Yield Loss Research Articles

Unveiling novel contrasting photosynthetic responses in Medicago truncatula under combined drought stress and Phoma medicaginis infection

Forage legumes face simultaneous abiotic and biotic stresses, causing substantial yield losses. This study explores the combined impacts of drought and Phoma medicaginis infection on the growth and photosynthetic activity of Medicago truncatula contrasting lines TN6.18 and F83005.5. The tolerant TN6.18 line exhibits superior tolerance to combined drought and P. medicaginis infection, manifesting in minimal leaf area reduction, the highest number of healthy leaves, increased carotenoids content, a consistently high and stable photosynthesis rate, and enhanced performance of photosystems PSI and PSII. On the contrary, the sensitive F83005.5 line shows pronounced leaf chlorosis, particularly under drought stress, and decreased pigment levels under the combination of drought and P. medicaginis infection stresses (combined stress). Moreover, the drought-stressed F83005.5, experiences reduced hydration and photosynthetic performance, linked to diminished gas exchange and chlorophyll fluorescence parameters. Chlorophyll fluorescence revealed more severe PSI impairment than PSII under combined stress. In conclusion, understanding the Pm8 infection-drought interaction enhances insights into M. truncatula resistance mechanisms to the combination of these stresses.

Temperature and time of season are the predominant drivers of cabbage stem flea beetle, Psylliodes chrysocephala, arrival at oilseed rape crops

Cabbage stem flea beetle (CSFB) is an economically important pest of oilseed rape crops responsible for substantial yield losses in recent years, particularly since the restrictions on neonicotinoid seed treatment use came into force in 2013. To effectively time sowing dates and target control measures, it is crucial that accurate estimates of when migratory adult CSFB will arrive at the crop can be made. A Bayesian hierarchical model was fitted to data from 19 sites containing adult CSFB traps over a period of three years to characterise the relationship between the day of year, temperature, rainfall, wind speed and solar radiation on beetle counts and to understand their relative importance. Day of the year was identified as the main driver of migration and temperature was the predominant environmental driver of CSFB migration. A hot day (based on the range of observed temperatures over the trapping window) resulted in approximately 300% of the expected CSFB migration relative to an average day during peak migration. The second most important environmental driver of migration was wind speed, but this resulted in a relatively negligible increase of approximately 15% from an average day to a still day. These findings suggest that efforts to predict timing of adult CSFB migration should focus on understanding how the phenology of CSFB and temperature interact to drive the timing of migration.

Cereal leaf beetle (Oulema spp.) damage reduces yield and is more severe when natural enemy action is prevented

Insect pests pose a global threat to crop yield. Biological control by natural enemies aims to reduce pest damage in a sustainable way. Cereal leaf beetles (CLB; Oulema spp.) are major pests in small-grain cereals. We studied the effect of natural enemies on CLB damage and its consequences on yield within its native distribution area in Europe. In exclusion cage experiments and by documenting a naturally occurring CLB damage gradient, we found that CLB damage reduced yield, but natural enemy action reduced the damage by CLB. Comparing exclusion and open treatments on artificially CLB-infested plants, plants accessible to natural enemies had 30% less leaf damage. CLB damage significantly affected yield parameters. Thousand grain weight was 22–29% less in maximum leaf damage scenarios. In the damage gradient field, maximal infestation reduced grain yield by 52%. However, maximal damage occurred only on a few plants and over small areas. In natural infestation cases, the number of CLB larvae per plant had a median of zero; nevertheless, there were more than 35 larvae on 10% of the plants. Patchiness explained 40% of CLB damage variance. Damage was unevenly distributed; as a result, thousand grain weight decreased only by 1.6% for 75% of the plants but by 18% for 10% of the plants. In the natural damage gradient, the estimated yield loss for the entire field was 16% due to CLB. Skewed CLB distribution may lead to perceptible yield losses locally, but natural enemies may limit overall damage to the crop.

