Primary Crop Research Articles

Novel Insights into Exogenous Phytohormones: Central Regulators in the Modulation of Physiological, Biochemical, and Molecular Responses in Rice under Metal(loid) Stress.

Rice (Oryza sativa) is a research model for monocotyledonous plants. Rice is also one of the major staple foods and the primary crop for more than half of the world's population. Increasing industrial activities and the use of different fertilizers and pesticides containing heavy metals (HMs) contribute to the contamination of agriculture fields. HM contamination is among the leading causes that affect the health of rice plants by limiting their growth and causing plant death. Phytohormones have a crucial role in stress-coping mechanisms and in determining a range of plant development and growth aspects during heavy metal stress. This review summarizes the role of different exogenous applications of phytohormones including auxin, cytokinin, gibberellins, ethylene, abscisic acid, strigolactones, jasmonates, brassinosteroids, and salicylic acids in rice plants for mitigating heavy metal stress via manipulation of their stress-related physiological and biochemical processes, and alterations of signaling and biosynthesis of genes. Exogenous administration of phytohormones and regulation of endogenous levels by targeting their biosynthesis/signaling machineries is a potential strategy for protecting rice from HM stress. The current review primarily emphasizes the key mechanistic phytohormonal-mediated strategies for reducing the adverse effects of HM toxicity in rice. Herein, we have provided comprehensive evidence for the effective role of exogenous phytohormones in employing defense responses and tolerance in rice to the phytotoxic effects of HM toxicity along with endogenous hormonal crosstalk for modulation of subcellular mechanisms and modification of stress-related signaling pathways, and uptake and translocation of metals. Altogether, this information offers a systematic understanding of how phytohormones modulate a plant's tolerance to heavy metals and may assist in directing the development of new approaches to strengthen rice plant resistance to HM toxicity.

Omics for Elucidating Heat Stress Tolerance Mechanisms in Wheat: A Review Update

For the vast majority of people on earth, wheat is a primary staple food crop. It is one of the most vulnerable crops, the production of which significantly suffers from the harmful effects of climate change. As the predicted increase in global temperature is supposed to jeopardize production, wheat improvement towards heat stress-resilience has gained pivotal importance. The large and complex allohexaploid wheat genome represents a genetic puzzle, where deciphering any trait-genetics is always challenging. Fortunately, the advancement in the ‘omics’ approach has paved the way for solving these issues in a multidisciplinary convergent manner. The approach has significantly contributed towards the complex molecular mechanisms of the heat stress tolerance in wheat. In the recent past, salient attainments have been observed in exploring heat tolerance mechanisms in wheat addressed through omics technologies. All these approaches have identified some of the key regulators behind this complex trait, the conglomeration of which is definitely promising for achieving heat tolerant cultivars. Besides, the epigenetic regulation of this important trait as well as the significant achievements in developing heat tolerant lines through a transgenic approach has been enumerated. This summarized review of an issue of global importance should enlighten the understanding of the complex regulation of heat tolerance mechanism in wheat, which is a prerequisite for the development of stable heat tolerant wheat cultivars in near future. Here we discussed current research on the genetic and molecular variables that alter one's ability to tolerate heat, including the effects of epigenetic regulation. At the end, we concluded the review by discussing integrative methods for enhancing heat tolerance through the use of current germplasm, such as contemporary cultivars, landraces, and related species.

Mechanical Stubble Righting after the Mechanical Harvest of Primary Rice Improves the Grain Yield of Ratooning Rice

