PAPAYA SEEDLING PRODUCTION UNDER DIFFERENT SHADING LEVELS AND SUBSTRATE COMPOSITIONS

ABSTRACT Papaya is characterized as one of the most important crops in Brazil. Thus, good quality seedlings are essential for formation of orchards in agricultural production. This study aimed to evaluate shading levels and substrate compositions for production of papaya seedlings. Growing environments were evaluated with 0, 18, 35, and 50% shading and substrates from combinations (%) of hillside soil (HS), cattle manure (CM), Bioplant® (BP), washed fine sand (FS), and super fine-grained vermiculite (FV). As there was no replication for the growing environments, the group of experiments were analyzed using a 4 × 4 factorial arrangement (4 shades × 4 substrates), with five replications. Growth and biometric relationships were analyzed. Substrates consisting of 30% HS + 15% CM + 20% BP + 20% FS + 15% FV and 45% HS + 0% CM + 20% BP + 20% FS + 15% FV, as well as environments with 18 and 35% shading formed seedlings with higher plant heights, diameters, phytomass, and Dickson quality indices. The results showed that substrates with a higher content of hillside soil and lower content of cattle manure, associated with an environment with 18 or 35% shading, provided high-quality seedlings.

摘要
番木瓜是巴西最重要的经济作物之一。优质种苗是农业生产中果园建植的核心要素。本研究旨在评估不同遮阳梯度与基质配比对番木瓜种苗生产的影响。试验设置0%、18%、35%、50%四个遮阳梯度，以及由山地土壤（hillside soil, HS）、牛粪（cattle manure, CM）、Bioplant®（BP）、水洗细沙（washed fine sand, FS）与超细粒蛭石（super fine-grained vermiculite, FV）按体积比例组合而成的4种基质配方。鉴于单一遮阳环境未设置重复，本试验采用4×4因子设计（4个遮阳梯度×4种基质），每组处理设置5次生物学重复。本研究分析了种苗的生长指标与生物量相关参数。结果显示，采用30% HS + 15% CM + 20% BP + 20% FS + 15% FV，以及45% HS + 0% CM + 20% BP + 20% FS + 15% FV的基质配方，结合18%与35%的遮阳梯度，可培育出株高、茎粗、生物量及迪克森质量指数（Dickson quality indices）更优异的种苗。研究表明，较高山地土壤占比、较低牛粪占比的基质配方，搭配18%或35%的遮阳环境，可获得高品质的番木瓜种苗。