Superior Yield Performance Research Articles

Comparative phenotypic and transcriptomic analysis reveals genotypic differences in nitrogen use efficiency in sorghum

Sorghum (Sorghumbicolor L.), a model for C4 grass and an emerging biofuel crop, is known for its robust tolerance to low input field. However, the focus on enhancing nitrogen use efficiency (NUE) in sorghum under low nitrogen (N) conditions has been limited. This study conducted hydroponic experiments and field trials with two sorghum inbred lines, contrasting in their N efficiency: the N-efficient (398B) and the N-inefficient (CS3541) inbred lines. The aim was to analyze the key factors influencing NUE by integrating phenotypic, physiological, and multi-omics approaches under N deficiency conditions. The field experiments revealed that 398B displayed superior NUE and yield performance compared to CS3541. In hydroponic experiments, the growth of 398B outperformed CS3541 following N deficiency, attributing to its higher photosynthetic and sustaining activity of N metabolism-related enzymes. Genomic and transcriptomic integration highlighted fewer genomic diversities and alterations in global gene expression in 398B, which were likely contributor to its high NUE. Additionally, co-expression network analysis suggested the involvement of key genes which impact N uptake efficiency (NUpE) and N utilization efficiency (NUtE) in both lines, such as an N transporter, Sobic.003G371000.v3.2leaf(NPF5.10) and a transcription factor, Sobic.002G202800.v3.2leaf(WRKY) in bolstering NUE under low-N stress. The findings collectively suggested that 398B achieved higher NUpE and NUtE, effectively coordinating photosynthesis and N metabolism to enhance NUE. The candidate genes regulating N uptake and utilization efficiencies could provide valuable insights for developing sorghum breeds with improved NUE, contributing to sustainable agricultural practices and bioenergy crop development.

IGF-I and GH Genes polymorphism and their association with milk yields, composition and reproductive performance in Holstein–Friesian dairy cattle

BackgroundThe insulin-like growth factor (IGF-I) and growth hormone (GH) genes have been identified as major regulators of milk yield and composition, and reproductive performance in cattle. Genetic variations/polymorphism in these genes have been found to influence milk production, yield and quality. This investigation aimed to explore the association between IGF-I and GH polymorphisms and milk yield and composition, and reproductive performance in a herd consisting of 1000 Holstein–Friesian (HF) dairy cattle from El-Alamia farm. The experimental animals were 76 ± 7.25 months in age, with an average live weight of 750 ± 50.49 kg, and raised under the same conditions of feeding and weather. The studied animals were divided into three categories; high producers (n = 280), medium producers (n = 318) and low producers (n = 402).ResultsThe digestion of 249 bp for IGF-I-SnaBI using the Restriction-fragment-length-polymorphism (RFLP) technique yielded two alleles; T (0.59) and C (0.41) and three genotypes; TT (0.52), TC (0.39) and CC (0.09) and this agrees with the results of DNA/gene sequencing technique. The sequencing analysis of the IGF-I gene revealed polymorphism in position 472 (C > T). Nucleotide sequencing of the amplified fragment of the IGF-I gene of different genotypes was done and submitted to the NCBI GenBank with Accession no. MH156812.1 and MH156811.1. While the digestion of 432 bp for GH-AluI using the RFLP technique yielded two alleles; A (0.81) and G (0.19) and two genotypes; AA (0.77) and AG (0.23) and this agrees with the results of DNA/gene sequencing technique. The sequencing analysis of the GH gene revealed polymorphism in the position 1758 C > G and in turn led to changes in amino acid sequence as Alanine for (A) compared to Glycine for (G). Nucleotide sequencing of the amplified fragment of the GH gene was done and submitted to the NCBI GenBank with Accession no. MH156810.1. The results of this study demonstrate the effects of variants of the GH-IGF-I somatotrophic axis on milk production and composition traits in commercial HF cattle. The greatest values of milk yield and reproductive performance were observed on IGF-I-SnaBI-TC and GH-AluI-AG genotypes. While the greatest % fat and % protein values were observed on IGF-I-SnaBI-CC and GH-AluI-AA genotyped individuals.ConclusionThe genetic variation of the studied genes can be utilized in selecting animals with superior milk yield, composition and reproductive performance in Holstein–Friesian Dairy Cattle under subtropical conditions.

Enhancing grain shape, thermotolerance, and alkaline tolerance via Gγ protein manipulation in rice.

