Search Results (71)

Several biogeochemical models have been applied to understand the potential effects of management practices on soil organic carbon (SOC) sequestration, crop growth, and yield. In this study, the denitrification and decomposition (DNDC) model was used to simulate soil SOC dynamics and harvested C-biomass in rice–wheat rotation under organic/inorganic fertilization with conventional tillage (CT) and reduced tillage (RT). Before calibration, DNDC underpredicted harvestable grain C-biomass of rice where percent difference (PD) varied from 29.22% to 42.14%, and over-simulated grain C-biomass of wheat where PD was −55.01% with 50% nitrogen–phosphorus–potassium (NPK) and 50% animal manure applied under the CT treatment. However, after calibration by adjusting default values of soil and crop parameters, DNDC simulated harvestable grain C-biomass of both crops very close to observed values (e.g., average PD ranged from −2.81% to −6.17%). DNDC also predicted the effects of nutrient management practices on grain C-biomass of rice/wheat under CT/RT using d-index (0.76 to 0.96) and the calculated root mean squared error (RMSE of 165.36 to 494.18 kg C ha⁻¹). DNDC simulated SOC trends for rice–wheat using measured values of several statistical indices. Regression analysis between modeled and observed SOC dynamics was significant with R² ranging from 0.35 to 0.46 (p < 0.01), and intercept ranging from 0.30 to 1.34 (p < 0.65). DNDC demonstrated that combined inorganic and organic fertilization may result in higher C-biomass and more SOC sequestration in rice–wheat systems. Full article

Cassava fresh root yield and dry matter content constitute major determinants of demand by end-users. Increased demand for the seeds of improved varieties will facilitate the development of a sustainable seed system. However, for wide acceptability, there is a need to continuously evaluate candidate varieties for stability across different agroecological zones. Participatory Demand Creation Trials (DCTs) were established to evaluate cassava varieties with farmers and processors utilizing the best agronomic practices. The multi-year DCTs were conducted in 20 environments (7 locations) during the 2016–2017, 2017–2018, 2018–2019, and 2019/2020 cropping seasons with two replications. The plot sizes were 320 m² with a spacing of 1 m × 0.8 m. The traits evaluated were Plant Vigor (PV), root number, fresh yield, dry yield, Dry Matter Content (DMC), and bundle estimation. The traits were subjected to a GGE biplot in R software to identify high-yielding and stable genotypes. Results obtained from the 20 environments showed that genotype (G), environment (E), and GXE interaction effects were significant (p < 0.01) for all the traits but PV. The heritability ranged from 56% (PV) to 96% (DMC). The average fresh yield t/ha ranged from 25.5 (IBA30572) to 35.4 (IBA980505). The DMC ranged from CR36/5 (36.1%) to IBA010040 (30.7%). The dry yield ranged from 8.8% (IBA30572) to 11.4 (IBA980505). Estimated bundles ranged from 13.5 (CR36-5) to 15.7 (IBA950289). Three varieties, IBA961632, TMEB419, and CR36/5, were identified as the most promising high dry matter content varieties for cassava processors and farmers in Nigeria, and genotype IBA961632 was the most stable. The study revealed greater genotypic effects than from the environment and high genetic advances. Full article

Wheat, the world’s most widely cultivated crop, is highly susceptible to Take-all disease caused by the soil ascomycete fungus Gaeumannomyces tritici (Gt). Crop rotations using different wheat cultivars can influence Take-all build up (TAB) in the following year’s wheat crop. The exact mechanism for this is unknown, but there may be a bacterial biocontrol component associated with TAB control. We cultured and characterised Pseudomonas isolates from the rhizosphere and endosphere of second-year field-grown wheat, in plots which, in the previous season, had been used to culture High-TAB cultivar Hereward or Low-TAB cultivar Cadenza. Analysis of two bacterial loci, wsm and fecB, showed that these genes were significantly and differentially associated with first-year wheat-planting regime: wsm was more abundant within the High-TAB Hereward-derived isolates, while fecB was more prevalent within the Low-TAB Cadenza-derived isolates. These findings were supported by a gyrB phylogenetic analysis and an in vitro Gt antagonism assay. These data show that the wheat cultivar grown in the first year plays an especially important role in the selection of the associated Pseudomonas spp. found in the second-season wheat-root environment, emphasising the importance of understanding agronomic practice in improving plant health and food security. Full article

