Crops

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

Meteorological factors have significant impacts on crop yield. To account for the impact of meteorological factors on foxtail millet (Setaria italica Beauv.) production in different water conditions, a total of 38 collected varieties were grown in nine seasons from 2011 to 2020 (except 2016) under well-watered (WW) and water-stressed (WS) conditions. The results showed that there was a large seasonal variation in GY; the variation ranged from 4.92 t ha⁻¹ to 6.95 t ha⁻¹ under the WW treatment and from 3.50 t ha⁻¹ to 5.77 t ha⁻¹ under the WS treatment. The impacts of meteorological factors on foxtail millet under the WW and WS treatments were different; sunshine duration during the whole stage, vegetative stage and reproductive stage had the greatest impact under the WW treatment, while under the WS treatment, sunshine duration and the diurnal temperature range during the whole stage and reproductive stage were the greatest impact factors on grain yield. This work could help us in high-yield foxtail millet cultivation and breeding. Full article

Rice is an indispensable crop in East and Southeast Asia, and the study of its biological characteristics has important value. We observed that different cultivars of rice have different levels of resistance to the brown planthopper (BPH), Nilaparvata lugens. In this study, transcriptome sequencing was used to analyze the differentially expressed genes (DEGs) of three rice varieties caused by BPH damage combined with physical stimulation and controls. We performed weighted correlation network analysis (WGCNA) and found a module positively related to physical stimulation. KEGG analysis showed that this module is strongly related to the ribosome pathway. Through comparative analysis with controls, we found the differential genes of each cultivar after BPH damage; through trend analysis, we found the differential genes shared by the three varieties after BPH damage. The KEGG/GO enrichment analysis of these genes found that they are mainly functionally concentrated in signal transduction, redox reactions, etc. The results of this research will be helpful to study the molecular mechanism of the BPH-rice interaction, identify resistance genes, and facilitate further studies on molecular resistance breeding and pest control. Full article

Background: Yerba-mate (Ilex paraguariensis) is a perennial native tree from South America. Improper management of yerba-mate crops results in low yield. This work evaluated the recovery and the vegetative capacity of the crop after coppicing. Methods: A 2-year field observation approach was used and the study area was monitored from 2019 to 2021 in a 20-year-old yerba-mate crop with low yield. Drastic coppicing was used as a strategy, aiming to study the effect of the month and the height of pruning. Four groups were defined combining the trunk heights of 10 and 40 cm and the months of pruning June and August. Results: Yerba-mate plants showed a low mortality rate of 2%. In the first year after the intervention, the height of the cutting was the most important factor that influenced the amount of primary and secondary branches, validating response surfaces with r² values of 0.9942 and 0.9084, respectively. In the second year of the experiment, full recovery in productivity was reached, with a mean rise of 109.7% in the plants of the group coppiced in June 40 cm above the soil. Conclusion: The techniques used in this study are appropriate for vigor recovery in yerba-mate plants inadequately managed and allow a new architecture on plants, enabling mechanical harvesting. Full article

Adapting agricultural systems to face persistent environmental hazards is at the center of global concerns. In line with this, understanding and highlighting the structural characteristics of agroforestry systems could strengthen their resilience in terms of disease management. This study was conducted to evaluate the effect of shade on the intensity of citrus leaf and fruit spot disease caused by Pseudocercospora (PLFSD). Investigations to assess the effects of shade components on the incidence of PLFSD were carried out on 15-year-old tangerine trees in a cocoa-based agroforestry plot (Bokito) during four fruits seasons. Tangerines under the shade of large forest trees were compared to others located under full sunlight. A complementary experiment was conducted on young grapefruit plants in an orchard with mango and avocado groves in Foumbot. Three shading conditions, i.e., under avocado trees, under mango trees, and without shade, were explored. Data on shade and PLFSD incidence were collected and analyzed. Our findings show that PLFSD incidence was null on tangerine leaves from trees under shade compared to those under full sunlight. The same trends were observed in fruits under shade and under full sunlight. Disease incidence on grapefruit leaves was lower on trees under shade compared to those under full sunlight. In short, shade trees appear to constitute potential physical barriers to disease progression. This study also highlights disease spatial distribution as beyond 12 m of distance between neighboring trees, no spatial dependence of disease spread was observed. Management actions based on the distance between citrus trees and regulating shade are envisaged. Full article

