Flag Leaf Stage Research Articles

Effect of Nitrogen Scheduling on Growth and Yield of Wheat (Triticum aestivum L.)

A field experiment was conducted at experimental farm, Department of Agronomy, Faculty of Agriculture and Veterinary Sciences, Mewar University Gangrar, Chittorgarh (Rajasthan) during Rabi season of 2023-24 to effect of nitrogen scheduling on growth and yield of wheat, variety “3077‟ was used in this study. The required quantities of fertilizers as per treatments were applied. The experiment was laid out in randomized block design with three replications consisting of twelve treatments. The data recorded maximum growth attributes like, plant height (94.45 cm), dry matter accum8lation per m row length (248.78 g) and yield attributes such as number of effective tillers per m row length (65.40), number of grains per spike (82.24), grain yield (5230 kg/ha), stover yield (6634 kg/ha), biological yield (11864 kg/ha) and maximum net return (156075 Rs/ha) was recorded with T12 : 1/3 at basal +1/3 at CRI (21-25 DAS) + 1/3 at Jointing stage (65-70 DAS) + 2.0% urea + 0.5% ZnSO4 spray at flag leaf stage (80-90 DAS). Therefore, it may be concluded that application of T12: 1/3 at basal +1/3 at CRI (21-25 DAS) + 1/3 at Jointing stage (65-70 DAS) + 2.0% urea +0.5% ZnSO4 spray at flag leaf stage (80-90 DAS) was the most suitable treatment for obtaining higher seed yield (5230 kg/ha), gross and net returns (Rs 156075.00/ha and 113116.00/ha) and B: C ratio (2.63) in wheat. However, these results are only indicative and require further experimentation to arrive at more consistent and final conclusion.

Stress-Inducible Expression of HvABF2 Transcription Factor Improves Water Deficit Tolerance in Transgenic Barley Plants.

Barley (Hordeum vulgare L.), a major cereal crop grown in arid and semi-arid regions, faces significant yield variability due to drought and heat stresses. In this study, the HvABF2 gene, encoding an ABA-dependent transcription factor, was cloned using specific primers from water deficit-stressed barley seedlings. Gene expression analysis revealed high HvABF2 expression in developing caryopses and inflorescences, with significant induction under stress conditions. The HvABF2 coding sequence was utilized to generate transgenic barley plants with both stress-inducible and constitutive expression, driven by the rice SNAC1 and maize Ubiquitin promoters, respectively. Selected transgenic barley lines, along with control lines, were subjected to water deficit-stress experiments at seedling and flag leaf stages under controlled and greenhouse conditions. The transgenic lines exhibited higher relative water content and stomatal resistance under stress compared to control plants. However, constitutive overexpression of HvABF2 led to growth retardation under well-watered conditions, resulting in reduced plant height, grain weight, and grain number. In contrast, stress-inducible expression mitigated these effects, demonstrating improved drought tolerance without adverse growth impacts. This study highlights that the stress-inducible expression of HvABF2, using the SNAC1 promoter, effectively improves drought tolerance while avoiding the negative pleiotropic effects observed with constitutive expression.

Phenological stages of wheat modulate effects of phosphorus fertilization in plant-soil microbial interactions

Abstract Aims Future phosphorus (P) fertilizer availability faces challenges due to limited phosphate rock mines and strict quality regulations regarding Cd contents in phosphate rock. In this study, conventional fertilization was partially substituted with meat bone meal (MBM), sludge (S), and the organo-mineral combination of S plus MBM (SMBM), in a wheat agroecosystem. Methods We investigated the impact of fertilization treatments and crop phenological stages on P availability, crop yield, and soil microbial responses. Analysis included enzyme activities, microbial biomass, and the composition of bacterial and fungal communities using metabarcoding. Additionally, we estimated functional genes related to the P cycle through qPCR. Crop yield and nutrient content in plants and soil were also determined. Results Replacing traditional fertilization with MBM and SMBM maintained crop yield at levels equivalent to conventional fertilization. S and SMBM produced 70% and 40% (respectively) more bioavailable P compared to conventional treatment (Trad). Significant differences between treatments in soil microbial biomass were observed in the flag leaf stage. S increased in 20% total soil microbial biomass compared to Trad. Crop phenology had a stronger impact on bacterial and fungal communities than fertilization treatments. The use of S enhanced microbial biomass and activity. Yield in both MBM and SMBM plots exhibited no statistically significant differences compared to traditional fertilization. Conclusion Organo-mineral fertilization emerges as a sustainable strategy for maintaining crop production while improving soil functionality. Our findings emphasize the primary influence of crop phenology on shaping soil microbial communities and influencing microbial biomass and functionality.

