Crop Yield Losses Research Articles

Enhancing Growth in Vigna radiata through the Inhibition of Charcoal Rot Disease: A Strategic Approach Using Plant Growth-Promoting Rhizobacteria.

Macrophomina phaseolina is a vital seed and soil-borne phytopathogen responsible for substantial crop yield losses. Although various methods exist for managing soil-borne pathogens, such as agronomic practices, chemical treatments, and varietal tolerance, biological control utilizing plant growth-promoting rhizobacteria (PGPR) or their secondary metabolites presents promising avenues. In this study, a screening of 150 isolates from the rhizosphere of Vigna radiata L. was conducted to identify strains capable of promoting host growth and controlling charcoal rot disease. Among the tested isolates, only 15 strains demonstrated the ability to produce plant growth-related metabolites, including indole acetic acid, hydrogen cyanide, ammonia, and lytic enzymes, and solubilize inorganic phosphate. Subsequently, these potent strains were evaluated for their antifungal activity against Macrophomina phaseolina in vitro. Three strains, namely MRP-7 (58% growth inhibition), MRP-12 (55% growth inhibition), and MRP-8 (44% growth inhibition), exhibited the highest percent growth inhibition (PGI.). Furthermore, a pot experiment demonstrated that the selected strains acted as effective growth promoters and ROS (reactive oxygen species) scavengers, and served as potential biocontrol agents, significantly reducing the incidence of charcoal rot disease and improving various agronomic attributes of the host plant. These findings highlight the potential of these strains to be utilized as biofertilizers and biocontrol agents for sustainable agricultural practices.

Arabinosylation of cell wall extensin is required for the directional response to salinity in roots.

Soil salinity is a major contributor to crop yield losses. To improve our understanding of root responses to salinity, we developed and exploited a real-time salt-induced tilting assay. This assay follows root growth upon both gravitropic and salt challenges, revealing that root bending upon tilting is modulated by Na+ ions, but not by osmotic stress. Next, we measured this salt-specific response in 345 natural Arabidopsis (Arabidopsis thaliana) accessions and discovered a genetic locus, encoding the cell wall-modifying enzyme EXTENSIN ARABINOSE DEFICIENT TRANSFERASE (ExAD) that is associated with root bending in the presence of NaCl (hereafter salt). Extensins are a class of structural cell wall glycoproteins known as hydroxyproline (Hyp)-rich glycoproteins, which are posttranslationally modified by O-glycosylation, mostly involving Hyp-arabinosylation. We show that salt-induced ExAD-dependent Hyp-arabinosylation influences root bending responses and cell wall thickness. Roots of exad1 mutant seedlings, which lack Hyp-arabinosylation of extensin, displayed increased thickness of root epidermal cell walls and greater cell wall porosity. They also showed altered gravitropic root bending in salt conditions and a reduced salt-avoidance response. Our results suggest that extensin modification via Hyp-arabinosylation is a unique salt-specific cellular process required for the directional response of roots exposed to salinity.

Drought risk management in agriculture: A copula perspective on crop diversification

AbstractDrought events are a major cause of large crop yield losses with implications for food security and farmers’ incomes. Growing multiple crops simultaneously during a cropping season is a well‐known on‐farm risk management strategy to cope with these drought risks. However, the effectiveness of this crop diversification under different severity levels of drought and how this effectiveness is influenced by the crop composition is unclear. This article provides new methodological and empirical insights to assess the effectiveness of such diversification, in particular to cope with extreme drought. We apply and evaluate nested Archimedean copulas and elliptical copulas to assess simultaneous farm‐level yield losses of different cash crops in German agriculture (winter wheat, winter barley, winter rapeseed, sugar beet, and grain maize) under different drought severity levels (N = 249,756; regionally pooled farm‐level crop‐yield pairs, 1995–2019). We show that on‐farm crop diversification contributes to cope with drought risks, but its effectiveness varies considerably across regions, crop pairs, and drought severity. Our results underline that cropping system diversification alone is often not sufficient to cope with drought risks, but that the right crop combinations are needed. For example, during a severe drought (one in 20 years event), 26.4% of farmers in eastern Germany suffered simultaneous yield losses of at least 20% in winter wheat and winter barley, while 19.1% of farmers in eastern Germany suffered simultaneous yield losses of at least 20% in winter wheat and sugar beet. Farmers should therefore be encouraged to grow crops with more diverse phenological requirements throughout the year.