Ratooning rice is an essential rice-planting method. However, mechanical harvesting of the primary rice crop, while increasing efficiency, can negatively affect the yield of ratooning rice. Therefore, it is crucial to find ways to improve the grain yield of ratooning rice after the mechanical harvest of the primary rice. A two-year field experiment was conducted; the grain yield of ratooning rice was assessed by stubble righting after mechanical harvesting of primary rice. The study used two popular rice cultivars, YLiangyou911 and Kenliangyou801, as experimental materials. The experimental treatments included three groups: one without righting after rolling rice stubble (CK), another with mechanized righting after rolling rice stubble (T1), and a third one without rolling rice stubble by the machine (T2). The results of the study demonstrate that stubble righting after the mechanical harvest of primary rice (T1) had a substantial impact on the grain yield of ratooning rice. It led to grain yields similar to ratooning rice without mechanical rolling of the rice stubble (T2) and significantly outperformed the treatment without stubble righting after the mechanical harvest of primary rice (CK). The study observed significant effects of the year of the experiment (Y), the treatment applied (T), and the interaction between year and treatment (Y×T) on grain yield. Additionally, the treatment showed a significant influence on the yield components. Specifically, in 2021, the T1 and T2 treatments showed remarkable grain yield increases in YLiangyou911 by 107.41% and 147.97%, respectively, compared to CK. For Kenliangyou801 in 2021, the T1 and T2 treatments also resulted in notable improvements in grain yield by 45.85% and 114.26%, respectively. Similarly, in 2022, the grain yield increased by 6.99% for T1 and 23.87% for T2 in YLiangyou911, and by 77.23% for T1 and 187.13% for T2 in Kenliangyou801, compared to CK. The study also detected enhancements in several aspects, including biomass accumulation, solar radiation and photosynthetic characteristics, antioxidant response and nitrogen metabolism, and bud-regeneration capacity due to T1 and T2 treatments. Furthermore, correlation analysis was conducted to assess the relationship between grain yield and the investigated parameters. In conclusion, stubble righting after the mechanical harvest of primary rice resulted in significantly improved grain yield for ratooning rice. This improvement can be attributed to enhanced biomass accumulation, solar radiation and photosynthetic characteristics, antioxidant response and nitrogen metabolism, and increased bud-regeneration capacity.

Effect of Planting Density on the Nutritional Quality of Grain in Representative High-Yielding Maize Varieties from Different Eras

Maize is essential in ensuring food security in China as a primary food and feed crop. One of the main ways to increase yield in maize production systems is to increase planting density as appropriate. Clarifying the relationship between planting density and grain nutritional quality can provide theoretical guidance for high-yielding high-quality maize cultivation and management practices. To this end, five representative high-yielding maize varieties from the 1970s to the 2010s in China were used as experimental material, and two planting densities of 45,000 plants hm−2 and 105,000 plants hm−2 were set to analyze the changing patterns of yield traits and grain nutrient quality of maize varieties in different eras, as well as their responses to densification conditions. The results showed that, under low-density conditions, the grain nutrient quality components of the 2010s’ variety (DH618) were all different 75 days after anthesis compared with the 1970s’–2000s’ varieties and yields also significantly increased by 11.15% to 19.18% (p < 0.05). The increase in planting density led to a rise in total grain starch and soluble sugar content 75 days post-anthesis in all varieties from the 1970s to the 2010s, with increases of 0.65–1.65% and 39.44–69.01%, and a decrease in crude grain protein and crude fat content, with reductions of 4.15–8.50% and 3.00–11.18%. The increase in total grain starch content 75 days post-anthesis was mainly due to the rise in grain starch accumulation between 23 and 47 days post-anthesis in the 1970s’–2010s’ varieties, with an increase of 7.72–9.19% in all varieties. The higher accumulation of crude fat and soluble sugar in the 0–23 days post-anthesis period also contributed to the increase in total starch accumulation in the 23–47 days post-anthesis period. Ultimately, densification conditions also contributed to a significant increase in yield across all eras of the varieties based on changes in grain nutritional quality, with a more significant increase in yield due to densification and a smaller decrease in grain crude fat content due to densification 75 days after anthesis in the 2010s’ variety (DH618). Therefore, in cultivation and production processes that do not have specific requirements for the nutritional quality components of maize grain, we suggest that the use of a representative high-yielding maize variety (DH618) from the 2010s, together with appropriate planting at close planting distances, can significantly increase maize yields based on an increase in the total starch content of the grain at physiological maturity.

Soil management considerations for water resiliency in a changing climate

AbstractProviding adequate water for crops is a key consideration for agricultural resiliency. Climate change is expected to exert substantial pressure on crop water supplies through increased rainfall variability and increased evaporative demand. The temporal and spatial variability of these climate change impacts, in combination with many feedbacks, at times operating at different scales, makes identifying specific, yet broadly applicable “one‐size‐fits‐all” soil management solutions challenging. Adaptations that work well in one location may represent a poor management choice in another. Considering the local combinations of climate, soils, and crop production systems is fundamental for identifying appropriate strategies. Nonetheless, some broadly applicable soil management pathways for increasing soil water availability can be identified: (i) maximizing rainfall capture, (ii) maximizing soil water storage capacity (intensity × volume), and (iii) suppressing unproductive evaporative water losses, particularly during intervals when leaf area of the primary crop is low. Selecting climate, soil, and production‐system‐appropriate tillage and surface cover management practices is among the most relevant considerations for improving soil water availability. Maintaining surface cover favors evaporation suppression and increased capture of precipitation. Tillage choices affect internal soil water storage through impacts on soil properties that influence storage intensity and by altering the volume of soil available for root growth, as well as through effects on surface cover. Promoted management practices aimed at improving soil water availability for increased agricultural resiliency must be practically feasible and cost‐effective in order to support their broad adoption, and such constraints should be an important consideration in their development.