Transplanted rice cultivation has caused groundwater depletion in several regions globally. Direct-seeded rice under aerobic conditions is a water-saving alternative. However, under aerobic conditions, iron in the soil is oxidized from the ferrous to ferric forms, which are not easily available to rice crops, resulting in iron-deficiency-induced chlorosis (IDIC) and causing significant reductions in yield. Cultivated rice accessions have limited variations in IDIC tolerance, while the wild Oryza germplasm could be a potential source of IDIC tolerance. In this study, 313 Oryza accessions were evaluated for IDIC tolerance at the tillering stage under aerobic conditions and 20 IDIC-tolerant lines were identified. The twenty lines showed no signs of chlorosis and had high levels of iron content and SPAD values, while the eight cultivated controls exhibited varying degrees of chlorosis symptoms and low levels of SPAD and iron content. To confirm their tolerance, the selected lines were evaluated again in a subsequent year, and they showed comparable levels of tolerance, indicating that these lines were efficient in iron uptake and utilization, resulting in maintained high chlorophyll and leaf area index. These accessions may be useful for developing IDIC-tolerant cultivars for aerobic rice cultivation and future studies of the molecular basis of IDIC tolerance. Full article

Winged bean [Psophocarpus tetragonolobus (L.) DC.] is an underutilized legume with the potential to contribute to nutrition and food security globally, particularly in sub-Saharan Africa (SSA). However, more attention needs to be paid to exploiting its full potential due to a lack of adequate knowledge of the existing genetic diversity in the available winged bean germplasm. To bridge this gap, thirty accessions of winged beans sourced from the Gene Bank of the International Institute of Tropical Agriculture (IITA), Ibadan, were evaluated for seed morphometric and selected agro-morphological traits at three agro-ecological zones in Nigeria. The data obtained were subjected to analysis of variance (ANOVA), principal component (PC) analysis, cluster analysis, and correlation analysis. Significant differences (p < 0.05) were observed among the accessions for all measured traits. The first two PCs accounted for 88.2% of the variation observed among the accessions for all measured traits. Accessions were grouped into three clusters based on the agro-morphological traits and three clusters under the multi-spectral imaging (MSI) system. TPt-31 had the highest seed yield per plant, pod weight per plant, and early maturity, while TPt-7 had an extended flowering and maturity period, the highest number of pods per peduncle and pods per plant, as well as the lowest seed yield. These accessions could be a good resource for future winged bean improvement programs. The result also confirmed that the MSI system is an invaluable tool for discriminating among accessions of the same crop species. The findings of this study provide insight into the genetic diversity of winged bean germplasm, which could contribute to improving its yield and quality in SSA and globally. Full article

Banana bunchy top disease (BBTD) is an invasive viral disease spreading in Africa. It is transmitted by banana aphids and infected planting material, causing production losses. Clean seeds and timely eradication of diseased plants are effective tools in BBTD management. These depend on timely disease detection. We assessed the relationship between symptom expression and infectivity of the virus in four cultivars of banana. Plantlets from four cultivars, ‘FHIA 25’; ‘Aloga’; ‘Ebenga’ and ‘Sotoumon’, were exposed to viruliferous aphids and monitored for symptom expression. They were also tested as sources for virus transmission fortnightly by allowing non-viruliferous aphids acquisition access prior to transfer to healthy test plants. The time required to show symptoms and the symptom expression were compared, and infection tested by PCR. Disease expression varied from four weeks in ‘FHIA 25’ to fifteen in ‘Sotoumon’. Only the symptomatic leaves tested positive and could act as infection sources. Overall, ‘FHIA 25’ was the most susceptible cultivar, while ‘Sotoumon’ was the least susceptible and most rapidly expressive of BBTD, yet there was no difference in the leaf emergence rate between the cultivars. These results present important aspects of BBTD control and the safety of planting materials that should be tested in the field. Full article

Nitrogen is the main nutrient required by plants for growth. The production of onions (Allium cepa) results in low nitrogen use efficiency (NUE) as nitrogen is applied when it is not required by the plant; resulting in loss to the environment. This work assessed the ability of stabilised amine nitrogen (SAN) to increase the NUE and yield of onion. In a glasshouse, two onion cultivars (F₁ Hybound (pelleted) and Ramrod) were grown and fertilised with 150 kg N ha⁻¹ as urea applied to the soil or 2.7 kg N ha⁻¹ as SAN applied foliarly at the three, four and five leaf stages. The survival percentage, number of leaves, height, weight, bulb diameter and stem diameter were recorded. For both cultivars, the survival percentage was increased with the SAN, with the increase being significant for Ramrod. While for all other parameters, SAN resulted in significant increases for both cultivars. In field plot trails, applications of 150 kg N ha⁻¹ were compared to applications of 7.56 kg N ha⁻¹ as SAN, which gave statistically similar yields and increased the NUE. This work shows that considerably reduced N as SAN was a significant improvement over the traditional 150 kg N ha⁻¹ for onion production. Commercial application of this work would significantly improve the profitability of onion production due to reduced purchase of N and increased yield. Full article

