台灣生物性植物保護製劑防治作物病害的研發與應用

Abstract

農業永續發展的目標是著眼循環利用自然資源及維護生態平衡的經營理念，祈能生產健康與安全的農產品，以造福社會大眾。因此，世界各地積極研發生物性植物保護製劑，以維護植物的健康與環境的安全。微生物、植物及其衍生物等研製的生物性植物保護製劑涵蓋有「微生物製劑」、「植物源農藥」及「生化農藥」等。相較於化學農藥，生物性植物保護製劑對人畜較無毒害，不易危及非標的生物，對生態環境較友善，除可防治植物病害外，尚有助於作物生長，並維護自然和諧與環境微生物多樣化。近年來，台灣積極推動有機農業的栽培管理法，其主要的策略就是儘量避免使用化學肥料與農藥，並採行栽培防治法，施用有機添加物及推動生物防治等技術，藉以有效達成作物病蟲害綜合管理的效益。利用微生物及植物資源研發生物性植物保護製劑是執行生物防治的主要方法之一，因此微生物與植物資源成為各國保育與挖掘的重點。在農田與栽培介質中蘊藏有許多的微生物資源，其中包括細菌、真菌、放線菌及病毒等，除具有防治植物病原菌、線蟲及農業害蟲外，某些微生物尚具有提高作物吸收營養元素或促進作物生長的功效。著名的生物防治菌種有枯草桿菌(Bacillus spp.)、螢光假單胞菌(Pseudomonas spp.)、木黴菌(Trichoderma spp.)、鏈黴菌(Streptomyces spp.)、粘帚黴菌(Gliocladium spp.)及囊叢枝菌根菌(Glomus spp.)等均已被推薦用於防治多種作物病害。此外，自然界中有許多植物富含許多特殊的抗菌成分如硫配糖體、生 物鹼、帖類、酚類、鞣質、類黃鹼素、皀素、類胡蘿蔔素、香豆素等，可用於研製植物源農藥，若直接施用於農作物亦可有效防治病蟲害。例如日本虎杖(Reynoutria japonica)萃取液可防治甜瓜白粉病、大風子(Hydnocarpus anthelminticus)萃取液可防治白菜炭疽病、扛板歸萃取液可防治水稻稻熱病。至於在植物油的應用方面，乳化的葵花油、丁香油分別可防治作物白粉病、炭疽病等。又萬壽菊、孔雀草及天人菊等對植物病原線蟲均具有拮抗作用，可做為輪作或間作作物，藉以減緩植物病原線蟲的族群密度，有效防治作物線蟲病的發生。植物殘渣亦可用於研發植物保護製劑，因此農業廢棄物經過堆肥化後，若能充分瞭解各種廢棄資材的特有抑菌或殺菌成分與掌控它們所擁有的微生物資源，也可調製具有抑制作物病原菌的製劑配方，例如中興大學研發的FBN-5A及CH100等植物保護製劑，已被推薦用於防治田間的作物病害。 The continuous development goals of agriculture is the realization of effective reutilization of nature resources and sustaining ecological balances, thus, produce safe and healthy agricultural products to benefit the public. Countries around the world have been actively and eagerly researching to protect the health of plants and the safety of environment. Biological plant protectant developed from microorganism, plant, and their secondary metabolism consists of “Microbial pesticides”, “Plant-Source-Pesticides”, and “Biochemical pesticides”. Comparing with chemical pesticide, biological plant protectant is less harmful to human and livestock, less likely to affect non-target organisms, and it is a lot more environmentally sound. Furthermore, it can effectively control plant diseases, assist the growth of crops, and maintain the harmony and diversity of microorganisms within nature. Recently, Taiwan is actively promoting the cultural management of organic farming. In order to achieve the maximum benefits of Integrated Pest Management (IPM), the main strategic techniques are trying to avoid using chemical fertilizer and pesticide, while adopting cultural control method, applying organic material, and promoting biological control. Utilizing microorganisms and plant resources to develop biological plant protectant is one of the main methods in carrying out biological control, therefore, microorganisms and plant resources became important issues in the fields of preservation and research and development worldwide. Hidden within the farm soil and culture media are many microorganism resources, including bacteria, fungi, actinomycetes, and viruses, which all possess the ability to control phytopathogens, nematodes, and pests, furthermore some even possess the ability to enhance the absorbency of nutrients in plants while assist the growth of crops. Some notable biological control organisms include Bacillus spp., Pseudomonas spp., Trichoderma spp., Streptomyces spp., Glioadium spp., and Glomus spp. have already been recommended in preventing plant diseases. Besides, there are many unique anti-microorganism elements exist within nature, such as glucosinolate, alkaloid, terpenes, phenols, tannins, flavonoids, saponins, carotenoids, and coumarin all could be used in manufacturing plant-incorporated-protectants to be applied directly on crops and effectively control pests. For example, the extract of Reynoutria japonica can control melon powder mildew disease, the extract of Hydnocarpus anthelminticus can control Chinese cabbage anthracnose, extract of Polygonum barbatum can control rice blight. As for the application of plant oil, such as emulsifying Sunflower Oil and clove oil, can control the powder mildew and anthracnose, respectively. It is known that Tagetes erecta, Aster pilosus, and Gaillardia pluchella have the antagonistic ability in against plant-parasitic nematodes, which could be used as rotational and intercropping crops, in order to reduce the population density of plant-parasitic nematodes and visibly prevent the occurrence diseases. Plant residues could also be applied on manufacturing plant protectant, thus, agricultural bi-products after composting process, with thorough understanding of various bi-product’s special inhibiting and disinfecting abilities could be prescribed into a formula with plant pathogen inhibiting ability and purposefully managing of the bi-product’s microorganism resources. Such as the FBN-5A and CH-100 plant protectants developed by national Chung-Hsing University have been recommended for control of plant diseases in farms.