:

Fig.04: The test of 0.5% CE carvacrol AS for controlling kiwifruit grey mold in Pujiang, Sichuan (0.5% CE carvacrol AS diluted 500 times mixed with Pyrimethanil 1500 times had the best result. Apply before the occurance of grey mold for 2 times with 7 days interval. The efficacy reached more than 80% after 19 days of 2nd application)

In summary, in the early stage of grey mold, use 0.5% CE carvacrol AS alone can significantly reduce the infection index and infection capacity of grey mold. During the outbreak of grey mold, use 0.5% CE carvacrol AS + chemical fungicide such as Pyrimethanil can have a significant control effect on grey mold.

As a natural botanical biopesticide, 0.5% CE carvacrol AS has a good preventive effect on grey mold, and mix with chemical fungicide can significantly reduce the resistance of grey mold and improve the control efficacy. Its raw material oregano is widely cultivated as a common medicinal herb in China. The average annual yield of oregano herb can reach 6.9mt/ha. In recent years, with the global development of biosynthesis technology, the synthesis of plant phenolic compounds through eukaryotic cell factory technologies such as yeast and plant stem cells has become a hot research direction at this stage, and the production of active ingredients through large-scale bioreactors has become possible through the adoption of advanced technologies such as chassis cell modification and protease engineering.

0.5% CE carvacrol AS not only has a significant effect on diseases caused by higher fungal such as grey mold, but also has very high safety, and is very safe for natural enemies and beneficial organisms. It is estimated that the global market size of grey mold control is 600 million to 800 million US dollars, of which the China's grey mold market is close to 200 million US dollars, and the market size is huge. In view of the advantages of market demand, huge market potential, suitable window period, excellent effect, and comprehensive technology, it is expected to be built into a new strategic product. In the future, 0.5% CE carvacrol AS will definitely help the establishment and promotion of green prevention and control technology of grey mold, promote the reduction and efficiency of chemical pesticides, provide a solid guarantee for food safety and the quality and safety of agricultural products, maintain biodiversity, reduce environmental pressure, and contribute to the value enhancement of agriculture and sustainable agricultural development, so as to promote the healthy development of biotechnology and promote harmonious coexistence between human and nature.

Newsun Crop Science's website: http://www.cdxzy.com E-mail: [email protected]

References:

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