An experiment was conducted to determine the effect of water stress on yield and various physiological parameters, including the crop water stress index for tomatoes in the Central Anatolian region of Turkey. For this purpose, the irrigation schedule used in this study includes 120%, 100%, 80%, and 60% (I₁₂₀, I₁₀₀, I₈₀, I₆₀) of evaporation from the gravimetrically. Water deficit was found to cause a stress effect in tomato plants, which was reflected in changes in plants’ morphological and pomological function (such as stem diameter, fruit weight, pH, titratable acidity, and total soluble solids). Irrigation levels had a significant effect on the total yield of tomatoes. The lowest water use efficiency (WUE) was obtained from the I_60, while the highest WUE was found in the I₁₀₀ irrigation level. The CWSI was calculated using an empirical approach from measurements of infrared canopy temperatures, ambient air temperatures, and vapor pressure deficit values for four irrigation levels. The crop water stress index (CWSI) values ranged from −0.63 to a maximum value of 0.53 in I₁₂₀, from −0.27 to 0.63 in I₁₀₀, from 0.06 to 0.80 in I₈₀, and from 0.37 to 0.97 in I₆₀. There was a significant relation between yield and CWSI. The yield was correlated with mean CWSI values, and the linear equation Total yield = −2398.9CWSI + 1240.4 can be used for yield prediction. The results revealed that the CWSI value was useful for evaluating crop water stress in tomatoes and predicting yield.

Sustainability in greenhouse farming, one of the areas where the most energy is needed in the agricultural sector, can be achieved by increasing energy efficiency. Due to increasing energy costs in Türkiye and worldwide, increasing energy efficiency in greenhouses is seen as possible using renewable energy sources that do not produce waste instead of fossil energy sources. This study determined the heat-energy demand in the provinces of Türkiye with continental (Kırşehir and Kütahya) and Mediterranean (Antalya and Mersin) climates. For this purpose, the heat-energy requirement was calculated for greenhouse types with three different insulation properties (S-1: roof and side walls polyethylene, S-2: roof polyethylene, side walls polycarbonate, and S-3: roof polyethylene, side walls polycarbonate, and thermal curtain). Then, the amount and cost of fossil (coal, fuel oil, and natural gas) and renewable energy sources (geothermal and biogas) to be used in obtaining this energy, the heating cost for unit tomato yield, and the amount of carbon dioxide (CO₂) released into the atmosphere were compared. According to the results obtained, the highest heat-energy requirement was 356.5 kWh m⁻² year⁻¹ in the S-1 greenhouse in the Kütahya province, and the lowest was 46.3 kWh m⁻² year⁻¹ in the S-3 greenhouse in the Mersin province. Depending on energy conservation, 6% of energy savings can be achieved in S-2 and 29% in S-3 compared to S-1. The highest heating cost for producing one kilogram of tomatoes was 0.70 USD kg⁻¹ in fuel oil and Kütahya province (S-1). The lowest was calculated as 0.06 USD kg⁻¹ in geothermally heated greenhouses in Kırşehir and Kütahya provinces (S-3). The highest CO₂ to be released into the atmosphere with fuels was equal to 253.1 kg m⁻² year⁻¹ in coal fuel in Kütahya province (S-1). The lowest was calculated as 1.1 kg m⁻² year⁻¹ in geothermally heated greenhouses in Kırşehir and Kütahya provinces (S-3). The results of this research can be used to develop feasibility studies for greenhouse companies, greenhouse sector policies, policymakers, environmental protection, and taking precautions against the climate crisis.

