Research Paper

Irrigation scheduling and programming are very effective tools for efficient water use in a plant factory with artificial lighting (PFAL). In order to confirm optimal irrigation schemes for the production of cucumber scions and rootstocks in a PFAL, in this study, four different start points of irrigation were applied by measuring the weight of the plug tray to compare the growth of cucumber scions and rootstocks cultivated in a PFAL. Additionally, the growth characteristics of cucumber seedlings grafted with scions and rootstocks cultivated between in a greenhouse and in a PFAL were investigated. Although the growth of cucumber scions and rootstocks was highest when irrigation was conducted at 70% of water content in a medium, the growth of grafted cucumber seedlings before and after transplanting was not significantly different among the irrigation treatments in a PFAL. However, water use efficiency (WUE) during cucumber scions and rootstock production in a PFAL was higher at 60% than at 70%. Considering seedling growth and the efficiency of irrigation such as WUE and irrigation schedule, the optimal start point of irrigation during the production of cucumber scions and rootstocks in a PFAL was determined as 60% of water content in a medium.

Scientists have produced a tomato enriched in the Parkinson’s disease drug L-DOPA in what could become a new, affordable source of one of the world’s essential medicines. The development of the genetically modified (GM) tomato has implications for developing nations where access to pharmaceutical drugs…

Biostimulants play an important role in the development of management practices able to reach adequate productivity to meet the food demand of a growing world population, while following a sustainable agriculture model. This work aims to evaluate the effect of a protein hydrolysate derived from legume seeds by enzymatic hydrolysis on plant growth and also to verify its ability to mitigate Fe deficiency, a widespread problem significantly limiting plant growth and crop productivity. Experiments were performed with tomato (Solanum lycopersicum L.—cv. AKRAI F1) and cucumber (Cucumis sativus L.—cv. EKRON F1). The plants were grown hydroponically under adequate or limited Fe supply. Changes in shoot and root fresh weight, leaf relative chlorophyll content and the accumulation of macro- and microelements in shoots and roots were measured. Plant ability to cope with Fe deficiency was measured by evaluating the activity of root Fe3+-chelate reductase. Our results indicate that the foliar treatments with the protein hydrolysate did not significantly affect growth parameters when plants were grown in full nutrient solution. However, the biostimulant was able to improve the growth performance of Fe-deficient plants. Therefore, the protein hydrolysate can be a powerful tool to stimulate crop growth under Fe-deficient environments, leading to reduced fertilizer inputs with related environmental and economic benefits.

Remotely observing global vegetation from space has endured for nearly 50 years. Many datasets have been developed to monitor vegetation status. Tailored to specifically monitor global food security concerning drought and crop yield, a suite of datasets based on vegetation health concepts and Advanced Very High Resolution Radiometer (AVHRR) observation was developed in the 1980s and utilized throughout the world. Nowadays, satellites based imaging radiometers have evolved into the Visible Infrared Imaging Radiometer Suite (VIIRS) era. With proper algorithm development, the blended version of the data suite, composed of the AVHRR dataset from 1981 to 2012 and VIIRS dataset from 2013 and afterwards, has bridged the long-term AVHRR observation and high-quality VIIRS data. This paper explains the blended version of the data suite.

The peach aphid, Myzus persicae (Hemiptera: Aphididae) and silver leaf whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae) are the major pests of capsicum under protected cultivation. The entomopathogenic fungi (EPF) are environmentally safe than the chemical pesticides. In a new study, different EPF…

Soil enhancements such as biochar (BC) are gaining attention as tools to mitigate climate change and also to promote crop growth. However, biochar use can disrupt soil ecosystems by changing the soil’s physical, chemical, and biological properties. The study aimed to determine how biochar influences soil physical changes such as specific surface area (SSA) and water vapor sorption, and how these conditions affect arbuscular mycorrhizal fungal (AMF) hyphae growth and glomalin production. The study analyzed these factors at different plant phenological phases (i.e., flowering, development of fruit, and ripening of fruit and seed) to better understand the changes within the system while varying biochar amounts. The study also investigated the effect of different soil physical and chemical parameters on mycorrhizal hyphae growth and glomalin production. Four treatments were investigated: 0, 0.5%, 2.5%, and 5.0% (w/w) biochar amended silt loam soil planted with pepper. Soil samples were taken at the beginning and weeks 6, 10, and 12 of the study. The amount of adsorbed water vapor increased with an increasing amount of biochar added to the soils. Compared to control, SSA was significantly higher in all biochar amended treatments based on adsorption data, and only in the highest biochar amended soils for the desorption data at the end of the experiment.

