Potential of combined biological control agents to cope with <Emphasis Type="Italic">Phytophthora parasitica,</Emphasis> a major pathogen of <Emphasis Type="Italic">Choisya ternata</Emphasis>

The Cook Agronomy Farm of Washington State University is a long-term precision agriculture study site. Since 2000, the farm has been in various three-year no-till rotations with winter wheat, spring wheat, and various rotation crops such as barley, canola, peas, lentils, and chickpea. The spatial distribution of root lesion nematodes (Pratylenchus spp.) and their relationships with soil and terrain variables were studied by collecting soil samples at 127 and 124 geo-referenced points in two 12-ha fields during the spring of 2010 and 2011, respectively. Pratylenchus spp. were detected in more than 85% of the sampled locations in both fields. Nematode densities spatially mapped using ArcGIS software occurred in an aggregated pattern. Previous rotation crops had no effect on the spatial distribution. Classification and regression tree analysis (CART) using soil and terrain variables, and nematode density, explained 61 and 34% of the variability associated with nematode density in 2010 and 2011, respectively. Soil edaphic factors, such as organic matter, were stronger predictors of nematode populations than rotation effects.     

Effects of summer fallow management on take-all of winter wheat caused by <Emphasis Type="Italic">Gaeumannomyces graminis</Emphasis> var. <Emphasis Type="Italic">tritici</Emphasis>

Crop rotation is the oldest, and perhaps the best cultural practice for reducing the risk of take-all. The effects of crops sown before wheat in a rotation are known in detail, but we know little about the opportunities for reducing take-all risk by planting certain crops in the summer period between wheat harvest and the planting of a subsequent winter wheat crop. We investigated the effects on take-all of five summer fallow crops, two soil tillage treatments and a fungicide seed treatment, in a five site-year experiment. We tested the effects of oats, oilseed rape, mustard, ryegrass and volunteer wheat crops. Bare-soil plots were also included. Take-all epidemics varied with year and site. Summer fallow crops had a greater effect on tilled plots. The incidence and severity of take-all were significantly higher in the wheat volunteer plots, whereas maintaining bare soil provided the lowest level of disease. Oilseed rape had no significant effect on take-all incidence in our experiment. The best candidates for reducing take-all risk appeared to be oats, mustard and ryegrass. These summer fallow crops decreased disease levels only when associated with conventional tillage. Summer fallow crops did not alter take-all decline in the same way as a break crop after a wheat monoculture.     

Hyperspectral quantification of wheat resistance to <Emphasis Type="Italic">Fusarium</Emphasis> head blight: comparison of two <Emphasis Type="Italic">Fusarium</Emphasis> species

Experiments were conducted to determine the extent of Fusarium langsethiae infection in wheat, barley and oats grown under identical experimental conditions. In total, four experiments were conducted with both winter and spring sown experiments at two locations. The amount of F. langsethiae infection was determined by quantifying F. langsethiae DNA and quantifying the combined concentration of the trichothecene mycotoxins HT-2 and T-2 (HT-2 + T-2) in cereal head fractions (grain and rest of the head) after threshing at harvest. Results of the study showed that under identical experimental conditions, oats had the highest F. langsethiae DNA and HT-2 + T-2 concentrations compared to wheat and barley. This indicates that the high levels detected on UK oats compared to wheat and barley from surveys of commercial crops is a consequence of genetic differences rather than differences in agronomy applied to the cereal species. The concentration of HT-2 and T-2 per unit of F. langsethiae DNA in oats compared to wheat and barley was also significantly higher indicating host differences in either the stimulation of HT-2 and T-2 production or in the metabolism of HT-2 and T-2. The study also showed that the proportion of F. langsethiae DNA in threshed grains was significantly lower than that in the rest of the cereal head.     

Survival of <Emphasis Type="Italic">Curtobacterium flaccumfaciens</Emphasis> pv. <Emphasis Type="Italic">flaccumfaciens</Emphasis> in the soil under Brazilian conditions

