Fusarium Wilt Disease Incidence Research Articles

First Report of Fusarium falciforme Causing Fusarium Wilt on pepper in Hainan, China.

Pepper (Capsicum annuum L.) is a significant vegetable crop, valued for its nutritional and economic importance (Pang et al. 2023). Pepper cultivation in China accounts for about 8-10% of the total vegetable planting area, contributing an output value of approximately 250 billion yuan. This makes pepper the leading vegetable in terms of both planting area and economic value. In December 2023, a total of 70% disease incidence of Fusarium wilt was observed in a 1200 m² pepper seed breeding base in Sanya City, Hainan Province, China (18°38'60″ N, 109°16'51″ E). Symptoms initially appeared as wilting on upper leaves. Subsequently, the base of the stem started to necrosis, browning, and gradually spreading upward along the stem. As the lesions expanded, the whole plant gradually wilted and died. Ten diseased plants were randomly selected from the most severely affected area (667 m²). Diseased tissues (5 mm²) were subsequently removed from the lesion edges of these plants, surface sterilized in 75% ethanol for 30 s, and rinsed with sterile distilled water three times, finally cultured on potato dextrose agar (PDA) at 25 °C. Six fungal isolates were obtained using the single-spore isolation method (HN-01 to HN-06). Colonies produced white aerial mycelia with apricot pigments in the PDA medium. The spore morphology and size were observed and measured using synthetic nutrient-poor agar (SNA) medium. Macroconidia were hyaline, slightly curved in shape with 3 or 4 septa, measuring 28.6 to 41.4 × 3.2 to 6.2 μm (av. = 34.8 ± 3.32 × 4.6 ± 0.85 um, n = 20). Microconidia were elongated, oval with 0 or 1 septum, and measured 11.2 to 16.8 × 2.6 to 5.8 μm (av. = 13.5 ± 1.47 × 4.12 ± 1.03 um, n = 20). Chlamydospores were spherical, terminal or intercalary, solitary or chain-forming, with diameters ranging from 2.8 to 10.5 um (av. = 5.8 ± 2.31 um, n = 20). For molecular identification, genomic DNA from all six isolates was extracted using the cetyl trimethyl ammonium bromide (CTAB) method, and the internal transcribed spacer of rDNA (ITS), translation elongation factor 1-α (EF1-α), and RNA polymerase II beta subunit (RPB2) regions were amplified and sequenced using the primers ITS1/ITS4, EF-1/EF-2, and RPB2-5F/7cR (White et al. 1990; O'Donnell et al. 2010). The sequences were deposited in GenBank (ITS: PP779839, PP779840, PP779841, PP779842, PP779843, PP779844; EF1-α: PP797138, PP797139, PP797140, PP797141, PP797142, PP797143; RPB2: PP797144, PP797145, PP797146, PP797147, PP797148, PP797149). The sequences of all three genes showed 99 to 100% similarity with Fusarium falciforme and other closely related Fusarium species (ITS: PP735125, EF1-α: OP163897 and RPB2: MF467484). A maximum likelihood phylogenetic tree was constructed based on the ITS, EF1-α, and RPB2 sequences of all isolates, along with other closely related Fusarium species. Based on morphological and phylogenetic characteristics, all isolates were identified as F. falciforme (Xu et al. 2023; Wang et al. 2023). Ten Pepper inbred line A23-41 (5 for the inoculation treatment and 5 for the control) were tested for pathogenicity using three representative isolates: HN-01, HN-02, and HN-03. A total of 20 ul of spore suspension with concentration 106 spores/ml was injected near the soil surface of the stem, while the control treatment was inoculated with 20 μl of sterile water. The plants were placed in a climatic chamber at RH80-90% and 25/20 °C (day/night) after inoculation. The experiment was repeated three times. After 10 days, Inoculated plants stem developed necrosis, browning, while the control group remained asymptomatic. The fungus reisolated from the artificially infected stems was identified through EF1-α and RPB2 sequence analysis as F. falciforme, thus fulfilling Koch's postulates. Fusarium falciforme has been previoulsy reported as causing various diseases on different hosts in several countries, including Korea (Kang et al., 2024), Malaysia (Balasubramaniam et al., 2023), and Mexico (Payán-Arzapalo et al., 2024). To the best of our knowledge, this is the initial report demonstrating that F. falciforme causes Fusarium wilt on peppers in China. The study results can provide the basis for future research on the occurrence, prevention, and management of this disease.