The sunflower (Helianthus annuus L.) is an oleaginous plant that shows high suitability for cultivation in Brazil. However, the performance of the crop is influenced by factors such as weed interference, mainly because of the few selective herbicide options. Thus, the objective of this study was to evaluate weed control and selectivity of four pre-emergent herbicides applied to two sunflower cultivars in sandy and clayey soils. Two field experiments were conducted in a randomized block design with a 2 × 6 factorial scheme, two cultivars (CF 101 and M 734) and six treatments with S-metolachlor (1920 g a.i. ha⁻¹), sulfentrazone (150 g a.i. ha⁻¹), flumioxazin (40 g a.i. ha⁻¹), and trifluralin (1780 g a.i. ha⁻¹) and two controls, one with weeding and the other without weeding and without herbicide application, in soils with contrasting textures (sandy and clayey). No injury symptoms were observed in both cultivars, regardless of soil texture. The cultivar M 734 exhibited the highest values of the agronomic parameters evaluated. The treatment with flumioxazin provided control of more than 90% of the weeds in clayey soil and more than 64% in sandy soil. The yield of both cultivars was lower in the sandy soil. Thus, all herbicide treatments were selective for both cultivars tested, since they did not interfere with sunflower grain yield. Full article

Antioxidant properties of phenolic compounds are presumed responsible for several health benefits due to their capacity to scavenge free radicals and chelate metals prevenient oxidative stress. Since these compounds are ubiquitous in plants, including cereals, the available antioxidant potential profile of wheat genotypes could allow the development of new cultivars with an increased nutritional value that may result in antioxidant-rich foods. In this study, total phenolics content (TPC) was quantified in the whole grain flour of 92 wheat (46 genotypes each from bread and durum) genotypes, which were evaluated under field conditions during 2 different crop seasons (2004-05 and 2009-10). Of the ninety-two, fourteen (six and eight from bread and durum wheat, respectively) genotypes were comprehensively evaluated for antioxidant activity [2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and reducing power] and ferulic acid contents. The results revealed that substantial genotypic variability exists for TPC in wheat genotypes with a mean value of 991 and 787 µg ferulic acid equivalents (FAE)/g DW in bread and durum wheat, respectively. Moreover, bound phenolics as a source of ferulic acid, including both cis- and trans-isomers, were observed as a major contributor to the total phenolics, which must be considered in assessing the antioxidant activity in wheat grain. In conclusion, these findings may also help improve wheat grains as natural sources of antioxidants utilizing selected genotypes in breeding programs. Full article

The phytopathogen Phytophthora parasitica, from the Oomycetes class, known to be the tobacco black shank agent, can induce devastating diseases in various crop, plant and forest ecosystems. The genus Phytophthora has been studied at the cellular level, suggesting that different developmental steps are induced by the expression of some specific genes. However, these studies have only been carried out on certain species, such as Phytophthora infestans and Phytophthora cactorum. As for Phytophthora parasitica, which can be considered as one of the top ten oomycete pathogens due to the economic impact and effect it has on food security, even less functional analyses and transcriptomics data are available. To date, little is known about the protein expression of Phytophthora parasitica, information that is essential for achieving a better understanding of this species. In this study, we aimed to gain insight into the proteomics of the mycelium of the Phytophthora parasitica strain INRA 310 by addressing the following questions: (i) how many predicted proteins can be detected on the mycelium of P. parasitica INRA 310, and (ii) what proteins can be detected? The proteomics experiments were performed on the mycelium of the strain Phytophthora parasitica INRA310, using the nanoliquid chromatography-MS/MS technique. A total of 219 proteins were identified, including ten unknown proteins and 209 proteins involved in lipid, carbohydrate, nucleotide, energy production and other metabolic pathways. This proteomics study is, to our knowledge, the first to be performed on the mycelium of Phytophthora parasitica INRA 310. It gives a brief first insight into its in vitro-expressed proteins. This work may be the first step before further, more comprehensive studies are undertaken with the aim of better understanding the biology of this species and its pathogenicity. Full article

Micronutrient fertilization is usually neglected by producers, especially for peanut, a crop that is frequently grown in crop rotation systems due to its low perceived nutrient requirements. New peanut cultivars are able to achieve high yields when grown under suitable conditions. However, fertilization recommendation tables are dated and do not consider the need for micronutrients. To support improvements in these recommendations, this study quantified the micronutrient demand (B, Cu, Fe, Mn, and Zn) of three runner peanut cultivars (IAC Runner 886, IAC 505, and IAC OL3) during the biological cycle and the transport of these micronutrients to pods and kernels. The experiment was carried out in a randomized complete block with a split-plot design and nine replications. The whole plots consisted of the three peanut cultivars, and the subplots comprised nine plant samplings (at 14, 28, 42, 56, 70, 84, 105, 126, and 147 days after emergence (DAE)). These modern peanut cultivars exhibited high uptake and accumulation of Fe, but the proportion of Fe removed by pods and kernels was lowest among all analyzed micronutrients. The second-most-accumulated micronutrient was Mn. The maximum requirement for micronutrients of peanut occurred around 84 DAE, and IAC 505 had the highest micronutrient uptake and accumulation among the cultivars (especially at later stages), followed by IAC OL3 and IAC Runner 886. Our results provide new insights into micronutrient requirements for peanut and demonstrate the need for new fertilizer recommendation programs for peanut cultivation. Full article