Effect of Water Deficit Stress on Reproductive Stage of Durum Wheat Near Isogenic Lines Carrying the NAM-B1 Gene

Background In wheat, the NAC family plays a crucial role in conferring cellular responses to different abiotic stresses, particularly drought. The functional NAM-B1 allele in durum wheat accelerates senescence, while its homologous genes contribute to improved water deficit stress tolerance. Therefore, the main objective of this study was to investigate the role of the NAM-B1 gene in durum wheat subjected to water deficit stress at two reproductive stages. Materials and Methods Three Near-Isogenic Lines carrying a functional NAM-B1 allele and their recurrent parent, Langdon (LDN), were used in this study. The study assessed NILs and LDN performance under varied water conditions (well-watered, 60%, and 80% water deficit of pot capacity) during flag leaf and anthesis stages. The agronomic performance of the three NILs and LDN was assessed for 16 traits, including plant height, grain yield, and thousand kernel weight. Additionally, physiological measurements, including stomatal resistance, chlorophyll content (SPAD values), and chlorophyll fluorescence (Fv/Fm) were taken. Results Significant genotypic effects were observed on seven agronomic traits, while 15 traits were influenced by the water stress treatment. The NILs exhibited accelerated maturity and a shorter grain-filling period, which were particularly pronounced under stress conditions. Severe water deficit resulted in reduced grain weight and thousand-grain weight in tested genotypes. Interestingly NILs carrying functional NAM-B1 showed taller plants and had higher tiller and spike numbers when compared to LND. Significant genotypic effects were observed for seven traits, and water stress treatments affected 15 traits. The NILs exhibited accelerated maturity and reduced grain weight under severe water deficit. Physiological measurements showed genotype and water-deficit differences, with NIL #504 displaying higher SPAD values, particularly under stress conditions, and a significant genotype X treatment effect was observed for stomatal resistance at the anthesis stage. Discussion Limited treatment × genotype interactions for most traits highlight the complexity of drought tolerance in the tested lines, which might be attributed to its quantitative nature influenced by multiple genes. The study emphasizes the necessity for future research to explore the role of other NAM-related genes in response to water deficit stress and their interactive effects with the NAM-B1 gene at different growth stages in wheat plants subjected to diverse stress conditions. Conclusion In conclusion, this study reveals pronounced genotypic effects, particularly in agronomic traits, such as maturation rate and grain filling period, under severe water deficit stress. Future studies are needed to understand the genetic mechanisms mediated by NAM-B1 genes in accelerating maturity in response to stress.

Halotolerant Endophytic Bacteria Regulate Growth and Field Performance of Two Durum Wheat Genotypes with Contrasting Salinity Tolerance Potential.

Soil salinity hampers durum wheat plant growth and development at various stages. The detrimental effects of salinity on plant cellular and physiological processes necessitate strategies to alleviate its negative impact and improve overall crop yield. This study investigates the efficacy of plant growth-promoting rhizobacteria (PGPR) bacteria inoculation in mitigating salinity stress on two durum wheat genotypes with contrasting degrees of salinity tolerance (Tamaroi, salt-sensitive and Line 5004, salt-tolerant) under greenhouse and field conditions. For this purpose, two halotolerant-PGPR strains, Pseudomonas jordanii strain G34 and Oceanobacillus jordanicus strain GSFE11, were utilized for the inoculation. For the greenhouse experiment, the two selected genotypes were subjected to salinity at the flag leaf stage with continuous irrigation with a Hoagland solution supplemented with 50 mM NaCl. Field experiments were conducted across two locations with contrasting salinity levels over two growing seasons. At the end of both experiments, various parameters including total weight, spike weight, grain weight, spike number, spikelet number, grains per spike and thousand kernel weight were measured. The halotolerant PGPRs, P. jordanii strain G34 and O. jordanicus strain GSFE11, proved effective in alleviating salinity-induced adverse effects and enhancing growth under greenhouse and field conditions. However, bacterial inoculation significantly improved growth in the salt-sensitive genotype and such effects were not observed in the tolerant genotype, emphasizing genotype-specific responses. Notably, inoculation with O. jordanicus increased Na+ and Ca2+ uptake in the salt-tolerant "Line 5004" without hindering growth, suggesting one of its potential mechanisms for salt tolerance. This research demonstrates the potential of halotolerant-PGPR inoculation in enhancing durum wheat production in saline environments, but also underscores the importance of understanding genotype-specific responses for tailored interventions.

