Saline-water irrigation and plant growth regulator application on zucchini fruit yield and quality

ABSTRACT The objective of this study was to evaluate the effect of a plant growth regulator (PGR; Stimulate®) on the yield and quality of zucchini fruits from plants of the cultivar Caserta-Italiana grown under different salinity levels of the irrigation water (SLIW). A randomized block design was used, in a 2 × 6 factorial arrangement consisted of two SLIW (0.5 and 5.0 dS m-1) and six PGR application modes: imbibition of seeds for 8 h in distilled water (PGR-T1; Control); imbibition of seeds for 8 h in PGR at 10 mL L-1 (PGR-T2); imbibition of seeds for 8 h in PGR at 10 mL L-1 plus foliar application at 10 mL L-1 at the flowering stage (PGR-T3); imbibition of seeds for 8 h in PGR at 10 mL L-1 plus two foliar applications at the flowering stage and at 20 and 30 days after sowing (PGR-T4); foliar application at 10 mL L-1 at the flowering stage (PGR-T5); and two foliar applications at 10 mL L-1 at 20 and 30 days after sowing (PGR-T6). The SLIW affected differently the variables of the zucchini crops evaluated. The PGR application to plants under no salt stress (0.5 dS m-1) increased the solid soluble concentration and biomass accumulation of zucchini fruits. The PGR application as seed treatment and foliar application at the flowering stage increased the fruit yield of zucchini plants irrigated with saline water.摘要 本研究旨在评估植物生长调节剂（plant growth regulator, PGR，商品名Stimulate®）对灌溉水盐度水平（salinity levels of the irrigation water, SLIW）不同条件下种植的Caserta-Italiana品种西葫芦果实产量与品质的影响。本实验采用随机区组设计，设置2×6因子排列，包含两个灌溉水盐度水平（0.5与5.0 dS·m⁻¹）以及六种PGR施用模式：1. 以蒸馏水浸种8小时（PGR-T1；对照组）；2. 以10 mL·L⁻¹的PGR浸种8小时（PGR-T2）；3. 以10 mL·L⁻¹的PGR浸种8小时，并于开花期以10 mL·L⁻¹浓度进行叶面喷施（PGR-T3）；4. 以10 mL·L⁻¹的PGR浸种8小时，并分别于开花期、播种后20天与30天各喷施一次10 mL·L⁻¹的PGR（PGR-T4）；5. 于开花期以10 mL·L⁻¹浓度进行叶面喷施（PGR-T5）；6. 于播种后20天与30天各喷施一次10 mL·L⁻¹的PGR（PGR-T6）。研究结果显示，灌溉水盐度对供试西葫芦的各项测定性状存在差异化影响。在无盐胁迫（0.5 dS·m⁻¹）条件下施用PGR，可提升西葫芦果实的可溶性固形物含量与生物量积累。对于采用盐水灌溉的西葫芦植株，采用种子浸种结合开花期叶面喷施的PGR施用方式，可有效提升果实产量。