Our findings highlight a valuable breeding resource, demonstrating the potential to concurrently enhance grain shape, thermotolerance, and alkaline tolerance by manipulating Gγ protein in rice. Temperate Geng/Japonica (GJ) rice yields have improved significantly, bolstering global food security. However, GJ rice breeding faces challenges, including enhancing grain quality, ensuring stable yields at warmer temperatures, and utilizing alkaline land. In this study, we employed CRISPR/Cas9 gene-editing technology to knock out the GS3 locus in seven elite GJ varieties with superior yield performance. Yield component measurements revealed that GS3 knockout mutants consistently enhanced grain length and reduced plant height in diverse genetic backgrounds. The impact of GS3 on the grain number per panicle and setting rate depended on the genetic background. GS3 knockout did not affect milling quality and minimally altered protein and amylose content but notably influenced chalkiness-related traits. GS3 knockout indiscriminately improved heat and alkali stress tolerance in the GJ varieties studied. Transcriptome analysis indicated differential gene expression between the GS3 mutants and their wild-type counterparts, enriched in biological processes related to photosynthesis, photosystem II stabilization, and pathways associated with photosynthesis and cutin, suberine, and wax biosynthesis. Our findings highlight GS3 as a breeding resource for concurrently improving grain shape, thermotolerance, and alkaline tolerance through Gγ protein manipulation in rice.

Investigating the dynamics of upland rice (Oryza sativa L.) in rainfed agroecosystems: an in-depth analysis of yield gap and strategic exploration for enhanced production

IntroductionAddressing the global demand for rice production necessitates innovative approaches to enhance upland rice yield in rainfed agroecosystems, considering the challenges posed by increasing population, limited land fertility, low productivity, and water availability.MethodsIn this study, our study investigated the impact of biochar and organic fertilizer on ten promising rice lines (G1 – G10) and two control (G11 – G12) cultivars under rainfed conditions. The experimental design used a split-plot design with four soil amendments as main plots, namely control, organic fertilizer, biochar, and biochar + organic fertilizer and 12 rice genotypes as subplot.ResultsThe absolute attainable yield gaps, differentiating organic and control (GAP1), biochar + organic and control (GAP2), and biochar and control (GAP3), ranged from 1.5 to 3.7 or increased of 91–580%, 0.8 to 3.5 (72–560%), and 0.6 to 2.58 tons/ha (58–472%), respectively. Notably, G2 + organic exhibited the highest positive absolute yield gap, ranging from 1.1 to 5.38 tons/ha, based on the yield gap matrix. Furthermore, genotype main effect plus genotype-environment interaction (GGE) biplot analysis identified G2 as the most promising rice line, displaying superior yield performance for cultivation in biochar and organic amended soils.DiscussionThese findings provide valuable insights for farmers, governments, and stakeholders, offering a roadmap to optimize rainfed areas for rice production, serving as practical guidance to enhance overall rice productivity in rainfed agroecosystems.

Phenotypic Assessment and Cluster Analysis for Economic Traits in Advanced Lowland Rice (Oryza sativa L.) Breeding Lines

Diversity for economic traits like yield is crucial in rice breeding programmes. In this context, the experiment aimed to identify genetically divergent rice genotypes for hybridization programs, analysing eleven yield and yield-related traits across 35 advanced breeding lines and four check varieties. Employing Mahalanobis’ D2 analysis, the study identified six clusters indicating significant genetic diversity, with the widest divergence observed between clusters VI and IV (203.42) and the closest proximity between clusters III and I (69.25). Traits such as the grain number per panicle and L/B ratio significantly contributed to genetic divergence. Notably, certain breeding line combinations, including KMLT-4 × KPR-2-4-3-1-1, JGL-1798 × KPR-2-7-2-3-4, KMLT-4 × KPR-2-1-7-1-2, KMLT-4 × KPR-2-2-3-1-2-4, and KMLT-4 × KPR-2-2-2-8-2-1-1-2-3, exhibited superior mean yield performance compared to the check varieties under lowland conditions. These promising genotypes offer potential as parental candidates for future hybridization endeavours, aiming to build elite rice cultivars with broader genetic bases, ultimately enhancing agricultural productivity and resilience.

