Faria Marcos, Mascarin Gabriel Moura, Butt Tariq, Lopes Rogerio Biaggioni
Embrapa Genetic Resources and Biotechnology, Parque Estação Biológica, W5 Norte, Brasília, DF, 70770-917, Brazil.
Embrapa Environment, Jaguariúna, SP, Brazil.
Neotrop Entomol. 2023 Apr;52(2):122-133. doi: 10.1007/s13744-023-01033-5. Epub 2023 Apr 4.
In Brazil, the production of beneficial microorganisms by growers exclusively for their own use is a practice known as "on-farm production". Regarding on-farm bioinsecticides, they were initially deployed for pests of perennial and semi-perennial crops in the 1970s but, since 2013, their use has extended to pests of annual crops such as maize, cotton, and soybean. Millions of hectares are currently being treated with these on-farm preparations. Local production reduces costs, meets local needs, and reduces inputs of environmentally damaging chemical pesticides, facilitating establishment of more sustainable agroecosystems. Critics argue that without implementation of stringent quality control measures there is the risk that the on-farm preparations: (1) are contaminated with microbes which may include human pathogens or (2) contain very little active ingredient, impacting on field efficacy. The on-farm fermentation of bacterial insecticides predominates, especially that of Bacillus thuringiensis targeting lepidopteran pests. However, there has been a rapid growth in the past 5 years in the production of entomopathogenic fungi, mostly for the control of sap-sucking insects such as whitefly (Bemisia tabaci (Gennadius)) and the corn leafhopper (Dalbulus maidis (DeLong and Wolcott)). In contrast, on-farm production of insect viruses has seen limited growth. Most of the ca. 5 million rural producers in Brazil own small or medium size properties and, although the vast majority still do not practice on-farm production of biopesticides, the topic has aroused interest among them. Many growers who adopt this practice usually use non-sterile containers as fermenters, resulting in poor-quality preparations, and cases of failure have been reported. On the other hand, some informal reports suggest on-farm preparations may be efficacious even when contaminated, what could be explained, at least partially, by the insecticidal secondary metabolites secreted by the pool of microorganisms in the liquid culture media. Indeed, there is insufficient information on efficacy and mode of action of these microbial biopesticides. It is usually the large farms, some with > 20,000 ha of continuous cultivated lands, that produce biopesticides with low levels of contamination, as many of them possess advanced production facilities and have access to specialized knowledge and trained staff. Uptake of on-farm biopesticides is expected to continue but the rate of adoption will depend on factors such as the selection of safe, virulent microbial strains and implementation of sound quality control measures (compliance with emerging Brazilian regulations and international standards). The challenges and opportunities of on-farm bioinsecticides are presented and discussed.
在巴西，种植者专门为自身使用而生产有益微生物的做法被称为“农场生产”。关于农场自制生物杀虫剂，它们最初于20世纪70年代用于多年生和半多年生作物的害虫防治，但自2013年以来，其使用范围已扩大到玉米、棉花和大豆等一年生作物的害虫防治。目前有数百万公顷土地正在使用这些农场自制制剂进行处理。本地生产降低了成本，满足了当地需求，并减少了对环境有破坏作用的化学农药的投入，有助于建立更具可持续性的农业生态系统。批评者认为，如果不实施严格的质量控制措施，农场自制制剂可能存在以下风险：（1）被包括人类病原体在内的微生物污染；（2）活性成分含量极低，影响田间防治效果。细菌杀虫剂的农场发酵占主导地位，尤其是针对鳞翅目害虫的苏云金芽孢杆菌的发酵。然而，在过去5年里，昆虫病原真菌的生产迅速增长，主要用于防治粉虱（烟粉虱（Gennadius））和玉米叶蝉（玉米叶蝉（DeLong和Wolcott））等刺吸式昆虫。相比之下，昆虫病毒的农场生产增长有限。巴西约500万农村生产者中的大多数拥有中小型农场，尽管绝大多数人仍未开展农场自制生物农药的生产，但这一话题已引起他们的兴趣。许多采用这种做法的种植者通常使用非无菌容器作为发酵罐，导致制剂质量不佳，并且已有失败案例的报道。另一方面，一些非正式报告表明，即使受到污染，农场自制制剂可能仍然有效，这至少可以部分地由液体培养基中微生物群体分泌的杀虫次生代谢产物来解释。事实上，关于这些微生物生物农药的功效和作用方式的信息不足。通常是大型农场，其中一些拥有超过20000公顷的连片耕地，可以生产污染水平较低的生物农药，因为它们中的许多拥有先进的生产设施，并能够获得专业知识和训练有素的员工。预计农场自制生物杀虫剂的使用将持续，但采用率将取决于多种因素，如安全、有活力的微生物菌株的选择以及完善的质量控制措施的实施（符合巴西新出台的法规和国际标准）。本文介绍并讨论了农场自制生物杀虫剂面临的挑战和机遇。