Pollinator visitation decline due to pesticide application beyond threshold frequency brings down crop yield

Abstract The deleterious effects of pesticides on pollinating insect abundance are well established but the relationship among pesticide application, pollinator decline and the corresponding change in marketable yield is not fully understood. In this study, we assessed what level of pesticide exposure causes maximum pollinator loss and at that level of pollinator loss if there is any crop yield loss. We primarily assessed pollinator crop flower visitation in 27 aubergine farms with different degrees of pesticide application. Subsequently, we also observed pollinator activity and aubergine yield (fruit set) in a semi‐controlled field experiment with four different pesticide treatments. Pesticide application frequency was the most important driver of pollinator visitation compared with quantity. Pesticide spray above once a week caused a drastic drop in pollinator visitation in a non‐linear fashion showing a threshold of pesticide application. In high pesticide frequency experimental plots, pollinator visitation was significantly lower than in control, low and medium frequency plots. This resulted in lowering of aubergine fruit set by 27.4% in high pesticide frequency plots. Use of synthetic pesticides to safeguard yield seems to be doing just the opposite by bringing down yield from pesticide‐induced pollinator limitation.

Water use efficiency and canopy temperature response of soybean subjected to deficit irrigation

Deficit irrigation is a key strategy for improving water use efficiency (WUE) under irrigated conditions. However, there is a lack of information regarding the optimal water replacement that have minimal negative effects on soybean productivity. The objective of this study was to determine the water replacement levels associated with insignificant grain yield (GY) losses in soybean crops. A rain shelter experiment was conducted using a randomized complete block design with six replicates. Eight irrigation replacement levels, L120, L100, L90, L80, L70, L60, L50, and L40, were applied, where L100 was the reference treatment that kept soil moisture content along the soil profile under field capacity conditions and all other replacement levels were a fraction of this reference level. Grain yield ranged from 2.2 Mg ha-1 in L40 to 4.4 Mg ha-1 in L100, with a significant GY reduction in irrigation levels below 70%. The average crop water stress index (CWSI) ranged between 0.26 at L120 and 0.66 at L40 irrigation levels. WUE varied significantly only for the extreme irrigation levels studied, with the greatest value at the L40 irrigation level (1.2 kg m-3) and the lowest value at the L120 irrigation level (0.65 kg m-3), whereas for the intermediate irrigation levels from 50 to 100%, the WUE was equal to approximately 1.1 kg m-3. The relationship between CWSI and GY (R2 = 0.85) suggested that the maximum GY occurred at a CWSI of 0.34. In addition, the relationship between CWSI and WUE (R2 = 0.73) showed that as evapotranspiration decreased, crop temperature increased. In conclusion, the implementation of a continuous water deficit in soybeans is feasible for farmers in water-scarce areas, but the minimum value of area productivity must be considered, even though WUE increases under more intensive values of water deficit.

Piriformospora indica modifies cucumber’s tolerance to Meloidogyne incognita by regulating various agro-physiological traits, antioxidant enzymes, and abscisic acid pathway genes

