Greenhouse Tomato Research Articles

Simulation Model Construction of Plant Height and Leaf Area Index Based on the Overground Weight of Greenhouse Tomato: Device Development and Application

Plant height and leaf area index (LAI) are crucial growth indicators that reflect the growth status of tomatoes in greenhouses, enabling accurate determinations to effectively estimate crop transpiration and formulate irrigation strategies for reducing agricultural water waste. There is a need for the increased application of related models to simulate tomato growth indices in the traditional greenhouse production in China. This study proposes a nondestructive, real-time monitoring and simulation device for measuring tomato plant height and leaf area index. The weight of aboveground tomatoes was obtained by suspending tomato plants on dynamometers, while the total weight of stem and leaf organs was determined using a distribution coefficient simulation model. The R2 value between the measurements from the electronic scale and those from the aboveground fresh weight device for tomatoes was 0.937, with an RMSE value of 0.05 kg. The monitoring device did not affect the average tomato growth during operation. The device will not affect the growth of tomatoes during monitoring. A multiple linear regression was used to compare the measured and simulated values of the plant height and leaf area index of various types of greenhouse tomatoes cultivated in different greenhouse types. The average R2 value for simulating plant height was 0.817 with an RMSE of 10.81 cm. The average R2 value for the leaf area index was 0.854, with an RMSE of 0.55 m2·m−2. The simulated values for plant height and leaf area index closely matched the measured values, indicating that the model has high accuracy and applicability in traditional Chinese greenhouses (solar greenhouses and insulated plastic greenhouses). However, further optimization is required for commercially produced, continuous plastic greenhouses equipped with greenhouse environmental control equipment.

First observation of the beetle Sericoderus lateralis consuming Cladosporium fulvum in a greenhouse tomato: potential for biological protection or risk to the crop?

For the first time, the mycophagous beetle Sericoderus lateralis (Gyllenhal, 1827) was documented feeding on tomato leaf mold ( Cladosporium fulvum Cooke, 1878) tissues. The phenomenon was observed during the years 2022 and 2023 in a hydroponic tomato greenhouse situated near the Czech-Polish border within the cadastre of Dolní Lutyně municipality in Czechia. Greenhouse and laboratory observations confirmed that adult and larvae feeding activity led to a reduction in tomato leaf mold lesions. In addition, there was a positive correlation between tomato leaf mold disease progression and increased populations of S. lateralis in the tomato crop. Petri dish observations confirmed egg laying occurred on a diet of tomato leaf mold. Further research is warranted to discern whether S. lateralis is a potential biological control agent for tomato leaf mold or if it acts to facilitate the spread of the disease by acting as a spore vector.

Outbreak of tomato fruit blotch virus in the most relevant tomato greenhouse production area of Sicily

Outbreak of tomato fruit blotch virus in the most relevant tomato greenhouse production area of Sicily

Isolation, identification, and pathogenicity of Rhizoctonia spp. recovered from soil samples of the greenhouse tomato growing area of the West Mediterranean region, Türkiye

AbstractThis study's objective was to identify the anastomosis groups and pathogenicity of Rhizoctonia species from soil samples in tomato production areas of Antalya, Burdur, and Isparta provinces in the West Mediterranean Region of Türkiye during the 2022 season. Soil samples were gathered from tomato plant rhizospheres in 223 different greenhouses, and isolations were done from the soil using the baiting technique. According to the results of morphological characterization and sequence analysis of the internal transcribed spacers of the ribosomal DNA, 47 Rhizoctonia isolates were defined as binucleate and 21 isolates as multinucleate. The collection of binucleate Rhizoctonia (Ceratobasidium sp.) isolates included representatives of Anastomosis Group‐F (61.76%), AG‐A (1.47%), and an unidentified binucleate Rhizoctonia (Ceratobasidium sp.) (5.88%). Multinucleate R. solani included AG 4 HG‐I (26.47%) and AG 4 HG‐II (4.41%). Pathogenicity tests showed statistically significant differences in virulence between binucleate Rhizoctonia (Ceratobasidium sp.) isolates and multinucleate Rhizoctonia isolates. All R. solani AG 4 HG‐II isolates and most of the AG 4 HG‐I isolates were pathogenic, causing severe necrosis symptoms and damping off in tomato seedlings, but binucleate AG‐A and AG‐F isolates were nonpathogenic. This study is the first detailed report about Rhizoctonia species isolated from the soil of tomato plants grown in greenhouse production areas in Türkiye.