Genetic Diversity for Effective Resistance in Wheat Landraces from Ethiopia and Eritrea to Fungal Diseases and Toxic Aluminum Ions.

To reveal genetic diversity for effective resistance to five foliar diseases and toxic aluminum ions, the entire collection of wheat species from the N.I. Vavilov All-Russian Institute of Plant Genetic Resources (VIR) originating from Ethiopia and Eritrea were studied regarding their traits. The collection contains 509 samples of four wheat species (Triticum aestivum-122 samples; T. aethiopicum-340 samples; T. polonicum-6 samples; and T. dicoccum-41 samples). The majority of accessions are new entries of landraces added to the Vavilov collection as a result of the Russian-Ethiopian expedition in 2012. Wheat seedlings were inoculated with causal agents of leaf rust (Pt), powdery mildew (Bgt), Septoria nodorum blotch (SNB), and dark-brown leaf spot blotch (HLB). The types of reaction and disease development were assessed to describe the levels of resistance. All samples of T. aethiopicum were also screened for seedling and adult resistance to Pt, Bgt, and yellow rust (Pst) under field conditions after double inoculation with the corresponding pathogens. To study tolerance to abiotic stress, seedlings were grown in a solution of Al3+ (185 µM, pH 4,0) and in water. The index of root length was used to characterize tolerance. Seedlings belonging to only two accessions out of those studied-k-68236 of T. aethiopicum and k-67397 of T. dicoccum-were resistant to Pt at 20 °C but susceptible at 25 °C. Specific molecular markers closely linked to the five genes for Pt resistance effective against populations of the pathogen from the northwestern region of Russia were not amplified in these two entries after PCR with corresponding primers. Four entries of T. dicoccum-k-18971, k-18975, k-19577, and k-67398-were highly resistant to Bgt. All samples under study were susceptible to HLB and SNB. Under field conditions, 15% of the T. aethiopicum samples were resistant to Pst, both at the seedling and the flag leaf stages, but all were susceptible to the other diseases under study. Among the evaluated samples, 20 entries of T. aestivum, 1 of T. polonicum (k-43765), and 2 of T. dicoccum (k-18971, k-67397) were tolerant to aluminum ions. The identified entries could be valuable sources for the breeding of T. aestivum and other wheats for resistance to biotic and abiotic stresses.

Induced responses to the wheat pathogen: Tan Spot—(Pyrenophora tritici-repentis) in wheat (Triticum aestivum) focus on changes in defence associated and sugar metabolism

IntroductionTan Spot (TS) disease of wheat is caused by Pyrenophora tritici-repentis (Ptr), where most of the yield loss is linked to diseased flag leaves. As there are no fully resistant cultivars available, elucidating the responses of wheat to Ptr could inform the derivation of new resistant genotypes.ObjectivesThe study aimed to characterise the flag-leaf metabolomes of two spring wheat cultivars (Triticum aestivum L. cv. PF 080719 [PF] and cv. Fundacep Horizonte [FH]) following challenge with Ptr to gain insights into TS disease development.MethodsPF and FH plants were inoculated with a Ptr strain that produces the necrotrophic toxin ToxA. The metabolic changes in flag leaves following challenge (24, 48, 72, and 96 h post-inoculation [hpi]) with Ptr were investigated using untargeted flow infusion ionisation-high resolution mass spectroscopy (FIE-HRMS).ResultsBoth cultivars were susceptible to Ptr at the flag-leaf stage. Comparisons of Ptr- and mock-inoculated plants indicated that a major metabolic shift occurred at 24 hpi in FH, and at 48 hpi in PF. Although most altered metabolites were genotype specific, they were linked to common pathways; phenylpropanoid and flavonoid metabolism. Alterations in sugar metabolism as well as in glycolysis and glucogenesis pathways were also observed. Pathway enrichment analysis suggested that Ptr-triggered alterations in chloroplast and photosynthetic machinery in both cultivars, especially in FH at 96 hpi. In a wheat-Ptr interactome in integrative network analysis, “flavone and flavonol biosynthesis” and “starch and sucrose metabolism” were targeted as the key metabolic processes underlying PF–FH–Ptr interactions.ConclusionThese observations suggest the potential importance of flavone and flavonol biosynthesis as well as bioenergetic shifts in susceptibility to Ptr. This work highlights the value of metabolomic approaches to provide novel insights into wheat pathosystems.

