Yield-limiting Factors Research Articles

Agroecological drivers of winter rye (Secale cereale) yield spatio-temporal variation

The study of yield-limiting factors of rye, a typical European cereal, is a crucial concern today as it significantly impacts global food safety. The objecive of the study was to determine the contribution of agroecological factors, namely bioclimatic variables, soil parameters, and landscape diversity, to the variation of rye yields in the central and northern regions of Ukraine, which is one of the world’s five largest producers of this crop. A symmetric log-logistic model was used to describe the dynamics of rye yields, and the parameters of this model can be used to analyze the spatial dynamics of yields, in particular, such characteristic points of the yield model as: the lower limit of the response (the lowest yield level); the upper limit (the highest yield level); the slope of the response curve in the vicinity of the inflection point, which shows the rate of yield change over time, ED50 – the time required to reach half of the maximum yield growth. In the preliminary principal component analysis, we identified 4 climate principal components and 6 soil principal components. Landscape diversity was assessed based on the Shannon index and distance to the protected areas. The results of the regression analysis revealed a statistically significant relationship between the parameters of rye yield and the identified environmental drivers. Among the rye yield parameters, the highest sensitivity to environmental factors was the upper yield limit (70%), and the lowest was the rate of yield increase (25%). Only the highest rate of yield growth demonstrated liner dependence on the Shannon index. Among the soil factors, the most influential for rye yields was the particle size distribution and especially the sand content. The rye yield parameters were primarily influenced by the variability of the temperature regime throughout extreme periods of the year and contrast in the temperature conditions. The yield parameters of rye were contingent upon the diversity of the landscape cover. The correlation between almost all yield characteristics and landscape-ecological diversity was not linear, leading to the identification of an optimal level of diversity in natural protected areas which results in the best rye yields.

A machine learning approach is effective to elucidate yield-limiting factors of irrigated lowland rice under heterogeneous growing conditions and management practices

ContextIn the context of the heterogeneous field conditions for lowland rice production in sub-Saharan Africa, yield is adversely affected by a diverse array of complexly related factors, including environmental conditions, soil fertility, and fertilizer management, making it difficult to unravel the factors with greatest impact. In the central highlands of Madagascar, yield is constrained by low temperatures, insufficient rainfall, phosphorus deficiency, inadequate fertilizer input, and suboptimal agricultural practices. Identifying the driving factors by interpreting reliable predictive algorithms for the yield will greatly improve the optimization of rice productivity. ObjectiveIn this study, we aimed to apply machine learning to comprehensively elucidate the complex yield-limiting factors for lowland rice production across the central highlands of Madagascar. MethodsA machine learning algorithm was applied to comprehensively evaluate the factors affecting yield using a total of 578 data points, i.e., P-applied and non-P-applied plots in 289 farmers’ fields, consisting of their yield, weather, soil, and crop management across the central highlands of Madagascar. ResultsThere were large variations in yield ranging from 0.07 to 10.26 t ha−1. Machine learning explained the large yield variation well, especially in the Random Forest model, which showed the highest yield prediction accuracy. As relevant factors, high rice yields were associated with high growing degree days and high cumulative rainfall around 2 weeks before and after the heading date. Then, earlier transplanting in high elevation sites gave the optimum growing degree days, and the use of greater shoot-to-root ratio of seedlings during transplanting has the potential to enhance rice yields in the lowland rice system. ConclusionsMachine learning was significantly effective in identifying the individual effects of various factors controlling rice-yields under the heterogenous growing conditions of lowland-rice grown by smallholder farmers in the central highlands of Madagascar. ImplicationsFurther accumulation of crop management datasets will be needed in order to untangle the multifactorial components that reduce crop yields, even for small-scale farms.

