Crop Yield Losses Research Articles

Fungal Endophytes: A Potential Application in Integrated Plant Health Management

Fungal endophytes are asymptomatic inhabitants of plant tissues in most plant species, providing tissue-specific protection from disease and reducing crop yield losses by 30 to 50% annually. They can increase plant fitness by inhibiting biotic and abiotic stressors, promote plant growth and development, and reduce crop yield losses. Endophytes enhance plant resistance to fungal pathogens by strengthening cell walls, increasing photosynthesis and promoting plant defense responses. They produce antibacterial and antifungal compounds that protect plants against bacterial pathogens, such as javanicin, which is effective against Bacillus species and Escherichia coli. Endophytic fungi can produce broad-spectrum antimicrobial compounds, some of which can be used as biocontrol agents for phytopathogenic bacteria. They also reduce viral diseases by increasing plant defenses or preventing viruses from spreading. Plant-parasitic nematodes attack plant roots and stems, creating wounds through which secondary opportunistic fungal, bacterial, or viral pathogens can enter. Fungi can inhibit nematode growth and spread by producing nematocidal compounds, parasitizing nematode larvae, or using hyphal loops for nematode capture. Endophytic fungi are a rich source of novel natural compounds, have a high level of biodiversity, and may produce pharmaceutical-significant compounds. Further molecular research is necessary to facilitate the recognition of endophytes carrying host genes.

Acinetobacter oleivorans IRS14 alleviates cold stress in wheat by regulating physiological and biochemical factors.

Climate change is responsible for extremely cold winters causing a significant loss in crop yield and productivity due to chilling stress. This study aims to investigate the potential of psychrotrophic plant growth-promoting rhizobacteria (PGPR) strain to promote wheat growth under cold stress and explore the adaptive responses of wheat. Wheat seeds and seedlings were inoculated with the psychrotrophic strain IRS14 and the plants were cultivated for five weeks at 6±2°C. The genetic, biochemical, physiological, and molecular analysis of the bacterium and plant was done to evaluate the effect of the PGPR strain in alleviating chilling stress. IRS14 possesses antioxidant activity and produced multiple phytohormones, which enhanced seed germination (∼50%) and plant growth (∼50%) during chilling stress. Here, we reported that the application of IRS14 helps to regulate the biochemical and metabolic pathways in wheat plants. It alleviates chilling stress and increases plant growth rate and biomass. Strain IRS14 in wheat effectively increased chlorophyll content, antioxidants, carotenoid, proline, and endogenous phytohormones compared with untreated wheat.

Modelling potato yield losses caused by Phytophthora infestans: Aspects of disease growth rate, infection time and temperature under climate change

Modelling crop yield loss due to pathogens remains a challenge due to the complex and dynamic interactions involved. Here, we develop a parsimonious dynamic yield loss simulation model that couples a simple epidemiological model of late blight disease with a basic model of potato crop growth. The model is parameterized using 17 years of field data on disease progress of potato late blight and potato yield in southern Sweden. Simulated actual yields (yields obtained under the presence of Phytopthora infestans) correlated well (R2 = 0.66) with the actual yields observed in field trials, using a few widely accessible meteorological variables. The results also underline the impact of disease growth rate and the time of infection on yield losses, with relatively low rates and early onset of the epidemic producing large yield reductions. In addition, the importance of increasing temperature due to climate change on both potato crop and Phytophthora infestans development was simulated, suggesting that higher temperatures may be more detrimental for the pathogen than for the crop. Additional ways to expand the model are discussed, and the inclusion of other diseases and pests are encouraged, indicating the potential to improve disease management in potato production.

PERBANDINGAN KETAHANAN DAUN CABAI RAWIT DAN TOMAT TERHADAP SERANGAN Thrips sp. BERBASIS PENGOLAHAN CITRA DIGITAL

The presence of thrips pests that attack the leaves of cayenne pepper and tomato can cause high yield losses in both crops. Plant resistance to thrips is thought to be related to the pest's preference for plant leaves. The difference in the resistance level of the two plants to thrips attack needs to be studied based on a digital image processing approach as an accurate method of assessing plant damage. This study compares the resistance of cayenne pepper and tomato leaves to thrips attack based on digital image processing. The study was designed for feed testing with the option of using cayenne pepper and tomato leaves as treatments that were placed in pairs in a testing container. There were five pairs of tests for the first and second repetitions, respectively, and each pair of tests used five individual thrips. The results showed tomato leaves were relatively more resistant to thrips attack because they tended to be less preferred than cayenne pepper. The average area of thrips attack on cayenne pepper leaves for two repetitions of testing was higher than tomato. The assessment of the extent of thrips attack tomato and cayenne pepper leaves based on image processing has high validity, characterized by the accuracy and precision of the assessment results, which reach 80-100%. However, the reliability of the assessment results for two repetitions of testing is still relatively low, especially in assessing damage to cayenne pepper leaves.