Physiological and Agronomic Characteristics of Alternative Black Barley Genotypes (Hordeum vulgare var. nigricans and H. v. var. rimpaui) under Different Hydrothermal Conditions of the Growing Seasons

Black-seeded barley can be a valuable raw material for functional food. However, its restoration to cropping should be preceded by the identification of the characteristics determining productivity. The field study was conducted to identify specific parameters of the black-seeded barley genotypes (Hordeum vulgare var. nigricans and H. v. var. rimpaui) and compare them with common barley (H. vulgare) under the different hydrothermal conditions of the two growing seasons of 2021 and 2022. Our research has shown that each genotype has a set of specific characteristics that best describe it at a given developmental stage. H. v. rimpaui was well characterized by chlorophyll fluorescence parameters such as FV/FM, FV/F0, and PIABS at the seedling stage and H. v. nigricans by FV/FM and FV/F0 at the flag leaf stage. Moreover, H. v. var. rimpaui was distinguished by a high biomass of shoot (726 g m−2) and straw yield (5.04 t ha−1) but H. v. var. nigricans by a high number of sterile generative tillers (103 m−2 in the dry year 2022). Further research should focus on the response of black-seeded barley genotypes to abiotic stresses, while in agronomic practice, efforts should be made to increase the number of grains per ear and 1000-grain weight.

Nitrogen management sensor optimization, yield, economics, and nitrogen use efficiency of different wheat cultivars under varying nitrogen levels

Excessive application of nitrogen (N) in wheat cultivation results in substantial decreases in yield and limited economic gains, leading to adverse environmental consequences. In this study, the main objective is to assess and optimize the values of different N-assessing tools at varying levels of N for three wheat cultivars. Three non-destructive sensing devices: Leaf color chart (LCC), soil plant analyzer development (SPAD), and Green Seeker, were optimized at three levels of N (0, 90, 120, and 150 kg N ha−1) in three wheat cultivars, HD 2967, HD 3059, and HD 3086. The results indicated that at 60 days after sowing (DAS), the optimum values for LCC, SPAD, and GreenSeeker were 4.17, 0.62, and 44.2, respectively. These values were observed at the flag leaf stage, where they measured 4.12, 0.60, and 43.8, respectively, and this could be achieved at 120 kg N ha−1 with a grain yield of 4.87 t ha−1. At 120 kg N ha−1, considerably better gross return (Rs. 97,444.4), net income (Rs. 66,681.4), and B:C ratio (2.2) were obtained. The highest agronomic efficiency of N (21.2%) was recorded at 120 kg N ha−1, while the N uptake and recovery (129 kg ha−1 and 59.2 %) were significantly higher, recorded at 150 kg N ha−1. We can conclude that optimized values of these sensors at different doses of N would provide better guidance for precision N management that may reduce the input cost, maximize return, and minimize N losses in wheat.