Priming corn resistance to Goss’s wilt using a weakly aggressive strain of Clavibacter nebraskensis

Goss’s wilt, caused by the gram-positive bacterium Clavibacter nebraskensis, has become one of the most widely spread corn diseases in the USA and Canada. Considered as a relatively new disease, with limited knowledge about the more recently renamed pathogen causing it is, it is today a serious yield-limiting factor in corn crops in North America. The diversity of C. nebraskensis strains translates into the differential plant responses it causes, ranging from hypersensitive-like response to partial resistance, or otherwise susceptibility expressed as dark, water-soaked spots and shiny patches of dried bacterial ooze on the lesions. Weakly aggressive strains of C. nebraskensis typically appear as the season winds down and the crop is about to be harvested, whereas highly aggressive strains can be found at any point during the growing season. Previous research showed that plant’s ethylene and reactive oxygen species (ROS) are essential in limiting the spread of Goss's wilt symptoms near infection sites by triggering programmed cell death (PCD). Preliminary observations that certain strains induce strong defense responses with very little to no symptoms fed the idea to use them for disease resistance priming. The induction of biosynthetic or responsive genes of ethylene, ROS, and salicylic acid (SA) both at the local and distal tissues is in line with the limited disease symptoms development in response to priming with the weakly aggressive strain before further inoculation with a highly aggressive one. The results further expand our understanding of differential host responses to strains with different levels of aggressiveness. The priming process led to an inhibition of the elongated lesions in the susceptible corn plants in comparison with the unprimed plants. The expression patters of a lectin receptor-like kinase, Salt Intolerance 2 (ZmSIT2), and blue copper binding protein (ZmBCP) suggests them as key mediators of ethylene and ROS homeostasis in corn tissues upon infection. This adds to the pool of knowledge on corn defenses against bacterial pathogens and the mechanism of its biopriming, which could serve as an environment-friendly alternative method to control Goss’s wilt.

Effect of marennine on the rearing medium and microbiota of Mytilus edulis larvae and its protective effect after exposure to the pathogenic Vibrio splendidus

ABSTRACT Opportunistic pathogens have been associated with yield-limiting factors in bivalve hatcheries. Numerous natural compounds are being investigated for their beneficial effects and potential to enhance larval resistance without requiring antibiotics. One of those is the use of marennine, a blue pigment, originating from the diatom Haslea ostrearia, which has demonstrated a positive effect on larvae survival. The aim of this study was to highlight the protective effect of marennine on Mytilus edulis larvae during bacterial challenges in relation to a potential modification of the marennine-treated larvae microbiota. D-larvae and post-larvae were exposed for 96 h to Vibrio splendidus (106 cell mL−1) with and without mareninne (500 µg L−1). The presence of marennine increased the survival rate of D-larvae exposed to the pathogen. The molecular analysis of the larvae microbiota diversity indicated a modification in the D-larval microbiota’s richness related to survival rates of larvae. Ultimately, our study sheds light on the importance of the larval microbiota in pathogen resistance during the bivalve rearing process.

Soil Sulfur Deficiency Restricts Canola (Brassica napus) Productivity in Northwestern Russia Regardless of NPK Fertilization Level

Canola cultivation at high latitudes is becoming more promising in terms of modern climate change. Sustainable crop production requires an understanding of yield-limiting factors, which need to be adjusted in agricultural management first. Therefore, our study was aimed at examining the effect of climate and soil fertility factors on the canola yield from 2012 to 2015 in northwestern Russia. Simultaneously, effectiveness of chemical fertilizer (N65P50K50 and N100P75K75) rates was tested. Studied soils had light texture, high acidity and severe sulfur deficiency. Canola yield (Y) varied from 0.81 to 1.60 t·ha−1 for the observed period. Applied fertilizer increased Y by around 30%, but this change was not significant. Climate effect testing with the FAO-AquaCrop simulation showed no noticeable water and heat stresses for the study period (0% to 20% reduction in potential Y). Among the tested soil properties, the content of organic carbon, available nitrogen and sulfur significantly correlated with Y (r = 0.58–0.66). Combining these factors together with soil pH in a path model explained 60% of variability in Y. Importantly, sulfur had the highest and most significant effect in this model. Thus, this soil parameter is the main yield-limiting factor in the study area, which must be the first to be adjusted in agricultural practice.