First report of Convolvulus arvensis and Polycarpon tetraphyllum as natural hosts of tomato brown rugose fruit virus.

Tomato brown rugose fruit virus (ToBRFV) is a tobamovirus recently identified on tomatoes in Jordan (Salem et al. 2016). New infections were rapidly reported all over the world becoming a serious threat to tomato production. About 40 species belonging to four families (Amaranthaceae, Apocynaceae, Asteraceae, and Solanaceae) have been reported as experimental hosts (Salem et al. 2023). Tomato and pepper have been reported as natural hosts of ToBRFV but recently Salem and coworkers (2022) detected the presence of the virus in 12 wild species. To identify potential natural hosts of the virus, 10 plants of bindweed (Convolvulus arvensis L.) and 7 of fourleaf allseed (Polycarpon tetraphyllum L.) were collected in the summer 2023 in a tomato greenhouse located in Pachino, Siracuse province (Sicily, Italy), with high-rate infection of ToBRFV. These two species were chosen because predominant among the spontaneous weeds inside the greenhouse. No symptoms ascribable to ToBRFV were observed on bindweed and fourleaf allseed during the surveys. All leaf samples were analyzed for ToBRFV infections by DAS-ELISA with a commercial antiserum (LOEWE Biochemica, Germany), including tomato positive and negative controls. Eight C. arvensis and seven P. tetraphyllum samples out of the total tested positive to ToBRFV. To confirm virus presence, total RNA was extracted from all samples using the RNeasy Plant Mini Kit (QIAGEN) and used as template for RT-PCR with ToBRFV-specific primers (Alkowni et al. 2019). RT-PCR products of the expected size (560bp) confirmed DAS-ELISA results. Amplicons from two isolates of each plant species (Conv-01, Conv-02, Poly-01, and Poly-02) were gel-purified and sequenced in both directions. Sequences were edited and deposited in GenBank (Acc. Num: Conv-01, OP150933; Conv-02, OP193999; Poly-01, OP150934; Poly-02, OP194000). According to sequence analysis, the four isolates shared 100% identity among them and 98.82% identity with the ToBRFV reference sequence (GenBank Accession No. KT383474). To our knowledge, this is the first report of ToBRFV natural infections in C. arvensis and P. tetraphyllum. Since these weeds are common in our tomato production areas, they could act as ToBRFV reservoirs.

Greenhouse tomato farmers' knowledge, perceptions, and management of tomato bacterial wilt (Ralstonia solanacearum) disease

A major constraint to tomato cultivation is bacterial wilt disease. The use of greenhouses to cultivate tomato is vital to controlling the bacterial wilt disease. Bacterial wilt can be successfully managed when farmers are well-informed with better knowledge of bacterial wilt in tomatoes. This study was conducted to assess farmers’ knowledge and experiences on the cultivation practices, prevalence, detection, spread, and control of bacterial wilt disease in tomato in greenhouses in the Volta, Eastern, Central, and Greater Accra regions of Ghana. Questionnaires were administered for fifty (50) greenhouse farmers, purposefully selected using a database of greenhouse tomato producers in southern Ghana provided by the Ministry of Food and Agriculture (MOFA). Frequency data was analyzed using descriptive statistical analysis. The majority (86%) of respondents had formal education. Most of the greenhouses in operation were in the Greater Accra Region, and none was under cultivation in the Volta region at the time of the study. Most respondents have been involved in greenhouse tomato cultivation for barely three years. The frequency of greenhouse tomatoes production varied from one region to the other. Only 28% of greenhouse farmers knew the test to detect the disease with 64% of greenhouse farmers without any knowledge about how the disease spreads. 62% of respondents used roughing and burying of the infected plants to control the disease. Out of the 54 greenhouses (domes) surveyed, 12 were infected with the bacterial wilt disease. Greenhouse farmers had little knowledge on the spread, detection, and control of the bacterial wilt disease of tomato. The findings of this study would lead to the design of targeted training programs on cultivation practices, detection, spread and management of bacterial wilt of tomato to increase yield and boost income levels of greenhouse tomato farmers in Ghana. Key words: bacterial wilt, tomatoes, spread, detection, control, greenhouse, farmers, constraints