Effects of drought stress induced by D-Mannitol on the germination and early seedling growth traits, physiological parameters and phytochemicals content of Tunisian squash (Cucurbita maximaDuch.) landraces.

Drought stress is one of the most devastating environmental stressors, especially in the arid and semi-arid regions of the world. Considering the major constraints that drought stress poses to crop production and the consequent yield losses in food crops, breeding for climate-resilient crops is an efficient means to mitigate stress conditions. This study aimed at evaluating the response of four squash (Cucurbita maxima Duchesne) landraces to drought stress at germination and at plant stage. Drought stress was induced by different concentrations of D-mannitol (-0.24, -0.47 and -0.73 MPa). The tested parameters at germination stage included germination percentage, seedling vigor index, seed water absorbance and seedling growth potential. At the plant stage, leaf chlorophyll and carotenoids content, chlorophyll fluorescence, evapotranspiration, photosynthesis activity and several biomarkers, namely malondialdehyde, proline, total phenols content, total flavonoids content and DPPH radical scavenging activity were evaluated in both roots and leaves. Our results indicate a magnitude of drought stress effects reflected via repression of germination and seedling growth as well as adjustments in physiological functions at later growth stages, in a genotype depended manner. Among landraces, "751" and "746" showed better performance, as evidenced by higher seed germination and seedling growth potential even at high stress levels (-0.47 and - 0.73 MPa), whereas "747" was the most sensitive landrace to drought stress at both tested stages. In conclusion, our findings highlight the importance of squash landraces selection for the identification of elite genotypes with increased tolerance to drought stress.

Phytopathological assessment of domestic potato varieties in the conditions of the North Caucasus

The article is devoted to the phytopathological evaluation of domestic varieties of potatoes of different maturity groups in the conditions of the foothill zone of North Ossetia. Fungi, bacteria and viruses pose a serious threat and cause significant crop yield losses. Annually, the loss of agricultural crops from the disease is up to 60 %. According to the results of phytopathological assessment, potato varieties with resistance to viral and bacterial diseases were identified. The varieties Fritella, Naiada, Flamingo, Triumph, Ariel were the most resistant to viral diseases. The varieties Grand, Krasa Meshchera, Prime, Fioletovy, Ariel, Vympel, Gulliver, Carmen, Lyubava, Triumph, Sineglazka, Azhur, Elizaveta, Izyuminka, Krasa, Nevsky, Farn, Sadon, Flamingo showed complex resistance to fungal diseases.

Occurrence of Tomato Leaf Curl New Delhi Virus in Cucurbit Plants in China.