Effect of Different Herbicides in Weed Management in Transplanted Rice

Weed is one of the major yield-limiting factors in rice cultivation. It causes yield losses of around 40-90%, depending on the situation. Manual weeding is the dominant weed management method in rice and limited farmers use herbicides in Nepal. Selecting effective herbicides for different weed species is a crucial task for farmers. So, an experiment with 9 treatments consisting of 5 herbicides was conducted in RCB Design with 3 replications during 2020 and 2021 to find effective herbicides. The recommended agronomic practices were followed. Rice variety Khumal 11 was transplanted in a 4m x 3m plot with a spacing of 20 cm between rows and 15 cm between plants. Pooled data of two years showed the lowest weed density (14.2 m-2) and highest (73.2 m-2) in the treatment pretilachlor @ 0.5 kg ha-1 (pre) as sand mix and in the weedy check. Similarly, the lowest weed dry biomass (7.4 g m-2) and the highest (42.4 g-2) were recorded in the same treatments. The grain yield was the highest (7253 kg ha-1) in pretilachlor applied at 0.5 kg a.i ha-1 as pre-emergence spray and the lowest (4339 kg ha-1) in the control. The treatment pretilachlor @ 0.5 kg a.i ha-1 (pre) applied as spray was superior in managing weed and resulting in the highest grain yield, so it is recommended for mid-hill ecologies under transplanted rice.

Lewis acid/acetic acid-catalysed electrophilic amidation of simple arenes with O-acetyl acetohydroxamic acid

Electrophilic arene CH amination constitutes an intrinsically more atom- and step-economical pathway towards arylamines than CX → CN methods. However, most literature examples are restricted to arenes with extensive directing groups (DG) and/or nitrogen coupling partners with large leaving groups (LG). Moreover, only few cases of EAs using cheap metals (e.g., Fe) have been reported. Herein, we demonstrate the catalytic activity of various Lewis acids in the electrophilic amidation of simple arenes with O-acetyl acetohydroxamic acid in acetic acid. With 5 mol% FeIII(citrate)·H2O, up to 27 % yield was achieved, whereas 5 mol% BiCl3 gave up to 31 % yield. Instability of the amidation agent and product inhibition were identified as the yield-limiting factors. The observed regioselectivity, as well as kinetic and spectroscopic data suggest an electrophilic aromatic substitution mechanism, in which acetic acid and the Lewis acid generate a highly electrophilic species from AcNHOAc.

Improving fertilizer response of crop yield through liming and targeting to landscape positions in tropical agricultural soils

Nutrient management research was conducted across locations to investigate the influence of landscape position (hill, mid-, and foot slope) in teff (Eragrostis tef) and wheat (Triticum aestivum) yield response to fertilizer application and liming in the 2018 and 2019 cropping seasons. The treatments included 1) NPS fertilizer as a control treatment (42 N + 10P + 4.2S kg ha−1 for teff and 65 N + 20P + 8.5S kg ha−1 for wheat); 2) NPS and potassium (73 N + 17P + 7.2S + 24 K kg ha−1 for teff and 103 N + 30P + 12.7S + 24 K kg ha−1 for wheat) and 3) NPSK and zinc (73 N + 17P + 7.2S + 24K + 5.3Zn kg ha−1 for teff and 103 N + 30P + 12.7S + 24K + 5,3Zn kg ha−1 for wheat) in acid soils with and without liming. Results showed that the highest teff and wheat grain yields of 1512 and 4252 kg ha−1 were obtained at the foot slope position, with the respective yield increments of 71% and 57% over the hillslope position. Yield response to fertilizer application significantly decreased with increasing slope owing to the decrease in soil organic carbon and soil water content and the increase in soil acidity. The application of lime with NPSK and NPSKZn fertilizer increased teff and wheat yields by 43–54% and 32–35%, respectively compared to the application of NPS fertilizer without liming where yield increments were associated with the application of N and P nutrients. Orthogonal contrasts revealed that landscape position, fertilizer application, and their interaction effects were significant on teff and wheat yields. Soil properties including soil pH, organic carbon, total N, and soil water content were increased down the slope, which might be attributed to sedimentation down the slope. However, available P is yet very low both in acidic and non-acidic soils. We conclude that crop response to applied nutrients could be enhanced by targeting nutrient management practices to agricultural landscape features and addressing other yield-limiting factors such as soil acidity and nutrient availability by conducting further research.