Substrate Comparison for Tomato Propagation under Different Fertigation Protocols

Greenhouse tomato production faces multiple challenges, including the excessive use of nonrenewable substrates that are difficult to dispose of after use. Currently, most growers propagate tomatoes in rockwool, but there is an increasing demand for sustainable media. The objective of this research was to evaluate sustainable and organic alternatives for greenhouse propagation of tomato seedlings intended for high-wire production. Different organic and inorganic substrates were evaluated in three experiments, using a nutrient solution composed of a complete water-soluble fertilizer. Germination and growth parameters, including height, stem diameter, number of leaves, leaf area, foliar chlorophyll levels (SPAD), and shoot fresh and dry weight, were measured. In the first experiment, which employed overhead irrigation, rockwool, coir, wood fiber–coir mix, medium-grade pine bark, pine bark < 0.64 cm, and pine bark < 0.32 cm were evaluated. Tomato germination was faster and achieved higher percentages with pine bark < 0.64 cm compared to other substrates. However, growth performance was similar or better in coir than in rockwool four weeks after transplantation. For the second experiment with sub-irrigation only, rockwool, coir, wood fiber–coir mix, pine bark < 0.32 cm bark, and peat were evaluated at different container heights. Peat resulted in greater growth across all parameters, followed by wood fiber–coir mix in all container heights, while pine bark had the least growth across all measured parameters. In the third experiment with overhead irrigation, rockwool, wood fiber–coir mix, pine bark < 0.32 cm, and a commercial peat-based mixture were evaluated under different fertilizer rates (electrical conductivity of 1.1 and 2.2 mS·cm−1). Wood fiber–coir mix, peat-based mix, and rockwool were the substrates with the highest values for all evaluated parameters. While all the organic substrates showed potential for use in tomato propagation, pine bark < 0.32 cm bark and wood fiber–coir mix provided the best media for germination. Peat and wood fiber–coir mix showed the best media for subsequent seedling growth and demonstrated potential to be used as substitutes for rockwool.

Optimizing irrigation schedules of greenhouse tomato based on a comprehensive evaluation model

In the context of climate change, water availability has emerged as a pressing concern in agriculture, indicating the urgency to enhance irrigation management. Nevertheless, accurately quantifying irrigation schedules in diverse climates and soil textures remains a complex challenge. Here, a three-year irrigation experiment (2020–2022) of greenhouse tomato was conducted at three typical locations (Yulin, Yangling and Hanzhong) in northwest China. The irrigation schedules were determined by the cumulative evaporation (CE) measured from a 20 cm pan. A total nine treatments were set by combining three irrigation frequencies (IF) with three single doses (ID). Twenty indices related to tomato growth, photosynthesis, yield and water use, fruit quality, and environmental benefit were evaluated comprehensively by using TOPSIS (technique for order preference by similarity to ideal solution) and GRA (grey relational analysis) methods of combining weights based on game theory. The results showed that the indicator with highest weight was yield, followed by crop water productivity and vitamin C. The optimal ranges of irrigation frequency (irrigation dose) were determined as follows: 10.00–11.08 mm (0.81–0.90 CE) in Yulin, 13.12–15.68 mm (0.77–0.89 CE) in Yangling, and 11.44–16.40 mm (0.67–0.77 CE) in Hanzhong, respectively. This study introduces a method applied to prioritize the key indicators for irrigation scheduling, providing a reference for optimizing irrigation practices in greenhouse tomato production and improving water management in agriculture.