In August 2022, melon (Cucumis melo), cucumber (Cucumis sativus) and luffa (Luffa aegyptiaca) plants showed virus-like symptoms characteristic of geminiviruses (yellowish green, mosaic patterns and severe curling of leaves, short internodes, and stunting) in 10 greenhouses in Fengxian district and 20 greenhoues in Jiading district of Shanghai, China. Fifty symptomatic leaf samples were randomly collected: 28 from melon, 17 from cucumber, and 5 from luffa. To investigate the etiology of the observed disease, total DNA and RNA was extracted via a DNA extraction kit (Tiangen, Not: DP350) and TRIzol reagent (Sigma-Aldrich, Not: T9424), respectively. Healthy melon plants grown in a growth chamber served as negative control. The DNA and RNA samples were screened for the presence of geminiviruses, Cucurbit chlorotic yellow virus (CCYV), Melon yellow spot virus (MYSV), Cucumber mosaic virus (CMV), Zucchini yellow mosaic virus (ZYMV) and Cucumber green mottle mosaic virus (CGMMV) through PCR or RT‒PCR with geminiviruses (Deng et al. 1994), CCYV, MYSV, CMV, ZYMV and CGMMV (Zeng et al. 2011, 2019) primers. The PCR results showed that 28 melon leaves and 17 cucumber leaves were positive for geminivirus and CCYV, respectively, 5 luffa samples were infected with only geminivirus, and virus was not detected from the healthy plants. These results indicate that these two viruses are widely distributed throughout cucurbit crops in Shanghai, China. All the geminiviruses sequences (approximately 510 bp) were quite similar to each other and were most similar (99.4%) to the Tomato leaf curl New Delhi virus (ToLCNDV) sequence (GenBank Accession No. OP356207) (Li et al. 2022). To confirm the presence of geminiviruses, the segments of DNA-A and DNA-B were amplified by PCR with 4 ToLCNDV-specific primer sets (Mizutani et al. 2011) and sequenced from 10 samples (4 melon, 4 cucumber and 2 luffa). Both DNA-A and DNA-B of the ToLCNDV sequences and features were deposited in GenBank under the accession numbers OQ190939-OQ190948 (DNA-A, 2739 nt) and OQ190949-OQ190958 (DNA-B, 2693 nt). BLASTn analysis of Shanghai isolates of ToLCNDV (DNA-A and DNA-B) showed that the sequences shared nucleotide identities ranged from 99.3% to 100% among them and with values of more than 99.4% nucleotide identity with ToLCNDV isolates from tomato in China (OP356207 and OP356208) (Li et al. 2022). To confirm the virus infection, we have successfully constructed an infectious clone for 0823-1 isolate in the binary plasmid and inoculated melon with and without an infectious clone. The melon plants inoculated with ToLCNDV 15 dpi showed the high accumulation of the virus and displayed symptoms similar to viruses in greenhouse. Based on the complete sequences, results of the molecular phylogenetic analysis (Fig. 2) and infectious clone, these geminiviruses were identified as ToLCNDV. ToLCNDV has been reported to occur and spread by the whitefly (Bemisia tabaci) in many Asian countries (Sohrab et al. 2003; Sohrab et al. 2011; Aamir et al. 2020) and Europe (Juárez et al. 2014; Ruiz et al. 2015; Luigi et al. 2019). Large populations of whiteflies were also present in all our surveyed areas. However, to our knowledge, this is the first report of the occurrence of ToLCNDV in cucurbit plants in China. The presence of ToLCNDV and CCYV can cause severe losses in crop yields or even crop failure. In addition to TYLCV, ToLCNDV is another major geminivirus-induced disease threatening cucurbit and other vegetable production in China.

Insecticide resistance reduces the profitability of insect-resistant rice cultivars

IntroductionPreventing crop yield loss caused by pests is critical for global agricultural production. Agricultural pest control has largely relied on chemical pesticides. The interaction between insecticide resistance and the adaptation of herbivorous pests to host plants may represent an emerging threat to future food security. ObjectivesThis study aims to unveil genetic evidence for the reduction in the profitability of resistant cultivars derived from insecticide resistance in target pest insects. MethodsAn experimental evolution system encompassing resistant rice and its major monophagous pest, the brown planthopper Nilaparvata lugens, was constructed. Whole genome resequencing and selective sweep analysis were utilized to identify the candidate gene loci related to the adaptation. RNA interference and induced expression assay were conducted to validate the function of the candidate loci. ResultsWe found that the imidacloprid-resistant population of N. lugens rapidly adapted to resistant rice IR36. Gene loci related to imidacloprid resistance may contribute to this phenomenon. Multiple alleles in the nicotinic acetylcholine receptor (nAChR)-7-like and P450 CYP4C61 were significantly correlated with changes in virulence to IR36 rice and insecticide resistance of N. lugens. One avirulent/susceptible genotype and two virulent/resistant genotypes could be inferred from the corresponding alleles. Importantly, we found that the virulent/resistant genotypes already exist in the wild in China, exhibiting increasing frequencies along with insecticide usage. We validated the relevance of these genotypes and the virulence to three more resistant rice cultivars. Knockdown of the above two genes in N. lugens significantly decreased both the resistance to imidacloprid and the virulence towards resistant rice. ConclusionOur findings provide direct genetic evidence to the eco-evolutionary consequence of insecticide resistance, and suggest an urgent need for the implementation of predictably sustainable pest management.