Root knot nematode (RKN), Meloidogyne incognita, is considered a major soil-borne pathogen that can cause severe yield losses for vegetables and diverse crops. Usually, reducing of M. incognita damage is mainly relies on the application of nematicides and good agricultural practices. However, the use of synthetic nematicides is restricted due to concerns about their impact on the environment and human health. As a result, the use of alternative strategies is becoming necessary to combat RKN resistance. This study evaluates the antagonistic impact of the root mutualistic fungus Pirforomospora indica on M. incognita. It also assesses its influence on the nutritional status, photo-synthesis, antioxidant enzyme activity, endogenous abscisic acid (ABA) levels, and selected ABA related-responsive genes in cucumber plants. Roots of cucumber seedlings were inoculated with P. indica and the second-stage juveniles (1000 J2 per plant). The results demonstrated that P. indica significantly reduced M. incognita invasion in roots, resulting in a 24% reduction in root galling and 42.6% decline in final population. Inoculating plants with both P. indica and RKN increased performance of root fresh and dry weight, as well as improved photochemical efficiency of PSII (Fv/Fm), photosystem II efficiency (PSII), catalase (CAT), peroxidase (POD), and superoxide dis-mutase (SOD). Furthermore, P. indica colonization, either alone or in combination with M. incognita, significantly improved number of fruits per plant, average fruit weight, the plant's marketable yield, and leaf nutrient content (N, P, K and Mg), Moreover, there was an increase in IAA content combined with a decrease in ABA content in roots of dual inoculation plants, if compared to M. incognita infested plants. The highest ABA content was recorded in the root of RKN-cucumber plants. The decline in ABA content due to P. indica treatment was consistent with the modulation of ABA pathway genes, specifically PP2C, PYL1, RK2,1, and RK2,2. The mixed of P. indica and M. incognita led to a decrease in the expression of PP2C, PLY1, RK2,1, and RK2,2 in comparison to the control group. These results indicate that P. indica application could help reduce the negative effects of RKN on important crops.

Aspirational nitrogen interventions accelerate air pollution abatement and ecosystem protection.

Although reactive nitrogen (Nr) emissions from food and energy production contribute to multi-dimensional environmental damages, integrated management of Nr is still lacking owing to unclear future mitigation potentials and benefits. Here, we find that by 2050, high-ambition compared to low-ambition N interventions reduce global ammonia and nitrogen oxide emissions by 21 and 22 TgN/a, respectively, equivalent to 40 and 52% of their 2015 levels. This would mitigate population-weighted PM2.5 by 6 g/m3 and avoid premature deaths by 817 k (16%), mitigate ozone by 4 ppbv, avoid premature deaths by 252k (34%) and crop yield losses by 122 million tons (4.3%), and decrease terrestrial ecosystem areas exceeding critical load by 420 Mha (69%). Without nitrogen interventions, most environmental damages examined will deteriorate between 2015 and 2050; Africa and Asia are the most vulnerable but also benefit the most from interventions. Nitrogen interventions support sustainable development goals related to air, health, and ecosystems.

Crop antiviral defense: Past and future perspective.

Viral pathogens not only threaten the health and life of humans and animals but also cause enormous crop yield losses and contribute to global food insecurity. To defend against viral pathogens, plants have evolved an intricate immune system to perceive and cope with such attacks. Although most of the fundamental studies were carried out in model plants, more recent research in crops has provided new insights into the antiviral strategies employed by crop plants. We summarize recent advances in understanding the biological roles of cellular receptors, RNA silencing, RNA decay, hormone signaling, autophagy, and ubiquitination in manipulating crop host-mediated antiviral responses. The potential functions of circular RNAs, the rhizosphere microbiome, and the foliar microbiome of crops in plant-virus interactions will be fascinating research directions in the future. These findings will be beneficial for the development of modern crop improvement strategies.

Assessment of future drought sensitivity shift associated with crop yield loss risk in the Anthropocene

ABSTRACT This study proposed a framework using artificial neural networks (ANNs), the designed residual regression method, and probabilistic indexing, for drought sensitivity shift analysis, associated with future yield loss risk in Anthropocene. The temporal assessment of the drought index (standardized precipitation evapotranspiration index, SPEI) illustrated prevalent occurrence of mild to moderate drought with a fluctuating trend. Furthermore, the optimal ANN model, with R2 = 0.86 for training and 0.7 for testing, was used to project yield for future analysis. The projected spatial changes in drought sensitivity patterns suggest most of the area will experience an increased sensitivity to drought in the far future (2036–2050). The estimated probability loss under the different risk levels defined by the yield reduction rate was 6.2–55.5%. Furthermore, the spatial distribution of the designed risk index (IR) revealed the districts with the highest probability of vulnerability and showed a probable increase in future vulnerability.

