Incidence of blast disease in oil palm plantation located in Akamkpa local government of Cross River State

The study into the outbreak of the blast disease in the oil palm plantation in Akamkpa local government of Cross River state was carried out with the aim of identifying the possible sources of contamination of the oil palm seedlings and also the physicochemical parameters of the soil samples. Fungi associated with the blast disease were isolated using the direct plating and bait methods while the physicochemical parameters of the soil were determined using standard methods. The symptoms of the blast disease in the palms begins with rotting of the tips of the roots and then further spreads into the media zone of the cortex resulting in the eventual death of the palm. Fungi isolated from different portion of the affected seedlings, water and soil samples include Pythium, Phytothora, Macrophomina, Aspergillus and Penicillium spp. The results of the soil physical properties of the soil samples showed the particle size analyses of the soils samples to range from 835 gkg1 to 840 gkg1 respectively. The soil texture was sandy loam with an acidic pH ranging from 5.3 to 5.8. The contents of organic matter ranged from 6.10g kg-1 to 14.25 g kg-1, total nitrogen 1.58 g kg-1 to 2.25 g kg-1, available phosphorus 5.08 mg kg-1 to 6.10 mg kg-1 and potassium 1.16 cmol kg-1 to 2.18 cmol kg-1. The result of this study has indicated that the source of water used for the watering of the oil palm nursery serve as the possible source of introduction of pathogenic pathogens to the oil palm seedlings.

本研究针对尼日利亚克罗斯河州（Cross River State）阿卡姆帕地方政府辖区内的油棕（oil palm）种植园瘟病（blast disease）暴发情况开展，旨在明确油棕种苗的潜在污染源，并测定土壤样品的理化参数。研究采用直接涂布法与诱饵法分离与该瘟病相关的真菌，并通过标准实验方法测定土壤理化指标。油棕植株的瘟病症状最初表现为根尖腐烂，随后病菌进一步扩散至皮层的基质区域，最终导致植株死亡。从受病种苗、水体及土壤样品的不同部位分离得到的真菌包括腐霉属（Pythium）、疫霉属（Phytophthora）、小穴壳菌属（Macrophomina）、曲霉属（Aspergillus）以及青霉属（Penicillium）等类群。土壤样品的粒度分析结果显示，其颗粒组成范围为835 g·kg⁻¹至840 g·kg⁻¹；土壤质地为砂壤土，pH呈酸性，取值范围为5.3至5.8；有机质含量介于6.10 g·kg⁻¹至14.25 g·kg⁻¹之间，全氮含量为1.58 g·kg⁻¹至2.25 g·kg⁻¹，有效磷含量为5.08 mg·kg⁻¹至6.10 mg·kg⁻¹，钾元素含量为1.16 cmol·kg⁻¹至2.18 cmol·kg⁻¹。本研究结果表明，用于浇灌油棕苗圃的水体是将病原真菌引入油棕种苗的潜在途径。