Determining cwsi to estimate eggplant evapotranspiration and yield under greenhouse and outdoor conditions

Document Type : Full Article


1 Department of Water Engineering, College of Agriculture, Shiraz University, Shiraz, I.R. Iran

2 Department of water sciences Engineering, College of Agriculture Shahid Chamran University, Ahwaz, I. R. Iran

3 Department of Irrigation, Jahrom Universtiy, Jahrom, I.R. Iran


ABSTRACT- The crop water stress index (CWSI) is the most common index to monitor and assess crop water stress, based on canopy temperature. To calculate CWSI, upper and lower baselines adaptable to different environments are needed. In this study, empirical and theoretical limiting baseline equations were developed to determine eggplant CWSI values at different levels of water deficit and salinity stress.  The limiting baseline and CWSI values of eggplant were obtained under different watering intervals (daily, weekly and every two weeks) and different irrigation water salinity levels (i.e. 0.8, 2.5, 5 and 7 dsm-1) for greenhouse and outdoor conditions. The impact of various levels of water deficit and salinity on total evapotranspiration, yield and CWSI was also studied. With the increase of water salinity, a decrease in the slope of lower baseline was met (from 0.195 to 0.146 in the greenhouse and from 0.134 to 0.098 in the outdoor conditions) along with a rise in the upper baseline. Increase in the levels of water deficit led to greater fluctuations in CWSI variations during the growing season. According to the Duncan's test results, CWSI values were significantly affected by water deficit and salinity in both environments


Main Subjects

Article Title [Persian]

تعیین CWSI به منظور برآورد تبخیر-تعرق و عملکرد بادنجان تحت شرایط گلخانه و مزرعه

Authors [Persian]

  • علی اصغر قائمی 1
  • هادی معاضد 2
  • محمد رفیع رفیعی 3
  • سعید برومند نسب 2
1 بخش آبیاری، دانشکده کشاورزی، دانشگاه شیراز، شیراز، ج. ا. ایران
2 دانشگاه شهید چمران اهواز
3 دانشگاه جهرم
Abstract [Persian]

چکیده- شاخص تنش آبی گیاه (CWSI) یکی از متداول‌ترین شاخص‌های مبتنی بر دمای پوشش سبز، برای پایش و تعیین تنش آبی گیاهان می‌باشد. برای محاسبه CWSI حدود مبنای بالایی و پایینی منطبق بر محیط های مختلف مورد نیاز می‌باشد. در این پژوهش، معادلات خطوط مبنای تجربی و نظری به منظور تعیین مقادیر CWSI گیاه بادنجان در سطوح مختلف تنش آبی و شوری ارائه گردیده است. خطوط مبنا و CWSI بادنجان تحت فواصل مختلف آبیاری ( روزانه، هفتگی و دو هفته‌ای) سطوح مختلف شوری آب ( یعنی 8/0 ، 5/2، 0/5 و 0/7 دسی زیمنس بر متر ) در شرایط گلخانه و مزرعه به دست آمد. تاثیر سطوح مختلف تنش آبی و شوری بر تبخیر-تعرق کلی، عملکرد و CWSI نیز مورد مطالعه قرار گرفت. با افزایش شوری آب، کاهشی در شیب خط مبنای پایینی ( از 195/0 به 146/0 در گلخانه و از 134/0 به 098/0 مزرعه) توام با صعود خط مبنای بالایی تنش مشاهده گردید.افزایش سطوح تنش آبی به نوسانات بیشتر در مقادیر CWSI در طول فصل رشد منجر گردید. با توجه به نتایج آزمون دانکن مقادیر CWSI در هر دو محیط کشت به طور معنی داری تحت تاثیر کمبود آب و شوری می‌باشند.

Keywords [Persian]

  • واژه های کلیدی:
  • CWSI
  • بادنجان
  • تبخیر-تعرق
  • گلخانه
  • خطوط مبنای تنش
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