Assessment of Fusarium wilt (Fusarium oxysporum f.sp. sesami) Disease Incidence in Sesame (Sesamum indicum L.) in Western Tigray, Northern Ethiopia

Fusarium wilt disease is one of the most serious diseases threatening sesame production in Tigray, northern Ethiopia. The aim of the present study was to assess Fusarium wilt disease incidence and its association with agronomic practices and environmental factors. Field survey was conducted in Kafta-Humera, Welkayt and Tsegedie districts in 2018 cropping season. A total of 92 farmers’ fields were assessed for the prevalence and incidence of the disease. Results indicated that 67% of farmers’ fields were infected by Fusarium wilt disease from the total assessed fields. Fusarium wilt disease incidence was varied from 0.22% to 80%. It was ranged from 0-72% in Kafta-Humera, 0-56% in Welkayt and 0-80% in Tsegedie. The mean disease incidence was 11.89% at Kafta-Humera, 11.14% at Welkayt and 10.69% at Tsegedie. According to the single predictor in the logistic regression model Fusarium wilt disease incidence was most affected significantly (p < 0.05) with the previous crop and altitude. Higher levels of disease incidence were recorded when the previous crop was sesame, lower altitudes and in clay loam soil texture. Overall results of the present study indicated that Fusarium wilt disease is the major challenge to sesame production in study areas. Therefore, efforts should be put in place to manage the disease via integration of appropriate strategies.

Streptomyces-triggered coordination between rhizosphere microbiomes and plant transcriptome enables watermelon Fusarium wilt resistance.

The use of microbial inoculant is a promising strategy to improve plant health, but their efficiency often faces challenges due to difficulties in successful microbial colonization in soil environments. To this end, the application of biostimulation products derived from microbes is expected to resolve these barriers via direct interactions with plants or soil pathogens. However, their effectiveness and mechanisms for promoting plant growth and disease resistance remain elusive. In this study, we showed that root irrigation with the extracts of Streptomyces ahygroscopicus strain 769 (S769) solid fermentation products significantly reduced watermelon Fusarium wilt disease incidence by 30% and increased the plant biomass by 150% at a fruiting stage in a continuous cropping field. S769 treatment led to substantial changes in both bacterial and fungal community compositions, and induced a highly interconnected microbial association network in the rhizosphere. The root transcriptome analysis further suggested that S769 treatment significantly improved the expression of the MAPK signalling pathway, plant hormone signal transduction and plant-pathogen interactions, particular those genes related to PR-1 and ethylene, as well as genes associated with auxin production and reception. Together, our study provides mechanistic and empirical evidences for the biostimulation products benefiting plant health through coordinating plant and rhizosphere microbiome interaction.

Effect of Fobio on Intensity of Moler Disease (Fusarium oxysporum) on Various Shallot Cultivars

Fusarium oxysporum is the pathogen that causes moler disease which can reduce the productivity of shallot plants. The use of cultivars greatly affects the production. Control method that is more environmentally friendly is currently being pursued towards organic farming. Fobio is a biopesticide containing plant root microorganisms as biological control agents. This study aims to determine the effect of Fobio biopesticide on Fusarium wilt (moler) disease incidence and production of three shallot cultivars. The experiment was conducted in the shallot planting area of Sukorejo Village, Rejoso District, Nganjuk Regency, East Java. This experiment was arranged in the split plot design with two factors. The main plot of the concentration of the biopesticide formula (Fobio) consisted of 3 levels namely control (chemical fungicide), 5 ml/liter, and 10 ml/liter, and the subplot of shallot cultivar consisted of 3 types namely Tajuk, Biru Lanchor, and Super Philip. The observation in this study were the incubation period, disease symptoms, disease intensity, and shallot bulb yield. The results showed that Fobio biopesticide at the concentration of 10 ml/liter caused the same disease suppression as chemical fungicide (control) in the three shallot cultivars with the disease incidence of 18.78%. Fobio biopesticide concentration of 10 ml/liter had also the same effect as chemical fungicide on the production of those shallot cultivars, with the average wet weight of 2.25 kg/treatment and dry weight of 1.49 kg/treatment.