Mustard clubroot, caused by Plasmodiophora brassicae, is a serious disease that affects Brassica juncea var. tumida Tsen, a mustard plant that is the raw material for a traditional fermented food manufactured in the Chongqing Municipality, People’s Republic of China. To find antagonistic bacteria for P. brassicae, 124 bacteria were obtained from the rhizosphere soil of B. juncea var. tumida grown in Fuling, Chongqing. Isolates were preliminarily chosen by evaluating the inhibition rate of the P. brassicae resting spore germination. The biocontrol effects of three antagonistic bacteria against clubroot on B. juncea var. tumida were evaluated in a greenhouse experiment. B18 showed the highest control efficiency, at 63.4% in the greenhouse test. In a field trial, B18 was also effective in controlling clubroot, but only at a 49.7% efficiency rate. According to 16S rDNA sequence analysis, strain B18 had a 100% sequence similarity with type strain Zhihengliuella aestuarii DY66^T (EU939716). Based on morphological, cultural, physiological and biochemical characteristics, the DNA G + C content, polar lipids, fatty acids, cell wall analysis, as well as DNA–DNA hybridization, strain B18 was identified as Z. aestuarii B18. Thus, the isolate B18 might have a potential biocontrol application for clubroot. We report for the first time that Z. aestuarii B18 can control clubroot.     

Adult attractiveness and oviposition preference of <Emphasis Type="Italic">Zabrotes subfasciatus</Emphasis> toward genotypes of common bean <Emphasis Type="Italic">Phaseolus vulgaris</Emphasis>

The Mexican bean weevil Zabrotes subfasciatus (Coleoptera: Chrysomelidae: Bruchinae) is among the key pests of common bean Phaseolus vulgaris L. around the world. Identifying resistance sources and the resistance types involved is important for development of pest-resistant bean varieties. This study assessed the adult attractiveness and oviposition preference of Z. subfasciatus toward eight genotypes of common bean, including seven pre-selected resistant genotypes and one standard for susceptibility. Attraction to the genotypes was assessed at one and four days after infestation. Oviposition preference was tested under free- and no-choice (confinement) conditions. We observed that IAC 853 was the least oviposited genotype in the free-choice test. However, this finding was not confirmed by the no-choice test. Therefore, IAC 853 could not be characterized as resistant to Z. subfasciatus. Presence of the toxic protein arcelin does not appear to influence host selection by Z. subfasciatus.     

Host-suitability of black medick (<Emphasis Type="Italic">Medicago lupulina</Emphasis> L.) and additional molecular markers for identification of the pea cyst nematode <Emphasis Type="Italic">Heterodera goettingiana</Emphasis>

A survey was conducted in 16 fields cultivated with broad bean (Vicia faba L.) and garden pea (Pisum sativum L.) in nine localities of Apulia, southern Italy, to determine whether annual weeds were susceptible to the pea cyst nematode (PEACN), Heterodera goettingiana, and could therefore serve as alternate host for the nematode. The results of this study showed that black medick (Medicago lupulina L.) is a good host for the nematode increasing its population levels in the soil in the absence of the primary hosts. The identity of the PEACN was confirmed by integrative taxonomic approaches (classical, and molecular), resulting identical in all cases (broad bean and garden pea, as well as the spontaneous black medick infections). The phylogenetic analyses using ITS and coxI gene regions strongly support the identification of the populations of H. goettingiana from Italy. Also, ITS and coxI gene sequences were obtained from the same cyst, confirming the species identity in comparison to other nematodes and populations in the Goettingiana group, demonstrating that ITS and coxI gene regions of the PEACN are suitable molecular markers for accurate and unequivocal identification of the PEACN. Reproduction and histopathological analyses demonstrated a good host-suitability of black medick to the PEACN. This record enlarges the relatively narrow host-range of the pea cyst nematode and indicates the need to control M. lupulina to avoid the increase of the nematode population in the absence of the main host crop.     

Survival of <Emphasis Type="Italic">Xanthomonas campestris</Emphasis> pv<Emphasis Type="Italic">. vitians</Emphasis> on lettuce in crop debris,irrigation water,and weeds in south Florida

Clubroot, caused by Plasmodiophora brassicae, has become a serious threat to canola (Brassica napus) production in western Canada. Experiments were conducted to evaluate the effect of rate of metam sodium fumigant (dithiocarbamate; sodium N-methyldithiocarbamate; trade name Vapam) and application methods including watering, soil surface covering, and soil incorporation on clubroot of canola. At higher rates (0.4–1.6 mL^?1 L soil) metam sodium increased canola seedling emergence and plant health, and reduced root hair infection, gall weight and clubroot severity under greenhouse conditions. Metam sodium application improved subsequent plant growth and reduced clubroot severity, but land preparation and volume of water applied did not affect efficacy. The incorporation of metam sodium into the soil and plastic covering after application improved fumigant efficacy. The study showed that soil fumigation with metam sodium can reduce clubroot severity and improve plant health in the subsequent canola crop.     

