Articles

Review of Systemic Fungicides for Seed Treatment

by New User Professional User
For the majority of agricultural crops across the world, pre-sowing seed treatment with systemic fungicides is a well-established practise. The procedure aims to safeguard the crop from soil- and seed-borne illnesses. In recent years, there has been mounting evidence that fungicides used to treat diseases may unintentionally also damage non-target species like endophytes. In addition to providing resistance to biotic and abiotic stressors, endophytes are always present in plants and support plant growth and development. Endophytes in seeds may influence seed germination, seed development, seedling establishment, and crop performance.

In this article, we examine new research on the unintended effects of fungicidal treatments on the endophytic fungus community and analyse the potential repercussions of systemic fungicide treatment of seeds without regard to their endophytic fungi. Endophytes are now widely acknowledged to be present throughout the whole plant, including the seeds. As with many grasses, they may spread vertically from seed to seed or be picked up horizontally from the soil and surroundings. Many studies have demonstrated that these organisms work in symbiosis to support plant growth and development, nutrient uptake, and defence against abiotic and biotic challenges, despite the fact that the origins and evolution of these organisms in plants are a topic of conjecture.

Given this context, it is logical to expect that applying systemic seed treatment fungicide may have an impact on both the seed endophytes and the advantages they provide for seedling establishment and growth. While there is evidence that fungicidal sprays to control plant diseases also have an impact on foliar endophytes, there aren't many research that have shown how seed treatment affects endophytes that are carried on seeds. Studies on how fungicide spraying affects the rye grass seed endophyte AR37 provide some compelling instances of the latter. Recent research has demonstrated that removing seed endophytes by the use of systemic fungicides results in a considerable loss of seedling vigour, which may be partially recovered by supplementing the seedlings with the endophytes that were removed. When taken as a whole, these studies highlight the significance of seed endophytes for seedling development and establishment and highlight the need to strike a balance between the advantages of seed treatments and the direct and indirect costs associated with endophyte loss. Use of low-risk fungicides and the detection of fungicide-resistant endophytes are two strategies that are recommended to maintain the endophyte contribution to early seedling development.

Systemic fungicide seed treatment is a common integrated crop management method for crops. Recent studies have raised some questions about the practise of treating seeds with fungicides, despite the benefits that have been shown, including enhanced seed emergence, increased plant vigour, and protection from soil- and seed-borne fungal diseases. The off-target consequences of such therapy on the seed-borne microbiota, particularly on fungus, are of particular concern. It has been shown by both culture-dependent and independent techniques that seeds contain a wide variety of fungus. These fungal endophytes (FE) may contribute to the early development and establishment of seedlings. It is crucial to evaluate the effects of seed treatments on these processes because the seed microbiota acts as a vital connection between the maternal sporophyte generation and the subsequent seedling generation.

First, we quickly go over the various fungicide kinds and their mechanisms of action before tracing the history of seed treatment. Second, we discuss the potential contribution of the seed microbiome to fundamental physiological functions such seed germination, seedling development, and establishment, as well as how systemic fungicides may alter these outcomes. We rely on research that has looked at how fungicidal treatments affect plants and seeds as well as how they affect endophytes and other non-target organisms. In our final section, we talk about how systemic fungicides should be used less often since they harm seed endophytes and seed health.

Wheat seeds were treated with a brine solution in the 17th century to rid them of the smut caused by Ustilago, which is when seed disinfection first became popular. Prevost demonstrated in 1807 that diluted copper sulphate solution decreased seed-borne smuts, and this method remained the standard of care for the duration of the 19th century. New seed treatment solutions were created as a result of the creation of the International Seed Testing Association in the late 1920s and the growing understanding of the harm caused by seed-borne viruses, both during storage and post-seedling growth. In the 1950s, Captan, the first contact fungicide, was applied to seeds as a therapy to guard them against several fungal infections. The fungus were prevented from penetrating the plant tissue by this kind of fungicide. During the same period, methylmercury's effectiveness in treating tiny grains was also acknowledged. But, in the early 1970s, it was no longer used because of environmental concerns. Systemic fungicides like carboxin and thiabendazole, which decreased both soil- and seed-borne infections, were the preferred method for treating seeds after their discovery in the early 1970s. For many field and vegetable crops across the world, systemic fungicide treatment of seed is a crucial disease management approach.

The methyl benzimidazole carbamate (MBC) series of fungicides, which includes carbendazim, is one of the most frequently used systemic fungicides to treat fungal illnesses. In 1973, it was released and registered with the USEPA.

The MBCs, such as bavistin and benomyl, bind to -tubulin in microtubules and prevent the multiplication of spindle fibres, which prevents cell division. A variety of agricultural and horticultural crops, including beet, banana, cereals, fodder rapeseed, mango, oranges, pomes, pineapples, strawberries, medicinal herbs, turf grasses, and decorative plants, are protected with MBC in pre- and post-harvest treatments. Mancozab and other fungicides are also used with it to treat fungal diseases in sunflower and mango. For the treatment of seeds, many additional fungicide classes are also utilised, including triazoles, phenylpyrroles, phenylamides, benzimidazoles, and strobilurines.

Field crops are routinely treated with fungicide before planting in several nations, including the United States, Australia, and France. Yet, there has been a growing focus in these nations on the use of low-risk fungicides that are very specific for their intended targets. MBC fungicide is approved for use in 18 crops, including apple, bean, brinjal, barley, mango, cucurbit, cotton, grape, groundnut, jute, pea, paddy, rose, sugar beet, wheat, potato, walnut, and tapioca, and it is consumed in India on an annual basis in excess of 2,000 metric tonnes.

Before planting, seed treatments like seed dressing, seed coating, or seed pelleting are typically offered. The most popular type of seed treatment, seed dressing, involves applying dry or wet fungicide and insecticide formulations to the seeds. To improve the performance of seeds in the field, natural bio-formulants like Pseudomonas, Trichoderma, and Rhizobia are used. Industries often coat huge quantities of seeds, and for crops with tiny seeds, such carrots and onions, seed pelleting is used. To preserve the quality of the seeds during storage and transportation, treatments may also be applied at the time of harvest.



Sponsor Ads


About New User Junior   Professional User

0 connections, 0 recommendations, 18 honor points.
Joined APSense since, March 6th, 2023, From New Delhi, India.

Created on Mar 29th 2023 11:54. Viewed 148 times.

Comments

No comment, be the first to comment.
Please sign in before you comment.