The effects of carvacrol on development and gene expression profiles in Spodoptera frugiperda

The fall armyworm, Spodoptera frugiperda, is a highly polyphagous agricultural pest that is widely distributed around the world and causes severe crop yield loss. Carvacrol showed adverse effects on many pests, such as larval death and growth inhibition. While the effects of carvacrol on S. frugiperda larvae are not yet known. In this study, the effects of carvacrol on S. frugiperda, including larval growth inhibition and mortality induction, were observed. The detoxification and digestive enzyme activities of larvae with 1.0 and 2.0 g/kg carvacrol treatments were analyzed. Carvacrol boosted the enzyme activities of carboxylesterase (CarE) and glutathione S-transferase (GST) while decreasing the activities of α-amylase (AMS), lipase (LIP), and trypsin. A total of 3422 differentially expressed genes were identified in the larvae treated with 2.0 g/kg carvacrol, of which the DEGs involved in xenobiotic detoxification, food digestion, and insecticidal targets were further examined. These results suggest that carvacrol could regulate growth and development by affecting the process of food digestion, and exert its toxicity on the larvae through interaction with a variety of insecticidal targets. While the altered expressions of detoxification enzymes might be related to the detoxification and metabolism of carvacrol. Our findings offer a theoretical foundation for the use of carvacrol for S. frugiperda control in the field.

Distribution and population density of plant parasitic nematodes in Kallakurichi, Vedaranyam and Bargur blocks of Tamil Nadu

India contribute 9 per cent share in world production and one of the main vegetables grown in Tamil Nadu. Major production area of Tamil Nadu is Coimbatore, Dharmapuri, Salem and Krishnagiri districts. In India an average, a national loss of Rs. 21,068.73 millions has been estimated due to plant parasitic nematodes. An overall average annual yield loss in major horticultural crops due to nematodes goes upto 60% under protected cultivation. Protected cultivation is an emerging technology for raising vegetable and flower crops under controlled environmental condition and continuous growing of crops. Plant parasitic nematodes has emerged as a major problem, causing enormous yield loss. The maximum population of Pratylenchus spp in soil and root (300.54 and 275.50) were recorded in Veerasolapurammadur village, Kallakurichi block in sugarcane eco system and maximum lesion index 5.0 was recorded in same location and no incidence for root knot nematode was recorded. In Vaedharanyam block, The maximum population of Melodogyne graminicola in soil and root (300.25 and 325.65) were recorded in Neivellakku village, Vedharanyam block in rice eco system and maximum root knot index 5.0 was recorded in same location and no incidence for Aphelenchoides besseyi was recorded. In Barugur block ,The maximum population of lesion nematode, Radopholus similis in soil and root (450.20 and 410.25) were recorded in Santhur village, burgur block in banana eco system and maximum root lesion index 5.0 was recorded in same location and minimum population of root knot nematode (110.20 and 120.54) was recorded in Errapatty village of Burgur block.

A robust SNP-haplotype assay for Bct gene region conferring resistance to beet curly top virus in common bean (Phaseolus vulgaris L.).

Beet curly top virus (BCTV), which is synonymous with curly top virus (CTV), causes significant yield loss in common bean (snap and dry beans) cultivars and several other important crops. Common bean cultivars have been found to be resistant to CTV, but screening for resistance is challenging due to the cyclical nature of epidemics and spotty feeding by the leafhopper that vectors the virus. We used an SNP dataset for the Snap Bean Association Panel (SnAP) agro-inoculated with CTV-Logan (CA/Logan) strain to locate the Bct gene region to a 1.7-Mb interval on chromosome Pv07 using genome-wide association study (GWAS) analysis. Recombinant lines from the SnAP were used to further narrow the Bct region to a 58.0-kb interval. A missense SNP (S07_2970381) in candidate gene Phvul.007G036300 Exonuclease V (EXO5) was identified as the most likely causal mutation, and it was the most significant SNP detected by GWAS in a dry bean population (DBP) naturally infected by the CTV-Worland (Wor) strain. Tm-shift assay markers developed for SNP S07_2970381 and two linked SNPs, S07_2970276 and S07_2966197, were useful for tracking different origins of the Bct EXO5 candidate gene resistance to CTV in common bean. The three SNPs identified four haplotypes, with haplotype 3-1 (Haplo3-1) of Middle American origin associated with the highest levels of CTV resistance. This SNP-haplotype assay will enable breeders to track resistance sources and to develop cultivars with better CTV resistance.