Combining Recurrent Neural Network and Sigmoid Growth Models for Short-Term Temperature Forecasting and Tomato Growth Prediction in a Plastic Greenhouse

Compared with open-field cultivation, greenhouses can provide favorable conditions for crops to grow through environmental control. The prediction of greenhouse microclimates is a way to reduce environmental monitoring costs. This study used several recurrent neural network models, including long short-term memory (LSTM), gated recurrent unit, and bi-directional LSTM, with varying numbers of hidden layers and units, to establish a temperature forecasting model for a plastic greenhouse. To assess the generalizability of the proposed model, the most accurate forecasting model was used to predict the temperature in a greenhouse with different specifications. During a test period of four months, the best proposed model’s R2, MAPE, and RMSE values were 0.962, 3.216%, and 1.196 °C, respectively. Subsequently, the outputs of the temperature forecasting model were used to calculate growing degree days (GDDs), and the predicted GDDs were used as an input variable for the sigmoid growth models to simulate the leaf area index, fresh fruit weight, and aboveground dry matter of tomatoes. The R2 values of the growth model for the three growth traits were all higher than 0.80. Moreover, the fitted values and the parameter estimates of the growth models were similar, irrespective of whether the observed GDD (calculated using the actual observed data) or the predicted GDD (calculated using the temperature forecasting model output) was used. These results indicated that the proposed temperature forecasting model could accurately predict the temperature changes inside a greenhouse and could subsequently be used for the growth prediction of greenhouse tomatoes.

Energy, economic, and environmental (3E) assessment of the major greenhouse crops: MFCA-LCA approach.

In order to develop sustainable production of greenhouse crops, the economic, energy, and environmental aspects of production should be considered. The purpose of this study was to evaluate the economic, energy, and environmental (3E) sustainability of cucumber, tomato, and bell pepper production in greenhouses by performing material flow cost accounting (MFCA) and life cycle assessment (LCA) material and methods. Calculating the economic and energy value of losses in agricultural sustainability assessment studies is not common. Using the LCA method alone does not allow us to calculate the monetary and energy value of waste. If this method is used simultaneously with MFCA, this gap will be filled. The system boundary for LCA was from cradle to farm, and for MFCA, foreground processes were considered. The production of each crop was compared at the level of 1000 m2 during 1year. Data were collected through questionnaire-based interviews. The gross value of production for cucumber, tomato, and bell pepper were 8982, 16387, and 17610 $/1000 m2, respectively. The negative production of cucumber, tomato, and bell pepper were 702, 718, and 449 $/1000 m2, respectively. The benefit-to-cost ratio in the production of cucumber, tomato, and bell pepper was calculated as 2.8, 5.17, and 5.8, respectively. The economic productivity in the production of cucumber, tomato, and bell pepper was calculated at 10.25, 7, and 4.4kg/$. Labor cost was the main cost in the production of all three crops. The total input energy for the production of cucumber, tomato, and bell pepper was estimated to be 99.4, 123.1, and 164.6 GJ/1000 m2, respectively. Negative products in the production of cucumber, tomato, and bell pepper were obtained at - 24.2, - 23.9, and - 13.5 GJ/1000 m2, respectively. The energy productivity of cucumber, tomato, and bell pepper was calculated as 0.23, 0.26, and 0.08kg/MJ, respectively. The specific energy indices were 4.32, 3.79, and 12.20MJ/kg for cucumber, tomato, and bell pepper, respectively. The energy ratio in the production of tomato (0.02) was higher than bell pepper (- 0.02) and cucumber (- 0.06). From the perspective of energy, electricity was recognized as the hotspot for the production of three crops. Global warming (GWP100a), ozone layer depletion (ODP), acidification (AC), and eutrophication (EP) indices were calculated for all three crops. Tomato production was ranked first in all impact categories. On-farm emissions and electricity consumption were identified as environmental hotspots. The subsidized price of electricity, natural gas, and chemical fertilizers has led to their excessive use in the production of greenhouse plants. It can be concluded that bell pepper has the best performance from an economic point of view. However, its production is not justified in terms of energy. Tomato was ranked first in terms of energy, and cucumber was ranked first in terms of low environmental impacts. The production of these plants with energy and chemical fertilizer subsidies is currently cost-effective. If the prices are corrected, the production of these plants will face serious challenges. Producing electricity from sunlight and mechanizing production processes can be a solution to these challenges.