Crude Saponins from Chenopodium quinoa Willd. Reduce Fusarium Wilt Infection in Tomato Seedlings

Quinoa saponins are pentacyclic triterpene compounds composed of one triterpenoid glycoside and two different sugar chains. Previous studies have showed that natural quinoa saponins showed little or no antifungal activity, and there are few reports about their antifungal effects in recent decades. Fusarium wilt caused by Fusarium oxysporum f. sp. lycopersici (FOL) is the most serious for tomatoes in the field and under greenhouse conditions. The main objective of this study was to investigate the effectiveness of different concentrations and application modes of crude saponins from quinoa bran against the causal pathogen of tomato wilt under a greenhouse experiment. The results showed that the anti-FOL activity of quinoa saponins was weak in vitro, but significantly enhanced in vivo. Tomato seeds and seedlings treated with solution of quinoa saponins at 0.5 and 1.0 g/L significantly reduced the disease incidence (%) of tomato Fusarium wilt. The treatment types of saponin solution have influence on the preventive effects (%) of tomato seedlings against Fusarium wilt, among them, root soaking > foliar spray > seed soaking. The treatment of seed soaking with quinoa saponins inhibited germination of tomato seeds to some extent. However, the germination rate of tomato seeds after saponin soaking was comparable to the chemical pesticide (thiram carboxin); therefore, it could be used to control tomato wilt disease. This is due to the fact that the antifungal activity of quinoa saponins in vivo was much higher than that in vitro when the saponin concentration was between 0.5–1.0 g/L, indicating that the antifungal activity of quinoa saponins may be achieved mainly by inducing resistance. This investigation supports the potential use of quinoa saponins as a supplier of antifungal compounds, and could be the foundation for a future study examining the use of quinoa bran as a new resource against FOL.

Intercropping with Trifolium repens contributes disease suppression of banana Fusarium wilt by reshaping soil protistan communities

Fusarium wilt disease of bananas, caused by the soil-borne pathogen Fusarium oxysporum, threatens banana production. Intercropping, cultivation of more than one crop simultaneously on the same field, has emerged as efficient and sustainable land management for suppressing Fusarium wilt disease. Although previous studies have proven the changes in soil microbial communities including bacteria and fungi under intercropping contributed to disease suppression, little is known about the role of protistan communities in driving this effect. In a field experiment, we assessed microbiome shifts with a focus on protists under intercropping of banana with the legume Trifolium repens. Our results showed that the reduced Fusarium wilt disease incidence and the decreased Fusarium pathogen density under intercropping could be attributed to the changes in protistan community compositions. Specially, we observed a significant negative correlation between the relative abundance of phagotrophic protists and Fusarium oxysporum. We further conducted a pot experiment to examine the impacts of the legume crop on phagotrophic protists across different spatial distances, which showing that intercropping enriched the relative abundance of phagotrophic protists, especially Cercomonas, with members of this group showing the capacity to directly inhibit the growth of Fusarium pathogen in vitro. We highlight that predatory protists are important agents underlying disease suppression in intercropping system, which can offer new venues to promote plant health in sustainable agriculture.

