ICAR-National Institute of Abiotic Stress Management, Baramati, 413115, Pune, India.
ICAR-National Institute of Abiotic Stress Management, Baramati, 413115, Pune, India.
J Environ Manage. 2020 May 15;262:110320. doi: 10.1016/j.jenvman.2020.110320. Epub 2020 Feb 29.
Deficit irrigation (DI) and plant growth regulators (PGRs) have strategic role for sustaining crop productivity and mitigating water stress in drought prone areas. However, their impacts are yet to be quantified for eggplant (Solanum melongena L.), a popular drought tolerant vegetable crop grown in water scarce Deccan Plateau of India. We conducted field experiments during 2016-17 and 2017-18 in a drought prone region of Deccan Plateau, India to evaluate the interactive effect of PGRs viz., 1.38 mg L salicylic acid (SA), 1.5% potassium nitrate (PN), 500 ppm thio-urea (TU) and 100 ml L bio-stimulant (BS) and varied levels of DI generated using line source sprinkler system. The marketable fruit yields were reduced to 86, 74, 50, 30, 12 and 8% with increased level of DI i.e. when the applied irrigation water (IW) equalled 0.00, 0.15, 0.30, 0.45, 0.60 and 0.75 times the cumulative open pan evaporation (CPE) against the recommended irrigation practice (IW:CPE 0.90). Application of PGRs improved fruit yields by 7.3-22.7% and their role to alleviate water stress was indicated by lower canopy temperatures, maintaining higher leaf relative water content, modulation of stomatal opening and higher consumptive use of water. Particularly SA and TU were superior under low to medium water stress (IW:CPE 0.45-0.75) whereas PN was effective in severe water stress (IW:CPE 0.0-0.44) while the effect of BS was almost similar with PGRs like TU under medium stress conditions. The maximum water productivity (WP) varied between 5.50 and 6.77 kg m for different PGRs and it was 5.16 kg m without PGRs indicating water savings to the order of 28.8-57.4% with the former. The fruit quality attributes such as mean diameter, sphericity, fruit weight and firmness traits declined with water stress while these were considerably rectified with PGRs. Higher accumulation of dry matter, sugar, protein, total phenolics, flavonoids and improved rehydration quality as well as potentially affecting enzymatic activity were monitored with PGRs. It is concluded that exogenous application of PGRs like SA and PN along with medium levels of DI can help in rational utilization of water resources and could effectively improve yield and post-harvest quality of eggplant fruits especially under water scarce environment of Deccan Plateau.
亏缺灌溉（DI）和植物生长调节剂（PGRs）在维持作物生产力和缓解干旱地区水分胁迫方面具有战略作用。然而，它们在印度德干高原缺水地区广泛种植的耐旱蔬菜茄子（Solanum melongena L.）中的影响尚未得到量化。我们在印度德干高原干旱地区进行了 2016-17 年和 2017-18 年的田间试验，以评估 PGRs 的交互作用，即 1.38 mg/L 水杨酸（SA）、1.5%硝酸钾（PN）、500 ppm 硫脲（TU）和 100 ml/L 生物刺激剂（BS）以及使用线源 sprinkler 系统产生的不同水平的 DI。随着 DI 水平的增加，即当应用的灌溉水（IW）等于 0.00、0.15、0.30、0.45、0.60 和 0.75 倍累积开敞式蒸发量（CPE）时，商品水果产量减少了 86%、74%、50%、30%、12%和 8%与推荐的灌溉实践（IW：CPE 0.90）相比。PGRs 的应用提高了果实产量 7.3-22.7%，其缓解水分胁迫的作用表现为较低的冠层温度，保持较高的叶片相对水分含量，调节气孔开度和更高的耗水量。特别是在低至中等水分胁迫（IW：CPE 0.45-0.75）下，SA 和 TU 表现优越，而在严重水分胁迫（IW：CPE 0.0-0.44）下，PN 有效，而 BS 的作用与 TU 等 PGRs 相似中等胁迫条件下。不同 PGRs 的最大水分生产率（WP）在 5.50 到 6.77 kg/m 之间变化，没有 PGRs 的 WP 为 5.16 kg/m，表明节约了 28.8-57.4%的用水量。随着水分胁迫，果实品质特性如平均直径、球形度、果实重量和硬度特性下降，而 PGRs 则显著改善了这些特性。PGRs 监测到干物质、糖、蛋白质、总酚、类黄酮的更高积累，以及更好的再水合质量，并可能影响酶活性。研究结论认为，SA 和 PN 等外源 PGRs 与中等水平的 DI 结合使用，可以帮助合理利用水资源，有效提高茄子果实的产量和产后品质，特别是在德干高原缺水环境下。