Organic and inorganic fertilizers combined with a water-saving technique increased soil fertilities and apple production in a rainfed hilly orchard

A high and stable apple yield is critical for rainfed hilly apple orchards; however, many factors threaten apple yield and sustainable apple production, including water shortage, soil erosion, and chemical fertilizer overuse. Therefore, we undertook a field trial with three treatments— (1) organic and inorganic fertilizer combining a water-saving technique (OIWS), (2) inorganic fertilizer combining a water-saving technique (IWS), and (3) inorganic fertilizer alone (CK)—to determine how to alleviate these yield-limiting factors and improve soil fertility. Averaged across five years (2016–2020), the OIWS treatment increased apple yield the most, by 24.87% and 67.34% relative to IWS and CK, respectively. The OIWS treatment also had the highest apple yield stability, despite no significant differences between treatments, indicating OIWS treatment could produce higher apple yield year by year relative to IWS and CK. In comparison to IWS and CK, OIWS treatment showed greater 0–1 m by 12.21% and 26.08% and 0–3 m soil water storage (SWS) by 14.81% and 19.12%, as well as the highest abundance of 0–1 m soil microaggregates (0.053–0.2 mm) and macroaggregates (0.2–2 mm). Moreover, relative to IWS and CK averaged across the five years and 0–2 m soil layers, OIWS treatment substantially enhanced soil organic carbon (SOC) by 4.23 and 3.93 g kg−1 and total nitrogen (TN) by 0.09 and 0.11 g kg−1, respectively. Furthermore, Changes in apple production were positively linked with variations in 0–1 m SWS, soil microaggregate and macroaggregate abundance, and SOC and TN. And the most relevant factor to apple yield is 0–1 m SWS. Overall, on the Loess Plateau, OIWS system is a sustainable approach for increasing apple productivity and soil fertilities in rainfed hilly orchards.

The Assessment of an Effect of Natural Origin Products on the Initial Growth and Development of Maize under Drought Stress and the Occurrence of Selected Pathogens

Poland, like other countries in the world, increasingly experiences the ongoing climate change that is a critical yield-limiting factor. The use of biostimulants in agriculture has shown tremendous potential in combating climate change-induced stresses such as drought, temperature stress, etc. They could be a promising tool in the current crop production scenario. Biostimulants are organic compounds, microbes, or amalgamation of both that could regulate plant growth behavior through molecular alteration and physiological, biochemical, and anatomical modulations. They can promote plant growth under various environmental stresses because they have a positive effect, in particular, on plant growth and resistance. There are many products of this type available on the market, including those of natural origin, which are part of the Integrated Pest Management. The ecotoxicity of chemical plant protection products, the negative effects of their use, and the change in regulations make it recommended to use low-risk chemicals and non-chemical methods, that involve the least risk to health and the environment, and at the same time ensure effective and efficient protection of crops. Natural origin biocomponents obtained by the supercritical CO2 extraction of plant material or by fermentation process in bioreactors were tested. Common maize (Zea mays L.) was selected as a test plant for growth tests at climate chambers. Results showed that the only supernatant (fermentation broth) obtained with the Paenibacillus bacteria (S2) had a positive effect on the germination index (GI > 100%) of maize seeds, compared to the obtained plant seed extracts from the crop of the legume family (Fabaceae) (E3) and from the crop of the smartweed family (Polygonaceae) (E9) (GI < 100%). The extracts E3, S1 (supernatant obtained with the use of bacteria from the genus Enterobacter) and S2 used as a single product and in combination with UAN+S, under optimal conditions of the experiment, had a positive effect on the maize root weight compared to the untreated, while under drought stress, a decrease in the root weight was observed. Moreover, on the basis of the conducted research, differences in the mycelial growth of selected fungi were found. The applied biocomponent S2 of microbial origin extract (supernatant 2) showed a mycelial growth-limiting effect on all tested Fusarium fungi isolated from the corn cobs.