Influence of drought and season on compartmentalization of black locust (<Emphasis Type="Italic">Robinia pseudoacacia</Emphasis> L.) inoculated with <Emphasis Type="Italic">Armillaria mellea</Emphasis>

Olive plantations and tree nurseries are economically and ecologically important agricultural sectors. However, Verticillium wilt, caused by Verticillium dahliae Kleb., is a serious problem in olive-growing regions and in tree nurseries worldwide. In this review we describe common and differentiating aspects of Verticillium wilts in some of the main economically woody hosts. The establishment of new planting sites on infested soils, the use of infected plant material and the spread of highly virulent pathogen isolates are the main reasons of increasing problems with Verticillium wilt in tree cultivation. Therefore, protocols for quick and efficient screening of new planting sites as well as planting material for V. dahliae prior to cultivation is an important measure to control Verticillium wilt disease. Furthermore, screening for resistant genotypes that can be included in breeding programs to increase resistance to Verticillium wilt is an important strategy for future disease control. Collectively, these strategies are essential tools in an integrated disease management strategy to control Verticillium wilt in tree plantations and nurseries.     

A comparative assessment of potential components of partial disease resistance to <Emphasis Type="Italic">Fusarium</Emphasis> head blight using a detached leaf assay of wheat,barley and oats

The relative resistance of 15 winter barley, three winter wheat and three winter oat cultivars on the UK recommended list 2003 and two spring wheat cultivars on the Irish 2003 recommended list were evaluated using Microdochium nivale in detached leaf assays to further understand components of partial disease resistance (PDR) and Fusarium head blight (FHB) resistance across cereal species. Barley cultivars showed incubation periods comparable to, and latent periods longer than the most FHB resistant Irish and UK wheat cultivars evaluated. In addition, lesions on barley differed from those on wheat as they were not visibly chlorotic when placed over a light box until sporulation occurred, in contrast to wheat cultivars where chlorosis of the infected area occurred when lesions first developed. The pattern of delayed chlorosis of the infected leaf tissue and longer latent periods indicate that resistances are expressed in barley after the incubation period is observed, and that these temporarily arrest the development of mycelium and sporulation. Incubation periods were longer for oats compared to barley or wheat cultivars. However, oat cultivars differed from both wheat and barley in that mycelial growth was observed before obvious tissue damage was detected under macroscopic examination, indicating tolerance of infection rather than inhibition of pathogen development, and morphology of sporodochia differed, appearing less well developed and being much less abundant. Longer latent periods have previously been related to greater FHB resistance in wheat. The present results suggest the longer latent periods of barley and oat cultivars, than wheat, are likely to play a role in overall FHB resistance if under the same genetic control as PDR components expressed in the head. However the limited range of incubation and latent periods observed within barley and oat cultivars evaluated was in contrast with wheat where incubation and latent periods were shorter and more variable among genotypes. The significance of the various combinations of PDR components detected in the detached leaf assay as components of FHB resistance in each crop requires further investigation, particularly with regard to the apparent tolerance of infection in oats and necrosis in barley, after the incubation period is observed, associated with retardation of mycelial growth and sporulation.     

Effect of cropping system on composition of the <Emphasis Type="Italic">Rhizoctonia</Emphasis> populations recovered from canola and lupin in a winter rainfall region of South Africa

Rhizoctonia spp. anastomosis groups (AGs) associated with canola and lupin in the southern and western production areas of the Western Cape province of South Africa were recovered during the 2006 and 2007 growing seasons and identified using sequence analyses of the rDNA internal transcribed spacer regions. The effect of crop rotation systems and tillage practices on the recovery of Rhizoctonia spp. was evaluated at Tygerhoek (southern Cape, Riviersonderend) and Langgewens (western Cape, Moorreesburg) experimental farms. Isolations were conducted from canola planted after barley, medic/clover mixture and wheat, and lupin planted after barley and wheat, with sampling at the seedling, mid-season and seedpod growth stages. In the 2006 study, 93.5% of the Rhizoctonia isolates recovered were binucleate and 6.5% multinucleate; in 2007, 72.8% were binucleate and 27.2% were multinucleate. The most abundant AGs within the population recovered included A, Bo, I and K, among binucleate isolates and 2-1, 2-2 and 11 among multinucleate isolates. Crop rotation sequence, tillage and plant growth stage at sampling all affected the incidence of recovery of Rhizoctonia, but certain effects were site-specific. The binucleate group was more frequently isolated from lupin and the multinucleate group from canola. AG-2-1 was only isolated from canola and AG-11 only from lupin. This study showed that important Rhizoctonia AGs such as AG-2-1, 2-2 and 11 occur in both the southern and the western production areas of the Western Cape province and that crop rotation consistently influences the incidence and composition of the Rhizoctonia community recovered from the cropping system.     

