The fundamental basis for the adequate development of avocado crops is the quality of the planting material, which must have genetic identity and high phytosanitary standards. It is considered that many of the pathologies present in the fields are introduced from the nursery stage, as asymptomatic infections. The objectives of this study were to identify the inoculum sources of different diseases and origin of disorders and to design management strategies to reduce pathogen inoculum and the occurrence of abiotic disorders in avocado at nursery stage. This experiment and survey involved the monitoring of six commercial avocado nurseries for a period of eight years. We evaluated seed, water, soils and substrate, size bags and soil moisture to determine the source of biotic and abiotic causal agents of the different diseases and disorders. In the second part, we evaluated the incidence and mortality of diseases and disorders under management practices associated with sanitation of all processes in nurseries to produce seedlings. It was found that seeds, irrigation and drainage water, and especially the substrate for germination and growth are the principal sources of inoculum of pathologies of biotic origin as Phytophthora cinnamomi, P. palmivora, Verticillium spp., Lasiodiplodia theobromae, Pythium spp., Fusarium oxysporum, Cylindrocarpon spp., Colletotrichum gloeosporioides, Penicillium sp., and Rosellinia sp. On the other hand, bag size and moisture regimes are involved in root atrophy and hypoxia-anoxia disorders. In addition, we suggest basic procedures based on seed quality and hygiene processes to improve disease prevention and pathologies reduction in avocado nurseries.

鳄梨作物充分发育的基本基础是种植材料的质量，必须具有遗传特性和高植物检疫标准。认为存在于该领域的许多病理是从育苗阶段引入的，是无症状的感染。这项研究的目的是确定不同疾病的接种源和疾病的起源，并设计管理策略以减少苗圃鳄梨鳄梨的病原体接种和非生物疾病的发生。这项实验和调查涉及对六个商业鳄梨苗圃的监测，为期八年。我们评估了种子，水，土壤和基质，大小袋和土壤湿度，以确定不同疾病和病症的生物和非生物致病原的来源。在第二部分中，我们根据与苗圃生产过程中所有过程的卫生相关的管理实践，评估了疾病和失调的发生率和死亡率。发现种子，灌溉和排水，尤其是发芽和生长的基质是生物起源的病原体接种物的主要来源，例如肉桂疫霉，P. palmivora，黄萎病菌，Lasiodiplodia theobromae，腐霉属，尖镰孢，柱孢属，炭疽病菌，青霉属，和Rosellinia藻。另一方面，袋子的大小和水分状况与根部萎缩和缺氧-缺氧性疾病有关。此外，我们建议基于种子质量和卫生过程的基本程序，以改善鳄梨苗圃的疾病预防和病理减少。