Fertigation is considered an efficient alternative to the enhanced use of chemical fertilizers. Since most of the fertigation systems rely on a theoretical electrical conductivity value of the nutrient solution, a team of Romanian researchers tried to evaluate if this is the real need of the plants as…

Bacterial spot of tomato and pepper caused by what we now know as X. euvesicatoria pv. euvesicatoria was described for the first time on tomato in 1920 in South Africa. Nowadays, bacterial spot is the name used to describe a specific set of symptoms on peppers and tomatoes - caused by four xanthomonad…

In hot climatic conditions, the temperature inside a greenhouse is much higher than the ambient temperature and requires significant cooling to maintain the temperature in the optimal range. A newly published study done by researches of the Hamad bin Khalifa University proposes a novel concept for a self-…

Just like humans, plants can get bacterial infections. These infections can negatively affect yield and quality of fruits and trees. Although some compounds have been developed to protect plants, few of them work on a wide variety of crops. Also, bacteria are constantly developing new resistances. Now,…

Abiotic and biotic stresses both decrease the quality and quantity of cultivated plants. In this study, in order to see the responses of cucumber plants to drought stress and cucumber downy mildew infection, downy mildew infestation at different two levels, B1 (disease infestation) and B2 (no disease infestation), along with three fertigation requirement levels, full fertigation T1, moderate nutrient solution deficit T2 and severe nutrient solution deficit T3, were applied in a greenhouse. Thus, six treatments, i.e., B1T1, B1T2, B1T3, B2T1, B2T2 and B2T3, were set. The leaf gas-exchange parameters were significantly increased under CK (control experiment, B2T1: no disease infestation and full irrigation) treatment, and leaf photosynthesis rate, transpiration rate and stomatal conductance were significantly decreased under the B1T1 treatment. Leaf intercellular CO2 concentration was significantly increased under B1T1 treatment. Leaf photosynthesis rate, transpiration rate, intercellular CO2 concentration and stomatal conductance were significantly decreased under B1T2, B1T3, B2T2 and B2T3 treatments.

Just like humans, plants can get bacterial infections. These infections can negatively affect yield and quality of fruits and trees. Although some compounds have been developed to protect plants, few of them work on a wide variety of crops. Also, bacteria are constantly developing new resistances. Now,…

Fertigation is considered an efficient alternative to the enhanced use of chemical fertilizers. Since most of the fertigation systems rely on a theoretical electrical conductivity value of the nutrient solution, we tried to evaluate if this is the real need of the plants as well as if all the nutrients are needed at once. Therefore, we analyzed the electrical signals of the nutrients applied individually or in different mixes, correlating the electrical signals with the leaf gas exchange processes, studying the relation between the electrical signals and different plant phenological stages and the influence of the treatments on the lycopene content, nutritional composition, and antinutritional factors as well as the mineral bioavailability of tomato fruits cv. Brillante F1. The study was carried out in a greenhouse under controlled conditions. Ten different treatments consisting of MaEs (major elements) (V1—MgSO4, V2—KNO3, V3—K2SO4, V4—Ca(NO3)2, V5—KH2PO4, V6—KCl, V7—MgSO4 + KNO3 + KH2PO4, V8—K2SO4 + Ca(NO3)2 + KCl, V9—the mix of V1 to V6, commonly used in agricultural practices, V10—one nutrient each day) were applied daily when plants were 42 days old. The results showed that the values of the electrical signals varied depending on the treatment and the plant phenological stage.