Cowpea Constraints and Breeding in Europe.

Cowpea (Vigna unguiculata (L.) Walp.) is a legume with a constant rate of cultivation in Southern European countries. Consumer demand for cowpea worldwide is rising due to its nutritional content, while Europe is constantly attempting to reduce the deficit in the production of pulses and invest in new, healthy food market products. Although the climatic conditions that prevail in Europe are not so harsh in terms of heat and drought as in the tropical climates where cowpea is mainly cultivated, cowpea confronts with a plethora of abiotic and biotic stresses and yield-limiting factors in Southern European countries. In this paper, we summarize the main constraints for cowpea cultivation in Europe and the breeding methods that have been or can be used. A special mention is made of the availability plant genetic resources (PGRs) and their potential for breeding purposes, aiming to promote more sustainable cropping systems as climatic shifts become more frequent and fiercer, and environmental degradation expands worldwide.

Yellowhorn Xso-miR5149-XsGTL1 enhances water-use efficiency and drought tolerance by regulating leaf morphology and stomatal density

Yellowhorn (Xanthoceras sorbifolium) is a unique edible woody oil tree species in China. Drought stress is the major yield-limiting factor of yellowhorn. MicroRNAs play an important role in regulating the response of woody plants to drought stress. However, the regulatory function of miRNAs in yellowhorn remains unclear. Here, we first constructed coregulatory networks integrated with miRNAs and their target genes. According to GO function and expression pattern analysis, we selected the Xso-miR5149-XsGTL1 module for further study. Xso-miR5149 is a key regulator of leaf morphology and stomatal density by directly mediating the expression of the transcription factor XsGTL1. Downregulation of XsGTL1 in yellowhorn led to increased leaf area and reduced stomatal density. RNA-seq analysis indicated that downregulation of XsGTL1 increased the expression of genes involved in the negative control of stomatal density, leaf morphology, and drought tolerance. After drought stress treatments, the XsGTL1-RNAi yellowhorn plants were less damaged and had higher water-use efficiency than the WT plants, while destruction of Xso-miR5149 or overexpression of XsGTL1 had the opposite effect. Our findings indicated that the Xso-miR5149-XsGTL1 regulatory module plays a critical role in controlling leaf morphology and stomatal density; hence, it's a potential candidate module for engineering enhanced drought tolerance in yellowhorn.

Leaf Nutrient Status of Commercially Grown Strawberries in Latvia, 2014–2022: A Possible Yield-Limiting Factor

The present study was carried out to evaluate the leaf nutrient status of commercially grown strawberries in Latvia during 2014-2022. The results of N, P, K, Ca, Mg, S, Fe, Mn, Zn, Cu, Mo and B in 200 strawberry leaf samples from different strawberry-producing farms were analysed over three periods: 2014-2016, 2017-2019, and 2020-2022. According to leaf analyses, plant fertilization was only partly well managed by the growers. During the research period, strawberries in Latvia were generally sufficiently supplied with N, P, K, Mg, Fe, Mn, Mo, and B, while the level of Ca, S, Zn, and Cu was considered low. The deficiency of these nutrients was characteristic for more than 50% of the samples. Since Ca, S, Zn, and Cu are essential for berry formation and quality and contribute to stress resistance; their deficiency could be one of the limiting factors for strawberry yield. The significant positive correlations found between nutrients, including deficient ones, confirmed their close relationship in the uptake process and the importance of sufficient supply. The results clearly indicated that fertilization could currently be an issue that limits the strawberry harvest in Latvia, and adequate provisions of Ca, S, Zn, and B should be the main focus.