Response of Blackgram Varieties to Various NPK Doses in the Bundelkhand Region, India

Pulses play a pivotal role in contemporary agriculture, influencing food security and climate change mitigation. Blackgram (Vigna mungo L.), with its nutritional richness and adaptability, addresses malnutrition and contributes to soil fertility. This study focuses on enhancing blackgram productivity in Bundelkhand, Uttar Pradesh, addressing challenges through tailored variety selection and balanced nutrient management. The experiment, conducted in 2022, evaluated three varieties (Azad-3, IPU 10-26, IPU 11-2) and three NPK doses (75% RDF, 100% RDF, 125% RDF) to comprehensively analyze growth, yield, and economic parameters of blackgram. Findings revealed that variety IPU 10-26 and NPK dose 100% RDF exhibited superior growth, yield, and economic performance, indicating its competitive and comparative advantage over the other varieties and nutrient management treatments. The study demonstrates that optimal blackgram production in Bundelkhand necessitates location-specific variety choices and a prudent balanced nutrient management strategy that could be exploited for increased productivity of the crop, as exemplified by IPU 10-26 and 100% RDF.

Sustainable Maize Farming: Organic Soil Amendments Boost Maize Production and Soil Quality

Soil organic matter depletion leads to soil structural degradation in cultivated ecosystems. Organic soil amendment reduces inorganic fertilizer dependency, maintains soil properties, and enhances crop production. Organic soil amendments are crucial for sustainable agriculture, providing nitrogen, phosphorus, and potassium to soil and plants. They help address soil organic carbon depletion and environmental issues, as inorganic fertilization hinders sustainable agriculture by affecting soil fertility and crop productivity. A two-year field experiment at the Agriculture Research Farm, University of Agriculture Peshawar-Pakistan, examined the effects of combining organic and inorganic amendments on maize variety Azam and hybrid CS 220, aiming to compensate for soil organic carbon loss. Treatments were Control, Half (H) NPK, Full NPK, Legume Residues (LR) @ 10 tons ha-1, Humic Acid (HA) @ 5 kg ha-1, Biochar (BC) @ 10 tons ha-1, LR + HNPK, HA + HNPK, BC + HNPK, HLR +HHA+ HNPK, HLR + HBC + HNPK and HBC + HHA + HNPK. The study used a two-factorial randomized complete block design with three replications to study maize two-year data. Results showed significant cob lengths in HLR + HBC + HNPK treatment, while maximum results in plant population, 1000 grain weight, and biological yield were in HBC + HHA + HNPK treatment. The highest soil organic matter was recorded in plots with only BC application at 10 tons ha-1, with the highest soil K recorded in BC + HNPK treatment. The hybrid CS 220 maize variety showed superior yield and component performance compared to the Azam variety, while the Azam variety yielded the best results in soil parameters. The maize production improved significantly in the second year compared to the first year. The study suggests that combining organic and half-inorganic fertilizers improves soil fertility, making it a viable strategy for crop yield regulation and sustainable maize production. This can be achieved using efficient organic soil amendments alone or in combination with commercially available inorganic fertilizers.

Effect of Fenton pre-oxidation on the physicochemical properties of sludge-based biochar and its adsorption mechanisms for ammonia nitrogen removal

Fenton pre-oxidation, as a promising technology for sludge deep dehydration, has been used intensively; however, the outputs (i.e., low-water-content sludge cakes) need to be further disposed for a full line sludge resource utilization. Carbonization presents a promising approach for disposing of the sludge cake within the process. Here, the physicochemical properties of sludge-based char obtained after Fenton pre-oxidation were studied. Both Fenton pre-oxidized sludge-based char (FSC) and raw sludge-based char (RSC) were produced within the temperature range of 400–600 ℃, and the adsorption performance of the prepared chars, exemplified by their ability to adsorb ammonia nitrogen (NH4+), was tested under various conditions. FSC exhibited superior char yield and adsorption performance compared to RSC, with chemical adsorption being the primary controlling factor. The optimum conditions for FSC were observed at 400 ℃, resulting in a char yield of 72.2 %, and an adsorption capacity of 221.7 mg/g. Notably, FSC demonstrated an increase in C-C, C-N, OC-O, C-O and CC functional groups in comparison to RSC, which suggests that pre-oxidation increases organic matter decomposition and chemical reactivity of the sludge. The introduction of Si-O-Si, Si-O-C and Fe-O-H functional groups in the FSC facilitated ion exchange with NH4+ in an aqueous solution. The key findings indicate that Fenton pre-oxidation not only enhances the adsorption performance of FSC but also reduces the required carbonization temperature for excellent-char preparation. These results demonstrated the potential to integrate sludge deep dewatering, including pre-oxidation, with char preparation.