Optimized Design of Robotic Arm for Tomato Branch Pruning in Greenhouses

Aiming at the robotic pruning of tomatoes in greenhouses, a new PRRPR configuration robotic arm consisting of two prismatic (P) joints and three revolute (R) joints was designed to locate the end effector to handle randomly growing branches with an appropriate posture. In view of the various spatial posture of the branches, drawing on the skill of manual pruning operation, we propose a description method of the optimal operation posture of the pruning end effector, proposing a method of solving the inverse kinematics of the pruning arm based on the multi-objective optimization algorithm. According to the spatial distribution characteristics of the tomato branches along the main stem, the robotic arm structure is compact and the reachable space is maximized as the objective function, and a method of optimizing the key geometric parameters of the robotic arm is proposed. The optimal maximum length of the arm’s horizontal slide joint was determined to be 953.149 mm and the extension maximum length of its telescopic joint was 632.320 mm. The verification test of the optimal structural parameter showed that the optimized robotic arm could reach more than 89.94% of the branches in the pruning target area with a posture that meets the pruning requirements. This study is supposed to provide technical support for the development of a tomato pruning robot.

Effects of Soluble Organic Fertilizer Combined with Inorganic Fertilizer on Greenhouse Tomatoes with Different Irrigation Techniques

A reasonable fertilization rate and appropriate irrigation technology can lead to the green development of greenhouse tomatoes. The purpose of this study was to explore suitable irrigation technology for greenhouse tomatoes and the appropriate application rate of the soluble organic fertilizer and inorganic fertilizer combination. In 2021 and 2022, the effects of different irrigation techniques and fertilization treatments on tomato plant growth, fruit quality, yield, and efficiency were studied. The irrigation techniques in this study were drip and Moistube irrigation, and there were seven types of fertilization treatment, namely, no fertilization treatment (CK); low-volume (T1, 330 kg/hm2), medium-volume (T2, 660 kg/hm2), and high-volume inorganic fertilizer treatments (T3, 990 kg/hm2); and three inorganic fertilizer treatments of low-volume inorganic fertilizer (T1, 330 kg/hm2) combined with low-volume (F1, T1 + 75 kg/hm2), medium-volume (F2, T1 + 225 kg/hm2), and high-volume (F3, T1 + 375 kg/hm2) organic fertilizer. A total of 14 experimental treatments were implemented for irrigation and fertilization. The results of the two-year experiment show that the growth effect on the height, stem diameter, and leaf area index of tomato plants was the best using the treatment of low-concentration inorganic fertilizer combined with medium-concentration organic fertilizer with Moistube irrigation and drip irrigation. Using the two irrigation methods, the application of soluble organic fertilizer increased the yield and improved the fruit quality of the tomato. The maximum yield increased by 28.52%, the soluble sugar content increased by 14.49%, the vitamin C content increased by 45.04%, and the lycopene increased by 18.79%. The entropy-weight TOPSIS model was used to comprehensively evaluate 14 evaluation objects with different irrigation methods and fertilization treatments. The results of the two-year experiment show that the best fertilization treatment under Moistube irrigation and drip irrigation conditions was low-concentration inorganic fertilizer combined with medium-concentration soluble organic fertilizer, which was combined with the best fertilization treatment, and the most suitable irrigation method for greenhouse tomato cultivation in the Loess Plateau was Moistube irrigation. The results of this study also provide practical experience and theoretical support for adaptive irrigation and the integrated management of water and fertilizer.