In vitro nematicidal efficacy of brassica-derived isothiocyanates against the root lesion nematode, Pratylenchus penetrans

Summary Brassica plants naturally produce glucosinolates as secondary metabolites hydrolysed to biocidal isothiocyanates (ITCs). As such, they have the potential for nematode management through a strategy known as biofumigation. Pratylenchus penetrans causes significant yield losses in many important crops. Understanding the relative impact of different ITCs on the motility and mortality of this nematode species could provide some insights into the selection of relevant brassica biofumigants. The effects of 3.125, 6.25, 12.5, 25, and 50 μg ml−1 of pure Allyl, 2-Phenylethyl and Benzyl ITCs on the motility and mortality of P. penetrans were evaluated in laboratory in vitro assays. Motility was assessed after incubating the nematodes in ITCs for 24, 48 and 72 h with distilled water as a negative control. Motile and non-motile nematodes were counted. After motility assessment at 72 h, nematodes were rinsed and incubated in water for 48 h, after which live and dead nematodes were counted. Nematodes were considered dead if they remained non-motile after probing with a picking needle. Nematode motility and mortality were significantly affected by the type of ITC, concentration and time of exposure. The number of non-motile nematodes increased with increasing concentration and time of exposure across all tested ITCs. The ED50 values (concentration required to cause 50% non-motility) of Allyl, 2-Phenylethyl and Benzyl were 37.4, 12.8 and 8.6 μg ml−1 after 24 h exposure. The ITC with potentially the greatest nematicidal effect was Benzyl (LD50 = 3.2 μg ml−1), followed by 2-Phenylethyl (LD50 = 5.2 μg ml−1), and Allyl (LD50 = 9.9 μg ml−1). The LD50 of all ITCs were not different from the ED50 after 72 h, meaning the effects of ITCs could be considered irreversible. This study suggests that brassica biofumigants that produce Benzyl, Allyl and 2-Phenylethyl ITCs are promising candidates for biofumigation of P. penetrans.

Resistance of Ascochyta rabiei isolates from chickpeas (Cicer arietinum L.) to fungicides

Ascochyta blight is a disease that causes significant yield losses in chickpea crops in Turkey under favorable environmental conditions. The fungal pathogen Ascochyta rabiei is the causative agent of this disease. The antifungal activity of previous fungicides against A. rabiei was not effective due to the heterothallic nature of the fungus. The aim of this study was to determine the sensitivity of A. rabiei to fungicides (25.2 g kgˉ1 boscalid + 12.8 g kgˉ1 pyraclostrobin; 50 % tebuconazole + 25 % trifloxystrobin; 62.5 g Lˉ1 propiconazole + 37.5 g Lˉ1 azoxystrobin; 80 % thiram; 80 % kükürt (sulphur); 80 % mancozeb; 80 % maneb) under in vitro and field conditions. Pure cultures of A. rabiei were isolated from infected chickpea plants collected in Boğazlayan, Sarıkaya, Sorgun, Merkez and Yerköy. A total of 14 A. rabiei isolates and 4 references were evaluated. The field test was conducted at Yozgat Bozok University, Yerköy Agricultural Application and Research Center Station. The trials began on March 14, 2021. The experimental area was divided into plots and the susceptible chickpea variety Sarı98 was used for the study. Two artificial inoculations were carried out approximately on the 40th and 80th days after sowing. Twenty-four hours after inoculation, the chickpea plants were sprayed with the fungicides Nativo® WG 75, Bellis®, Dikotan® M45 and Thiovit Jet® using a handheld sprayer. In vitro testing revealed that A. rabiei was resistant to kükürt (sulphur), thiram, maneb, and mancozeb. A field study showed that the percentage of A. rabiei isolates treated with the mancozeb fungicide was between 14 and 21 % of the control. Therefore, effective disease management strategies should include not only the use of fungicides, but also alternative approaches such as the use of resistant varieties. Moreover, the study focused on phenotypic resistance and suggests that future research should investigate the genetic and molecular mechanisms underlying A. rabiei resistance to enable better resistance management.