Citrus crop performance and fruit quality in response to different scion-rootstock combinations

Aim of study: To address diversification of citrus cultivars to increase the variety and profitability of orchards to adapt them to environmental changes. Area of study: State of São Paulo, a subtropical region of southeastern Brazil. Material and methods: The study evaluated the phenological intervals, thermal sum, vegetative and productive performance, and fruit quality of the sweet orange cultivars ‘Rubi’ (R), ‘Lue Gin Gong’ (LGG) and ‘Valencia Delta Seedless’ (VDS) grafted onto 'Rangpur' lime (RL) and 'Swingle' citrumelo (SC). The field experiment was conducted over consecutive growing seasons 2018-2021. Main results: The duration of the phenological intervals was little influenced by the rootstocks. The harvest time was approximately 245 days after anthesis (DAA) for R, 402 DAA for LGG, and 407 DAA for VDS, regardless of rootstock. Scion cultivars grafted onto RL showed larger canopy volumes and greater weight, length, and diameter of fruits than those of SC trees, and the combinations with SC were more productively efficient than RL due to lower canopy volume. The R scion cultivar presented superior yield performance and fruit colouration than LGG and VDS. The physicochemical quality of the fruits showed improved results with the combinations of LGG/RL, LGG/SC, VDS/RL, and VDS/SC. Research highlights: These results may be useful when planning the diversification of scion/rootstock combinations for new orchards, identifying dual-market orange cultivars for industrial processing and natural consumption, and determining the combinations that are better adapted to undesirable climatic conditions.

Adaptability of Genetically Engineered Bt Cotton Varieties in Different Growing Regions of Ethiopia

Cotton varieties that are high yielding and resistant to pests are required to improve production and productivity and to capitalize on the crop’s enormous potential and its critical role in Ethiopia’s expanding textile industry. Lack of improved cotton technology has forced farmers to recycle local varieties for ages which have become very susceptible to pests which are the major causes of very low productivity and quality of cotton in the country. Among major pests, bollworms (Helicoverpa armigera and Pectinophora gossypiella) account for 36–60% of yield losses. In the absence of genetically resistant or tolerant varieties, genetically engineered bollworm-resistant Bacillus thuringiensis (Bt) cotton has offered a great opportunity to reduce crop losses from bollworms. The objective of the study was to evaluate the efficacy of bollworm resistance and adaptability of Bt cotton varieties across cotton growing environments in Ethiopia and provide recommendations. Two Bt cotton hybrids (JKCH 1947 and JKCH 1050), one Bt OPV (Sudan), and three OPV conventional varieties (Weyito 07, Stam-59A, and Deltapine-90) were evaluated at seven different agro-ecologies using a randomized complete block design (RCBD) with three replications. Results showed significant differences among genotypes for yield and other traits. Hybrids JKCH 1947 and JKCH 1050 were the top high yielders under high and mild bollworm infestations, with mean seed cotton yield of 3.10 t·ha−1 each and lint yield of 1.20 and 1.19 t·ha−1, respectively, whereas the standard check Deltapine-90 (popular variety) recorded a mean seed cotton and lint yield of 2.3 t·ha−1 and 0.8 t·ha−1, respectively. Combined analysis showed that genotypes, environment, and the genotypes × environment interactions had a highly significant effect ( P < 0.05) on fiber quality. Weyito 07 and the two hybrids (JKCH 1947 and JKCH 1050) had upper half mean fiber lengths in the range of 27.78 to 32.11 mm. For fiber strength, genotypes Weyito 07, JKCH 1050, Stam-59A, and JKCH 1947 had 33.50 g/tex, 28.59 g/tex, 28.00 g/tex, and 27.75 g/tex, respectively. The fiber quality values of the hybrids were within acceptable limits, with staple lengths ranging from 27.78 to 28.44 mm and fiber strengths ranging from 27.75 to 28.59 g/tex. Results show potential adaptation of the hybrids under different cotton growing environments and their superior yield performance due also to added protection of yield losses from damage by bollworms. The contrast is bigger under high insect pressure conditions due to the genetically engineered Bt trait compared to the conventional varieties. The effective field resistance against bollworms in most locations shows that wider use of these hybrids can enhance cotton productivity and quality in Ethiopia.