Role of Reductive Soil Disinfestation and Chemical Soil Fumigation on the Fusarium Wilt of Dioscorea batatas Decne Suppression

Reductive soil disinfestation (RSD) and chemical soil fumigation (CSF) comprise the most popular pre-planting soil management strategies. Their efficiency in suppressing several plant diseases in agricultural production systems has been compared. However, the disease-control effect of these methods on Fusarium wilt disease in Dioscorea batatas Decne (D. batatas) remains unclear. Importantly, dissimilarities in the impact of their bio-predictors on plant health have not been well characterized. Herein, four treatments, including no treatment (CK), RSD with gran chaff (GC-RSD) and molasses (MO-RSD), and CSF with dazomet (DA-CSF), were performed in a pot experiment using D. batatas-diseased soil. Compared with the CK treatment, the Fusarium oxysporum population significantly decreased by 88.89–97.78% following the DA-CSF, GC-RSD, and MO-RSD treatments. The bacterial community and functional composition of the soil were considerably altered by these treatments. However, the incidence of Fusarium wilt disease in D. batatas was significantly decreased in the two RSD-treated soils, rather than in DA-CSF-treated soils. Bacterial α-diversity and population as well as some key nitrogen-related functional gene expressions as bio-predictors were significantly lower in DA-CSF-treated soil than in RSD-treated soil. In particular, the core (e.g., Azotobacter, Phenylobacterium, Clostridium, Bradyrhizobium, Microvirga, and Caulobacter) and unique (e.g., Pseudomonas, Brevundimonas, Flavobacterium, Ochrobactrum, and Sphingobacterium) functional microbiomes in RSD-treated soil exerted a positive impact on soil functional composition of the soil and plant growth. Taken together, our results indicate that RSD outperformed CSF in promoting plant health by regulating the bacterial community and functional composition.

Evaluation of organics, antagonists and carbendazim against Fusarium wilt of pigeonpea (Cajanus cajan L.)

In India, pigeonpea [Cajanus Cajan (L.) Millsp.] wilt caused by Fusarium udum is prevalent in all areas it cultivated. Among the major soil borne diseases pigeonpea, the Fusarium wilt caused by Fusarium udum is one of the most important diseases and can cause 30-100% loss in grain yield. A pot experiment was conducted to assess the efficacy of Trichoderma harzianum, Pseudomonas fluorescens, farm yard manure, spent mushroom substrate of oyster mushroom and the fungicide Carbendazim 50% WP against Fusarium wilt of pigeonpea in terms ofseed germination and disease incidence under artificial inoculation conditions during Kharif 2021. Among the treatments assessed, maximum seed germination (95.83%) was recorded in treatments in which seed were treated with Carbendazim 50% WP or soil amended with the combination of spent mushroom substrate+Trichoderma harzianum or spent mushroom substrate+(Trichoderma harzianum+ Pseudomonas fluorescens) prior to sowing. Maximum reduction in disease incidence (73.81%) of Fusarium wilt over the control was recorded in treatment in which soil was amended with combination of spent mushroom substrate+(Trichoderma harzianum+ Pseudomonas fluorescens). The results revealed that all the treatments applied as prophylactic measure, reduced the Fusarium wilt and increased the seed germination significantly over the unprotected crop.

Incorporating the Plant Disease Triangle Framework for Analyzing the Effect of FWB Incidence on Soil Attributes

FWB (FWB), also known as Panama disease and caused by Fusarium oxysporum f. sp. cubense (Foc), is the most destructive disease in the banana industry. Foc is the most virulent pathogen and is capable of surviving in agricultural soil for an indefinite period. The complex interaction between Foc, bananas, and the environment has restricted efforts to develop FWB prevention and control. Thus, it is essential to investigate all dimensions of the interactions relating to the occurrence of FWB in plantations. The purpose of this preliminary study was to assess the reversed interaction of soil attributes and FWB. The relationships between Fusarium wilt disease incidence and soil characteristics were analyzed using a forward linear regression analysis with dummy variables. Age, as well as shrubs and weeds, were incorporated as dummy variables. The first model of forward linear regression with soil moisture as the dependent variable significantly revealed that R2 is larger and more strongly correlated when plant conditions and banana tree age variables are included in the model (p = 0.0). Still, a comprehensive experimental approach is required for better understanding since an increasing human population in the future may pose a threat to food security.