Intermittent Stop-Move Motion Planning for Dual-Arm Tomato Harvesting Robot in Greenhouse Based on Deep Reinforcement Learning.

Intermittent stop-move motion planning is essential for optimizing the efficiency of harvesting robots in greenhouse settings. Addressing issues like frequent stops, missed targets, and uneven task allocation, this study introduced a novel intermittent motion planning model using deep reinforcement learning for a dual-arm harvesting robot vehicle. Initially, the model gathered real-time coordinate data of target fruits on both sides of the robot, and projected these coordinates onto a two-dimensional map. Subsequently, the DDPG (Deep Deterministic Policy Gradient) algorithm was employed to generate parking node sequences for the robotic vehicle. A dynamic simulation environment, designed to mimic industrial greenhouse conditions, was developed to enhance the DDPG to generalize to real-world scenarios. Simulation results have indicated that the convergence performance of the DDPG model was improved by 19.82% and 33.66% compared to the SAC and TD3 models, respectively. In tomato greenhouse experiments, the model reduced vehicle parking frequency by 46.5% and 36.1% and decreased arm idleness by 42.9% and 33.9%, compared to grid-based and area division algorithms, without missing any targets. The average time required to generate planned paths was 6.9 ms. These findings demonstrate that the parking planning method proposed in this paper can effectively improve the overall harvesting efficiency and allocate tasks for a dual-arm harvesting robot in a more rational manner.

Evaluation of Crop Water Stress Index (CWSI) for High Tunnel Greenhouse Tomatoes under Different Irrigation Levels

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 I60, 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.

Sodium accumulation vs. nitrate leaching under different fertigation regimes in greenhouse soils in South Uruguay

In greenhouse conditions, soil salinity and N leaching depend on the provision of irrigation, the irrigation water quality and the application of fertilizers and organic amendments. The objective of this study was to quantify and analyze the accumulation and/or leaching process of NO3- and Na+ in greenhouse tomato production in the south region of Uruguay in fine-textured soil under different fertigation regimes. The study was conducted in four tomato crops during 2019/20/21 seasons. Three fertigation regimes were applied. Irrigation volume was the same for all treatments. Drainage was determined by using free drainage lysimeters. Concentration in soil solution and leaching of NO3- and Na+ was measured by monitoring soil solution and drainage solution. Yield, N uptake and N utilization efficiency were determined for each treatment. Soil total drainage was the main factor explaining N and Na+ leaching. The leaching of N ranges from 0 to 23.4 kg N ha-1 per tomato crop with total drainage between 0 and 46.2 % of total irrigation. Drainage necessary to avoid Na+ accumulation was 13 % of total irrigation. This drainage produced 8.4 kg of N leaching per ha-1 during tomato cropping period. Optimizing irrigation is the key factor to the salinity-nitrogen leaching paradox. Irrigation amount and timing should attempt: (1) to avoid excessive irrigation when NO3- concentration in soil solution is high, and (2) to apply leaching irrigation when Na+ concentration in soil solution is high. Soil solution monitoring with suction probes and rapid chemical analysis systems could be a useful tool to identify periods of high risk of N leaching and the right time for leaching irrigation.

