Trichoderma in the promotion of growth and nutrition of dwarf cashew rootstock[]

ABSTRACT Inoculation of microorganisms in plants performs important functions related to plant growth and nutrition. The responses are based on hormonal stimulation and improved absorption and efficiency in the use of nutrients. Thus, the objective of this study was to evaluate the ability of Trichoderma strains (T. longibrachiatum and T. asperellum) to promote growth and improve the nutrition in dwarf cashew rootstock. The experiment was conducted in a shade net house with 50% of shading located in the Experimental Field of Pacajus, belonging to Embrapa Agroindústria Tropical, in Pacajus/CE, Brazil. The experimental design used was completely randomized, with three treatments and ten replicates. Each experimental unit consisted of a tube with a 288 cm3 capacity containing one seedling of dwarf cashew. At sixty days (60) after germination, the plants were evaluated for biometric parameters, Dickson's quality index, and nutritional diagnosis of leaves. To verify the growth-promoting mechanisms, the strains were reisolated by indirect plating of roots. Nutrient accumulation in the leaves was not influenced by the application of the isolates; however, the seedlings were adequately supplied. The strains showed similarities in relation to growth-promotion mechanisms. The Trichoderma longibrachiatum strain promoted an increase in the growth, so its use as a supplement for the planting substrate is recommended.

摘要
将微生物接种于植物体内，可在植物生长及营养代谢方面发挥重要功能，此类效应通过激素刺激以及提升养分吸收与利用效率得以实现。为此，本研究旨在评估木霉菌（Trichoderma）菌株（长枝木霉T. longibrachiatum与棘孢木霉T. asperellum）对矮腰果砧木的生长促进作用及营养改善效果。
本试验于巴西塞阿拉州帕卡茹斯市巴西热带农业食品工业研究公司（Embrapa Agroindústria Tropical）下属的帕卡茹斯试验田内的50%遮光率遮阳网棚中开展。试验采用完全随机设计，设置3个处理组，每组设10次重复。每个试验单元为一个容积288 cm³的栽培管，内植1株矮腰果幼苗。播种后60天，对植株的生物测量参数、迪克森质量指数（Dickson's quality index）以及叶片营养诊断情况进行测定。
为验证促生长机制，通过根系间接涂布法对菌株进行了分离回收。结果显示，接种分离株并未影响叶片的养分积累，但幼苗的养分供应处于充足状态；两种菌株在促生长机制方面表现出相似性。其中，长枝木霉（T. longibrachiatum）菌株可显著促进植株生长，因此推荐将其作为栽培基质添加剂使用。