Integrating machine learning and change detection for enhanced crop disease forecasting in rice farming: A multi-regional study

Crop diseases are increasingly causing devastating yield losses each year, posing a significant threat to global food security. Currently, fungicide treatment is one of the most effective measures to mitigate these disease-induced yield losses. Accurately predicting disease occurrence, onset timing, and development is critical for optimizing fungicide application schedules to achieve high efficacy. In this study, we compiled weekly disease observations, crop management, and weather data from 207 locations across China, India, and Japan. We compared six machine learning (ML) models for their performance in simulating disease severity. By mimicking disease development curves and trends at early stages, we developed a novel change detection (CD) model, named rolling linear regression (RLR), and combined it with the best-performing ML model to predict the occurrence, severity, and onset dates of four major rice diseases: leaf blast (Magnaporthe oryzae), panicle-neck blast (Magnaporthe oryzae), sheath blight (Rhizoctonia solani), and false smut (Ustilaginoidea virens). Our findings showed that the RandomForestRegressor demonstrated the highest performance in simulating disease severity, with mean absolute errors (MAE) below 0.5 % and root mean square errors (RMSE) below 2.5 %. The RLR model showed a distinct advantage over the other four widely used CD models based on five evaluation metrics. Additionally, the paired RandomForestRegressor+RLR model achieved the highest F1-score, ranging from 0.7 to 0.8, in predicting disease occurrence, outperforming 29 other ML+CD model pairs. Furthermore, the RandomForestRegressor+RLR model predicted onset dates with fewer than 6 error days and accuracies ranging from 74 % to 87 %. Combining ML with CD models not only shows robust generalization across diverse environmental conditions but also proves highly effective for large-scale disease risk forecasting in rice farming regions. The adaptability of ML techniques, when sufficient training data are available, particularly enhances decision support systems aimed at optimizing rice disease management practices for growers across various regions. Our hybrid model thus presents a compelling advancement in the precision agriculture domain, with significant implications for improving disease management strategies for crops beyond rice through timely intervention. This approach can contribute to safeguarding global food security by reducing crop losses due to disease damage.

Revolutionizing Tomato Cultivation: CRISPR/Cas9 Mediated Biotic Stress Resistance.

Tomato (Solanum lycopersicon L.) is one of the most widely consumed and produced vegetable crops worldwide. It offers numerous health benefits due to its rich content of many therapeutic elements such as vitamins, carotenoids, and phenolic compounds. Biotic stressors such as bacteria, viruses, fungi, nematodes, and insects cause severe yield losses as well as decreasing fruit quality. Conventional breeding strategies have succeeded in developing resistant genotypes, but these approaches require significant time and effort. The advent of state-of-the-art genome editing technologies, particularly CRISPR/Cas9, provides a rapid and straightforward method for developing high-quality biotic stress-resistant tomato lines. The advantage of genome editing over other approaches is the ability to make precise, minute adjustments without leaving foreign DNA inside the transformed plant. The tomato genome has been precisely modified via CRISPR/Cas9 to induce resistance genes or knock out susceptibility genes, resulting in lines resistant to common bacterial, fungal, and viral diseases. This review provides the recent advances and application of CRISPR/Cas9 in developing tomato lines with resistance to biotic stress.

The role of carcass processing (hot vs. cold boning) on pork belly morphological and mechanical characteristics