Unraveling On-Farm Wheat Loss in Fars Province, Iran: A Qualitative Analysis and Exploration of Potential Solutions with Emphasis on Agricultural Cooperatives

Given wheat’s global significance as a primary food crop, and its importance in providing essential nutrition to millions of people worldwide, reducing on-farm losses is crucial to promoting food security, sustainable agriculture, and economic stability. Wheat plays a critical role in food security in Iran, as it is a staple food consumed daily by a large proportion of the population, and is also a vital component of the country’s food self-sufficiency policy. The present study aims to identify the causes and extent of on-farm wheat loss in Fars province, a major wheat-producing area in Iran. Nine experts were interviewed, using open-ended questions, in October 2018. The study revealed that a considerable amount of wheat is lost due to seed overuse, pest infestation, and improper harvesting. The paper discusses the underlying factors associated with these over-arching causes, and highlights their adverse environmental, economic, and societal impacts. The paper also explores potential approaches to take in addressing the issue, and suggests empowering agricultural cooperatives through changes in the government’s engagement with wheat production. This study provides valuable insights for policymakers and stakeholders which are useful for developing effective strategies to reduce on-farm loss, particularly in countries where intensified farming is promoted. These strategies may include limiting the government’s central control and, instead, empowering agricultural cooperatives, as well as adopting supportive approaches, such as improving farmers’ access to proper machinery, and enhancing their sovereignty and freedom.

Effect of Pesticides on Human Health

The demand for pesticides has increased in today’s world of expanding population in order to boost crop productivity and eliminate undesirable plants (weeds) that grow alongside the primary crop. Along with the various benefits, it is also used in animal farms to get rid of pests. This has an impact not only on humans but also on animals and the environment. The usage of pesticides has increased, and occasionally some of them linger in the food products they are applied to, a condition known as pesticide residue. This residue is linked to human health and can result in a variety of diseases and disorders. In the current environment, even pesticides that are marketed as benign have negative long-term effects and exacerbate issues like bioaccumulation and bio-magnification. To avoid food contamination with pesticides, different methods like crop rotation, organic farming, and integrated pest management should be used as alternatives. Today, it is essential for all pesticide users to be aware of the risk and proper handling of these pesticides. New methods of pest management should be fostered in the realm of development.

Functional characterization of novel mutations in the conserved region of EPSPS for herbicide resistance in pigeonpea: structure-based coherent design

Prospectively, agroecosystems for the growth of crops provide the potential fertile, productive, and tropical environment which attracts infestation by weedy plant species that compete with the primary crop plants. Infestation by weed is a major biotic stress factor faced by pigeonpea that hampers the productivity of the crop. In the modern era with the development of chemicals the problem of weed infestation is dealt with armours called herbicides. The most widely utilized, post-emergent, broad-spectrum herbicide has an essential active ingredient called glyphosate. Glyphosate mechanistically inhibits a chloroplastic enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) by competitively interacting with the PEP binding site which hinders the shikimate pathway and the production of essential aromatic amino acids (Phe, Tyr, Trp) and other secondary metabolites in plants. Moreover, herbicide spray for weed management is lethal to both the primary crop and the weeds. Therefore, it is critical to develop herbicide-resistant crops for field purposes to reduce the associated yield and economic losses. In this study, the in-silico analysis drove the selection and validation of the point mutations in the conserved region of the EPSPS gene, which confers efficient herbicide resistance to mutated-CcEPSPS enzyme along with the retention of the normal enzyme function. An optimized in-silico validation of the target mutation before the development of the genome-edited resistant plant lines is a prerequisite for testing their efficacy as a proof of concept. We validated the combination of GATIPS mutation for its no-cost effect at the enzyme level via molecular dynamic (MD) simulation. Communicated by Ramaswamy H. Sarma