The interplay of different mechanisms shaping the biochar impact on soil structure remains relatively unexplored. We investigated the impact of biochar application to two contrasting soils on the stability of soil aggregates under an intensive intermittent leaching regime. A greenhouse experiment was established using PVC columns filled with 500 g soil from an Acrisol or Calcisol amended with three biochar applications (0, 1 and 2% w/w). The columns were watered weekly (100 mL) during two leaching cycles (each lasting 10 weeks). The amount of leached base cations, the stability of 1–2 mm aggregates fraction and soil chemical properties were determined. Biochar enhanced the leaching of the studied cations, but the content of base cations and effective cation exchange capacity remained higher in the biochar-amended Acrisol when compared to control soil. In both soils, biochar reduced the amount of water-stable aggregates, which seemed to be attributed to the increase of K in the exchange complex in the Acrisol while no significant correlation was detected between aggregation in Calcisol and other variables. The negative impact of biochar on soil aggregation is likely linked to higher sensitivity of biochar-amended soils to aggregate disruption under changing moisture conditions caused by frequent and intensive leaching events.

Research by A. Richa, S. Touil and M. Fizir highlights the recent developments in the treatment of hydroponic wastewater. The rapid development of hydroponic farming produces a large amount of wastewater rich in nutrients and organic matters thus imposes great harm to humans and the environment if the…

This paper focuses on the agronomic evaluation of a synthetic NPK (N in the form of urea, P and K in the form of phosphate monopotassium) fertilizers blended with four types of pine (Pinus sylvestris L.) wood biochar prepared at different thermal regimes (300 °C, 400 °C, 600 °C and 700 °C). The evaluation of benefits was done based on crop nutritional status and soil fertility. The pot experiment was set up with fertile Haplic Luvisol fertilized with 1.85 g kg−1 of blends of biochar (1.25 g) with urea (310 mg) and KH2PO4 (290 mg), which is equivalent to 500 kg ha−1 (biochar ~67.6%; N ~7.8%; P ~3.6%; K ~4.7%) applied before sowing. Only NPK blends made with biochar containing 75% or 85% carbon increased the biomass of 27-day old wheat seedlings from 12% to 20% in comparison to NPK applied alone. These blends raised the content of Mn and Fe in plants but decreased the contents of Ca and Mg. All the tested mixtures enhanced soil fertility by increasing the content of humic acids. Additionally, the content of potentially phytotoxic phenolic compounds was lower. In general, the addition of biochar to NPK fertilizer did not show a negative effect on crop quality. The overall results of the study suggest that the application of low doses of biochar to synthetic fertilizer can benefit crops and can support soil fertility.

Researchers of the Sindh Agriculture University have completed a paper on the use of chrysoperla carnea larvae to control whitefly on tomato plants in greenhouses.  "In the last ten years, whitefly has presented a serious risk to vegetables most commonly the tomatoes and natural products in the field. Another…

Plants are capable of using mainly the quanta of the red and blue parts of a spectrum for the reception of energy during photosynthesis. However, for many crops grown indoors in high latitudes or under conditions of insufficient insolation, the average daily intensity of the red and blue parts of the…

The application of biostimulants to prevent stress-related losses and increase productivity is becoming an increasingly common practice. A study was carried out to determine the effect of the type and methods of biostimulant application and long-term storage on the content of antioxidant compounds determining the processes of the enzymatic browning of carrot roots. The natural seaweed biostimulant Kelpak and synthetic Asahi were applied as part of the study. A quality assessment of carrot roots was carried out directly after harvest and after six months of storage in air at a temperature of 1 °C and a relative humidity of 95%. A single application of Kelpak seaweed extract in the four-leaf phase (2 or 3 dm3 ha−1) proved to be the most effective for reducing oxidative darkening processes (by 33.5%). The oxidative potential was most strongly dependent on the anthocyanin (r = −0.477) and chlorogenic acid (r = −0.474) contents. The concentration of polyphenols (r = 0.836; r = 0.719) and flavonoids (r = 0.671; r = 0.729) had the greatest effect on the antioxidant capacity (FRAP and ABTS respectively). It was observed that pectin, polyphenol, chlorogenic acid, flavonoid and anthocyanin concentrations tended to increase after a single application of Kelpak in a dose of 2 dm3 ha−1.