Photosynthetic activity and metabolic profiling of bread wheat cultivars contrasting in drought tolerance.

The rapid increase in population growth under changing climatic conditions causes drought stress, threatening world food security. The identification of physiological and biochemical traits acting as yield-limiting factors in diverse germplasm is pre-requisite for genetic improvement under water-deficit conditions. The major aim of the present study was the identification of drought-tolerant wheat cultivars with a novel source of drought tolerance from local wheat germplasm. The study was conducted to screen 40 local wheat cultivars against drought stress at different growth stages. Barani-83, Blue Silver, Pak-81, and Pasban-90 containing shoot and root fresh weight >60% of control and shoot and root dry weight >80% and 70% of control, respectively, P (% of control >80 in shoot and >88 in root), K+ (>85% of control), and quantum yield of PSII > 90% of control under polyethylene glycol (PEG)-induced drought stress at seedling stage can be considered as tolerant, while more reduction in these parameters make FSD-08, Lasani-08, Punjab-96, and Sahar-06 as drought-sensitive cultivars. FSD-08 and Lasani-08 could not maintain growth and yield due to protoplasmic dehydration, decreased turgidity, cell enlargement, and cell division due to drought treatment at adult growth stage. Stability of leaf chlorophyll content (<20% decrease) reflects photosynthetic efficiency of tolerant cultivars, while ~30 µmol/g fwt concentration of proline, 100%-200% increase in free amino acids, and ~50% increase in accumulation of soluble sugars were associated with maintaining leaf water status by osmotic adjustment. Raw OJIP chlorophyll fluorescence curves revealed a decrease in fluorescence at O, J, I, and P steps in sensitive genotypes FSD-08 and Lasani-08, showing greater damage to photosynthetic machinery and greater decrease in JIP test parameters, performance index (PIABS), maximum quantum yield (Fv/Fm) associated with increase in Vj, absorption (ABS/RC), and dissipation per reaction center (DIo/RC) while a decrease in electron transport per reaction center (ETo/RC). During the present study, differential modifications in morpho-physiological, biochemical, and photosynthetic attributes that alleviate the damaging effects of drought stress in locally grown wheat cultivars were analyzed. Selected tolerant cultivars could be explored in various breeding programs to produce new wheat genotypes with adaptive traits to withstand water stress.

Screening Spring Wheat Genotypes for TaDreb-B1 and Fehw3 Genes under Severe Drought Stress at the Germination Stage Using KASP Technology.

Drought stress is a major yield-limiting factor throughout the world in wheat (Triticum aestivum L.), causing losses of up to 80% of the total yield. The identification of factors affecting drought stress tolerance in the seedling stage is especially important to increase adaptation and accelerate the grain yield potential. In the current study, 41 spring wheat genotypes were tested for their tolerance to drought at the germination stage under two different polyethylene glycol concentrations (PEG) of 25% and 30%. For this purpose, twenty seedlings from each genotype were evaluated in triplicate with a randomized complete block design (RCBD) in a controlled growth chamber. The following nine parameters were recorded: germination pace (GP), germination percentage (G%), number of roots (NR), shoot length (SL), root length (RL), shoot-root length ratio (SRR), fresh biomass weight (FBW), dry biomass weight (DBW), and water content (WC). An analysis of variance (ANOVA) revealed highly significant differences (p < 0.01) among the genotypes, treatments (PEG25%, PEG30%) and genotypes × treatment interaction, for all traits. The broad-sense heritability (H2) estimates were very high in both concentrations. They ranged from 89.4 to 98.9% under PEG25% and from 70.8 to 98.7% under PEG30%. Citr15314 (Afghanistan) was among the best performing genotypes under both concentrations for most of the germination traits. Two KASP markers for TaDreb-B1 and Fehw3 genes were used to screen all genotypes and to study the effect of these on drought tolerance at the germination stage. All genotypes with Fehw3 (only) showed a better performance for most traits under both concentrations compared to other genotypes having TaDreb-B1 or having both genes. To our knowledge, this work is the first report showing the effect of the two genes on germination traits under severe drought stress conditions.