Growth Performance of Clarias gariepinus in Paddy Rice Field in Kwadon, Gombe, Nigeria

In this scenario, a rice and fish farming system is merged, where the fish are farmed alongside or interchangeably with the rice. Integrated fish farming is a sequential linkage between two or more farming operations. However, occasionally the advancement of rice-fish farming has been ham-pered by changes in rice growing methods as well as the widespread use of insecticides and artifi-cial fertilizers. A cutting-edge agricultural technique where the primary crop is rice and fish fin-gerlings are used as a secondary source of income. By generating employment opportunities and ensuring food security, rice cum fish culture not only helps farmers who are living in poverty to earn more money but also increases the output of their paddy crops. This study aims to assess the performance of the fish as a result of the rice-fish culture. Kwadom, in the Yamaltu-Deba local government area of Gombe State, Nigeria, practiced rice-fish culture. The study used six (6) rice paddy fields with the labels "pond X and X1 received artificial feed, pond Y and Y1 received poultry dropping, and pond Z and Z1 serve as control." at twenty-one (21) days following plant-ing, local rice seedlings Jamila and improved rice seedlings Faro 44 were transferred into the paddies. Each pond received 5 g of Clarias gariepinus per fingerling. But only one treatment (X and X1) produced positive results for the rice variety faro 44, which managed to live. When compared to the other 2 treatments (poultry dropping and control), the fish output in treatment one (artificial feed) had an overall weight (g) of 54000 g, which is considerably greater. The study's high mean in faro 44 reading of 96264.73 g was observed. An analysis of resource use efficiency found that, with the exception of labour, irrigation, and insecticide, most resources in the rice-fish industry were underutilized by farmers. In order to improve food security and maintain sustained rural development, it is crucial that the government actively supports the integration of rice and fish farming.

Biochemical Defenses Induced by Natural Silicon in the Management of Rice Yellow Stem Borer, Scirpophaga incertulas (Walker)

Rice (Oryza sativa L.) one of the primary and staple food crops consumed throughout Asia belongs to Poaceae family. Yellow stem borer, Scirpophaga incertulas W. is a predominant insect pest infesting rice in India which damages the crop throughout the cropping season.
 Aim: Present investigation was carried out to study the efficacy of foliar sprayed natural silicon in inducing biochemical defenses and reducing the damage caused by yellow stem borer in rice.
 Study Design: Field experiment was laid out by using Randomized Block Design consisting of three different treatments replicated seven times.
 Place and Duration of Study: The experiment was carried out at Paddy Breeding Station, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, India during the year 2022.
 Methodology: Field experiment was carried out to study the effect of natural silicon on per cent damage caused by rice yellow stem borer. In addition, enzyme studies were carried out to find the biochemical changes occurred in the plants due to different treatments. Treatments comprised of foliar spray of 2% natural silicon (100% SiO2) at 15, 30 and 45 days after transplanting (DAT) (T1), TNAU organic package of practices for rice (T2) and untreated control (T3).
 Results: Foliar spray of 100% pure natural silicon along with stem borer feeding resulted in significant increase in the activities of defense associated enzymes namely, peroxidase (PO), polyphenol oxidase (PPO) and phenylalanine ammonia lyase (PAL). In addition to defensive enzymes, total phenol content was found to be significantly higher in silicon treated plants when compared to other two treatments. Such increase in biochemical parameters viz., the defensive enzymes and phenols resulted in significant reduction in the damage caused by stem borer with the lowest mean of 2.78 %, followed by 6.32 % in organic practice as against 9.34 % in untreated control.
 Conclusion: Silicon obtained from natural sources can be employed as a safe and promising organic amendment in the management of yellow stem borer infesting rice by inducing resistance in plants.

