Purple Blotch Disease Research Articles

Unveiling the germination patterns of Alternaria porri (Ellis) by using regression analysis and hydrothermal time modeling

Purple blotch disease is a major fungal disease of Allium cepa L. plants which is caused by the fungus Alternaria porri. The best conditions for the growth of Alternaria porri are temperatures between 22 °C and 25 °C and relatively high humidity. The Hydrotime, Thermal Time, and Hydrothermal Time models were used to measure different parameters of seed germination; therefore, we used them to measure the interactive effects of temperature and water potential on the germination conidia of Alternaria porri. The laboratory experiments were carried out at five constant temperatures, between 5 and 30 °C, and five different water potentials between 0 MPa and − 6 MPa. The germination of Alternaria porri conidia was highest at 25 °C and 0 MPa and lowest at 5 °C and − 6 MPa. The percentage of conidia germination decreased rapidly after 25 oC. Conidia germination was also affected by different water potentials, decreasing at lower water potential. Models based on HTT showed a reasonable fit to the germination and growth rate datasets. The best fitting model for conidia germination (R2 = 0.98491) was based on variable base and maximum temperature as a function of water potential. Based on the TT, HT, and models, the highest and lowest values for θT1 were observed at -6.0 MPa at 30 °C, and 0 MPa at 5 °C and the highest and lowest θT2 values were recorded at -6.0 MPa at 5 °C and 0 MPa at 30 °C while the lowest and highest θH values were recorded at -6.0 MPa at 5 °C and 0 MPa at 25 °C, respectively, for the HTT model, the predicted θHTT average value is 16.32 (MPa°Ch-1). Based on the statistical analysis, the cardinal hydrothermal time constant (θHTT) accurately explains the interactive effect of T and Ψ on the germination of Alternaria porri conidia under different environmental conditions.

Study about Identification of Purple Blotch and Thrips Resistant Lines of Onion (Allium cepa L.)

Thirty six elite genotypes were evaluated during the winter season (rabi) 2022-23 at three different environments in 3 replications. RO-1, RO-59, RO-1 × RO-59, RO-1 × Pusa Madhavi, RO-59 × Pusa Madhavi, RO-59 × Kashi No. 1 genotypes had showed thrips population less than 22.90 and highly resistant to thrips infestation. Purple blotch disease, caused by Alternaria porri is the most common devastating disease of onion under field conditions throughout the globe. RO-1, Pusa Shobha, RO-1 × RO-59 and Bhima Kiran × Bhima Shakti were found resistant with a grade scale of 1. The per cent leaf area infection ranged from 1-10 per cent.

Identification of Alternaria species associated with purple blotch disease of onions in Southern Punjab of Pakistan and evaluation of plant-based fungicides for disease control

Identification of Alternaria species associated with purple blotch disease of onions in Southern Punjab of Pakistan and evaluation of plant-based fungicides for disease control

The effectiveness of Liliaceae phyllospheric Actinomycetes as biocontrol agent of purple blotch disease (Alternaria porri Ell. Cif) on shallot

Purple blotch, caused by Alternaria porri, affects leaves and tubers, leading to reduced yields. Traditionally, synthetic chemical fungicides were heavily relied upon for control. As an alternative, biocontrol agents like actinomycetes have gained attention. Some actinomycetes can suppress plant pathogens by producing antifungal compounds. This research aimed to investigate the efficacy of phyllosphere actinomycetes from Liliaceae plants as biocontrol agents against purple blotch disease on shallots in the greenhouse. Conducted at the IPB University Plant Bacteriology and Mycology Laboratory and the greenhouse at Bogor Agricultural Development Polytechnic, West Java, the research involved several stages, including pathogen identification, preparation of actinomyces inoculum and A. porri, and application of actinomycetes biocontrol agents to shallots in the greenhouse. A. porri isolates were obtained from shallot production centers in the Brebes area, Central Java. The use of the actinomycetes from the phyllosphere effectively suppressed purple blotch disease, with the lowest area under the disease development curve (AUDPC) recorded at 635.9% for the CFS28 isolate. Lower AUDPC values indicated slower disease progression. Actinomycetes biocontrol agents showed promising efficacy, with the CFS28 isolate achieving the highest efficacy percentage of 78.37%. Additionally, plant growth was significantly enhanced by actinomycete application, with tuber sizes ranging from 1.44 to 2.06 g, fresh weights from 17.63 to 24.72 g, and dry weights of shallot bulbs from 5.43 to 17.96 g. The incubation period for A. porri could be extended by actinomycetes, ranging from 5.43 to 8.5 days for purple blotch symptoms to manifest on shallots. The use of Actinomyces phyllosphere biocontrol agents holds promise for disease control on other plants’ leaves, contributing to environmentally friendly and sustainable agricultural practices.

