SALT STRESS AND AMBIENCE ON THE PRODUCTION OF WATERMELON SEEDLINGS

ABSTRACT The objective of this study was to evaluate the production of watermelon seedlings irrigated with saline waters and cultivated in different types of environments and substrates. The experimental design was completely randomized with split-split plots, in which the plot corresponded to two growing environments (EN1 = full sun and EN2 = 50% shade black net), the subplot to two types of irrigation water (IW1 = 0.8 and IW2 = 2.5 dS m-1) and the sub-subplot to four types of substrates (SB1 = vermiculite + coconut fiber, SB2 = manure + soil, SB3 = carbonized rice husk + soil, SB4 = biochar + soil), with four replicates of twenty-five seeds. The variables analyzed were: emergence percentage (EP), emergence speed index (ESI), mean time of emergence (MTE), number of leaves (NL), stem diameter (SD), seedling height (SH) and root length (RL), shoot dry mass (SDM), root dry mass (RDM) and total dry mass (TDM). The EN2 treatment provided better conditions for emergence and initial growth, and EN1 was also favorable to the emergence and initial growth of watermelon seedlings, when the substrates SB1 and SB2 were used.摘要 本研究旨在评估经盐水灌溉、于不同环境与基质中培育的西瓜幼苗生产性能。本实验采用完全随机裂裂区设计：主区为2种生长环境（EN1=全光照，EN2=50%遮阳黑色网）；副区为2种灌溉水质（IW1=0.8 dS·m⁻¹，IW2=2.5 dS·m⁻¹）；副副区为4种基质（SB1=蛭石+椰糠，SB2=厩肥+土壤，SB3=碳化稻壳+土壤，SB4=生物炭+土壤），每个处理设置4次重复，每次使用25粒种子。 本研究分析的指标包括：出苗率（emergence percentage, EP）、出苗速率指数（emergence speed index, ESI）、平均出苗时间（mean time of emergence, MTE）、叶片数（number of leaves, NL）、茎粗（stem diameter, SD）、幼苗株高（seedling height, SH）、根长（root length, RL）、地上部干质量（shoot dry mass, SDM）、地下部干质量（root dry mass, RDM）及总干质量（total dry mass, TDM）。 结果表明，当采用SB1与SB2基质时，EN2处理可为西瓜幼苗的出苗与初期生长提供更优条件；而当使用SB1、SB2基质时，EN1同样对西瓜幼苗的出苗及初期生长具有促进作用。