This study assessed the effect of boning processing method (hot vs. cold) on pork belly morphological and mechanical traits and the evolution of these traits during refrigerated storage postmortem (PM). A total of 14 crossbred pigs were slaughtered and their carcasses and bellies processed under two conditions: hot boning (n = 14, right sides of carcasses cut immediately after slaughter) and cold boning (n = 14, left sides of carcasses cut 24 h PM). Morphological and mechanical evaluations were made at 1-, 5-, 24- and 48-h PM on the hot-boned bellies, and at 24 and 48 h on the cold-boned ones. Compared to the cold-boned bellies, the hot-boned ones were shorter, wider and thicker (P < 0.01), with greater firmness (flop distance and angle) (P < 0.001) and cohesiveness (skin-fat separation) (P < 0.05 in the dorsal and central sections). At 48 h PM, hot-boned bellies had a thicker skin (P < 0.001) and softer subcutaneous fat in the dorsal-cranial and central sections (finger scores and compression textural test) (P < 0.05). Morphological and mechanical traits for hot-boned bellies confirmed an intense shortening and hardening (increased firmness and cohesiveness), and a slight yield loss from 1 to 24 h PM. From 24 to 48 h PM, there was a certain flattening in hot-boned bellies that was associated with a slight softening (reduced firmness). Although a larger sample may be needed to corroborate these findings, they demonstrate the impact of carcass processing method and refrigerated storage time on belly quality. This may be useful for the pork industry for obtaining the desired type of belly.

Impact of land use/land cover change on surface water hydrology in Akaki river catchment, Awash basin, Ethiopia

Watershed reactions to environmental changes is critical for water resource use and management planning. The change in land use/land cover (LUCC) alters surface water hydrology and water balance, subsequently it affects the availability of water resources. This study examined Akaki River catchment surface hydrological responses to future land use scenarios. The future LULC simulated using Cellular Automata-Markov Chain (CA-Markov) model in IDRISI software for 2031, 2041, and 2051 under Business as Usual (BAU) and Forest Patch Protection (FPP) scenarios. Water yield (WY), sediment export (SE), and soil loss (SL) were simulated using the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model. The findings indicate that under BAU, forest and settlement areas increased 42.64% and 31.47%, whereas water body, grass land, and agriculture dropped 31.99%, 25.72%, and 10.4%, respectively, from 2021 to 2051. The FPP scenario shows a 66.42% increase in forest coverage and a 31.97% decrease in cultivated land between 2021 and 2051. Overall settlement expansion will expand by 31.44%, while water body and grassland will decline by 11.12% and 24.9%. As a result of LULC changes in BAU scenario, the proportions of WY (4.36%), SE (26%), and SL (22.45%) increased. The hydrological components exhibited more gradual variations of 0.55%, 18.8%, and 14.24% for the WY, SE, and SL, respectively, under the FPP scenario. Therefore, the alteration has resulted in a concerning state within the area, necessitating the implementation of comprehensive management techniques to restore the hydrology of the catchment.

The Influence of Chitosan Derivatives in Combination with Bacillus subtilis Bacteria on the Development of Systemic Resistance in Potato Plants with Viral Infection and Drought.

Viral diseases of potatoes are among the main problems causing deterioration in the quality of tubers and loss of yield. The growth and development of potato plants largely depend on soil moisture. Prevention strategies require comprehensive protection against pathogens and abiotic stresses, including modeling the beneficial microbiome of agroecosystems combining microorganisms and immunostimulants. Chitosan and its derivatives have great potential for use in agricultural engineering due to their ability to induce plant immune responses. The effect of chitosan conjugate with caffeic acid (ChCA) in combination with Bacillus subtilis 47 on the transcriptional activity of PR protein genes and changes in the proteome of potato plants during potato virus Y (PVY) infection and drought was studied. The mechanisms of increasing the resistance of potato plants to PVY and lack of moisture are associated with the activation of transcription of genes encoding PR proteins: the main protective protein (PR-1), chitinase (PR-3), thaumatin-like protein (PR-5), protease inhibitor (PR-6), peroxidase (PR-9), and ribonuclease (PR-10), as well as qualitative and quantitative changes in the plant proteome. The revealed activation of the expression of marker genes of systemic acquired resistance and induced systemic resistance under the influence of combined treatment with B. subtilis and chitosan conjugate indicate that, in potato plants, the formation of resistance to viral infection in drought conditions proceeds synergistically. By two-dimensional electrophoresis of S. tuberosum leaf proteins followed by MALDI-TOF analysis, 10 proteins were identified, the content and composition of which differed depending on the experiment variant. In infected plants treated with ChCA, the synthesis of proteinaceous RNase P 1 and oxygen-evolving enhancer protein 2 was enhanced in conditions of normal humidity, and 20 kDa chaperonin and TMV resistance protein N-like was enhanced in conditions of lack of moisture. The virus coat proteins were detected, which intensively accumulated in the leaves of plants infected with potato Y-virus. ChCA treatment reduced the content of these proteins in the leaves, and in plants treated with ChCA in combination with Bacillus subtilis, viral proteins were not detected at all, both in conditions of normal humidity and lack of moisture, which suggests the promising use of chitosan derivatives in combination with B. subtilis bacteria in the regulation of plant resistance.