<em>Brochothrix thermosphacta</em> as a microbiological indicator in determining the expiration date of meat products

Microbial spoilage of food products leads to significant losses with negative social and economic consequences. In order to better control contamination and microbiological spoilage of food products, a new GOST P 70354-22 has been introduced. Meat and meat products. General requirements and procedure for testing to justify expiration dates (publication date 09/29/2022). Great importance is attached to the identification and quantification of the additional microbiological indicator Brochothrix termosphacta in meat, meat and meat-containing products packed using vacuum or modified gas atmosphere. Brochothrix sp. may become the dominant type of meat spoilage in MHA packaging and vacuum packed in the presence of sufficient oxygen. Brochothrix causes mucus and stickiness of the meat surface, unpleasant odors. Brochothrix also causes mucus and stickiness on the meat surface. GOST P 70354-22 describes a method for detecting and counting the number of bacteria Brochothrix sp. For their cultivation, a dense selective medium STAA was proposed. It allows you to isolate, identify and determine the amount of Brochothrix in samples. The technique described in GOST P 70354-2022 was tested. According to the results of cultivating primary crops, we observed the growth of characteristic small, round, shiny, gray-white colonies of Brochotrix on the surface of a special medium. The studied bacteria were oxidase-negative and catalase-positive.

Performance Evaluation of a Cascade Cropping System

Minimum environmental impact and improved resource efficiency is attainable for soilless cascade systems where the nutrient solution drained from a primary (donor) crop is reused to fertigate a secondary (receiver) crop. However, it is not clear whether the nutrient solution drained from the primary crop can completely satisfy the needs of a secondary crop and if the productivity of the secondary crop is compromised. To test this hypothesis, a prototype soilless cascade system was developed and evaluated. To assess the performance of the system in terms of yield, water and nutrient productivity, a tomato crop was used as the primary crop, while lettuce, spinach and parsley were tested as secondary crops under different drainage management strategies. Measurements of plant growth, crop fresh and dry matter production, leaf chlorophyll and nutrient content, and photosynthesis rate were performed in the secondary crops. In addition, the water productivity and nutrient use efficiency for the fertigation of the primary and secondary crops were recorded. The results showed that the yield of the cascade spinach crop increased by up to 14% compared to the control treatment (monoculture of secondary crop fertigated by standard nutrient solution). The yield of the lettuce and parsley crop was not affected by the reuse of the tomato crop drainage solution. The water productivities of the lettuce, spinach and parsley plants fertigated with pure drainage solution were 50%, 30% and 14% higher than in the control treatment, respectively. The nitrogen and phosphorus use efficiency was improved by more than 50% compared to the control treatments.

The Primary Crop of Phytoplankton and Total Organic Matter Destruction in Varvara Reservoir, One of the Main Reservoirs of Azerbaijan

The role of phytoplankton in regulating the flow of physico-chemical processes in ecosystems, including hydrobionts, which is involved in the formation of biological products, the circulation of substances in the life of reservoirs, the creation of their energy source, is very large. Fhytoplankton ecosystems are very sensitive to abiotic factors and anthropogenic influences to many physical, chemical and biological factors present in the environment. Therefore, phytoplankton is considered the basis of trophic relationships in the hydroecosystem.

Finger Millet- A Possible Source of Human Nourishment and Health

Accessible for a significantly lower cost than other items, finger millet, the primary crop in human nutrition is regarded as a healthful diet for low-income populations. In Africa's West, East, and Great Lakes Regions, it is a reliable source of food. Furthermore, native to Ethiopia, it can withstand drought well. The chemical makeup of various finger millet types is crucial in determining which has a high nutritional value. Ethiopian research on the crop's chemical makeup is, however, lacking. This analysis evaluates the nutritional benefits, overall health, and application of finger millet in value-added foods. Its product is one of the most significant and is widely grown in several locations in Ethiopia and Eritrea. This little millet provides an essential amino acid in the form of foodstuffs lacking in leucine, isoleucine, methionine, and phenylalanine. The polyphenol and fiber content are also useful for various health advantages, including antioxidant, anti-diabetic, anti-atheroclerogenic, and anti-tumorigenic actions. Generally speaking, these millets are crucial for many items and are also utilized as a healthful food for newborns when fermented. They are also recognized as a significant source of fiber for diabetes patients.

Sugarcane Disease Recognition using Deep Learning

This paper "Sugarcane Disease Recognition Using Deep Learning" describes the concept of a "CNN" as a Convolution Neural Networks. Convolutional neural network (CNN) is a type of feed-forward artificial Neural Network whose connectivity structure is inspired by the organization of the animal visual cortex. Recognizing sugarcane diseases using deep learning techniques can be an effective approach to automate the disease detection process. Deep learning models, such as Convolution Neural Networks (CNN), have shown promising results in image recognition tasks, including plant disease recognition. The primary crop used to produce sugar and ethanol in the globe is sugarcane. The eradication of growing crops infected with the illness is one issue in the sugar sector, and if these diseases are not treated and recognized early, small-scale farmers may suffer financial loss. The rationale for undertaking this study was the rapidly expanding classes of diseases and farmers' insufficient knowledge of disease identification and recognition. As a result, this research offers a suggestion for using deep learning algorithms to assist farmers in identifying and categorize sugarcane infections. The paper also discusses the existing literature in the field, addresses the limitations of previous research, and presents the methodology and functioning of the proposed system