Host-delivered RNAi-mediated root-knot nematode resistance in <Emphasis Type="Italic">Arabidopsis</Emphasis> by targeting <Emphasis Type="Italic">splicing factor</Emphasis> and <Emphasis Type="Italic">integrase</Emphasis> genes

Root-knot nematodes (RKNs) are one of the most important biotic factors limiting crop productivity in many crop plants. The major RKN control strategies include development of resistant cultivars, application of nematicides and crop rotation, but each has its own limitations. In recent years, RNA interference (RNAi) has become a powerful approach for developing nematode resistance. The two housekeeping genes, splicing factor and integrase, of Meloidogyne incognita were targeted for engineering nematode resistance using a host-delivered RNAi (HD-RNAi) approach. Splicing factor and integrase genes are essential for nematode development as they are involved in RNA metabolism. Stable homozygous transgenic Arabidopsis lines expressing dsRNA for both genes were generated. In RNAi lines of splicing factor gene, the number of galls, females and egg masses was reduced by 71.4, 74.5 and 86.6%, respectively, as compared with the empty vector controls. Similarly, in RNAi lines of the integrase gene, the number of galls, females and egg masses was reduced up to 59.5, 66.8 and 63.4%, respectively, compared with the empty vector controls. Expression analysis revealed a reduction in mRNA abundance of both targeted genes in female nematodes feeding on transgenic plants expressing dsRNA constructs. The silencing of housekeeping genes in the nematodes through HD-RNAi significantly reduced root-knot nematode infectivity and suggests that they will be useful in developing RKN resistance in crop plants.     

Characterization of <Emphasis Type="Italic">Fusarium</Emphasis> species associated with tobacco diseases in Northwestern Argentina

Phenotypic traits are regularly used to diagnose the development of Fusarium head blight (FHB) in the field, whereas mycotoxin accumulation in wheat grains can only be accurately evaluated through costly methods, such as high–performance liquid chromatography (HPLC). The aim of this study was to determine whether: (i) the results provided by existing commercial decision support tools could be anticipated using phenotypic measurements, including a novel technique of computer–assisted image analysis of spikes; and (ii) these measurements could avoid using HPLC. We monitored the FHB development during two consecutive years in highly contaminated plots in the Burgundy region (France). Contamination by crop residues was simulated through a field inoculation with barley grains artificially colonized by Fusarium graminearum. The development of the disease on spikes and harvested grains was assessed on one tolerant and two susceptible wheat varieties. The accumulated amounts of mycotoxins were measured in harvested grains using HPLC. As expected, the measured traits revealed that the inoculum responsible for infection on spikes mainly came from residues left on the soil surface, and the susceptible varieties were more diseased than the tolerant variety. Weather conditions had a strong effect on disease development. The novel computer–assisted image analysis technique had a better prediction power of deoxynivalenol accumulation, was more objective and time–saving than classical visual symptom assessments. This assessment method could be suitable to supplement the use of existing prediction tools and might avoid systematic and costly mycotoxin measurements in likely infected plots.     

Molecular diversity in <Emphasis Type="Italic">Fusarium oxysporum</Emphasis> isolates from common bean fields in Brazil

The common bean (Phaseolus vulgaris L.) is widely cultivated in Brazil and is known as a very important crop for families in this country. Fusarium wilt severely harms common beans and has become a big issue for this crop. In order to assist the breeding programs that target resistance to this disease, the evaluation of genetic diversity of the pathogen and its molecular characterization are crucial. Thus, the present goal was to identify Fusarium isolates obtained from several places in Brazil using molecular tools; select molecular markers for these isolates; and analyze their diversity. All of isolates were molecularly identified as Fusarium oxysporum f. sp. phaseoli (Fop). By using seven selected SSR markers, the results of diversity obtained by the dendrogram and the Bayesian analysis formed four groups where a large diversity of this fungus was found within each state. However, the groups were more homogenous according to the collection source and the pathogenicity test. More specifically, group 2 was composed of the most virulent strains and originated from Minas Gerais State – UFV, and group 3 was mostly composed by isolates from Goias state. Group I was also more diverse in terms of location and virulence. The overall results indicated a positive correlation between Fusarium diversity and its virulence to common bean. Furthermore, the use of these markers was effective in molecular identification and in detecting polymorphism within F. oxysporum f. sp. phaseoli.     