Lime and Vermicompost Application to Acid Soils and Their Effects on Maize Yield and Yield Components in Lalo Asabi District, West Wollega Zone, Oromia, Ethiopia

Soil acidity is one of the major yield-limiting factors for crop production worldwide, particularly on highly weathered and leached tropical soils. Different reports have indicated that there is significant soil acidity coverage in Ethiopia. In particularly, in the western part of the country, soil acidity is a well-known problem limiting crop production and productivity. As part of the solution to such a problem in soils, the combined application of lime and VC on maize has not been investigated in the area, in which maize was one of the potential cereal crops in the area. A field experiment was conducted at Lalo Asabi district in western Wollega during the 2020 cropping season to evaluate the responses of maize to the combined application of lime and vermicompost (VC). The experimental treatments were five rates of lime (CaCO3) (0, 25, 50, 75, and 100% of lime requirement (LR)) and three levels of vermicompost (0, 2.5, and 5 t ha-1). The treatments were arranged in factorial combinations in a randomized complete block design with three replications. One composite surface soil samples from a depth of (0-15 cm) was collected from the experimental field before the commencement of the experiment. Maize yield and yield components were measured following standard procedures. The yield components and yield results revealed the main effects of lime and VC showed a significant effect (p&lt;0.05) on the number of days to 50% tasseling and silking, ear height, number of cobs per plant, number of grains per cob, thousand grain weight, above ground biomass, and harvest index of maize. However, days to 90% physiological maturity, plant height, cob length and grain yield of maize were significantly affected (p&lt;0.05) by lime and VC interactions. Even though both were statistically equal, the combined application of lime at 100% LR + 5 t VC ha-1 yielded the highest grain yield (7.99 t ha-1) followed by the combined application of lime at 75% LR + 2.5 t VC ha-1 whereas the lowest grain yield (2.97 t ha-1) from control plots. The results of economic analysis indicated that the combination of lime at 75% LR + 2.5 t VC ha-1 showed a marginal rate of return of 2322.74%, with the highest net benefit of 49980 Ethiopian Birr compared to other treatments. This study indicates combined use of lime and VC could ameliorate the adverse effect of soil acidity, and application of 75% LR + 2.5 t VC ha1 enhances grain yield and produces the highest net benefit of maize grown on acidic soil of the Lalo Asabi district.

Molecular Breeding for Incorporation of Submergence Tolerance and Durable Bacterial Blight Resistance into the Popular Rice Variety 'Ranidhan'.

Ranidhan is a popular late-maturing rice variety of Odisha state, India. The farmers of the state suffer heavy loss in years with flash floods as the variety is sensitive to submergence. Bacterial blight (BB) disease is a major yield-limiting factor, and the variety is susceptible to the disease. BB resistance genes Xa21, xa13, and xa5, along with the Sub1 QTL, for submergence stress tolerance were transferred into the variety using marker-assisted backcross breeding approach. Foreground selection using direct and closely linked markers detected the progenies carrying all four target genes in the BC1F1, BC2F1, and BC3F1 generations, and the positive progenies carrying these genes with maximum similarity to the recipient parent, Ranidhan, were backcrossed into each segregating generation. Foreground selection in the BC1F1 generation progenies detected all target genes in 11 progenies. The progeny carrying all target genes and similar to the recipient parent in terms of phenotype was backcrossed, and a total of 321 BC2F1 seeds were produced. Ten progenies carried all target genes/QTL in the BC2F1 generation. Screening of the BC3F1 progenies using markers detected 12 plants carrying the target genes. A total of 1270 BC3F2 seeds were obtained from the best BC3F1 progeny. Foreground selection in the BC3F2 progenies detected four plants carrying the target genes in the homozygous condition. The bioassay of the pyramided lines conferred very high levels of resistance to the predominant isolates of bacterial blight pathogen. These BB pyramided lines were submergence-tolerant and similar to Ranidhan in 13 agro-morphologic and grain quality traits; hence, they are likely to be adopted by farmers.