Brown Manuring a Reliable Method of Weed Control and Source of Nutrients in Direct Seeded Rice (DSR)

Aim: This review provides an overview of the reliability and utilization of SBM on the DSR system. And its effectiveness in the real world. Effective weed and nutrient management are crucial for optimizing rice production while minimizing environmental impacts. The BM or specifically SBM has emerged as a valuable method for both weed and nutrient management in rice cultivation.
 Methodology: Simply said, brown manuring is a "no-till" variation of green manuring that uses a selective herbicide to desiccate the crop prior to flowering rather than cultivating it. In accordance with this method, green manure crops are produced alongside the crop while being eradicated with herbicide. The plants' leftovers are left standing in the field alongside the primary crop without integration or in-situ plowing until the leftovers begin to break down in the soil. Along with weed control due to its shadow impact, organic manure is helpful to add. Brown manuring signifies the application of a post-emergence herbicide most prominently 2,4-d to green manure leaves which results in the loss of chlorophyll and browning of the leaves. The sustainability of crop yields depends on effective fertilizer management. Only when all possible nutrient sources are integrated and crop needs are met then only yield sustainability can be determined. Organic manures can be quite helpful in this regard. But because these manures are heavy and deficient in nutrients, a replacement is necessary. Another option for providing nutrients to crops from organic sources is green manure, but this option has some drawbacks because it is primarily used with rice crops, which need 45 to 60 days from seeding to decomposition with ideal temperature and moisture levels.
 Results: Brown manuring as a method for integrated nutrition management is the remaining viable choice. In addition to being useful for weed control and enhancing soil health, brown manuring is well capable of providing all the nutrients needed by the crops.

Changes in Soil Properties and Crop Yield under Sustainable Conservation Tillage Systems in Spring Wheat Agroecosystems

The cultivated soils in several semi-arid areas have very low organic matter due to climatic constraints that limit primary crop yield. Conservation tillage systems, outlined here as no tillage, no tillage with straw return and straw incorporation into the field, have been accepted as capable systems that preserve soil’s resources and sustain soil productivity. However, in semi-arid climates, there is presently no knowledge about the influence of different conservation tillage techniques on soil’s physical, chemical and biological properties at different soil depths in spring wheat fields and only little information about spring wheat yield in these management systems. Therefore, the present study was carried out with the objective of examining the impact of conservation tillage systems on soil properties (physical, chemical and biological) and spring wheat yield. The three conservation tillage treatments consisted of no tillage system (NT), wheat stubble return with no tillage (NTS) and straw incorporation with conventional tillage (CTS), as well as one conventional tillage (CT) control treatment, which were evaluated under randomized complete block design with three replications. The three conservation tillage treatments were compared with the conventional tillage control. Conservation tillage significantly increased the bulk density, gravimetric water content, water storage, hydraulic conductivity and soil aggregates and decreased the pore space and soil temperature compared to CT; however, no significant difference was found in the case of field capacity. Soil chemical properties in the 0–40 cm soil layer increased with conservation tillage compared to CT. Conservation tillage also notably increased the soil microbial counts, urease, alkaline phosphatase, invertase, cellulase and catalase activities relative to CT. Microbial biomasses (carbon and nitrogen) and wheat yield significantly elevated under conservation tillage compared to CT. Therefore, conservation tillage could significantly improve soil properties and maintain wheat yield for the research zone.

Photosynthetic Acclimation of Shade-Grown Soybean Seedlings to a High-Light Environment.