(Invited) Metal Corrosion Mitigation in Fine Geometries during Chemical Mechanical Planarization

In the Si semiconductor industry, aggressive device geometry scaling has given rise to new processing challenges to each new technology nodes over the past 6 decades. When the feature size shrinks to nanometer regime, new phenomenon emerges whereby significant loss in metal vias and lines can be observed after CMP.Findings from our previous studies suggest just a few nanometers of metal loss imposes serious yield loss in sub-5nm technology nodes MOL and BEOL metallization. Post CMP clean process can be responsible for ~ 50% of the metal loss after CMP. The phenomenon was observed with W, Co, and Cu alike. It affects conductors as well as liner/barrier metals, and exhibits strong dependence on pattern density, feature size, and even underlying layer. [1, 2]. Properly formulated slurries and post CMP clean chemicals can modulate the amount of metal loss and partially alleviate the issue.In this study, we continue to assess how post CMP clean chemicals and modified de-ionized water can influence the amount of metal loss for Cu interconnects. As a starter, blanket wafers resembling several different Cu/liner/low-k stacks were evaluated. The were subjected to polish with the same alkaline slurry followed by various alkaline post clean chemicals (Clean 1, pH ~ 10.2; Clean 2, pH 9.8). It was observed on the attached figure that brush clean only process with DIW alone can induce small amount of Cu loss. For wafers with polish and post clean, on a comparison basis, Clean1 resulted in slightly more Cu loss than Clean2. However, when dilute NH4OH solution (pH ~ 9.6) was introduced to replace DIW during brush clean with Clean1, the amount of Cu loss is reduced, on par with that of Clean2. The observation suggests NH4OH-treated DIW can help alleviate part of Cu loss during post CMP clean process. Patterned wafers with various combination of liner stacks will be subjected to clean process with various combinations of chemistries and/or NH4OH-treated DIW. The amount of Cu or liner loss will be characterized.

Physiological and Transcriptome Responses of Sweet Potato [Ipomoea batatas (L.) Lam] to Weak-Light Stress.

In the relay intercropping system of maize/sweet potato, the growth of the sweet potatoes is seriously limited by weak light stress in the early stage due to shade from maize plants. However, it is not clear how the weak light affects sweet potatoes and causes tuberous root loss. By setting two light intensity levels (weak light = 30% transmittance of normal light), this study evaluated the responses of two sweet potato cultivars with different tolerances to weak light in a field-based experiment and examined the divergence of gene expression related to light and photosynthesis in a pot-based experiment. The results showed that under weak light, the anatomic structure of functional leaves changed, and the leaf thickness decreased by 39.98% and 17.32% for Yuhongxinshu-4 and Wanshu-7, respectively. The ratio of S/R increased, and root length, root superficial area, and root volume all decreased. The photosynthetic enzyme rubisco was weakened, and the net photosynthetic rate (Pn) declined as well. The level of gene expression in Wanshu-7 was higher than that of Yuhongxinshu-4. The KEGG analysis showed that differentially expressed genes from the two cultivars under weak-light stress used the same enrichment pathway, mainly via glutathione metabolism and flavonoid biosynthesis. After full light levels were restored, the differentially expressed genes were all enriched in pathways such as photosynthesis, photosynthetic pigment synthesis, and carbon metabolism. These findings indicated that weak light changed the plant morphology, photosynthetic physiology and gene expression levels of sweet potatoes, which eventually caused losses in the tuberous root yield. The more light-sensitive cultivar (Wanshu-7) had stronger reactions to weak light. This study provides a theoretical basis and strategy for breeding low-light-tolerant varieties and improving relay intercropping production in sweet potatoes.