Agrivoltaic systems are a strategic and innovative approach to combine solar photovoltaic (PV)-based renewable energy generation with agricultural production. Recognizing the fundamental importance of farmer adoption in the successful diffusion of the agrivoltaic innovation, this study investigates agriculture sector experts’ perceptions on the opportunities and barriers to dual land-use systems. Using in-depth, semistructured interviews, this study conducts a first study to identify challenges to farmer adoption of agrivoltaics and address them by responding to societal concerns. Results indicate that participants see potential benefits for themselves in combined solar and agriculture technology. The identified barriers to adoption of agrivoltaics, however, include: (i) desired certainty of long-term land productivity, (ii) market potential, (iii) just compensation and (iv) a need for predesigned system flexibility to accommodate different scales, types of operations, and changing farming practices. The identified concerns in this study can be used to refine the technology to increase adoption among farmers and to translate the potential of agrivoltaics to address the competition for land between solar PV and agriculture into changes in solar siting, farming practice, and land-use decision-making.

The sustainable development of agricultural systems where nutrients and water are recycled to a high degree is of enormous importance. Traditional aquaponics, where fish and plants are cultivated in one recirculating system, addresses these ecological challenges, but still struggles with its economical…

Cucumber green mottle mosaic virus (CGMMV) is a re-emerging threat to greenhouse cucumber and other Cucurbitaceae crop production worldwide. This seed-borne virus can easily spread from a contaminated seeds to seedlings and to adjacent plants through mechanical contact of the foliage of diseased and healthy plants causing extensive yield losses. Additionally, infection may not be limited to the current crop but may also affect subsequent crops due to the long-term persistence of the virus on contaminated crop residues, greenhouse hard surfaces and soil or soil-less greenhouse substrates. In the present work, three greenhouse experiments were conducted to develop an integrated pest management strategy towards controlling CGMMV in commercial cucumber greenhouses, by implementing an effective sanitization program and using resistant and grafted cucumber varieties. Results of sanitization highlighted that pressure washing and cleansing with an alkaline foam cleanser eliminated CGMMV on some of the most heavily infested areas. However, three successive applications of cleanser and disinfectants were essential to completely eliminate CGMMV on porous and uneven surfaces, such as cement alleyway, tray gutters and floor mats.

Magnesium (Mg) is essential to many plant physiological and biochemical processes; however, understanding how Mg nutrition quantitatively affects the production, partitioning, and utilization of photoassimilates is still lacking, especially in soilless culture systems. We focused on the roles of Mg in yield formation and interactions with potassium (K) nutrition of cherry tomato. Cherry tomato yield, photosynthetic parameters, dry matter weight, and K, Mg, and calcium (Ca) uptake were investigated in two soilless experiments with seven Mg levels and five K levels. The results showed that low (<1 mM) and high (>4 mM) Mg supply limited cherry tomato yield by decreasing dry matter accumulation by22.6–78.1% and harvest index by 13.9–40.7%. The critical leaf Mg concentrations required for adequate photosynthate production in the first and second harvest periods were 4.67 and 5.52 g·kg−1, respectively. However, over-supply of Mg reduced leaf K and Ca concentrations and limited plant uptake of K and Ca. Moreover, adjusting K concentrations in solution could influence plant Mg functions in photosynthesis and, therefore, cherry tomato growth. Overall, balanced Mg and K application increased Mg, K, and Ca uptake, as well as Mg concentrations in leaves, which could maintain a sustainable photosynthetic rate and plant dry matter formation.

When switching to LEDs, your electricity bill will lower and your heating bill will increase. Sounds fair, and most growers are completely aware of this. But by how much? That's often unclear, even when the LEDs have already been installed. "Since electricity is measured in kwH and gas is measured in…

500Foods shared this story from Agronomy.