Environmental genome-wide association studies across precipitation regimes reveal that the E3 ubiquitin ligase MBR1 regulates plant adaptation to rainy environments

In an era characterized by rapidly changing and less-predictable weather conditions fueled by the climate crisis, understanding the mechanisms underlying local adaptation in plants is of paramount importance for the conservation of species. As the frequency and intensity of extreme precipitation events increase, so are the flooding events resulting from soil water saturation. The subsequent onset of hypoxic stress is one of the leading causes of crop damage and yield loss. By combining genomics and remote sensing data, it is now possible to probe natural plant populations that have evolved in different rainfall regimes and look for molecular adaptation to hypoxia. Here, using an environmental genome-wide association study (eGWAS) of 934 non-redundant georeferenced Arabidopsis ecotypes, we have identified functional variants of the gene MED25 BINDING RING-H2 PROTEIN 1 (MBR1). This gene encodes a ubiquitin-protein ligase that regulates MEDIATOR25 (MED25), part of a multiprotein complex that interacts with transcription factors that act as key drivers of the hypoxic response in Arabidopsis, namely the RELATED TO AP2 proteins RAP2.2 and RAP2.12. Through experimental validation, we show that natural variants of MBR1 have different effects on the stability of MED25 and, in turn, on hypoxia tolerance. This study also highlights the pivotal role of the MBR1/MED25 module in establishing a comprehensive hypoxic response. Our findings show that molecular candidates for plant environmental adaptation can be effectively mined from large datasets. This thus supports the need for integration of forward and reverse genetics with robust molecular physiology validation of outcomes.

Development of SWAT, a Solar and Wind Powered Agricultural Pest Trap-peller

In the Philippines, pest infestation has been a major challenge for farmers which led to significant losses in crop yields and income due to the lack of access to effective pest management techniques. To address this issue, the researchers developed a pest management device powered by solar and wind energy used to minimize pest infestation in the fields. This research utilized the phases of the System Development Life Cycle in developing the prototype. This system utilized an ultrasonic speaker and ultraviolet light (UV) bug zapper as the main components of the device. The device was able to collect insects and moths in the farmland and was able to decrease the number of insects and moths collected from 3 kg to 0.01 kg in one week. The researchers were also able to prove that the ultrasonic speaker with a frequency of 15 kHz was effective for deterring birds up to 40 meters away from the device. Comparison between the traditional method and the developed prototype showed that the latter requires less amount of work and human intervention thus, eliminating the adverse health effects from continuous exposure to loud sounds and insecticides used in the traditional ways. End-user evaluation results showed excellent functionality, very easy to use, high-performance efficiency, strong security, and very easy to maintain proving the prototype’s effectiveness as an alternative solution to the problem of pest infestation in farmlands.

Hormetic dose response induced by sublethal-dose sulfoxaflor leads to reproductive stimulation of Aphis gossypii

Aphis gossypii Glover is one of the most agriculturally important phloem-feeding economic pests, causing tremendous loss in crop yield annually. The hormesis is an important cause of A. gossypii resistance formation, population resurgence, and re-outbreak. However, whether the hormesises induced by different insecticides interact mutually remain largely unclear. In the study, four-generation A. gossypii experiment found that the 24-h sublethal-dose (LC20) sulfoxaflor treatment on G0 significantly increased the net reproductive rate (R0) and fecundity of G1 and G2 generation A. gossypii, but it did not significantly affect the fecundity of G3 and G4 individuals. Transcriptomic analyses revealed that the insecticide-induced significant up-regulation of pathways ribosome, energy metabolism, and the DNA replication and reparation might be responsible for the enhancement of fecundity in G1 and G2 A. gossypii. Notably, G0 exposure to LC20 sulfoxaflor followed by G1 exposure to LC30 deltamethrin resulted in a stronger reproductive stimulation than sulfoxaflor or deltamethrin exposure alone. Our findings provide valuable reference for optimizing sulfoxaflor application in integrated pest management strategies.