Cytokinins along with Osmoprotectant Trehalose Overcome the Deleterious Effect of Drought Stress on Wheat

Experiment was conducted to evaluate, how the foliar application of trehalose (tre) along with kinetin (kn) and benzyl adenine (BA) affect the wheat genotypes (HD2967, PBW660 and WH1105) under drought stress conditions. Trehalose, Kn and BA tested in laboratory studies for their best concentrations, were applied in field grown wheat under drought. Presently, significant reduction was observed in leaf area, relative growth, Hill reaction and harvest index and sharp increase was recorded in concentration of non-enzymatic antioxidants constituents at both stages except reduced ascorbic acid content showed decline at flag leaf stage along with the upsurge in the activities of enzymatic antioxidants of wheat under drought as compared to control or irrigated ones. Foliar application of growth regulators altered activities of enzymatic and non-enzymatic antioxidants at both vegetative and flag leaf stage and helps in mitigation of negative impact of drought by regulation of Hill reaction, leaf area and growth rate of wheat that tends to maintain the final harvest of wheat crop.

Plasticity of wheat yield components in response to N fertilization

Nitrogen fertilization is one of the major issues of crop productions in west-Europe. Every year, large quantities of synthetic nitrogen are used to fertilize crops, such as winter wheat (Triticum aestivum), and ensure them high yielding conditions. In return, substantial amount of nitrogen ends up in the environment where it generates pollutions. The combination of strategic and tactical approaches has been suggested to improve the accuracy of nitrogen fertilization decisions and their implementation. Combining strategic and tactical approaches requires a detailed understanding of the dynamic of nitrogen use by the plant to both anticipate and adapt fertilization practices. Inspired by the concept of yield component phenotypic plasticity, this study aimed to analyze the influence of nitrogen fertilization dynamics on yield elaboration and infer strategic decision rules dedicated to wheat yield optimization in a Belgian context. The analysis, implemented from ten-year experiment, was conducted in two different steps. (1) We characterized the effect of nitrogen fertilization on yield and yield components when the crop was submitted to different agro-pedo-climatic contexts, (2) we analyzed the specific influence of nitrogen fertilization dynamic on yield elaboration, normalizing the variables of the experiment to exclude genetic and environmental influences. The study revealed that highest nitrogen fertilization did not automatically lead to the highest yields. High nitrogen fertilization contributed to increase the negative trade-offs between yield components, which limited the efficiency of nitrogen supplies. Conversely, a balanced dynamic of nitrogen supplies was essential to reach high yields while supplying effective amount of nitrogen. From this Belgian dataset, optimal nitrogen fertilization strategies supposed early nitrogen supplies split in two applications to support the initiation phases of grains per m² and another nitrogen supply at flag leaf stage to maintain components of grain per m² while still allowing grain filling. This fertilization structures, adapted to different pedoclimatic contexts would support strategic approach in crop nitrogen nutrition.

Mapping and validation of a novel major QTL for resistance to stripe rust in four wheat populations derived from landrace Qishanmai.

Wheat yield has been constrained by stripe rust disease globally. A wheat landrace (Qishanmai, QSM) consistently showed lower stripe rust severities in multiple year studies than susceptible check varieties including Suwon11 (SW) at the adult plant stage. To detect QTL for reducing the severity in QSM, 1218 recombinant inbred lines (RILs) were developed from SW × QSM. QTL detection was conducted firstly using 112 RILs selected for similarity in pheno-morphological characters. The 112 RILs were assessed for stripe rust severity at the 2nd leaf, 6th leaf and flag leaf stages under field and greenhouse conditions, and genotyping was done primarily with a single nucleotide polymorphism (SNP) array. On the basis of these phenotypic and genotypic data, a major QTL (QYr.cau-1DL) was detected on chromosome 1D at the 6th leaf and flag leaf stages. Further mapping was conducted by genotyping 1218 RILs using new simple sequence repeat (SSR) markers, which were developed by referring to the sequences of the wheat line Chinese Spring (IWGSC RefSeq v1.0). QYr.cau-1DL was mapped within a 0.5 cM (5.2 Mb) interval delimited by the SSR markers 1D-320.58 and 1D-325.79. These markers were applied to select for QYr.cau-1DL by screening F2 or BC4F2 plants of the wheat crosses RL6058 × QSM, Lantian10 × QSM and Yannong21 × QSM. F2:3 or BC4F2:3 families derived from the selected plants were assessed for stripe rust resistance in the fields of two locations and in a greenhouse. Wheat plants carrying the resistant marker haplotype in homozygous state for QYr.cau-1DL showed lower stripe rust severities (by 44% to 48%) than plants lacking this QTL. The trial of RL6058 (a carrier of Yr18) × QSM also indicated that QYr.cau-1DL had larger effect than Yr18 on reducing severity; they acted synergistically, yielding an elevated level of stripe rust resistance.