Efficacy of different agro-techniques on growth, yield and disease incidence on tomato (Solanum lycopersicum l.) crop of north western Himalayan region

A field experiment was conducted during 2 consecutive years (2017-18 and 2018-19)with 12 treatment combinations at Vegetable Research Farm, Nauni, Solan with an objective to study the effects of different planting methods, mulches and training systems on flowering, fruiting, yield and incidence of diseases of tomato (Solanum Lycopsersicum L.) var. Solan Lalima. Plants grown on raised beds had minimum incidence of buckeye rot (4.19%), severity of Alternaria leaf blight (3.80%), incidence of bacterial leaf spot (2.38%) and incidence of Fusarium wilt (3.45%) and higher yield per plot (127.57 kg) and per hectare (899.96 q). Black polythene mulch responded best for lower incidence of buckeye rot (4.45%), severity of Alternaria leaf blight (4.01%), incidence of bacterial leaf spot (2.47%) and incidence of Fusarium wilt (3.62%) and higher yield per plot (129.42 kg) and per hectare (913.05 q), respectively. T1 also recorded lower incidence of buckeye rot (4.09%), severity of Alternaria leaf blight (3.67%), incidence of bacterial leaf spot (2.33%) and incidence of Fusarium wilt (3.36%) and higher yield per plot (46.46 kg) and per hectare (327.74 q). Regarding consortium effect, the minimum incidence of buckeye rot (3.46%), severity of Alternaria leaf blight (2.80%), incidence of bacterial leaf spot (1.84%) and incidence of Fusarium wilt (2.60%) disease was recorded in P1M1T1 treatment combination (raised bed + black polythene mulch + two stem training system). This combination was also better for all the growth and yield contributing characters.

Treatment with organic manure inoculated with a biocontrol agent induces soil bacterial communities to inhibit tomato Fusarium wilt disease.

Organic manure, plant growth-promoting microorganisms, and biocontrol agents are widely used to sustainably control soil-borne diseases. However, how and whether organic manure inoculated with biocontrol agents alters soil microbiota and reduces disease severity is poorly understood. Here, we examined changes to the soil microbial community, soil properties, and incidence of Fusarium wilt disease in response to several fertilization regimes. Specifically, we studied the effects of inorganic chemical fertilization (CF), organic manure fertilization (OF), and Erythrobacter sp. YH-07-inoculated organic manure fertilization (BF) on the incidence of Fusarium wilt in tomato across three seasons. BF-treated soils showed increased microbial abundance, richness, and diversity compared to other treatments, and this trend was stable across seasons. BF-treated soils also exhibited a significantly altered microbial community composition, including increased abundances of Bacillus, Altererythrobacter, Cryptococcus, and Saprospiraceae, and decreased abundances of Chryseolinea and Fusarium. Importantly, BF treatment significantly suppressed the incidence of Fusarium wilt in tomato, likely due to direct suppression by Erythrobacter sp. YH-07 and indirect suppression through changes to the microbial community composition and soil properties. Taken together, these results suggest that Erythrobacter sp. YH-07-inoculated organic manure is a stable and sustainable soil amendment for the suppression of Fusarium wilt diseases.

Survey on the incidence of Fusarium wilt of tomato incited by Fusarium oxysporum f. sp. lycopersici (FOL) in major tomato growing areas of Khordha district, Odisha, India

One of the main issues with tomato production is fusarium wilt, often known as vascular wilt or Fusarium oxysporum f. sp. lycopersici. In order to determine the disease incidence of fusarium wilt in several tomatogrowing regions of the Khordha district, Odisha, in the years 2021–22 and 2022–23, a survey was conducted. A total of ten villages (one village from each block) were visited, and each village’s five fields were examined. This was done by counting the number of sick or infected plants in each field’s randomly chosen five-byfive-meter tomato field. Pichukuli village (25.70%), Jankia village (23.69%), and Jagannathpur village (22.59%) had the highest per cent disease incidence. Nachuni village (16.72%) and Siko (17.28%) had the lowest per cent disease incidence, respectively. The survey’s findings showed that there was a disease incidence that was causing output and crop losses for tomatoes.