Assessment of future drought sensitivity shift associated with crop yield loss risk in the Anthropocene

ABSTRACT This study proposed a framework using artificial neural networks (ANNs), the designed residual regression method, and probabilistic indexing, for drought sensitivity shift analysis, associated with future yield loss risk in Anthropocene. The temporal assessment of the drought index (standardized precipitation evapotranspiration index, SPEI) illustrated prevalent occurrence of mild to moderate drought with a fluctuating trend. Furthermore, the optimal ANN model, with R2 = 0.86 for training and 0.7 for testing, was used to project yield for future analysis. The projected spatial changes in drought sensitivity patterns suggest most of the area will experience an increased sensitivity to drought in the far future (2036–2050). The estimated probability loss under the different risk levels defined by the yield reduction rate was 6.2–55.5%. Furthermore, the spatial distribution of the designed risk index (IR) revealed the districts with the highest probability of vulnerability and showed a probable increase in future vulnerability.

OsCKq1 Regulates Heading Date and Grain Weight in Rice in Response to Day Length.

Photoperiod sensitivity is among the most important agronomic traits of rice, as it determines local and seasonal adaptability and plays pivotal roles in determining yield and other key agronomic characteristics. By controlling the photoperiod, early-maturing rice can be cultivated to shorten the breeding cycle, thereby reducing the risk of yield losses due to unpredictable climate change. Furthermore, early-maturing and high-yielding rice needs to be developed to ensure food security for a rapidly growing population. Early-maturing and high-yielding rice should be developed to fulfill these requirements. OsCKq1 encodes the casein kinase1 protein in rice. OsCKq1 is a gene that is activated by photophosphorylation when Ghd7, which suppresses flowering under long-day conditions, is activated. This study investigates how OsCKq1 affects heading in rice. OsCKq1-GE rice was analyzed the function of OsCKq1 was investigated by comparing the expression levels of genes related to flowering regulation. The heading date of OsCKq1-GE lines was earlier (by about 3 to 5 days) than that of Ilmi (a rice cultivar, Oryza sativa spp. japonica), and the grain length, grain width, 1,000-grain weight, and yield increased compared to Ilmi. Furthermore, the culm and panicle lengths of OsCKq1-GE lines were either equal to or longer than those of Ilmi. Our research demonstrates that OsCKq1 plays a pivotal role in regulating rice yield and photoperiod sensitivity. Specifically, under long-day conditions, OsCKq1-GE rice exhibited reduced OsCKq1 mRNA levels alongside increased mRNA levels of Hd3a, Ehd1, and RFT1, genes known for promoting flowering, leading to earlier heading compared to Ilmi. Moreover, we observed an increase in seed size. These findings underscore OsCKq1 as a promising target for developing early-maturing and high-yielding rice cultivars, highlighting the potential of CRISPR/Cas9 technology in enhancing crop traits.

Reverse Transcription-polymerase Chain Reaction (RT-PCR) Based Detection and Identification of Monopartite Bean Common Mosaic Virus in Mungbean