Analysis of Transgenic Cotton Plants Containing Universal Stress Protein (GaUSP-1, GaUSP-2) and Zinc Finger Transcriptional Factor (GaZnF) Genes under Drought Stress.

Water is the most limiting factor for plant growth and crop productivity. Drought stress adversely affects crop yield throughout the world. Up to 50% of crop yield in Pakistan is severely affected by the shortage of water. Cotton is an important cash crop for Pakistan known as "white gold." It accounts for 8.2% of the value added in agriculture and about 3.2% of GDP. Besides, being the world's fourth-largest cotton producer, our yield per acre ranks 13th in the world. If we look at the Pakistan scenario, water deficiency is one of the major yield-limiting factors. Limitations related to conventional breeding and the advancements in plant genomics and biotechnology applications have opened new horizons to plant improvements. Therefore, in the current study, we carry out a comparative analysis to evaluate the morphological, physiological biochemical and molecular parameters in transgenic plants containing GaUSP-1, GaUSP-2 and GaZinc Finger genes under different drought stress conditions. Data showed that transgenic plants showed more tolerance as compared to non-transgenic plants. Transgenic and non-transgenic assist us in our better understanding of the drought-responsive mechanism and its effect on different plant growth traits, so, in this way, we would be able to explore drought tolerance mechanism and this will open the doors for the identification of drought-related genes.

Split Application of Lime on Acid Soil Amelioration and Bread Wheat Yield at Dember, SNNPR Ethiopia

Soil acidity is major yield-limiting factors for crop production in the highlands areas with heavy rainfall. Soil acidity affects the growth of crops due to high concentration of toxic acidic cations to plant. Field experiments was conducted under permanent plots to study the influence of splits application of recommended lime rate on yield and yield attributes of wheat in acidic soils during three main cropping seasons.

The effect of crop rotation and tillage practice on Fusarium crown rot and agronomic parameters of wheat in South Africa

Fusarium crown rot (FCR) of wheat (Triticum aestivum) is a stubble-borne disease of global concern and a known yield-limiting factor in the Western Cape Province of South Africa. Disease management options is limited, with a focus on crop rotation and tillage, the effect of which has not yet been quantified locally. Crop rotation and tillage practices were, therefore, investigated in two wheat production areas of the Western Cape over two years (2020 and 2021) to determine its effects on FCR disease- and agronomic parameters of wheat. Crop rotation with non-host crops, including annual medics (Medicago spp.), canola (Brassica napus) and lupin (Lupinus spp.) significantly reduced FCR disease incidence and severity, while increasing grain yield and quality over the two-year study period. Significant negative correlations (P < 0.05) were established between FCR disease incidence and – severity with grain yield and – quality. Tillage practices were comprised of conventional tillage (deep soil disturbance with a plough), minimum tillage (shallow tine tillage), no tillage (no primary soil disturbance, tine planter) and zero tillage (no primary soil disturbance, disc planter). Zero tillage decreased FCR incidence and disease severity, without impeding wheat grain yield and quality. Better soil water conservation later in the season, along with shallower seeding depth in zero tillage, contributed to FCR disease management. Crop rotation with non-host crops, combined with zero tillage can, therefore, be integral to FCR disease management strategies.