Fall Armyworm Tolerance of Maize Parental Lines, Experimental Hybrids, and Commercial Cultivars in Southern Africa

Fall armyworm [Spodoptera frugiperda (J./E. Smith); FAW] is negatively impacting sustainable maize production, particularly in smallholder farming systems in sub-Saharan Africa. Two sets of germplasm (commercial cultivars and experimental hybrids, and local and exotic inbred lines) were evaluated under managed and natural FAW infestation to identify FAW tolerant material with superior grain yield performance. Significant genotypic effects on foliar FAW damage, ear FAW damage, and grain yield were observed. Commercial cultivars were significantly more affected by FAW infestation than experimental hybrids, as evidenced by high foliar and ear damage scores, yet they out-yielded experimental genotypes. The introduced FAW donor lines (CML338, CML67, CML121, and CML334) showed better tolerance to FAW, individually and in hybrid combinations. Local inbred lines, SV1P, CML491, and CML 539, also showed FAW tolerance. Hybrids and open pollinated varieties were more vulnerable to FAW damage at early growth stages, but they grew out of it through the mid to late whorl stages. Inbred lines showed increasing damage as they grew to maturity. Husk cover, ear rot, anthesis date, and plant height were highly correlated with FAW tolerance. The identified local and exotic lines with FAW tolerance will contribute to FAW resistance breeding in southern Africa.

Canopy cooling traits associated with yield performance in heat-stressed oat

In the upper U.S. Midwest, oat is a promising crop for diversifying local cropping systems and providing local consumers with a healthy food option. However, as a result of climate change, the crop is facing increasingly severe episodes of high temperature (HT) stress during reproductive development, which limit its yield potential. The goal of this 3-year field study was to identify locally-adapted HT stress-tolerant oat breeding lines, propose a parsimonious mechanistic basis for HT stress tolerance and leverage it to develop a screening method with the potential to support a breeding program. Because water supply is rarely limiting in the region, we tested the hypothesis that canopy latent cooling would be a desirable trait. To this end, we deployed “heat tents” on a core panel of 30 oat lines between booting and heading, where we measured i) grain yield and quality traits (protein, oil and beta-glucan), ii) pollen viability, percentage of filled florets, and grain number, iii) gas exchange and canopy cooling parameters (e.g., photosynthesis, transpiration rate, stomatal conductance, canopy temperature depression). Additionally, we developed a thermal imaging approach to remotely quantify canopy temperature on contrasted lines. Significant genotypic variability was detected in yield and quality trait responses to the HT stress and a physiological path model identified canopy cooling as a main process explaining superior yield performance of HT stress tolerant lines. Interestingly, pollen viability was not found to be the main driver of yield declines, suggesting a role played by other reproductive processes, including those underlying female tissue/organs sensitivity to HT stress. Finally, canopy cooling parameters correlated with geographic locations of breeding programs from which the tested germplasm originated, indicating that they are under selection. Overall, this study opens the way for a breeding program targeting the development of more climate-resilient oats adapted to northern climates.

Variation in Nutritional Components in Roots from Ahipa (Pachyrhizus ahipa (Wedd.) Parodi) Accessions and an Interspecific Hybrid (P. ahipa × P. tuberosus (Lam.) Spreng.)

Among the many neglected underutilized species, tuberous Andean root crops such as the ahipas (Pachyrhizus ahipa) constitute a promising alternative for increasing diversity in nutrient sources and food security at a regional level. ahipa × P. tuberosus). A significant objective was to determine protein and free amino acids in the roots to evaluate their food quality as protein supply. The interspecific hybrids have been found to possess the root quality to provide the crop with a higher dry matter content. The high dry matter content of the P. tuberosus Chuin materials is retained in the root quality of the hybrids. Food functional components such as carbohydrates, organic acids, and proteins were determined in several ahipa accessions and a stable (non-segregating) progeny of the interspecific hybrid, X207. The X207 roots showed a significantly higher dry matter content and a lower content in soluble sugars, but no significant differences were found in starch content or organic acids compared to the ahipa accessions. Regarding the root mineral contents, Fe and Mn concentrations in X207 were significantly raised compared to the average of ahipa accessions. Among the ahipa and the hybrid, no prominent differences in protein content or protein amino acids were found, being both partially defective in providing sufficient daily intake of some essential amino acids. Root weight, a central component of root yield, was significantly higher in X207, but thorough field studies are required to substantiate the hybrid’s superior yield performance.