Background: Bean common mosaic virus (BCMV) which belongs to the genus Potyvirus and the family Potyviridae, causes significant yield losses in legumes across the globe. Traditional methods for BCMV detection and diagnosis, such as visual inspection and serological assays, are often time-consuming, labour-intensive and may lack the sensitivity required for early detection. Advances in molecular techniques have made RT-PCR a powerful tool for the accurate detection of BCMV-infected plants. Methods: Three pairs of specific primers that flank the BCMV coat protein and polyprotein gene were designed using the Primer 3web tool to amplify fragments approximately ranging from 191 to 205 bp. The RT-PCR protocol was then standardized, including the optimization of annealing temperatures for all three primers, followed by the sequencing of the amplified PCR products. The, specificity and sensitivity of primer pair BCMV2 were then established. Result: Three pairs of specific primers were designed and RT-PCR protocol was standardized. The sequenced PCR products showed 98.03% to 99.50 % nucleotide similarity with the corresponding sequences of BCMV isolates used in primer designing. Further, the BCMV2 primer pair specifically amplified the target amplicon (200 bp) from the suspected leaf sample and no amplicon was observed when tested against other pathotypes of potyvirus such as BCMNV, BYMV, CABMV, SMV and PeMoV. The designed primer was sensitive enough to detect 0.05% of target cDNA. Additionally, the RT-PCR protocol was validated using field samples collected from Hyderabad, India. ELISA in combination with RT-PCR using the developed specific BCMV primer pair will ensure a foolproof, sensitive and rapid, procedure for diagnosis of BCMV in the quarantine processing of imported germplasm.

Grapevine Pinot gris virus spreads in infected vineyards: latent infections have no direct impact on grape production

BackgroundGrapevine Pinot gris virus (GPGV) infects grapevines worldwide and causes symptoms such as chlorotic mottling and deformations on leaves, stunted shoots and short panicles, or none of these symptoms if it appears as latent infection. So far, the consequences of GPGV infections for winegrowers are difficult to assess since important information such as plant performance at different GPGV infection levels and symptom expression are not fully clarified.MethodsIn order to investigate the course of GPGV spread, annual visual evaluations and ELISA tests were conducted over 3–4 consecutive years in four GPGV-infected vineyards in southern Germany: GEM, HEC, NIM, and REI. The program PATCHY was used to analyze spatial disease patterns. Sanger sequencing was used to determine virus isolates in vines at different GPGV infection levels, to test their respective influence on symptom expression. Yield and GrapeScan (FTIR) analyses were conducted to test the impact of different GPGV infection levels and isolates on fruit quantity and quality.ResultsGPGV infections significantly increased in all four vineyards (GEM 22–32%, HEC 50–99%, NIM 83–90%, REI 56–76%) with significant spreading patterns across and along rows. Specific symptom progression patterns were not observed. According to our results, the virus isolate has an influence on whether symptoms develop during a GPGV infection. While yield analyses revealed that yield losses only occur in symptomatic vines and range from 13 to 96% depending on the severity of symptoms, latent infections have no impact on grape production. No relevant effects of GPGV infections on must quality were observed.ConclusionsSecondary spread of GPGV was observed in all vineyards monitored, indicating vector-borne transmission that is likely to be accelerated by human viticultural management. GPGV should be further monitored to prevent the accumulation of detrimental symptomatic isolates. The results of this study can be used to assess the risk of GPGV to viticulture and should be considered when developing management strategies against the virus.

Assessment of Yield Losses due to Major Insect Pests in Sesame

Yield losses due to major insect pests viz., leaf webber and capsule borer Antigastra catalaunalis (Duponchel) and gall fly Asphondylia sesami (Felt) in promising sesame varieties was carried out at the Regional Agricultural Research Station, Jagtial, during summer, 2019 and 2020 under protected and unprotected conditions. The highest % avoidable yield losses was recorded in Hima variety (35.45) followed by Swetha, Sharada, GT 10, Madhavi, Gouri, VRI 1 and Rajeswari with 34.27, 33.17, 32.48, 31.05, 30.53, 30.01 and 29.75, respectively. Regarding cost benefit ratio, highest was recorded in Hima variety (1:2.23) followed by Swetha (1:2.05) and Sharada (1:1.75).

Molecular Investigations to Improve Fusarium Head Blight Resistance in Wheat: An Update Focusing on Multi-Omics Approaches.