Neem and Castor Oil–Coated Urea Mitigates Salinity Effects in Wheat by Improving Physiological Responses and Plant Homeostasis

Soil salinity is abiotic stress of growing concern, whose effects can be potentially mitigated by the use of suitable fertilisers. Based on this, an experiment was conducted to determine the role of vegetable oil–coated urea on the performance of wheat (Triticum aestivum) under salinity. Neem oil–coated urea (NOCU), castor oil–coated urea (COCU), and normal urea (NU) were compared in wheat plants growing in pots at three soil salinity levels (0, 6, and 12 dS m-1). Plant morphology, growth, element contents (Na, Cl, K, and N), and several traits were assessed at the flag leaf stage; biological yield, grain yield, and its components were assessed at maturity. Salinity stunted growth (approximately -50% yield with high salinity vs. control); boosted Na and Cl concentrations while abating K and N concentrations in plant organs; impaired leaf water status; reduced photosynthetic pigments and increased antioxidant activities and osmo-regulating compounds. NOCU and, to a lesser degree, COCU mitigated salinity effects by upgrading antioxidant activities, reducing oxidative stress markers, increasing leaf water status, photosynthetic pigments, and osmo-regulating compounds. However, NOCU under high salinity could only achieve the levels of NU under intermediate salinity. Lastly, NOCU and COCU restricted plant entry of adverse ions (Na and Cl) while increasing K and N accumulation. Vegetable oil–coated urea, namely NOCU, significantly contributed to improving wheat behaviour and final yield under salinity. These outcomes are associated with the two fertilisers’ properties of slow nitrogen release.

Tiller demography of tall fescue and tall wheatgrass cut at different times during the reproductive phase

AbstractBackgroundTall fescue (TF) and tall wheatgrass (TW) are the main temperate perennial grasses used for livestock grazing in the Pampas region of Argentina. In this region, pastures based on these grasses show low tiller density and the presence of bare soil in winter.MethodsAn experiment was performed in pots kept outdoors. Plants of TF and TW were cut every 550°C day and 700°C day, respectively. In each species, reproductive tillers were removed at different times: (i) at each cut, (ii) when they reached the flag leaf stage, or (iii) when they reached full bloom. Tiller appearance, tiller death, and type of bud (basal or axillary) of the tillers present were determined.ResultsTiller appearance decreased from July to April. Minimum values were 0.2 and 1.1 tillers 100 tillers−1 day−1 in TF and TW, respectively. In TF, tiller death began in September–October and increased from 0.2 to 0.8 tillers 100 tillers−1 day−1 in March–April. In TW, tiller death began in October–November and increased from 0.6 to 0.8–1.0 tillers 100 tillers−1 day−1 from February to April.ConclusionsDefoliation of reproductive tillers affected the tiller density of TF plants in spring and in the following fall. In TW, the treatments did not modify the tiller density of the plants.

Phylogenomic Analysis of micro-RNA Involved in Juvenile to Flowering-Stage Transition in Photophilic Rice and Its Sister Species

Vegetative to reproductive phase transition in phototropic plants is an important developmental process and is sequentially mediated by the expression of micro-RNA MIR172. To obtain insight into the evolution, adaptation, and function of MIR172 in photophilic rice and its wild relatives, we analyzed the genescape of a 100 kb segment harboring MIR172 homologs from 11 genomes. The expression analysis of MIR172 revealed its incremental accumulation from the 2-leaf to 10-leaf stage, with maximum expression coinciding with the flag-leaf stage in rice. Nonetheless, the microsynteny analysis of MIR172s revealed collinearity within the genus Oryza, but a loss of synteny was observed in (i) MIR172A in O. barthii (AA) and O. glaberima (AA); (ii) MIR172B in O. brachyantha (FF); and (iii) MIR172C in O. punctata (BB). Phylogenetic analysis of precursor sequences/region of MIR172 revealed a distinct tri-modal clade of evolution. The genomic information generated in this investigation through comparative analysis of MIRNA, suggests mature MIR172s to have evolved in a disruptive and conservative mode amongst all Oryza species with a common origin of descent. Further, the phylogenomic delineation provided an insight into the adaptation and molecular evolution of MIR172 to changing environmental conditions (biotic and abiotic) of phototropic rice through natural selection and the opportunity to harness untapped genomic regions from rice wild relatives (RWR).