Cross-kingdom synthetic microbiota supports tomato suppression of Fusarium wilt disease

The role of rhizosphere microbiota in the resistance of tomato plant against soil-borne Fusarium wilt disease (FWD) remains unclear. Here, we showed that the FWD incidence was significantly negatively correlated with the diversity of both rhizosphere bacterial and fungal communities. Using the microbiological culturomic approach, we selected 205 unique strains to construct different synthetic communities (SynComs), which were inoculated into germ-free tomato seedlings, and their roles in suppressing FWD were monitored using omics approach. Cross-kingdom (fungi and bacteria) SynComs were most effective in suppressing FWD than those of Fungal or Bacterial SynComs alone. This effect was underpinned by a combination of molecular mechanisms related to plant immunity and microbial interactions contributed by the bacterial and fungal communities. This study provides new insight into the dynamics of microbiota in pathogen suppression and host immunity interactions. Also, the formulation and manipulation of SynComs for functional complementation constitute a beneficial strategy in controlling soil-borne disease.

Survey, identification and management of Fusarium wilt of banana in Tamirabarani tract of Southern districts of Tamil Nadu

In Tamil Nadu state, Thoothukudi district ranked second in banana production and especially the Tamirabarani tract of Thoothukudi and Tirunelveli districts are known for the production of various banana cultivars like Rasthali, Andhra Kozhi, Karpooravalli, Neypoovan, Poovan, Peyan and Chakkai. Among these varieties, cultivation of Rasthali faces 50-60% yield loss due to the incidence of Fusarium wilt disease. As the farmers have been practising ratooning for 6-7 year continuously which enhances the inoculum load of the pathogen and make the plantains succumb to Fusarium oxysporum f. sp. cubense (Foc). Studies carried out on different treatments in the management of Fusarium wilt of banana, Trichoderma sp. Tsp1(ALG) showed a maximum reduction of mycelial growth of Foc (72.18%) over control which was on par with Pseudomonas fluorescence 1(Pf1). Under pot culture conditions the combination of three treatments, Tsp1(ALG)+Pf1+ neem cake excelled and showed an 80% reduction of wilt incidence. A multifaceted approach comprising the application of biocontrol agents (Trichoderma sp.) + Pseudomonas sp. 1 (TNAU) and organic amendments was found to be the best management practice in containing the wilt.

Disease incidence of fusarium wilt in organic garlic cultivation with compost plus Gliocladium on endemic land

Fusarium wilt (Fusarium oxysporum f.sp. cepae) is the most important soil-borne disease in garlic. This pathogen is a weak parasite so that it can be controlled through healthy plant cultivation approaches such as the use of organic compost fertilizer and soil microbes as biological control agents. Gliocladium sp. is an antagonist fungus that can be used as a soil borne disease control agent. This study aims to evaluate the effectiveness of compost plus Gliocladium to control garlic root rot in endemic land. The experiment was carried out in Tawangmangu Karanganyar at 1000 meters asl. The experiment consisted of 5 treatments arranged by completely randomized design with three replications. The main variables are disease incidence of fusarium wilt and control efficacy. The other variables observed were the fresh and dry weight of the biomass and the yield in the form of the weight of garlic bulbs per plant. Data processing carried out was analysis of variance and DMRT at 5% level. The results showed that compost plus Gliocladium produced higher effectiveness than compost alone or Gliocladium alone. The effectiveness of compost plus Gliocladium was more effective in suppressing fusarium wilt compared to farmers using fungicides and artificial chemical fertilizers.

Grafting Compatibility, Scion Growth, and Fusarium Wilt Disease Incidence of Intraspecific Grafted Tomato

