GROWTH AND MINERAL COMPOSITION OF PAPAYA AND PASSION FRUIT SEEDLINGS IRRIGATED WITH GRAY WATER

ABSTRACT The semi-arid region has long periods of drought, so reusing water is an important alternative to enable irrigated agriculture. The objective of this study was to evaluate the growth and mineral composition of papaya and passion fruit seedlings irrigated with gray water effluents. Two experiments were carried out with papaya and passion fruit seedlings. For nondestructive analyses, the experimental arrangement was in splitplots in time, with plots consisting of three types of irrigation water (gray water effluent; supply water and mixture of gray water and supply water, at 1:1 ratio) and subplots formed by the evaluation times 30, 60 and 75 days after sowing, with three replicates and five plants per replicate. For destructive analyses, the experimental arrangement was a simple randomized block design, with three treatments, corresponding to the irrigation waters, with three replicates and five plants per replicate. The seedlings irrigated with gray water effluent had higher values of plant height, stem diameter, length of the largest root, shoot dry mass and root dry mass. N, K, Ca, Mg, Fe, Mn and Zn contents in the tissue of papaya seedlings, cv. ‘Golden’, were not altered by irrigation with gray water effluent. N, Fe and Zn contents in the tissue of passion fruit seedlings, cv. ‘Redondo Amarelo’, were increased by the application of gray water effluent, while P, K, Ca, Mg and Mn contents were not influenced.摘要 半干旱地区长期遭受干旱胁迫，水资源回用是发展灌溉农业的重要替代方案。本研究旨在评估灰水出水（gray water effluent）灌溉对木瓜与西番莲幼苗生长性状及矿质元素组成的影响。本研究针对木瓜与西番莲幼苗开展两组试验：针对无损分析试验，采用裂区时间设计，主区设置3种灌溉用水类型，分别为灰水出水、供水（supply water）以及按1:1体积比混合的灰水与供水；副区为播种后30、60、75天三个测定时间点，试验设置3次重复，每重复包含5株幼苗。针对破坏性分析试验，采用简单随机区组设计，设置3种灌溉用水处理，同样设置3次重复，每重复5株幼苗。结果显示，采用灰水出水灌溉的幼苗，其株高、茎粗、主根长度、地上部干质量与根部干质量均显著更高。‘金冠’（Golden）品种木瓜幼苗的组织内氮（N）、钾（K）、钙（Ca）、镁（Mg）、铁（Fe）、锰（Mn）及锌（Zn）含量，均未因灰水出水灌溉发生显著变化。‘Redondo Amarelo’品种西番莲幼苗的组织内氮（N）、铁（Fe）与锌（Zn）含量因灰水出水灌溉显著提升，而磷（P）、钾（K）、钙（Ca）、镁（Mg）及锰（Mn）含量则未受显著影响。