Chlorophyll Meter: A Precision Agricultural Decision-Making Tool for Nutrient Supply in Durum Wheat (Triticum turgidum L.) Cultivation under Drought Conditions

How crop biodiversity adapts to drought conditions and enhances grain yield became the most important issue facing agronomists and plant breeders at the turn of the century. Variations in genetic response, inadequacy of nutrients in the soil, and insufficient access to nutrients are factors that aggravate drought stressors. The development of screening tools for identifying drought tolerance is important in the deployment of durum wheat varieties suited to drought-prone environments. An experiment was conducted to evaluate durum wheat varieties under a range of nutrient supplies in naturally imposed drought conditions. The treatments consisting of two nitrogen regimes (i.e., control and 60 kg ha-1), four durum wheat varieties, and three types of nutrients (control, sulfur, and zinc) that were arranged in a split-split plot design with three replications. Both foliar-based sulfur and zinc fertilization were employed at the flag leaf stage, at a rate of 4 and 3-L ha-1, respectively. The results showed a significant (p < 0.05) genetic variation in chlorophyll concentration, grain protein content, tillering potential, and leaf area index. Varieties that contained better leaf chlorophyll content had improved grain yield by about 8.33% under 60 kg/ha nitrogen. A combined application of nitrogen and zinc at flag leaf stage significantly improved grain yield of Duragold by about 21.3%. Leaf chlorophyll content was found to be a more important trait than spikes per m2 to discriminate durum wheat varieties. Foliar application of sulfur increased the grain yield of drought-stressed plants by about 12.23%. Grain yield and protein content were strongly correlated with late-season SPAD readings. Significant (p < 0.05) correlation coefficients were obtained between normalized difference vegetation index, leaf area index, grain yield, and protein content with late-season chlorophyll content, revealing the importance of chlorophyll content in studying and identifying drought-tolerant varieties.

Effect of Copper Sulfate Pentahydrate and Cultivar Resistance on Reducing Bacterial Leaf Streak in Hard Red Spring Wheat in North Dakota

Bacterial leaf streak (BLS) is one of the most significant foliar diseases affecting hard red spring wheat (HRSW) production in North Dakota. The most effective management tool for BLS is the use of host resistance; however, the adoption and availability of resistant cultivars is limited for HRSW producers. This has led to questions pertaining to the use of copper-based products to suppress BLS severity in HRSW production. Four field experiments were conducted from 2020 to 2022 in North Dakota to evaluate the efficacy of copper sulfate pentahydrate (CSP) applied at the flag leaf stage on reducing BLS severity and protecting HRSW yield and test weight. Experiments were conducted in a randomized complete block design with a split-plot arrangement with four replications. Three treatments served as the main plots (noninoculated, inoculated, and inoculated + CSP applied at flag leaf). Five HRSW cultivars varying in host resistance served as subplots. A high level of disease occurred across all experiments. A combined analysis suggested that the use of CSP did not provide adequate BLS suppression and did not protect HRSW yield or test weight regardless of HRSW susceptibility. The lowest mean yield loss was associated with the moderately resistant cultivar Boost (9%), and the highest was associated with the susceptible cultivar SY Rockford (19%). Variability in yield loss values among cultivars suggests that more research is needed to strengthen our understanding of BLS in HRSW.