Leptin Gene (T117C) Polymorphism and Its Association with Milk Yield Performance in Crossbred Anglo-Nubian Goats

This study was performed to determine polymorphism in the leptin gene (T117C) and investigate the association between genotypes and milk yield in 101 crossbred Anglo-Nubian dairy goats from Awang, Opol, Misamis Oriental and Talay, Dumaguete City, Negros Oriental in the Philippines. Milk yield performance data were standardized to 90 and 140 d milking periods. The goat’s hair follicles were collected to extract genomic DNA. Polymerase chain reaction– restriction fragment length polymorphism (PCR-RFLP) was the method used in genotyping with NmuCI as the restriction enzyme. Statistical analysis was performed following the two-way factorial (2 x 4) in a randomized complete block design (RCBD), where leptin genotypes and parity were used as main factors and farm as the blocking factor. Two genotypes (TT and TC) were obtained. Genotypic frequencies between TT (0.50) and TC (0.50) were evenly distributed, while allele T (0.75) occurred more frequently than allele C (0.25) in the total population studied. Observed heterozygosity is higher than the expected heterozygosity and the genetic variation observed in the overall population was in Hardy-Weinberg equilibrium (p > 0.05). Milk yield traits at 140 d milking period in crossbred Anglo-Nubian dairy goats were significantly influenced by polymorphisms in leptin (T117C). Goats having TT genotype had superior milk yield performance (140dADMY: 0.90L ± 0.058L, 140dTMP: 124.65L ± 8.51L) than those with TC genotype (140dADMY: 0.78L ± 0.051L, 140dTMP: 107.90L ± 7.21L). Further studies should be conducted in other goat breeds to validate associations of leptin polymorphism with milk production and in other economically important traits.

Grain-Filling Characteristics in Extra-Large Panicle Type of Early-Maturing japonica/indica Hybrids

Early-maturing japonica/indica hybrids (EJIH) have recently been released, performing a yield potential of 13.5 t ha−1 and greater yield increase over conventional japonica rice (CJ) and hybrid indica rice (HI) in production. More spikelets per panicle and improved grain-filling efficiency underlined the basis for the superior yield performance of EJIH. However, few studies are available on the panicle traits and grain-filling characteristics of EJIH, as well as their differences to CJ and HI. In our study, two EJIH, two CJ, and two HI cultivars with similar growth patterns were grown in the same fields. EJIH had a 12.2–18.8% increased (p < 0.05) grain yield relative to CJ and HI, mainly attributed to their higher daily grain yield. Although it had a lower panicle per m2, EJIH exhibited 28.0–38.3% more (p < 0.05) spikelets per m2 from an increase of 58.0–87.8% (p < 0.05) in spikelets per panicle than CJ and HI. Compared with CJ and HI, EJIH had a higher single panicle weight and more grains in the six parts of the panicle, especially in the upper secondary branches (US) and middle secondary branches (MS). EJIH exhibited a higher leaf area index (LAI), leaf area duration (LAD), leaf photosynthetic rate, and SPAD values after heading, which helped increase shoot biomass weight at heading and maturity and post-heading biomass accumulation. For CJ and HI, the grain-filling dynamics of grains in the six parts were all well simulated by the Richards equation. For EJIH, the grain-filling dynamics of grains in the lower secondary branches (LS) were well fitted by the logistics equation, with the Richards equation simulating grain positioning on the other five parts. EJIH had a lower mean grain-filling rate (GRmean) and longer days and grain filling amounts (GFA) during early, middle, and late stages than CJ and HI. Our results suggest EJIH gave a yield advantage over CJ and HI through a higher daily grain yield. The panicle traits and grain-filling characteristics differed greatly among the three cultivar types. Compared with CJ and HI, EJIH had lower GRmean and higher days and more grains in the panicle during early, middle, and late stages, which contributed to an increased GFA after heading, improved filled-grain efficiency, and higher grain yield.