To investigate responses of two winter wheat genotypes under different crop management systems (rotation and tillage), a split–split plot experiment was conducted based on a randomized complete block design (RCBD) with three replications during 4 years in Maragheh, Iran. Three crop rotation treatments [vetch–wheat (V–W), chickpea–wheat (C–W), and safflower–wheat (S–W)] were considered in main plots, three tillage treatments (conventional-tillage (CT), minimum-tillage (MT), and no-tillage (NT)) were located in subplots, and two winter dryland wheat genotypes (Baran and Azar2) were allocated in sub-sub plots. Results indicated that soil moisture content in NT was greater than that in MT and CT. The highest relative water content (RWC), normalized difference vegetative index (NDVI), stomatal conductance (gs), and transpiration rate (E) were obtained from the Baran genotype in the V–W rotation under NT. In the last year of the experiment, rainfall productivity in NT treatment improved by 32%, compared to CT. The Baran genotype had higher rainfall productivity in both MT and NT treatments with 0.71 and 0.70 kg m⁻³, respectively. Crop water requirement was not affected by crop rotation or tillage treatments. Maximum grain yields in V–W, C–W, and S–W rotations were recorded as 2231, 2105, and 1991 kg ha⁻¹, respectively. With increasing soil moisture storage and improving rainfall productivity under full implementation of conservation agriculture components (after 4 years), grain yield of Baran and Azar2 improved in NT compared to that of CT by about 6–9% and 6–14%, respectively. Therefore, the application of V–W rotation with NT in cold dryland areas is recommended for developing of conservation agriculture system. Full article

Amaranthus caudatus is a nutrient-rich Andean pseudocereal with wide genetic variability. Six productive varieties (Oscar Blanco, Pucara, Tomina, Cotahuasi, Barbechos, and Guindo Criollo) were compared by proximate, mineral, and fatty acid composition. The proximal content showed certain singularities in the varieties. Barbechos and Guindo Criollo stood out for their fat content (9.50% and 9.01%, respectively), while Tomina stood out for their carbohydrate content (72.6%), and Pucara and Oscar Blanco for their fiber content (4.59% and 4.48%, respectively). The mineral content presented differences, highlighting the Ca content for Pucara (108 mg/100 g), and Tomina with micro-minerals (Zn, Mn, Fe, and Cu, 4.67, 5.90, 9.13 and 1.03 mg/100 g, respectively). All varieties showed high tricosanic acid (C23:0) content, and Cotahuasi was highlighted for its high linoleic acid (C18:2) content. Multivariate analysis showed negative correlations between proteins and carbohydrates, and between fat and fiber in their proximal content, as well as between Fe and Na for their mineral content, and C18:1 and C18:2 for the fatty acids. Although certain differences were found, the total nutritional composition tended to have minor differences between the investigated varieties. Full article

Rice protein is considered an important dietary protein source. Information regarding rice nutrient-related protein expression is still scarce, hence further study investigating this aspect is highly needed. Herein, we applied sequential window acquisition of all theoretical mass spectra (SWATH-MS) for a comparative proteomic analysis across six different Malaysian rice varieties. These consisted of black rice (BR: PH9 and BALI), red rice (RR: MRQ100 and MRM16), and white rice (WR: MRQ76 and MR297). This study aimed to unravel rice nutrient-related proteins and if their expressions were significantly different across varieties. A total of 4022 quantified proteins were found to be significantly expressed across all varieties with a false discovery rate (FDR) < 1% and p < 0.05. While among 1792 differentially expressed proteins (DEPs) that were identified, 74 DEPs had functions related to nutrient biosynthesis. There were significantly higher expressions of key enzymes for the carotenoid and amylopectin biosynthesis pathways and seed storage proteins, i.e., prolamins and glutelins in RR. Glycoproteins such as cupin and germin-like protein, as well as enzymes that are involved in the biosynthesis of thiamine and anthocyanin were abundantly found in BR. WR was particularly enriched with biosynthesis enzymes for essential amino acids (methionine and arginine), vitamin B, and unsaturated fatty acid. This study provides us insights into the differential expressions of storage and functional proteins with nutrient-related properties in shaping rice grain pigmentations and plant immunity, as well as in contributing diverse health benefits as daily functional food for human consumption. Full article