Fusarium head blight (FHB) is mainly caused by Fusarium graminearum (Fg) and is a very widespread disease throughout the world, leading to severe damage to wheat with losses in both grain yield and quality. FHB also leads to mycotoxin contamination in the infected grains, being toxic to humans and animals. In spite of the continuous advancements to elucidate more and more aspects of FHB host resistance, to date, our knowledge about the molecular mechanisms underlying wheat defense response to this pathogen is not comprehensive, most likely due to the complex wheat-Fg interaction. Recently, due to climate changes, such as high temperature and heavy rainfall, FHB has become more frequent and severe worldwide, making it even more urgent to completely understand wheat defense mechanisms. In this review, after a brief description of the first wheat immune response to Fg, we discuss, for each FHB resistance type, from Type I to Type V resistances, the main molecular mechanisms involved, the major quantitative trait loci (QTLs) and candidate genes found. The focus is on multi-omics research helping discover crucial molecular pathways for each resistance type. Finally, according to the emerging examined studies and results, a wheat response model to Fg attack, showing the major interactions in the different FHB resistance types, is proposed. The aim is to establish a useful reference point for the researchers in the field interested to adopt an interdisciplinary omics approach.

Genetic diversity analysis of tropical and sub-tropical maize germplasm for Striga resistance and agronomic traits with SNP markers.

Striga hermonthica (Sh) and S. asiatica (Sa) are major parasitic weeds limiting cereal crop production and productivity in sub-Saharan Africa (SSA). Under severe infestation, Striga causes yield losses of up to 100%. Breeding for Striga-resistant maize varieties is the most effective and economical approach to controlling the parasite. Well-characterized and genetically differentiated maize germplasm is vital to developing inbred lines, hybrids, and synthetic varieties with Striga resistance and desirable product profiles. The objective of this study was to determine the genetic diversity of 130 tropical and sub-tropical maize inbred lines, hybrids, and open-pollinated varieties germplasm using phenotypic traits and single nucleotide polymorphism (SNP) markers to select Striga-resistant and complementary genotypes for breeding. The test genotypes were phenotyped with Sh and Sa infestations using a 13x10 alpha lattice design with two replications. Agro-morphological traits and Striga-resistance damage parameters were recorded under a controlled environment. Further, high-density Diversity Array Technology Sequencing-derived SNP markers were used to profile the test genotypes. Significant phenotypic differences (P<0.001) were detected among the assessed genotypes for the assessed traits. The SNP markers revealed mean gene diversity and polymorphic information content of 0.34 and 0.44, respectively, supporting the phenotypic variation of the test genotypes. Higher significant variation was recorded within populations (85%) than between populations using the analysis of molecular variance. The Structure analysis allocated the test genotypes into eight major clusters (K = 8) in concordance with the principal coordinate analysis (PCoA). The following genetically distant inbred lines were selected, displaying good agronomic performance and Sa and Sh resistance: CML540, TZISTR25, TZISTR1248, CLHP0303, TZISTR1174, TZSTRI113, TZDEEI50, TZSTRI115, CML539, TZISTR1015, CZL99017, CML451, CML566, CLHP0343 and CML440. Genetically diverse and complementary lines were selected among the tropical and sub-tropical maize populations that will facilitate the breeding of maize varieties with Striga resistance and market-preferred traits.

Garlic as a Botanical Pesticide against Army Worm &lt;i&gt;Spodoptera litura&lt;/i&gt; (F) on Lettuce

Army worm Spodoptera litura (F) is one of the potential pests that attack lettuce plants and can cause yield losses. Botanical pesticides from garlic are an alternative to control this. This study aims to determine the most effective concentration and the LC50 value of garlic-based botanical pesticides on the mortality of army worms. This study used a one-factor completely randomized design (CRD) method in the form of botanical pesticides treatment of neem leaf extract (M) with 5 concentration levels with 5 replications; P1 = control, P2 = 10% garlic extract (30 ml extract mixed with 270 ml water), P3 = 20% garlic extract (60 ml extract mixed with 240 ml water), P4 = 30% garlic extract (90 ml extract mixed with 210 ml of water). The treatment of botanical pesticides from garlic caused death of army worms, the most effective concentration was P2 with a mortality of 68% and a mortality rate of 2.5 larva/ hr. The LC50-48, LC50-60 and LC50-72 hr values were 28.09%, 24.09% and 19.10%, respectively.