Integrating Smart Greenhouse Cover, Reduced Nitrogen Dose and Biostimulant Application as a Strategy for Sustainable Cultivation of Cherry Tomato

Fruit yield and quality of greenhouse tomatoes are strongly influenced by light conditions and nitrogen (N) availability, however, the interaction between these factors is still unclear. We evaluated the effects on cherry tomatoes of two tunnel plastic covers with different optical properties and three N doses, also in combination with a biostimulant treatment. We compared a diffuse light film (Film1) and a conventional clear film (Film2), and three N levels, corresponding to 50% (N50), 75% (N75) and 100% (N100) of the optimal dose, with and without a microbial plus a protein hydrolysed biostimulant, compared to a non-treated control. The three experimental treatments significantly interacted on several yield and quality parameters. In control plants (untreated with biostimulants), the early yield was higher at reduced N doses compared to N100, with greater increments under the diffusive Film1 compared to the clear Film2 (+57.7% and +37.0% vs. +31.7% and +16.0%, in N50 and N75 respectively). Film1 boosted the total fruit production at all the N rates and with or without biostimulants, compared to Film2, with stronger effects under sub-optimal N (+29.4% in N50, +21.2% in N75, and +7.8% in N100, in plants untreated with biostimulant). Total yield decreased with decreasing N levels, while it always increased with the application of biostimulants, which counterbalanced the detrimental effects of N shortage. Quality traits were mainly affected by the cover film and the biostimulant treatment. The diffusive film increased the content of carotenoids, lycopene and total phenols compared to the clear one, and the biostimulants increased texture, soluble solids, phenols and ascorbic acid compared to the untreated control. It is worth noting that in plants fertilized at 75% of the reference N dose, the biostimulants determined higher yield than the N100 untreated control, under both the covers (+48% in Film1 and +20% in Film2). In conclusion, the diffusive film improved the fruit yield and quality of greenhouse tomatoes in the spring–summer period, presumably avoiding plant stress due to high-intensity direct light. Reduced N rates limited the plant productivity, however, the biostimulant application was effective in compensating for the detrimental effects of sub-optimal supply of N synthetic fertilizers.

Peanut shell wastes as a culture medium for greenhouse tomato in soilless culture

Peanut shell wastes as a culture medium for greenhouse tomato in soilless culture

Effects of Foliar Selenium Application on Oxidative Damage and Photosynthetic Properties of Greenhouse Tomato under Drought Stress.

Both drought stress and exogenous selenium (Se) cause changes in plant physiological characteristics, which are key factors affecting crop yield. Although Se is known to be drought-resistant for crops, its internal physiological regulatory mechanisms are not clear. This study analyzed the effects of selenium application (SeA) on antioxidant enzyme activities, osmoregulatory substance contents, and photosynthetic characteristics of greenhouse tomatoes under drought stress and related physiological mechanisms. The results showed that drought stress induced oxidative damage in cells and significantly increased the content of the membrane lipidation product malondialdehyde (MDA) and the osmoregulatory substance proline (p < 0.001) compared with the adequate water supply. The proline content of severe drought stress (W1) was 9.7 times higher than that of the adequate water supply (W3), and foliar SeA increased glutathione peroxidase (GSH-PX) activity, and SeA induced different enzymatic reactions in cells under different drought stresses; catalase (CAT) was induced under severe drought stress (p < 0.01) and was significantly increased by 32.1% compared with the clear water control, CAT. Peroxidase (POD) was induced under adequate water supply conditions (p < 0.01), which was significantly increased by 15.2%, and SeA attenuated cell membrane lipidation, which reduced MDA content by an average of 21.5% compared with the clear water control, and also promoted photosynthesis in the crop. Meanwhile, through the entropy weighting method analysis (TOPSIS) of the indexes, the highest comprehensive evaluation score was obtained for the S5W3, followed by the S2.5W3 treatment. Therefore, this study emphasized the importance of SeA to reduce oxidative damage and enhance photosynthesis under drought stress.