The purpose of this study is to determine the performances of luffa and greenhouse shading netting (which can be used as alternatives to commercial cellulose pads, that are popular for cooling greenhouses), the contribution of external shading to the evaporative cooling performance, and the energy consumption of the direct evaporative cooler. In this experiment, eight different applications were evaluated: natural ventilation (NV), natural ventilation combined with external shading net (NV + ESN), cellulose pad (CP), cellulose pad combined with external shading net (CP + ESN), luffa pad (LP), luffa pad combined with external shading net (LP + ESN), shading net pad (SNP), and shading net pad combined with external shading net (SNP + ESN). The cooling efficiencies of CP, CP + ESN, LP, LP + ESN, SNP, and SNP + ESN were found to be 37.6%, 45.0%, 38.9%, 41.2%, 24.4%, 29.1%, respectively. Moreover, their cooling capacities were 2.6 kW, 3.0 kW, 2.8 kW, 3.0 kW, 1.7 kW, 2.0 kW, respectively. The system water consumption values were 2.9, 3.1, 2.8, 3.2, 2.4, 2.4 l h⁻¹, respectively. The performance coefficients of the system were determined to be 10.2, 12.1, 11.3, 11.9, 6.6, 7.8. The system’s electricity consumption per unit area was 0.15 kWh m⁻². As a result of the study, it was determined that commercially used cellulose pads have advantages over luffa and shading net materials. However, luffa pads can be a good alternative to cellulose pads, considering their local availability, initial cost, cooling efficiency, and capacity.

In order to reduce the impact of outdoor extreme weather events on crop production in winter, energy saving in greenhouses that are regularly heated is of great importance in reducing production costs and carbon footprints. For this purpose, the variations in indoor temperature, relative humidity and dew point temperature in the vertical direction (2 m, 4 m, 5.7 m) of thermal curtains in greenhouses were determined. In addition, depending on the fuel used, the curtains’ effects on heat energy consumption, heat transfer coefficient, carbon dioxide equivalents released to the atmosphere and fuel cost were investigated. To reach this goal, two greenhouses with the same structural features were designed with and without thermal curtains. As a result of the study, the indoor temperature and relative humidity values in the greenhouse with a thermal curtain increased by 1.3 °C and 10% compared to the greenhouse without a thermal curtain. Thermal curtains in the greenhouse significantly reduced fuel use (59.14–74.11 m³·night⁻¹). Considering the heat energy consumption, the average heat energy consumption was 453.7 kWh·night⁻¹ in the greenhouse with a curtain, while it was 568.6 kWh·night⁻¹ in the greenhouse without a curtain. The average heat transfer coefficient (U) values were calculated at 2.87 W·m⁻² °C with a thermal curtain and 3.63 W·m⁻² °C without a thermal curtain greenhouse. In the greenhouse, closing the thermal curtain at night resulted in heat energy savings of about 21%, related to the decrease in U values. The use of a thermal curtain in the greenhouse reduced the amount of CO₂ released to the atmosphere (116.6–146.1 kg·night⁻¹) and fuel cost (USD 21.3–26.7·night⁻¹). To conclude, extreme weather events in the outdoor environment adversely affect the plants grown in greenhouses where cultivation is performed out of season. A thermal curtain, used to reduce these adverse effects and the amount of energy consumed, is essential in improving indoor climate conditions, providing more economical greenhouse management and reducing the CO₂ released into the atmosphere due to fuel use.

This study was conducted in pots under a polycarbonate greenhouse to determine the effects of different irrigation levels and vermicompost doses on the morphological and phenological characteristics, water consumption, water use efficiency, and yield parameters of tomato plants. For this purpose, different irrigation levels of 100%, 75%, 50% (I100: full irrigation, I75, I50) and vermicompost (VC) doses of 0, 10% and 20% (VC0, VC10 and VC20, w/w) were applied as the treatments. The study’s results determined the irrigation levels and vermicompost doses affected the tomato plants’ morphological and fruit quality parameters. The highest and lowest plant water consumption (ET) values for the treatments were determined as 47.8 L (I100VC10) and 21.2 L (I50VC0), respectively. Moreover, irrigation water levels and vermicompost doses significantly influenced the total yield of tomatoes. The highest and lowest total and marketable yields were obtained from the I100VC20 and I50VC0 irrigation levels and vermicompost doses. Similarly, the highest and lowest total water use efficiencies were achieved from the I100VC20 (21.9 g L⁻¹) and I50VC0 (11.0 g L⁻¹) treatments. Furthermore, the highest and lowest marketable water use efficiencies were obtained from the I100VC20 (21.9 g L⁻¹) and I50VC0 (7.8 g L⁻¹) treatments. The yield response factor (ky) was found to be 1.42. Although the highest efficiency was achieved from 100% full irrigation and a 20% vermicompost dose in the study, it is suggested that 75% irrigation level and 10% fertilizer doses can also be applied in places where water is limited and fertilizer is expensive. The results revealed that the appropriate irrigation level and vermicompost doses could reliably be used to enhance tomato yield.