Assessing Fungal Plant Pathogen Presence in Irrigation Water from the Rio Grande River in South Texas, USA

Irrigation is important in many crop production systems. However, irrigation water can be a carrier of plant pathogens that can enter the system and spread to fields, resulting in crop damage and yield losses. The Lower Rio Grande Valley of South Texas is an important area for agricultural production which depends on the Rio Grande River as a source of water for irrigation. Thus, the presence of plant pathogens in the Rio Grande River could have important implications for crop productivity in the region. Cultured-based methods and molecular identification methods are used for monitoring plant pathogens in irrigation water. However, these methods are labor-intensive and just detect targeted pathogens. To overcome these limitations, in this study, the ITS2 amplicon metagenomic method was applied for evaluating the fungal diversity, composition, and presence of fungal plant pathogens in irrigation water from the Rio Grande River as it leaves the water reservoir (WR) and it arrives at an irrigation valve at a farm (FA). Results from the Shannon (WR = 4.6 ± 0.043, FA = 3.63 ± 0.13) and Simpson indices (WR = 4.6 ± 0.043, FA = 3.63 ± 0.13) showed that there are significant differences in the fungal diversity and community structure between the two locations and the PCA analysis showed a clear differentiation between both fungal communities. Several OTUs identified in both locations included potential plant pathogens from diverse genera including Cladosporium, Exserohilum, and Nigrospora, while others such as Colletotrichum and Plectosphaerella were found only in one of the two locations assessed. This work indicates that microbes, including plant pathogens, may enter or exit throughout the irrigation-water distribution system, thereby modifying the microbial community composition along the way. Understanding the dynamics of plant pathogen movement in irrigation water systems can help growers identify risk factors to develop measures to mitigate those risks. This study also shows the usefulness of the metagenomic approach for detecting and monitoring plant pathogen in irrigation water.

Long time-series variation of crop yield under drought stress and drought vulnerability curves in Songnen Plain, Northeast China

It is of practical significance to reveal the long-term characteristics of drought and its impacts on crop yield in Songnen Plain, an important commodity grain base in Northeast China. This study firstly explored the long time-series variation of Modified Soil Water Deficit Index (MSWDI) and crop yield at multiple sites in Songnen Plain during 1960–2014 based on numerical simulation with the World Food Studies (WOFOST) model. This study then revealed the mutation of the drought and crop yield with three mutation point test methods, and thereafter explored their relationship between the drought and crop yield with the cross wavelet transform (XWT) and drought vulnerability curve. Results suggested the precipitation was at the lowest level in the 1970 s, which significantly increased in the 1980 s and thereafter exhibited a slow declining trend. Mutation points of drought conditions occurred at multiple stations in 1983, and the crop yields also showed obvious mutation in 1983 or 1984 at two stations. Besides, the drought and crop yield had significant 2–4 year resonance cycles during 1978–1980 at four stations. In particular, periods with high correlation between these two variables were generally years prone to abrupt changes. In addition, determination coefficients of the drought vulnerability curves based on the linear function, cubic curve function and hyperbolic tangent function reached 0.55, 0.65, and 0.64, respectively, suggesting the cubic curve function performed best. The drought vulnerability curve based on the cubic curve function suggested the crop yield loss showed a firstly decreasing and then increasing trend, which may be related to the compensation mechanism of crops. Overall, combination of the mechanistic drought index and crop models provides an effective way to reveal impacts of drought stress on crop yield and offer support information for coping with drought.