Control of <Emphasis Type="Italic">Verticillium dahliae</Emphasis> at a strawberry nursery by paddy-upland rotation

Effects of crop rotation between rice paddy fields and strawberry nurseries on the control of Verticillium wilt of strawberry were studied. For detecting Verticillium dahliae, the causal agent of Verticillium wilt, in soil, eggplant was used as an indicator plant. We were thus able to detect as low as 1 microsclerotium/g dry soil. In field surveys of Chiba and Hokkaido from 2000 to 2003, V. dahliae was detected in 9 of 10 upland fields but in none of 21 paddy-upland fields. In Hokkaido during 2000–2007, strawberry mother plants were planted, and plantlets were produced in upland and paddy-upland fields to assess V. dahliae infestation. Verticillium wilt of strawberry had never occurred in 72 tested paddy-upland fields, compared to 13.2–73.9% of plantlets infected with V. dahliae in upland fields. In a pot experiment in a greenhouse, two flooding treatments or two paddy rice cultivations suppressed Verticillium wilt symptoms on eggplant. In field experiments, one paddy rice cultivation in Chiba and two in Hokkaido prevented development of Verticillium wilt symptoms on eggplant. Verticillium wilt of strawberry was controlled completely with one paddy rice cultivation in infested fields in Chiba. In these field experiments, the number of microsclerotia of V. dahliae decreased under the flooding conditions for paddy rice cultivation. Based on the reduction in microsclerotia, a crop rotation system with paddy rice for 3 years (three times), green manure for 1 year, and strawberry nursery for 1 year was designed for Hokkaido.     

Molecular epidemiology of <Emphasis Type="Italic">Pseudomonas syringae</Emphasis> pv. <Emphasis Type="Italic">syringae</Emphasis> strains isolated from barley and wheat infected with bacterial black node

A repetitive sequence-based (rep)-polymerase chain reaction (PCR) and inter-simple sequence repeat (ISSR)-PCR were used to molecular type Pseudomonas syringae pv. syringae (PSS) strains isolated from barley and wheat plants with bacterial black node symptoms grown in 22 different locations and six different seed-production districts in Japan. Eighteen genomic fingerprinting (GF) genotypes were obtained from the combined results of BOX-, REP-, and GTG₅-PCR, indicating that the PSS population in Japan has high genetic diversity. The result based on logistic regression indicated that the population of GF genotype A was significantly related to a seed-producing district and that the epidemic of PSS strains in fields originated mainly from seed infection. This study will be applicable to future studies of the molecular epidemiology of bacterial plant diseases that have multiple infection routes.     

The effects of <Emphasis Type="Italic">Gibberella zeae</Emphasis>, <Emphasis Type="Italic">Barley Yellow Dwarf Virus</Emphasis>, and co-infection on <Emphasis Type="Italic">Rhopalosiphum padi</Emphasis> olfactory preference and performance

Insect-borne viruses promote several changes in plant phenotype, which can modify plant-vector interactions in favor of virus survival and dissemination. Although co-infections commonly occur in the field, little is known about their effects on interactions with the vector. The ecological interactions between Barley Yellow Dwarf Virus (BYDV) and its aphid vector, Rhopalosiphum padi, have been investigated extensively, but the vector’s behavior in more complex scenarios has yet to be examined. We assessed olfactory response and performance of R. padi to wheat singly and doubly infected by the pathogenic fungus Giberella zeae and BYDV. Non-viruliferous aphids preferred odors of BYDV-infected wheat over healthy wheat, as previously reported in the literature, and they were still preferentially attracted to BYDV-infected plant during co-infection. However, around 35% more non-viruliferous aphids chose healthy wheat over G. zeae-infected wheat. Viruliferous aphids did not show any preference to the treatments. BYDV-infected wheat was a superior host than healthy wheat for the aphids whose population increased in 25%. We observed a synergistic effect of the co-infected wheat, which was the best host for aphids, and promoted an elevation of 42% on population growth. Our results indicate that co-infection might be beneficial for virus spread as does not interfere with aphid olfactory preference and provides greater colony growth than in singly infected plants.     