Comparison of population photosynthesis characteristics and grain yield of wheat under various sowing dates and seeding rates

AbstractThis study investigated the effects of sowing dates and seeding rates on photosynthetic characteristics and grain yield in wheat (Triticum aestivum L.). A field experiment was conducted with three sowing dates—early sowing date (SD‐E), normal sowing date (SD‐N), and delay sowing date (SD‐D)—and three seeding rates—90 low seeding rate (SR‐L), 108 moderate seeding rate (SR‐M), and high seeding rate 126 kg ha−1 (SR‐H). The results revealed that the grain yield at SR‐L in the SD‐E regime, SR‐M in the SD‐N regime, and SR‐H in the SD‐D regime was increased by 7.48%–9.93%, 14.1%–16.7%, and 19.0%–41.6%, respectively, compared to other combinations under the same sowing date. Consistent with the yield performance, the aboveground biomass accumulation, nonstructural carbohydrates (NSC) accumulation in stems, and NSC remobilization amount from anthesis to maturity were the highest at SR‐L in the SD‐E, at SR‐M in the SD‐N, or at SR‐H in the SD‐D regime, among other treatment combinations. Improved canopy photosynthetic characteristics (i.e., leaf area index, leaf photosynthetic rate, canopy photosynthetically active radiation interception rate, and radiation use efficiency) were also observed at the SR‐M in the SD‐N or at SR‐H in the SD‐D regime. Collectively, a suitable sowing date combined with an optimum seeding rate could enhance grain yield, and increasing the seeding rate could mitigate the yield loss when sowing was delayed by optimizing traits photosynthesis in wheat.

Genetic variability for salinity tolerance of tomato (Solanum lycopersicon MILL.) genotypes determined by stress tolerance indices

BackgroundTomato is an important vegetable crop; however, salinity hampers its growth and yield-related traits. Different tomato genotypes significantly differ in their salinity tolerance; thus, selecting the tolerant genotypes could improve yield and productivity under saline environments. MethodsThis study investigated salinity tolerance of five tomato genotypes, i.e., ‘Pakit’, ‘Riogrande’, ‘Roma’, ‘Continental’, and ‘Nagina’ under 0-, 100-, 150- and 200-mM salinity levels. Data relating yield-related traits (plant height, shoot fresh and dry weights, number of fruits per plant, single fruit weight and fruit yield per plant) and nine different stress tolerance indices were employed to infer salinity-tolerance of the genotypes. ResultsIncreasing salinity levels negatively affected the yield-related traits of genotypes; however, genotypes exhibited varied tolerance to salinity. The better and the poor yield-related traits were noted under 0- and 200-mM salinity levels, respectively. Similarly, genotypes ‘Pakit’ and ‘Nagina’ recorded the highest and the lowest values of yield-related traits. The genotype ‘Pakit’ proved the most tolerant to tested salinity levels compared to the rest of the genotypes. The ‘Pakit’ genotypes had the highest stress tolerance index (0.19, 1.06 and 1.79) and the lowest relative change in yield (6.00, 32.59, and 55.75%) under all salinity levels. Principal component analysis biplot revealed that ‘Pakit’ genotypes had superior yield traits and tolerance indices. ConclusionThe genotype ‘Pakit’ exhibited a higher level of salinity tolerance (6 % yield reduction under 100 mM salinity compared to 27.67 % reduction in ‘Nagina’ genotype. Therefore, genotype ‘Pakit’ can be recommended for cultivation on low to moderate saline soils without significant yield losses. On the other hand, ‘Nagina’ genotype proved the most sensitive to salinity (27.67 %, 56.79 %, and 68.90 % yield reduction under 100-, 150-, and 200-mM salinity, respectively). Therefore, this genotype should not be cultivated on saline soils.