Soybean in relay intercropping is initially exposed to a shade environment, followed by exposure to full sunlight after the harvesting of primary crops, e.g., maize. Therefore, soybean's ability to acclimate to this changing light environment determines its growth and yield formation. However, the changes in soybean photosynthesis under such light alternations in relay intercropping are poorly understood. This study compared the photosynthetic acclimation of two soybean varieties with contrasting shade tolerance, i.e., Gongxuan1 (shade-tolerant) and C103 (shade-intolerant). The two soybean genotypes were grown in a greenhouse under full sunlight (HL) and 40% full sunlight (LL) conditions. Subsequently, after the fifth compound leaf expanded, half of the LL plants were transferred to a high-sunlight environment (LL-HL). Morphological traits were measured at 0 and 10 days, while chlorophyll content, gas exchange characteristics and chlorophyll fluorescence were assayed at 0, 2, 4, 7 and 10 days after transfer to an HL environment (LL-HL). Shade-intolerant C103 showed photoinhibition 10 days after transfer, and the net photosynthetic rate (Pn) did not completely recover to that under a high light level. On the day of transfer, the shade-intolerant variety, C103, exhibited a decrease in net photosynthetic rate (Pn), stomatal conductance (Gs) and transpiration rate (E) in the low-light (LL) and low-light-to-high-light (LL-HL) treatments. Additionally, intercellular CO2 concentration (Ci) increased in low light, suggesting that non-stomatal factors were the primary limitations to photosynthesis in C103 following the transfer. In contrast, the shade-tolerant variety, Gongxuan1, displayed a greater increase in Pn 7 days after transfer, with no difference observed between the HL and LL-HL treatments. Ten days after transfer, the shade-tolerant Gongxuan1 exhibited 24.1%, 10.9% and 20.9% higher biomass, leaf area and stem diameter than the intolerant C103. These findings suggest that Gongxuan1 possesses a higher capacity to adapt to variations in light conditions, making it a potential candidate for variety selection in intercropping systems.

A comparative study of oil, protein, and fatty acid content of 12 cultivars of peanut (Arachis hypogaea L.) grown from two regions in Shandong province, China

AbstractPeanut is a primary oil crop that is cultivated on a large scale in Shandong province, China. This study evaluated the oil, protein, and fatty acid compositions of different types of peanut cultivars growing in different ecological regions (Yantai and Heze) in Shandong province from 2019 to 2020. The results showed that the oil content ranged from 38.83% to 56.48%, and the protein content ranged from 21.80% to 31.65% among the studied sites. The oleic acid content and ratio of oleic acid to linoleic acid (O/L) ranged from 39.19% to 52.58% and from 0.92 to 1.77, respectively. Accessions TY107, TY109, and HS‐D‐1 were identified as the most promising oil varieties; HY20 and HY6314 were identified as optimal protein varieties; and HY9311, HY9310, and LH09‐2 were identified as promising varieties for oleic acid production. A significant and positive relationship between seed oil content and accumulated growing degree days (GDD) and insolation duration demonstrated that environments with high temperatures and a long insolation duration promoted oil synthesis. However, a positive relationship was observed only between GDD and protein content. Based on the meteorological conditions of Shandong province, the southwest (such as Heze) is an optimal region for cultivating peanuts with high oil content; the east (Yantai) is most suitable for high‐protein peanut production. The results indicate that the growing conditions should carefully be considered for sustainable and healthy development of the peanut industry as climate variables will likely influence seed composition, thus affecting the suitability for various end uses.

Spatial changes to climatic suitability and availability of agropastoral farming systems across Kenya (1980–2020)

Productive global agriculture is under a convergence of pressures, and particularly climate change and population growth. The impact is especially stark in East Africa where crop production is mostly rain-fed and population growth rates are among the highest in the world. Our objective for this study was to understand how climate change and population growth have impacted the size of agropastoral areas across Kenya over 40 years. Climate-suitable areas for all primary crops decreased 28% over the study period. Climate-suitable areas for primary crops increased 3% in highly productive counties, decreased 25% in moderately productive counties, and decreased 62% in low productive counties. Climate-suitable areas over the study period decreased 13% for ranching areas, 21% for dairying areas, 24% for mixed crop and ranching areas, and 28% for mixed crop and dairying areas, while climate-suitable areas for pastoralism increased 12%. Population across Kenya more than tripled over the study period, while population relative to climate-suitable areas for crops increased nearly fourfold, and population relative to climate-suitable areas for pastoralism nearly tripled. Population relative to available climate-suitable areas for crops more than doubled in highly productive counties, increased more than four-fold in moderately productive counties, and was nearly 15 times higher in low productive counties. Examining the cumulative effects of climate change and population growth on agricultural sectors across Kenya can help to develop policies and strategies to reach the UN Sustainable Development Goals.