Agronomic and physiological traits facilitating better yield performance of japonica/indica hybrids in saline fields

• JIH exhibited yield superiority over IH not only in non-saline fields, but also in saline fields. • Limited shoot and root growth were responsible for the yield penalty of rice under saline field conditions. • The improved agronomic and physiological traits of JIH facilitated superior grain yield over IH in saline fields. It is of great interest to utilize saline fields to promote rice production in China. Previous studies reported greater yield productivity of japonica/indica hybrids (JIH) over indica hybrids (IH) under nonsaline fields. It has still not been established how salinity stress intervenes with rice yield and whether JIH would exhibit superior grain yield than IH under saline field conditions. This study investigated three JIH and three IH cultivars grown at the two sites that differed significantly in soil salinity, namely, nonsaline (Wulie, abbreviated as WL) and saline (Tiaozini, abbreviated as TZN) fields, in Yancheng, Jiangsu, China. The panicles per m 2 , spikelets per panicle, filled-kernel percentage, and kernel weight of JIH and IH were reduced, and a 36.0 %–43.5 % loss in grain yield was observed with salinity stress at TZN compared with WL. For JIH and IH, the shoot biomass and leaf area index (LAI) at jointing, heading, and maturity were all reduced at TZN compared to those at WL; similar results were also detected for root biomass, root length and volume, and root bleeding rate after heading. Compared with IH, JIH produced a 24.8 % higher grain yield under saline field conditions at TZN across two years. Four agronomic and physiological traits were summarized for superior grain yield of JIH compared to that of IH with salinity stress under field conditions. First, JIH had an enlarged sink size potential of a greater number of spikelets per panicle. Second, a synergistically increased biomass accumulation and harvest index of JIH, supported by higher biomass accumulation and LAI at the main growth stages and improved NSC remobilization after heading. Third, JIH had an improved stay-green characteristic, indicated by a higher leaf area per plant, SPAD values, and leaf photosynthetic rate after heading. Fourth, JIH exhibited a better root morpho-physiology than that of IH after heading, showing a larger and deeper root structure and higher root bleeding rate. These results indicated that the limited shoot and root growth were responsible for the yield penalty of rice under saline field conditions. JIH's improved agronomic and physiological traits facilitated superior yield performance over IH with salinity stress under field conditions.

Determination of Stability and G × E Interaction of Legume and Cereal Genotypes in Different Agro-Ecologies of Central Tanzania

Legumes and cereals are essential components of sustainable agricultural production systems and are vital in sustaining food, nutrition, income security as well as improving soil health status in the semi-arid tropics. Field experiments were conducted during the 2019-2020 cropping season in different sub agro-ecologies of central Tanzania to determine stability and genotype x environment interaction (GEI) of legume and cereal genotypes for grain yield in the different sub agro-ecologies. An incomplete randomized block design with farmers as replications was used at each sub agro-ecology. Grain yield data of the fourteen genotypes in total of the four crops (groundnut, pigeon pea, sorghum and pearl millet) was collected. Results from the experiments generally revealed that G x M x E interactions were insignificant in terms of grain yield for all the crop genotypes studied. Among the groundnut and pigeon pea genotypes, significant differences were observed across the sub-ecologies while significant genotypic effects were observed in both sorghum and pearl millet genotypes. Although early planting outperformed late planting for the crop genotypes tested in terms of grain yield, non-significant differences in planting dates were observed. Furthermore, crop genotypes in the high potential generally out performed those under the moderate and low potential sub-ecologies. The above findings revealed that genotypes ICGV-SM 05650, ICEAP 00040, GAMBELA 1107 and IP8774 with superior grain yield performance were more adapted thus, recommended for deployment in these sub agro-ecologies of central Tanzania

Identification of Spring Barley Breeding Lines With Superior Yield Performance and Stability

The aim of the present study was to substantiate theoretically and to test in practice scheme of multi-environment trials at the final stage of spring barley breeding process and to distinguish the genotypes which combine superior yield performance and stability. In the first year of competitive testing (2015) nine promising spring barley breeding lines have been selected under condition of the Central part of Forest-Steppe of Ukraine (latitude 49°64′, longitude 31°08′, altitude 153 m). In 2016 and 2017, the genotypes were additionally tested in two other different agro-climatic zones of Ukraine: Polissia (latitude 50°93′, longitude 31°69′, altitude 126 m) and Northern Steppe (latitude 48°56′, longitude 32°32′, altitude 171 m). In addition to the standard variety Vzirets, the breeding lines were compared with ten widespread spring barley varieties in agricultural production. Significant total yield variability of the genotypes and cross-over genotype by environment interaction has been revealed. It confirmed the validity of proposed combination of spatial (zones) and temporal (years) gradients for more efficient evaluation of the genotype by environment interaction and differentiation of genotypes in terms of yield performance and stability. As a practical result, using additive main effects and multiplicative interaction (AMMI) and genotype main effects plus genotype by environment interaction (GGE) models, four spring barley breeding lines with combination of superior yield performance and high stability have been identified.