CRISPR-Cas9 mediated understanding of plants' abiotic stress-responsive genes to combat changing climatic patterns.

Multiple abiotic stresses like extreme temperatures, water shortage, flooding, salinity, and exposure to heavy metals are confronted by crop plants with changing climatic patterns. Prolonged exposure to these adverse environmental conditions leads to stunted plant growth and development with significant yield loss in crops. CRISPR-Cas9 genome editing tool is being frequently employed to understand abiotic stress-responsive genes. Noteworthy improvements in CRISPR-Cas technology have been made over the years, including upgradation of Cas proteins fidelity and efficiency, optimization of transformation protocols for different crop species, base and prime editing, multiplex gene-targeting, transgene-free editing, and graft-based heritable CRISPR-Cas9 approaches. These developments helped to improve the knowledge of abiotic stress tolerance in crops that could potentially be utilized to develop knock-out varieties and over-expressed lines to tackle the adverse effects of altered climatic patterns. This review summarizes the mechanistic understanding of heat, drought, salinity, and metal stress-responsive genes characterized so far using CRISPR-Cas9 and provides data on potential candidate genes that can be exploited by modern-day biotechnological tools to develop transgene-free genome-edited crops with better climate adaptability. Furthermore, the importance of early-maturing crop varieties to withstand abiotic stresses is also discussed in this review.

Transcriptome analysis of resistant and susceptible Medicago truncatula genotypes in response to spring black stem and leaf spot disease

Ascochyta blights cause yield losses in all major legume crops. Spring black stem (SBS) and leaf spot disease is a major foliar disease of Medicago truncatula and Medicago sativa (alfalfa) caused by the necrotrophic fungus Ascochyta medicaginicola. This present study sought to identify candidate genes for SBS disease resistance for future functional validation. We employed RNA-seq to profile the transcriptomes of a resistant (HM078) and susceptible (A17) genotype of M. truncatula at 24, 48, and 72 h post inoculation. Preliminary microscopic examination showed reduced pathogen growth on the resistant genotype. In total, 192 and 2,908 differentially expressed genes (DEGs) were observed in the resistant and susceptible genotype, respectively. Functional enrichment analysis revealed the susceptible genotype engaged in processes in the cell periphery and plasma membrane, as well as flavonoid biosynthesis whereas the resistant genotype utilized calcium ion binding, cell wall modifications, and external encapsulating structures. Candidate genes for disease resistance were selected based on the following criteria; among the top ten upregulated or downregulated genes in the resistant genotype, upregulated over time in the resistant genotype, hormone pathway genes, plant disease resistance genes, receptor-like kinases, contrasting expression profiles in QTL for disease resistance, and upregulated genes in enriched pathways. Overall, 22 candidate genes for SBS disease resistance were identified with support from the literature. These genes will be sources for future targeted mutagenesis and candidate gene validation potentially helping to improve disease resistance to this devastating foliar pathogen.

Combining biological control approaches for managing insect crop pests in the field can generate interactive effects