Management of spot blotch of barley through different dates of sowing and chemical and organic amendments

Spot blotch caused by Bipolaris sorokiniana is one of the most serious diseases of barley in tropical areas where barley and wheat are grown. A field experiment was conducted at Regional Research Station Masodha, ANDUA&amp;T, Kumarganj, Ayodhya, Uttar Pradesh during Rabi season. To evaluate the effect of different dates of sowing and chemical and organic amendments on spot blotch and consequently on seed quality of barley. The experiment was conducted during the Rabi season 2016-17 under hotspot area of spot blotch. RD-2794 was sown in a split plot manner with two dates of sowing.The experiment was performed in split plot design with three replications comprising two different dates of sowing, i.e. mid- November (D1 ) and mid-December (D2 ) in the main plot and chemical and organic amendments viz., RDF (60N:30P:20K kg/ hectare) -T1 , FYM @ 5 t/h-T2 , T1 + Mulch@ 6 t/h-T3 , T1 + FYM @ 5t/hec + Mulch @ 6t/ hec.-T4 , T4 + 2 spray of zinc sulphate @ 0.5 %-T5 , T4 + 2 spray of KCl @0.5%-T6 and T5 + 2 spray of KCl @ 0.5 %-T7 in the sub plot. Results revealed that minimum disease severity (46.9%) with maximum disease control (39.98%) and per cent seed infection (5.5%) were recorded in D1 × T7 . The interpretation of data revealed that there was highly positive and significant correlation (r=0.95) between disease severity and per cent seed infection. The maximum 1000-seed weight (43.41g) and yield (38.67 q/ha) with maximum yield gain (57.25%) was also recorded in D1 × T7 . The same treatment combination was also useful in maximizing the seed quality in terms of seed viability (98%), Germination (97%), seedling length (27.30cm) and vigour index-I (2648.153) when the freshly harvested seeds were tested in seed testing laboratory. Spot blotch is a serious disease of barley spreads primarily through infected seeds and reduced the yield up to 30%. The disease can be minimized by sowing the crop timely i.e. mid-November with recommended dose of fertilizers + FYM @ 5 t/ha+ Mulch@ 6 t/ha+ 2 spray of zinc sulphate @ 0.5 % + 2 spray of KCl @ 0.5 % at flag leaf and post anthesis stage which improves the seed quality.

HERBICIDE UNIKO, CSC FOR SPRING CEREAL CROPS PROTECTION AGAINST WEED PLANTS

In the article the results of researches on biological and economic efficiency of a new herbicide Uniko, CSC (fluroxypyr, 100 g/l + florasulam, 2,5 g/l) AO “Shchelkovo Agrokhim”, Russia production are presented. It is determined that by this herbicide application in spring wheat and barley at tillering stage, the biological efficiency has made more than 90,0 %, by crops weeding at flag leaf stage – the efficiency has made 80,0–85,0 %, for this, the reliable yield increase has made 80,0–85,0.

UAV Remote Sensing Prediction Method of Winter Wheat Yield Based on the Fused Features of Crop and Soil

The early and accurate acquisition of crop yields is of great significance for maintaining food market stability and ensuring global food security. Unmanned aerial vehicle (UAV) remote sensing offers the possibility of predicting crop yields with its advantages of flexibility and high resolution. However, most of the existing remote sensing yield estimation studies focused solely on crops but did not fully consider the influence of soil on yield formation. As an integrated system, the status of crop and soil together determines the final yield. Compared to crop-only yield prediction, the approach that additionally considers soil background information will effectively improve the accuracy and reduce bias in the results. In this study, a novel method for segmenting crop and soil spectral images based on different vegetation coverage is first proposed, in which pixels of crop and soil can be accurately identified by determining the discriminant value Q. On the basis of extracting crop and soil waveband’s information by individual pixel, an innovative approach, projected non-negative matrix factorization based on good point set and matrix cross fusion (PNMF-MCF), was developed to effectively extract and fuse the yield-related features of crop and soil. The experimental results on winter wheat show that the proposed segmentation method can accurately distinguish crop and soil pixels under complex soil background of four different growth periods. Compared with the single reflectance of crop or soil and the simple combination of crop and soil reflectance, the fused yield features spectral matrix FP obtained with PNMF−MCF achieved the best performance in yield prediction at the flowering, flag leaf and pustulation stages, with R2 higher than 0.7 in these three stages. Especially at the flowering stage, the yield prediction model based on PNMF-MCF had the highest R2 with 0.8516 and the lowest RMSE with 0.0744 kg/m2. Correlation analysis with key biochemical parameters (nitrogen and carbon, pigments and biomass) of yield formation showed that the flowering stage was the most vigorous season for photosynthesis and the most critical stage for yield prediction. This study provides a new perspective and complete framework for high-precision crop yield forecasting using UAV remote sensing technology.