Geographical distribution and first molecular detection of an <Emphasis Type="Italic">Emaravirus,High Plains wheat mosaic virus</Emphasis>, in Argentina

High Plains wheat mosaic virus (HPWMoV) has recently been assigned to genus Emaravirus and is the causal agent of High Plains disease. In this work the geographical distribution and first molecular detection of HPWMoV in Argentina are reported. The virus was detected in six provinces and nine hosts, including wheat, corn, oat and barley, as well as weeds, which play an important role in the epidemiology of this disease. Molecular and phylogenetic analyses of a portion of RNA3 nucleoprotein gene sequence showed that five HPWMoV isolates from different wheat growing regions of Argentina were identical, and suggest a single introduction of HPWMoV to this country, possibly through corn seeds. To the best of our knowledge, this is the first molecular detection of HPWMoV in South America. These results highlight the importance of certification of viruses-free cereal seeds and strict controls for material transfer between different countries to prevent the entry not only of new pathogens but also of new variants or strain at sites where the pest has already been detected.     

Management of laurel wilt of avocado,caused by <Emphasis Type="Italic">Raffaelea lauricola</Emphasis>

Laurel wilt is caused by Raffaelea lauricola, a nutritional symbiont of an Asian ambrosia beetle, Xyleborus glabratus. American members of the Lauraceae plant family are most susceptible and 300 million trees have been killed by the disease in the southeastern USA since 2003. Recently, commercial production of an important crop in the laurel family, avocado (Persea americana), has been affected in southern Florida. We summarize studies in which diverse measures were tested for managing the disease. In all studies, trees were treated with potential laurel wilt control measures and subsequently inoculated with R. lauricola. On potted plants in greenhouse experiments, commercial nutritional products (Greenstim and Keyplex 350) and SAR products (Agri-Fos and Nutri-Phite), when applied as soil drenches or foliar sprays, had either no impact on, or increased laurel wilt symptom development compared to non-treated control treatments. Bark applications of Tilt (a propiconazole fungicide for which emergency registration had been obtained in 2010) in a surfactant (Pentrabark) enabled significant laurel wilt protection in greenhouse studies on small potted plants, but Pentrabark and other surfactants moved little propiconazole into the xylem of fruit-bearing trees in field studies. In efficacy studies in the field, Propiconazole Pro (an injectable formulation of propiconazole), Tilt, and two experimental formulations of another triazole fungicide, tebuconazole, decreased the development of laurel wilt compared to nontreated control trees when applied as undiluted injections into branches and scaffold limbs (microinjection), or injection of dilute fungicide into tree flare roots (macroinfusion). However, symptoms developed in all treated trees by 10–11 months after inoculation with R. lauricola, indicating that trees would need to be re-treated at least on an annual basis. Regardless of how fungicides were applied, insignificant levels of different active ingredients entered fruit. Although fungicide treatment of fruit-bearing avocado trees is not a concern for food safety and several triazole and DMI fungicides can protect avocado trees from laurel wilt, cost-effective measures with which the xylem could be loaded with and protected by these products remains a challenge. Management of laurel wilt in commercial avocado production areas is discussed.     

Improved control of black rot of broccoli caused by <Emphasis Type="Italic">Xanthomonas campestris</Emphasis> pv. <Emphasis Type="Italic">campestris</Emphasis> using a bacteriophage and a nonpathogenic <Emphasis Type="Italic">Xanthomonas</Emphasis> sp. strain

We examined the potential for biological control of black rot of broccoli, caused by Xanthomonas campestris pv. campestris (Xcc), using nonpathogenic Xanthomonas sp. strain 11-100-01 (npX) mixed with bacteriophage XcpSFC211 (pXS). Inoculation of intact broccoli plants in greenhouse trials with either npX or pXS did not control black rot. After injured plant inoculation, however, npX alone or npX with pXS significantly controlled black rot. When a mixed suspension of npX with pXS was placed on a membrane filter, then washed with distilled water and air-dried, a substantial amount of pXS adsorbed to the surface of npX. In a field trial, broccoli plants were sprayed with a suspension of npX with pXS, then inoculated with Xcc. A meta-analysis of the results from five field trials showed an integrated risk ratio (IRR, the ratio of disease incidence in inoculated broccoli plants to the incidence in control plants) of 0.69 after treatment with only npX and 0.59 with npX with pXS, indicating that black rot incidence was significantly reduced by each treatment. The difference between these two treatments was also significant. IRR was 1.24 when comparing suppression by npX with pXS and that by basic copper sulfate wettable powder; thus, their control was comparable. The combination of npX with pXS improved the preventive effect against black rot. This is the first report describing that a nonpathogenic Xanthomonas sp. strain mixed with a bacteriophage effectively controlled black rot of broccoli in field trials.