Abstract With the loss of effective chemical controls of crop pests, a move towards biological controls is a way to future‐proof our agricultural system. Floral field margins have shown successes in reducing crop pests, though the effect may not be precise enough to control infestations in commercial crops. Entomopathogenic nematodes (EPNs) may provide a more species‐ and time‐specific control and combining these methods may have synergy. Three in‐field vegetation margins, divided into four plots each (two floral and two grass), were established in March 2022. Three strips of sprouting broccoli were planted parallel in April, May and June. Each strip had a split‐plot design, with eight replicates of four nematode treatments placed alongside each floral/grass plot: Steinernema carpocapsae, S. feltiae and Heterorhabditis bacteriophora and a nematode‐free control. Pest pressure was assessed using adult counts. Assessments of crop yield and crop damage associated specifically with the swede smidge (Contarinia nasturtii) were also made. It was found that utilising a combination of control measures was successful in controlling a wider range of pests, though the success of each control method was highly dependent on the time of crop plantings. Field margins had a significant influence on crop damage associated with the swede midge. The EPN H. bacteriophora was an effective control method for the cabbage stem flea beetle and the swede midge, as well as reducing crop damage and yield loss. Field margins and EPNs combined have an interactive effect on crop yield, highlighting the need for control methods to be tested in combination in future integrated pest management research to accurately understand their effects within an integrated system.

A glycine-rich nuclear effector VdCE51 of Verticillium dahliae suppresses plant immune responses by inhibiting the accumulation of GhTRXH2

Verticillium dahliae is an important soil-borne fungal pathogen that causes great yield losses in many cash crops. Effectors of this fungus are known to regulate plant immunity but the mechanism much remains unclear. A glycine-rich nuclear effector, VdCE51, was able to suppress immune responses in tobacco against Botrytis cinerea and Sclerotinia sclerotiorum. This effector was a required factor for full virulence of V. dahliae, and its nuclear localization was a requisite for suppressing plant immunity. The thioredoxin GhTRXH2, identified as a positive regulator of plant immunity, was a host target of VdCE51. Our findings show a virulence regulating mechanism whereby the secreted nuclear effector VdCE51 interferes with the transcription of PR genes, and the SA signaling pathway by inhibiting the accumulation of GhTRXH2, thus suppressing plant immunity.

Cytochrome P450 CYP81A104 in Eleusine indica confers resistance to multiherbicide with different modes of action.

Developing herbicide-resistant (HR) crop cultivars is an efficient way to control weeds and minimize crop yield losses. However, widespread and long-term herbicide application has led to the evolution of resistant weeds. Here, we established a resistant (R) E. indica population, collected from imidazolinone-resistant rice cultivar fields. The R population evolved 4.5-fold resistance to imazamox. Acetolactate synthase (ALS) gene sequencing and ALS activity assays excluded the effect of target-site resistance in this population. P450 inhibitor malathion pretreatment significantly reversed resistance to imazamox. RNA sequencing showed that a P450 gene CYP81A104 was expressed higher in R versus susceptible (S) plants. Arabidopsis overexpressing CYP81A104 showed resistance to ALS inhibitors (imazamox, tribenuron-methyl, penoxsulam and flucarbazone-sodium), PSII inhibitor (bentazone), hydroxyphenyl pyruvate dioxygenase inhibitor (mesotrione) and auxin mimics (MCPA), which was generally consistent with the results presented in the R population. This study confirmed that the CYP81A104 gene endowed resistance to multiherbicides with different modes-of-action. Our findings provide an insight into the molecular characteristics of resistance and contribute to formulating an appropriate strategy for weed management in HR crops. © 2024 Society of Chemical Industry.

The Impacts of Floods on Crop Production in Kilosa District, Tanzania

Floods pose a major threat to agricultural production in Kilosa District, Tanzania, with the Mkondoa River being a primary source of flooding. This study aimed to assess the impacts of floods on crop production in Kilosa District. A cross-sectional research design was employed, involving a household survey of 120 respondents, focus group discussions and key informant interview with various stakeholders. The results show that floods have had significant negative impacts on crop production in the district. Over 80% of the population in Kilosa depend on agriculture, and this sector is affected by floods. Respondents reported substantial losses in crop yields and damage to farmland due to recurring flood events. The study also identified several initiatives conducted by the local community, organizations and the government to reduce the impact of floods. However, more effort is needed to minimize the impact on crop damage. The insights from this assessment can inform policymakers and development practitioners in designing and implementing effective flood management strategies for Kilosa District