Tr en Akdeniz iklimine sahip ve ülkemizde seracılığın yoğun olarak yapıldığı Antalya ili ve karasal iklim özelliği gösteren ve seracılığın gelişmekte olduğu Kırşehir illerinde farklı donanım özelliğine sahip seralarda iç sıcaklığın 18 °C’de sabit tutulması durumunda gereksinim duyulan ısı enerjisi, yakıt miktarı, karbondioksit emisyon değerleri ve rekabet edebilirlik açısından jeotermal enerjinin fiyat belirlemesinin yapıldığı çalışmada, Kırşehir ve Antalya illerinde kurulacak tek katlı polietilen plastik ile örtülü seralarda içi sıcaklığın 18 °C’de sabit tutulması durumunda ihtiyaç duyulan maksimum ısı gücü gereksinimi Kırşehir ili için (253 W m^-2), Antalya ili için (141 W m^-2) olarak belirlenmiştir. Bunun yanında ülkemizde yaygın olarak kullanılan tek katlı PE plastiğin ısı korunum önlemleri alınmadan kullanılması halinde üretim periyodu süresince ihtiyaç duyulan ısı enerjisi gereksinimi Kırşehir ili için 589.02 kWh m^-2 yıl^-1 ve Antalya ilinde 219.06 kWh m^-2 yıl^-1 olarak hesaplanmıştır. Seralarda çift katlı PE plastiğin ve yalıtımı iyi yapılmış ısı perdelerinin kullanılması durumunda ise bu değerler Kırşehir ili için 304.09 kWh m^-2 yıl^-1 ve Antalya ili için 103.35 kWh m^-2 yıl^-1 olarak belirlenmiştir. Elde edilen sonuçlara göre Kırşehir ilinde seralar için gerekli olan ısı enerjisinin fosil yakıtlar ile sağlanması durumunda Kırşehir ilinin Antalya ili ile rekabet edebilme şansı bulunmamaktadır. Ancak sahip olduğu jeotermal enerjinin seracılıkta kullanılması ve kWh maliyetinin en fazla 0.115 TL olması durumunda Kırşehir ilinin Antalya gibi seracılığın geliştiği iller ile rekabet edebilmesinin yanında, fosil yakıtların (ithal kömür, kalorifer yakıtı ve doğalgaz) atmosfere verdiği karbondioksit salınımının azaltması açısından da önemli üstünlükleri olacaktır. In the study in which the cost of geothermal energy is determined in terms of required heat energy, fuel quantity, carbon dioxide emission values and competitiveness if the internal temperature is kept constant at 18 °C in the greenhouses with different characteristic features in Antalya province, which has a Mediterranean climate and is heavily used for greenhouses in our country, and in Kırşehir province, which has a continental climate and the greenhouse cultivation has been developing. The maximum heat power requirement if the temperature inside the greenhouse is kept constant at 18 °C was determined as 253 W m-² for Kırşehir province and as 141 W m^-2 for Antalya province. In addition, the required heat energy requirement during the production period was calculated as 589.02 kWh m^-2 year^-1for Kırşehir province and as 219.06 kWh m^-2 year^-1for Antalya province if the single-layer PE plastic which is widely used in our country is used without heat protection measures. When the double-layer PE plastic and well-insulated heat curtains are used, these values were determined as 304.09 kWh m-² year-¹ for Kırşehir province and as 103.35 kWh m-² year-¹ for Antalya province. According to the results obtained, if the heat energy required for greenhouses in Kırşehir province is supplied with fossil fuels, Kırşehir province does not have a chance to compete with Antalya province. However, when geothermal energy is used in the greenhouse and the maximum cost of kWh is 0.115 TL, Kırşehir province will have significant advantages in terms of reducing the carbon dioxide emissions from fossil fuels (imported coal, heating oil and natural gas) to the atmosphere as well as being able to compete with the provinces where greenhouse cultivation is well-developed like Antalya.