Maize is the most represented grain crop on the world’s arable land. It is mostly grown using standard sowing at an inter-row distance of 70 cm. However, growing in two rows (double-row sowing) is increasingly common today. The aim of this research was to determine the influence of different spatial distributions of the same population of maize plants on the yield of maize grains in a larger range of the FAO maize hybrid maturing group. The experiment lasted 5 years and was set up at two locations in Jakšić (Požeško-Slavonia County) and Lužani (Brodsko-Posavina County). Maize sowing with standard sowing was carried out with a PSK OLT seed drill with an inter-row spacing of 70 cm, while double-row sowing was carried out with a MaterMacc Twin Row-2 seed drill in two rows spaced 22 cm apart in a zigzag arrangement and 48 cm apart between adjacent sowing furrows. In the experiment, a total of three types of maize hybrids were used: H1-Kashmir (FAO 390 maturing group), H2-Kapitolis (FAO 400 maturing group) and H3-Konfites (FAO 450 maturing group). With standard maize sowing, an average set of plants was achieved: 71,946 plants ha⁻¹ (Kashmir), 71,714 plants ha⁻¹ (Kapitolis) and 72,205 plants ha⁻¹ (Konfites), while the double-row sowing achieved a set of plants of 72,166 plants ha⁻¹, 72,104 plants ha⁻¹ and 72,576 plants ha⁻¹. The two-row sowing of the hybrid Kapitolis and Konfites recorded a statistically significant higher set of maize plants. The yield of maize grains in all three types of the hybrid was statistically and significantly higher by 943 kg ha⁻¹ using two-row sowing, and the highest yield was achieved by the Kashmir hybrid (13,406 kg ha⁻¹). Full article

The low agricultural productivity of key crops and food insecurity continue to be a problem in sub-Saharan Africa (SSA), and Tanzania in particular. The growing population and climate change further increase the food shortage. Irrigation has been strategized to reduce poverty and food insecurity, and improve the livelihoods of communities in African countries, and in particular Tanzania. Transformational leadership for small-scale irrigation is urgently needed to attain the planned agenda for irrigation schemes. This study assessed the challenges of leadership in leading and transforming small-scale irrigation schemes. The questionnaires were distributed to leaders of the agriculture sector in four strata (agriculture extension officer (25), AMCOS leaders (6), agriculture engineers (2), irrigation committee (9)) with a total of 42 leaders as participants. A total of 118 farmers were interviewed from four irrigation canals (Ngollo (32), Ngarasero I (32), Ngarasero II (33), and Abisinia (21)) in the Usa River ward. The study found that the challenges of leaders in leading the transformation of small-scale farming for success were commitment of leaders, market chain, pest control mechanisms, irrigation extension service, planning, technological transformation and adoption, mobilization of farmers and professionals, monitoring and evaluation, knowledge of irrigation, and agro-input supply. This study shows that leaders’ transformation skills can play a great role in poverty reduction in small-scale irrigation in the Usa River ward. Therefore, leaders in the study area should play the role of transformational leadership effectively in managing small-scale irrigation by practicing a participatory approach to farmers problem-solving. Full article

The non-turning or only superficial turning of soil is considered to be a gentle tillage method. Nevertheless, conventional ploughs are widely used in organic farming for crop production reasons. For the further development of reduced tillage, and up to no tillage, the effects of three cover crop species and their incorporation with different tillage intensities on nitrogen (N) dynamics, weed emergence and the yield of the subsequent main crop, oats, were examined in a repeated organic one-year trial. Sinapis alba, Trifolium resupinatum, Vicia sativa and bare fallow were tested and incorporated using (1) a plough (PL), (2) reduced tillage (RT), (3) mulching + drilling (MD) and (4) direct drilling (DD). V. sativa was the most promising cover crop in combination with RT, MD and DD. In Trial 1, the soil mineral N content and oat yields after the introduction of V. sativa were on a similar level as those in the PL treatments, and weeds were not yield-limiting there. In Trial 2, the biomass production of V. sativa was only about half of that of Trial 1 and did not offer sufficient weed control, but V. sativa was still successful in the RT treatments. In both trials, the yield differences were more pronounced between the cover crop treatments after RT than after PL. RT, therefore, was more dependent on an adequate cover crop species than PL. The no-till method was not only dependent on an adequate cover crop species but also on its proper biomass production for sufficient weed control. Full article