Abstract The tomato (Solanum lycopersicum L.) is one of the most important vegetables grown globally. However, the production of tomatoes is restricted by Fusarium oxysporum f. sp. lycopersici (Fol). This study aims to investigate the ability of Fol-resistant tomato genotypes to be a rootstock for the susceptible cultivar. In this study, a tomato cultivar was grafted on rootstocks of the same species (intraspecific), and grafting compatibility, peroxidase gene expression, and fusarium wilt disease incidence of tomato scion was evaluated. A Fol-susceptible tomato ‘Sidathip 3’ (SDT3) was grafted onto four different Fol-resistant tomato genotypes and compared with self-grafted cultivar/cultivar and rootstock/rootstock. The survival rate of all grafted plants was 100% at 20 days after grafting (DAG) without significant differences in incompatibility evaluated at 42 days after grafting. The expression of the peroxidase gene (Solyc02g084800.2) using the qPCR technique was compared in self-grafted rootstock LE472/LE472 and SDT3/LE472. The expression level was three times higher in heterografted plants than in self-grafted ones at 15 DAG, indicating graft incompatibility. The rootstocks did not affect the height of the plant, the number of branches, the size of the fruit, or the yield of SDT3 scion. All intraspecific heterografted plants significantly controlled Fol when evaluated 60 days after inoculation. These results showed the usefulness of intraspecific grafting by using the proper rootstock genotypes to increase pathogen resistance in addition to stimulating growth and fruit yield.

Influence of Variety and Poultry Manure Rates on Growth, Yield, Incidence and Severity of Fusarium Wilt Disease on Three Pepper (Capsicum annum) Varieties

A field experiment was conducted to study the effect of different rates of poultry manure on growth, yield, incidence and severity of fusarium wilt on three varieties of pepper (Capsicum annuum). The research was carried out at the Crop Science and Horticulture research farm of the Faculty of Agriculture, Nnamdi Azikiwe University Awka, Anambra State-06⁰15ˈ2ˈˈN,7⁰6ˈ59ˈˈand 51m above sea level. The experiment lasted from June to August 2019 wet season planting. The pepper varieties used include: California wonder (green), Efia red and Nsukka yellow. The three pepper varieties received 0tons/ha, 8tons/ha and 16tons/ha of poultry manure. It was a 3 x 3 factorial experiment laid out in a Randomized Complete Block Design (RCBD) and replicated thrice. Variety influenced (P<0.05) plant height where the Nsukka yellow pepper gave the tallest plants (46.60cm) while the shortest was the green variety (27.0cm) at 8WAT. Highest number of leaves were obtained in red variety (167.9) which was significantly different (P<0.05) from the other varieties. No significant difference was observed in the leaf area of the three varieties (P>0.05) at the second and fourth WAT though Nsukka yellow had the largest leaf area at 4WAT and, Efia red was largest at 6WAT. Poultry manure application influenced leaf area (P<0.05) at 2nd, 4th and 6WAT. Poultry manure at 16 tons/ha gave the largest leaf area at 2nd, 4th, 6th and 8WAT. There was a significant (P<0.05) varietal effect on incidence and severity of diseases where the green variety had the highest incidence and severity of wilt. Poultry manure also influenced incidence and severity of Fusarium wilt disease where highest incidence and severity was obtained at 0tons/ha. There was a significant interaction (P<0.05) effect of variety and poultry manure rates which was observed on plant height at 2nd,4th ,6th and 8WAT. Yellow x 8tons/ha gave the tallest plants at 8WAT. Effect poultry manure rates on the number of fruits, weight gain, fruit length, fruit diameter, number of locus and fruit girth were not significantly different (P>0.05), though the highest (5.70) number of fruits was obtained at 8ton/ha poultry manure application This was followed by 4.93 at 16ton/ha, while the least number of fruits was produced when 0ton/ha was applied Poultry manure at 8tons/ha also produced the highest pepper fruit weight with a mean value of (5.700g) though not statistically different from the other two varieties. It is therefore that farmers should adopt the application of 8tons/ha poultry manure, as this was most suitable in terms of yield and increase beyond this level may not lead to appreciable marginal increase in yield as observed in this investigation.