Effects of saline-fresh water rotation irrigation on photosynthetic characteristics and leaf ultrastructure of tomato plants in a greenhouse

To reveal the mechanisms of saline-fresh water rotation irrigation that affect the leaf ultrastructure and photosynthetic characteristics of tomato plants and to optimize the strategy of saline water irrigation of greenhouse tomatoes, a two-season tomato experiment with four treatments of saline-fresh water rotation irrigation was conducted in a greenhouse in southern Xinjiang. The four treatments consisted of rotation irrigation with four times saline-fresh water (W1), rotation irrigation with two times saline water and two times fresh water (W2), rotation irrigation with two times fresh water, four times saline water, and two times fresh water (W3), and freshwater irrigation as a control (CK). The three rotation patterns had the same amount of saline water and fresh water, but the rotational interval was different. The results indicated that the saline-alkali stress introduced by saline water significantly reduced the gas exchange parameters of tomato leaves and water use efficiency at the leaf scale, and both stomatal and non-stomatal factors played a key role in limiting leaf gas exchange. The chloroplast granular lamellae structure was disrupted in tomato leaves treated with W1 and W2. Compared with CK, W1 and W2 decreased leaf chlorophyll content by 4.59% and 10.89%, net photosynthetic rate by 26.82% and 40.11%, and yield by 60.62% and 67.63%, respectively. In contrast, W3 presented a relatively intact mesophyll cell structure and relatively high chlorophyll content and photosynthetic efficiency. In W3 treatment, no significant differences were found in the number of fruits per plant (only increased by 8.16% and the yield by 4.03%), while with better quality compared with CK. The results suggested that tomato growth and yield were neither poor nor detrimental when rotated with saline water during the flowering and fruiting stage-fruit expansion stage and freshwater irrigation during other growth stages. W3 can be used as a saline-fresh water rotation pattern for tomato production in greenhouses in arid and saline areas.

Kraft Lignin-Derived Microporous Nitrogen-Doped Carbon Adsorbent for Air and Water Purification.

The study presents a streamlined one-step process for producing highly porous, metal-free, N-doped activated carbon (N-AC) for CO2 capture and herbicide removal from simulated industrially polluted and real environmental systems. N-AC was prepared from kraft lignin─a carbon-rich and abundant byproduct of the pulp industry, using nitric acid as the activator and urea as the N-dopant. The reported carbonization process under a nitrogen atmosphere renders a product with a high yield of 30% even at high temperatures up to 800 °C. N-AC exhibited a substantial high N content (4-5%), the presence of aliphatic and phenolic OH groups, and a notable absence of carboxylic groups, as confirmed by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and Boehm's titration. Porosity analysis indicated that micropores constituted the majority of the pore structure, with 86% of pores having diameters less than 0.6 nm. According to BET adsorption analysis, the developed porous structure of N-AC boasted a substantial specific surface area of 1000 m2 g-1. N-AC proved to be a promising adsorbent for air and water purification. Specifically, N-AC exhibited a strong affinity for CO2, with an adsorption capacity of 1.4 mmol g-1 at 0.15 bar and 20 °C, and it demonstrated the highest selectivity over N2 from the simulated flue gas system (27.3 mmol g-1 for 15:85 v/v CO2/N2 at 20 °C) among all previously reported nitrogen-doped AC materials from kraft lignin. Moreover, N-AC displayed excellent reusability and efficient CO2 release, maintaining an adsorption capacity of 3.1 mmol g-1 (at 1 bar and 25 °C) over 10 consecutive adsorption-desorption cycles, confirming N-AC as a useful material for CO2 storage and utilization. The unique cationic nature of N-AC enhanced the adsorption of herbicides in neutral and weakly basic environments, which is relevant for real waters. It exhibited an impressive adsorption capacity for the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) at 96 ± 6 mg g-1 under pH 6 and 25 °C according to the Langmuir-Freundlich model. Notably, N-AC preserves its high adsorption capacity toward 2,4-D from simulated groundwater and runoff from tomato greenhouse, while performance in real samples from Fyris river in Uppsala, Sweden, causes a decrease of only 4-5%. Owing to the one-step process, high yield, annual abundance of kraft lignin, and use of environmentally friendly activating agents, N-AC has substantial potential for large-scale industrial applications.