Plants have developed mechanisms to cope with stresses in their environments as they grow in diverse settings. Such means include releasing plant defense compounds upon attacks by pests or other stressors. Plants with these characteristics are essential as a plant germplasm source for breeding resistance against herbivores and insect pests. Therefore, this study aimed to screen germplasms for whitefly resistance and characterize the secondary metabolites responsible for this. Thirty local tomato accessions were screened for resistance against whiteflies (Bemisia tabaci Gennadius) in the screen house located at Tanzania Plant Health and Pesticides Authority (PTHPA) between January and April 2021. From this screening, seven local tomato cultivars: TZA3729, TZA5554, TZA5545, TZA5562, TZA5552, TZA3177 and TZA5157, showed resistance, and one accession (TZA5496) that showed susceptibility to whiteflies (negative control) and accession V1030462 that was a standard (positive control) were selected for the subsequent experiments. The experiment was conducted in July–October 2021 in the screen house at TPHPA and repeated in January–April 2022 using a completely randomized block design with three replications. From this experiment, three accessions: TZA3729, TZA5562 and TZA5157, showed resistance against whiteflies. However, accession TZA3729 was more resistant than TZA5562 and TZA5157 when compared to the resistant accession V1030462. Therefore, these accessions were further screened for secondary metabolites responsible for resistance against herbivores and insect pests—in this case, whiteflies. The GS-MS methanol extract results showed accession TZA3729 to possess a wide array of secondary plant metabolites responsible for plant self-defenses, such as diterpenes, Tetraterpenes, alkaloids, carotenoids and fatty acid esters. Therefore, the study recommends accession TZA3729 as a source of tomato plant germplasm for breeding tomatoes resistant to whiteflies. Full article

Rice is an important food crop, and its production is significantly affected by salt stress under the changing climate. Soil-inhabiting microbial inoculants as well as efficient nitrogen (N) nutrition may have ameliorative effects on rice growth and yield under salt stress. However, the effects of the interaction between N application and microbial inoculants on the growth and grain yield of rice under salt stress is not yet fully understood. This study aimed to clarify whether the use of the Bacillus pumilus strain TUAT-1 biofertilizer, along with the right amount of N fertilizer, would alleviate salt stress in lowland rice production. We applied the Bacillus pumilus strain TUAT-1 as a biofertilizer in combination with different rates of N fertilizer: control (0% N), 2.64 g (NH₄)₂SO₄ per nursery tray (100% N: the farmer-recommended amount), and 3.96 g (NH₄)₂SO₄ per nursery tray (150% N). Salinity (100 mM of NaCl) was applied at the heading stage of rice plants in pot culture in the greenhouse, and the growth and yield components were accessed at harvest. In the nursery phase, the application of the biofertilizer TUAT-1 significantly increased seedling vigor and the root development of 21-day-old seedlings. Salinity stress at the heading stage significantly reduced chlorophyll content, panicle number, straw biomass, and grain yield; however, either the application of N alone or in combination with TUAT-1 ameliorated the salinity-related reduction in grain yield and yield component parameters. Plants receiving a high amount of N fertilizer (150% N) showed similar straw biomass and grain yield with or without TUAT-1 inoculation, regardless of saline or non-saline conditions. In both saline and control conditions, straw biomass and grain yield were higher in the plants inoculated with TUAT-1 than in those without TUAT-1. Specifically, the combined application of TUAT-1 and the farmer-recommended N level (100% N) led to an increase of 8% in straw biomass and 15% in grain yield under saline stress when compared with their respective plants without TUAT-1. Straw biomass and grain yield were similar in the (un-inoculated) plants grown under normal conditions and TUAT-1 + 100% N under salinity treatments, because TUAT-1 enhanced root development, which may promote soil nutrient uptake. Our results indicated that combined nursery application of TUAT-1 biofertilizer and 100% N fertilizer rate has the potential to boost the capacity of this bacteria to increase seedling vigor, which subsequently ameliorated the salt-induced reduction in the grain and straw yield. Full article