Assessment of Weather Parameters on Per Cent Disease Incidence and Forewarning Models of Fusarium Wilt in Pigeonpea as Influenced by Different Sowing Windows

Background: Fusarium wilt caused by Fusarium udum (Butler) var. cajani is one of the most important soil-borne diseases of pigeonpea capable of causing 30-100% loss in grain yield. So it is essential to establish the relationship with weather parameters and prediction of per cent disease incidence. Methods: An experiment was laid out in split plot design with three replications and sixteen treatment combinations considering different varieties and sowing windows. Correlation and multiple linear regression equations were elucidated between weather parameters and per cent disease incidence (PDI) of Fusarium wilt on different pigeonpea varieties under different sowing windows during 2017-18 and 2018-19. Result: The correlation of weather parameters with PDI of Fusarium wilt indicated that significant and positively correlation with maximum and minimum temperature and negative correlation with evening relative humidity. Among all sowing windows 30th meteorological week (MW) sowing window with the variety ICPH 2740 PDI for two weeks prior was significantly positively correlated with maximum temperature (0.871** and 0.919**) and morning relative humidity (0.727* and 0.056). The prediction of PDI of Fusarium wilt with multiple linear regression equations were recorded the highest R2 valueas 95.5% in case of treatment combination of 30th MW and the variety Vipula.

Variation of Soil Microbial Community and Sterilization to Fusarium oxysporum f. sp. niveum Play Roles in Slightly Acidic Electrolyzed Water-Alleviated Watermelon Continuous Cropping Obstacle.

It is critical to exploit technologies for alleviating watermelon continuous cropping obstacle which frequently occurs and results in the limiting production and economic losses of watermelon. This study aimed to explore the effects of slightly acidic electrolyzed water (SAEW) on watermelon continuous cropping obstacles. The results showed that SAEW significantly improved the growth of watermelon seedlings cultivated in continuous cropping soil and caused a mass of changes to the diversity of the soil microbial community. Compared with Con, SAEW decreased the diversity index of bacteria by 2%, 0.48%, and 3.16%, while it increased the diversity index of fungus by 5.68%, 10.78%, and 7.54% in Shannon, Chao1, and ACE index, respectively. Besides, the enrichment level of Fusarium oxysporum f. sp. niveum (FON) was remarkably downregulated by 50.2% at 14 days of SAEW treatment, which could decrease the incidence of Fusarium wilt disease. The wet and dry weights of FON mycelia in the fluid medium were depressed more than 93%, and the number of FON colonies in continuous cropping soil was reduced by 83.56% with SAEW treatment. Additionally, a strong correlation between watermelon, FON, and SAEW was presented by correlation analysis. Furthermore, the content of endogenous reactive oxygen species (ROS) was over quadruply increased by SAEW, which may contribute to the sterilizing effect of SAEW on FON. Taken together, our findings demonstrated that exogenous SAEW could alter the soil microbial diversity and decrease the accumulation of FON, which improved the growth of watermelon seedlings and finally alleviated continuous cropping obstacles of watermelon.

Trophic interactions between predatory protists and pathogen-suppressive bacteria impact plant health.

Plant health is strongly impacted by beneficial and pathogenic plant microbes, which are themselves structured by resource inputs. Organic fertilizer inputs may thus offer a means of steering soil-borne microbes, thereby affecting plant health. Concurrently, soil microbes are subject to top-down control by predators, particularly protists. However, little is known regarding the impact of microbiome predators on plant health-influencing microbes and the interactive links to plant health. Here, we aimed to decipher the importance of predator-prey interactions in influencing plant health. To achieve this goal, we investigated soil and root-associated microbiomes (bacteria, fungi and protists) over nine years of banana planting under conventional and organic fertilization regimes differing in Fusarium wilt disease incidence. We found that the reduced disease incidence and improved yield associated with organic fertilization could be best explained by higher abundances of protists and pathogen-suppressive bacteria (e.g. Bacillus spp.). The pathogen-suppressive actions of predatory protists and Bacillus spp. were mainly determined by their interactions that increased the relative abundance of secondary metabolite Q genes (e.g. nonribosomal peptide synthetase gene) within the microbiome. In a subsequent microcosm assay, we tested the interactions between predatory protists and pathogen-suppressive Bacillus spp. that showed strong improvements in plant defense. Our study shows how protistan predators stimulate disease-suppressive bacteria in the plant microbiome, ultimately enhancing plant health and yield. Thus, we suggest a new biological model useful for improving sustainable agricultural practices that is based on complex interactions between different domains of life.