ЭНЕРГЕТИЧЕСКАЯ МАТЕМАТИЧЕСКАЯ МОДЕЛЬ ОПРЫСКИВАТЕЛЯ

The research was carried out in order to develop an energy mathematical model of a plant protection unit with a trailed sprayer, which makes it possible to optimize the parameters and operating modes, taking into account their influence on the size and loss of crop yield. For comparison with the tendencies of changes in the parameters of sprayers established in practice, computational experiments were performed using the developed mathematical model. The object of study is an analogue of MTZ-82 tractor, the main parameters of which (mass, engine power, kinematic length, etc.) can be changed, an analogue of a trailed sprayer with variable parameters (width, operating speed, tank volume, drawbar length, location of the center of mass, profile width and support wheel diameter, etc.). The optimization criterion was composite and included the sum of direct and indirect energy costs during the operation of the unit, taking into account the energy of the crop lost due to deviations from the optimal parameters and operating modes of the sprayer. Incorrect choice of unit parameters leads to yield losses, resulting from its decrease due to a violation of the deadline for performing a technological operation to protect crops from weeds, trampling down part of the crops by the unit's movers during processing, especially if there is no possibility of turning outside the field, due to soil compaction in the zone of growth and development of plant root systems. Computational experiments carried out using the developed energy mathematical model showed that an increase in sprayer coverage from 16 to 32 m at an aggregate speed of 12 km/h leads to a decrease in total energy costs from 3250 MJ/ha to 1692 MJ/ha, an increase in the unit speed from 7 to 12 km/h, with a working width of 32 m reduces the total energy costs from 1971 to 1692 MJ/ha. Reducing the width of the sprayer wheel tire profile from 0.6 to 0.2 m is accompanied by a decrease in total energy costs from 2793 MJ/ha to 1692 MJ/ha.

Semiochemicals from Trichosanthes anguina (Cucurbitaceae) plants influence behavior in Diaphania indica.

First to third instars of Diaphania indica (Saunders) (Lepidoptera: Crambidae) feed on the lower surface of leaves, while fourth and fifth instars gregariously consume leaves of Trichosanthes anguina L. After defoliating, the caterpillar also attacks flowers and fruits of the plant and finally, results in loss of crop yield. Therefore, behavioral responses of D. indica adults were investigated to volatiles from undamaged (UD), insect-damaged (ID, plants after feeding by D. indica larvae) and jasmonic acid (JA) treated T. anguina plants. Females showed attraction to volatiles of UD and ID plants of three T. anguina cultivars [MNSR-1 (MNS), Baruipur Long (BAR) and Polo No. 1 (POLO)] in Y-tube olfactometer bioassays. Females did not show significant negative responses from volatiles of JA treated plants. Females were more attracted to volatiles of ID plants than UD plants. Females showed attraction to volatiles of UD or ID plants compared to JA treated plants. Females were attracted to certain synthetic blends resembling volatiles of insect-damaged MNS, BAR and POLO plants in olfactometer bioassays. Females could not distinguish among these three certain synthetic blends in olfactometer bioassays. A synthetic blend of 3Z-hexen-1-ol, α-pinene, hexyl acetate, benzyl alcohol and 6Z-nonenal at mole ratios of 1.47:1.20:1:1.82:1.21 was prepared at 20 mg/mL dichloromethane and 100 μL when used as lure in funnel traps resulted in the capture of the highest number of D. indica adults in field trails. The earlier five-component chemical lure could be used in traps in an integrated pest management program of the insect pest, D. indica. © 2023 Society of Chemical Industry.

Crop yield anomaly forecasting in the Pannonian basin using gradient boosting and its performance in years of severe drought

The increasing frequency and intensity of severe droughts over recent decades have led to substantial crop yield losses in the Pannonian Basin in southeastern Europe. Their socioeconomic consequences can be minimized by accurate crop yield forecasts, but such forecasts often underestimate the impact of severe droughts on crop yields. We developed a gradient-boosting-based crop yield anomaly forecasting system for the Pannonian Basin and examined its performance, with a focus on drought years. Winter wheat and maize yield anomalies are forecasted for 42 regions in the Pannonian Basin using predictor datasets from Earth observation and reanalysis describing vegetation state, weather, and soil moisture conditions.Our results show that crop yield anomaly estimates in the two months preceding harvest have better performance (maize errors 14–17%, wheat 13–14%) than earlier in the year (maize errors 21%, wheat 17%). The forecast models can satisfactorily capture the interannual yield anomalies, but spatial yield variability is only partially reproduced. In years of severe drought, the wheat model performs better than under average conditions with errors below 12%. The errors of the maize forecasts in drought years are larger than average forecast skill: 31% two months ahead and 20% one month ahead. However, for both crops the yield losses remain underestimated by the forecasts in severe drought years. The feature importance analysis shows that during the last two months before harvest, wheat yield anomalies are controlled by temperature and evaporation and maize by the combined effects of temperature and water availability as expressed by several drought indices. In severe drought years, during the two months before harvest the seasonal temperature forecast becomes the most important predictor for the wheat forecasts and soil moisture for the maize model. Overall, this study provides in-depth insights into the impact of droughts on crop yield forecasts in the Pannonian Basin.