GROWTH AND YIELD OF OKRA VARIETIES AS AFFECTED BY RATES OF ORGANO-BASED FOLIAR FERTILIZERS IN RAINFOREST AND RAINFOREST/SAVANNA TRANSITION AGRO-ECOLOGY OF NIGERIA

A field experiments were conducted at the Directorate of University Farms, Federal University of Agriculture, Abeokuta (FUNAAB) and National Horticulture Research Institute (NIHORT), Ibadan between May and August 2015 to assess the effect of different f organo-based fertilizer (fertilizer applied on the leaves) and their rate on growth and yield of two Okra Varieties: LD88 (Late Maturity), and NHAe–47 (Early Maturity). The experiment was laid out in randomized complete block design and replicated three times. The experiment was a 2 × 2 × 5 factorial combinations laid out in a Randomized Complete Block Design in a split-split-plot arrangement, with three replicates at both locations. Factors were okra varieties (LD88 and NHAe–47), the fertilizer types (D.I grow green ® and D.I grow red®) and four rate of foliar applications (0, 300, 600 and 900 ml/ha) while NPK 15:15:15 served as check were applied at 4,6, and 8 Weeks After Sowing (WAS). Agronomic data were obtained from growth and yield variables. Results showed that varieties had significant (P≤ 0.05) effect on growth and yield variables. Variety of LD88 had higher plant height and more leaves than NHAe-47 at both locations. Foliar fertilizer had significant (P≤ 0.05) effect on growth and yield variables. The D.I Grow Green® produced significantly numbers of leaves (11, 9). Application rate of 300 ml/ha and 600 ml/ha D.I.Grow Green® gave a better performance. The LD88 variety produced significantly (P< 0.05) longer pod length (4.68 cm), fresh fruit weight (4.84 t/ha) and dry fruit weight (0.31 t/ha) than NHAe-47. Application rate of 600 mls/ha D.I.Grow Red® produced significantly fresh fruit weight (5.79 t/ha) compared to control (1.32 t/ha). In conclusion, okra variety LD88 had superior growth and yield performance. Application of D.I.Grow Red® at the rate of 300 ml/ha at Funaab and 600ml/ha at Nihort enhance fruit yield performance on okra. Therefore, 300ml/ha and 600ml/ha could be recommended to farmers in Rainforest/Savanna transition (Abeokuta) and Rainforest agro-ecology (Ibadan), respectively
 
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Progress check of yielding ability and stability of selected pre-release bread-wheat cultivars in Zimbabwe

The Crop Breeding Institute (CBI) develops new bread-wheat varieties as part of its research mandate. These are tested every year in multi-environmental trials (METs) so as to identify best performers suitable for commercial release. Here, we used METs’ datasets collected across 57 locations in Zimbabwe during the 2009–17 winter seasons, on yield and agronomic performance of CBI-bred, 156 advanced experimental lines and 69 check cultivars. Twenty-five genotypes were tested each year, but the number of sites varied accordingly. The wheat genotypes were planted using an alpha (0.1) lattice design replicated thrice, and each replication constituted five incomplete blocks, with a block size of five. Significant differences in grain yield (GY) on some locations, as well as, significant GE interactions on GY were observed. GY averages of the best five experimental lines in the year 2013 and 2015 significantly differed from those of the best five check cultivars. Furthermore, yield increments were shown from the season, 2010–15, and GY averages of the best five experimental cultivars, successively differed between these seasons. Significant correlations were shown between GY and the other agronomic traits, particularly days to anthesis and days to physiological maturity. Experimental genotypes identified as G12|2014 (7.3 tha−1), G8|2013 (5.5 tha−1), and G8|2009 (5.4 tha−1) showed superior yield performance and stability hence, can be recommended for commercialization. Generally, an observable trend in yield increments was observed between the seasons, 2009–17, and experimental lines that showed superior performance can be possible targets for gene introgressions and integrations in breeding programs in the other regions.