Agronomy, Vol. 10, Pages 1752: Effects of Elevated CO2 on Tomato (Lycopersicon esculentum Mill.) Growth and Rhizosphere Soil Microbial Community Structure and Functionality

Agronomy doi: 10.3390/agronomy10111752

Authors: Hehua Wang Haoxin Fan Huaiying Yao

Protected cultivation systems such as greenhouses are becoming increasingly popular globally and have been adopted because of unpredictable climatic conditions and their ability to easily control micro- and macroenvironments. However, limitations such as hazardous work environments and shortages in labor are major concerns for agricultural production using these structures. This has led to the development and adoption of robotic systems. For the efficient use of robots in protected cultivation systems, we formulate the work efficiency problem and model a three-dimensional standard strawberry greenhouse to analyze the effectiveness of a strawberry-harvesting robot compared to different levels of human workforce (experienced, average, and beginner). Simulations are conducted using Quest software to compare the efficiency of different scenarios of robotics to humans. Different methods of improvement from battery capacity and charge rate to harvesting speed are investigated and optimal conditions are recommended. The average hourly production of the robot is about five times lower than that of skilled workers. However, robots are more productive due to their ability to work around the clock. Comparative analyses show that a reduction in harvesting time per strawberry from 3 to 1 s would result in an increase in daily production from 347.93 to 1021.30 kg. This would lead to a five-fold increase in comparison to present daily production.

Tomato is an economic crop worldwide. Many limiting factors reduce the production of tomato, with bacterial wilt caused by Ralstonia solanacearum being the most destructive disease. A previous study showed that the disease resistance to bacterial soft rot is enhanced by Bacillus amyloliquefaciens strain…

The transfer of genetic variability from related species into crops has been a main objective for decades in breeding programs. Breeders have used interspecific genetic crosses and alien introgression lines to achieve this goal, but the success is always dependent on the interspecific chromosome associations between the alien chromosomes and those from the crop during early meiosis. In this Special Issue, the strength of chromosome manipulation in a breeding framework is revealed through research and review papers that combine molecular markers, cytogenetics tools and other traditional breeding techniques. The papers and reviews included in this Special Issue “Chromosome manipulation for plant breeding purposes” describe the development and/or characterization of new plant material carrying desirable traits and the study of chromosome associations and recombination during meiosis. New tools to facilitate the transfer of desired traits from a donor species into a crop can be developed by expanding the knowledge of chromosome associations during meiosis.

In order to inhibit spindling growth and improve quality of cucumber seedlings under low irradiance, effects of supplemental light-emitting diodes (LED) light (SL) on morphological and physiological characteristics of cucumber seedlings at different growth stages under extremely low irradiance (ELI) were investigated. Supplementary monochromatic, dichromatic and trichromatic LED light on cucumber seedlings were conducted in experiment one, and supplements of combination ratios and intensity of blue and red LED light (RB) were conducted in experiment two. The morphological and physiological parameters of cucumber seedlings were promoted effectively by supplemental monochromatic red light or dichromatic containing red light (RB and RG) under ELI as early as one-leaf seedling stage, as demonstrated by suppressed length of hypocotyl and first internode, increased stem diameter and biomass, higher net photosynthetic rate (Pn) and soluble sugar content. Monochromatic or additional green light was not beneficial to cucumber seedlings under the ELI. The length of shoot and hypocotyl decreased, while stem diameter and leaf area increased as early as one-leaf seedling stage by RB SL. Root activities, root–shoot ratio, activities of catalase (CAT) and peroxidase (POD), as well as palisade–spongy ratio in the leaf of cucumber seedlings were promoted effectively by increasing blue light proportion (1R1B/1R2B).

Machine-vision-based crop detection is a central issue for digital farming, and crop height is an important factor that should be automatically measured in robot-based cultivations. Three-dimensional (3D) imaging cameras make it possible to measure actual crop height; however, camera tilt due to irregular ground conditions in farmland prevents accurate height measurements. In this study, stereo-vision-based crop height was measured with compensation for the camera tilt effect. For implementing the tilt of the camera installed on farm machines (e.g., tractors), we developed a posture tilt simulator for indoor testing that could implement the camera tilt by pitch and roll rotations. Stereo images were captured under various simulator tilt conditions, and crop height was measured by detecting the crop region in a disparity map, which was generated by matching stereo images. The measured height was compensated for by correcting the position of the region of interest (RoI) in the 3D image through coordinate transformation between camera coordinates and simulator coordinates. The tests were conducted by roll and pitch rotation around the simulator coordinates. The results showed that crop height could be measured using stereo vision, and that tilt compensation reduced the average error from 15.6 to 3.9 cm. Thus, the crop height measurement system proposed in this study, based on 3D imaging and a tilt sensor, can contribute to the automatic perception of agricultural robots.