Development of organic phosphorus vermicompost from raw phosphate rock using microorganisms and enzymes and its effect on tomato yield

Chemical phosphorus and other chemical fertilizers undergo certain changes in the soil. These changes cause crop yield loss because of changes in soil pH and EC. In addition, other toxic compounds accumulate. They also lead to serious soil contamination and threaten the environment. In this study, vermicompost was developed from raw phosphate rock by using microorganisms and phosphorus solubilizing enzymes (protease, lipase, dehydrogénase, hydrolase, urea, nitrogenesis, cellulose) to eliminate phosphorus deficiency in soil. Two-year greenhouse trials were conducted to determine the effectiveness of the organic phosphorus humus produced after six months of mineralization, and tomato plants were grown. As a result of these experiments, the effects on yield and physicochemical properties of the tomato plant were studied. Earthworm fertilizer at a rate of 4500 kg ha−1 increased the tomato yield of 22.12% compared to the control application, in the two-years means. In addition, the effect on nutrient content of tomato plants resulted in statistically significant increases (p < 0.05). When the macronutrient concentrations in the leaves of the plant were examined, they were considered to have reached the level of sufficiency. It was also found that the content of amino acids, chlorophyll and antioxidants in the tomato plant reached the highest levels compared to the control application. Based on our results, it was concluded that this organic fertilizer will contribute to higher crop yields in plants of cultural and commercial importance and to other plant growth parameters.

Effects of fungicides on fitness and Buchnera endosymbiont density in Aphis gossypii.

Several agricultural fungicides are known to affect insect pests directly and these effects may be transgenerational and mediated through impacts on endosymbionts, providing opportunities for pest control. The cotton aphid Aphis gossypii is a polyphagous pest that can cause large crop yield losses. Here, we tested the effects of three fungicides, pyraclostrobin, trifloxystrobin and chlorothalonil, on the fitness and Buchnera endosymbiont of A. gossypii. The formulations of trifloxystrobin and pyraclostrobin, and the active ingredient of pyraclostrobin produced dose-dependent mortality in A. gossypii, whereas there was no dose-dependent mortality for chlorothalonil. The formulations of trifloxystrobin and pyraclostrobin significantly reduced the lifespan and fecundity of A. gossypii, and increased the density of Buchnera in the parental generation but not the (unexposed) F1 . When the active ingredient of pyraclostrobin was tested, the lifespan of the F0 generation was also reduced, but the density of Buchnera was not, indicating that non-insecticidal chemicals in the fungicide formulation may affect the density of the endosymbiont of A. gossypii. There was no transgenerational effect of the active ingredient of pyraclostrobin on the lifespan and Buchnera of (unexposed) F1 . Our results suggest that formulations of two strobilurin fungicides have immediate impacts on the fitness of A. gossypii, and chemicals in the formulation impact the density of the primary Buchnera endosymbiont. Our study highlights the potential effects of non-insecticidal chemicals of fungicides on aphid pests and their primary endosymbionts but direct connections between fitness and Buchnera densities remain unclear. © 2023 Society of Chemical Industry.

Heat stress in wheat: a global challenge to feed billions in the current era of the changing climate

Crop failure is largely caused by various climate hazards, and among them, heat stress is the primary factor hindering crop production. The significant global loss of crop yield is primarily due to heat-related damage during the reproductive phase. Terminal heat stress has been well documented in wheat, causing morphophysiological alterations, biochemical disruptions, and reduction of genetic potential. The formation of shoots and roots, the effect on the double ridge stage, and early biomass in the vegetative stage are also impacted by heat stress. The final negative outcomes of heat stress include reduced grain number and weight, slower grain filling rate, reduced grain quality, and shorter grain filling duration. Plants have developed mechanisms to adapt to heat stress through modifications in their morphological or growth responses, physiological and biochemical pathways, and changes in enzyme reactions. Numerous heat tolerance genes have been identified in wheat, but the more extensive study is needed to increase heat tolerance in crops to satisfy the food demands of the world’s growing population. The global food policy needs to prioritize and promote additional joint research and the development of heat-tolerant wheat breeding to ensure the world’s food security.

Vegetal protein hydrolysates reduce the yield losses in off-season crops under combined heat and drought stress.

The online version contains supplementary material available at 10.1007/s12298-023-01334-4.