Heat stress is a major factor affecting growth and productivity of wheat. A study was conducted at Ludhiana, Punjab, India with an objective to find out the impact of periodic (15 days) heat stress in wheat grown under natural field conditions. The heat stress treatments consisted of control (no heat stress), heat stress during 0–15, 16–30, 31–45, 46–60, 61–75, 76–90, 91–105, 106–120, 121–135, 136 days after sowing (DAS) to harvest. Heat stress (seasonal average maximum temperature higher than optimum temperature by 4.3 and 2.7°C during 2016–2017 and 2017–2018, respectively) was imposed by using mini heat tents made of galvanized iron pipes covered with transparent polyethene sheets. The mini heat tents were installed for 15 days duration in the plots according to the treatments and were removed at the end of 15th day. On the next day, they were installed in plots of the next treatment level. Heat tents were never installed on control plots. Increase in temperature in the mini heat tents was not controlled and was allowed to increase naturally. However, the excessive heating in the tents was prevented by opening the southern side during day time. Heat stress resulted in a significant increase in the membrane injury index and a decrease in chlorophyll content. Heat stress reduced the activity of dehydrogenase in rhizosphere and bulk soil. Heat stress from 76–90 and 91–105 DAS significantly reduced the ear length and number of grains ear^‐1. Heat stress during 106–120 and 121–135 DAS decreased thousand grain weight significantly. Application of heat stress between 61–75, 76–90, 91–105, 106–120 and 121–135 DAS decreased grain yield significantly by 16.0, 19.8, 22.1, 16.4 and 14.8% during 2016–2017 and 11.8, 15.3, 18.8, 13.9 and 12.6% during 2017–2018, respectively, as compared to that obtained under control conditions. Apart from effects of heat stress on crops, the present study also highlights the design and possibility of using cost‐effective, small size and portable mini heat tents for conducting heat stress studies in different field crops.

中文翻译：

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微型帐篷施加周期性热胁迫下小麦的产量响应。

热应激是影响小麦生长和生产力的主要因素。在印度旁遮普邦的卢迪亚纳（Ludhiana）进行了一项研究，目的是找出周期性（15天）热应激对自然田间条件下种植的小麦的影响。热应激治疗包括控制（无热应激），0-15、16-30、31-45、46-60、61-75、76-90、91-105、106-120、121-121期间的热应激。 135天，播种后136天（DAS）收获。通过使用由覆盖有透明聚乙烯薄板的镀锌铁管制成的微型热帐篷施加热应力（季节性平均最高温度在2016–2017年和2017–2018年期间分别比最佳温度高4.3和2.7°C）。根据处理情况，微型加热帐篷在地块中安装了15天，并在第15天结束时被拆除。下一天，将它们安装在下一个处理级别的地块中。从未在控制区安装过加热帐篷。小型加热帐篷中的温度升高不受控制，可以自然升高。但是，白天白天打开南侧可以防止帐篷过热。热应激导致膜损伤指数显着增加和叶绿素含量降低。热胁迫降低了根际和块状土壤中脱氢酶的活性。76–90和91–105 DAS的热应力显着减少了耳朵的长度和穗粒数 通过在白天打开南侧，可以防止帐篷过热。热应激导致膜损伤指数显着增加和叶绿素含量降低。热胁迫降低了根际和块状土壤中脱氢酶的活性。76–90和91–105 DAS的热应力显着减少了耳朵的长度和穗粒数 通过在白天打开南侧，可以防止帐篷过热。热应激导致膜损伤指数显着增加和叶绿素含量降低。热胁迫降低了根际和块状土壤中脱氢酶的活性。76–90和91–105 DAS的热应力显着减少了耳朵的长度和穗粒数^‐1。在106–120和121–135 DAS期间，热应力显着降低了千粒重。在2016-2017年和61年间分别在61-75、76-90、91-105、106-120和121-135 DAS上施加热胁迫，谷物单产显着降低了16.0、19.8、22.1、16.4和14.8％，以及11.8、15.3、18.8与对照条件下相比，2017-2018年分别为13.9和12.6％。除了热胁迫对农作物的影响外，本研究还突出了设计和使用具有成本效益的小型便携式小型热帐篷在不同田间作物上进行热胁迫研究的可能性。