The effectiveness of Liliaceae phyllospheric Actinomycetes as biocontrol agent of purple blotch disease (Alternaria porri Ell. Cif) on shallot

Purple blotch, caused by Alternaria porri, affects leaves and tubers, leading to reduced yields. Traditionally, synthetic chemical fungicides were heavily relied upon for control. As an alternative, biocontrol agents like actinomycetes have gained attention. Some actinomycetes can suppress plant pathogens by producing antifungal compounds. This research aimed to investigate the efficacy of phyllosphere actinomycetes from Liliaceae plants as biocontrol agents against purple blotch disease on shallots in the greenhouse. Conducted at the IPB University Plant Bacteriology and Mycology Laboratory and the greenhouse at Bogor Agricultural Development Polytechnic, West Java, the research involved several stages, including pathogen identification, preparation of actinomyces inoculum and A. porri, and application of actinomycetes biocontrol agents to shallots in the greenhouse. A. porri isolates were obtained from shallot production centers in the Brebes area, Central Java. The use of the actinomycetes from the phyllosphere effectively suppressed purple blotch disease, with the lowest area under the disease development curve (AUDPC) recorded at 635.9% for the CFS28 isolate. Lower AUDPC values indicated slower disease progression. Actinomycetes biocontrol agents showed promising efficacy, with the CFS28 isolate achieving the highest efficacy percentage of 78.37%. Additionally, plant growth was significantly enhanced by actinomycete application, with tuber sizes ranging from 1.44 to 2.06 g, fresh weights from 17.63 to 24.72 g, and dry weights of shallot bulbs from 5.43 to 17.96 g. The incubation period for A. porri could be extended by actinomycetes, ranging from 5.43 to 8.5 days for purple blotch symptoms to manifest on shallots. The use of Actinomyces phyllosphere biocontrol agents holds promise for disease control on other plants’ leaves, contributing to environmentally friendly and sustainable agricultural practices.

Effectiveness of onion germplasm, fungicides, and plant extracts in managing purple blotch disease of onion

In the present study conducted at Ayub Agricultural Research Institute, Faisalabad, ten specific onion lines were evaluated for disease resistance against purple leaf blotch. The variety Phulkara emerged as the top performer with the lowest disease incidence of 6.57% and an AUDPC value of 55.67, indicating resistance to this disease. Various fungicides demonstrated differing effects on disease management. Copper hydroxide proved to be the most effective at 0.10%, reducing disease incidence from 17.59% in the first spray to 12.70% in the third. The second-best fungicide was trifloxystrobin 25% + tebuconazole, which reduced disease incidence from 67.51% in the first spray to 61.67% in the third compared to the control. Among all plant extracts, three sprays of Nicotiana tabacum extract at S/50, S/25, and S/15 proved to be most effective, reducing disease incidence from 43.51% to 35.59%. Similarly, Moringa oleifera extract reduced disease incidence from 42.61% to 35.70% compared to the control. These findings suggest that the onion variety Phulkara, copper hydroxide fungicide at a concentration of 0.10%, and extracts of N. tabacum and M. oleifera exhibit promising potential in managing purple leaf blotch disease in onions. However, further studies are necessary to corroborate these results and to fully understand the biological and chemical implications of their usage.

Efficiency of bio-agents and green-synthesized silver nanoparticles in controlling purple blotch disease caused by Alternaria porri in onion plants

One of the most fatal diseases that harm Allium species is purple blotch, which is brought on by Alternaria porri. As the disease's severity rises, crop production may decrease. In this study, 12 isolates of A. porri exhibiting purple blotch symptoms have been isolated from diseased onion plants. Sequencing of the internal transcribed spacer region (ITS) allowed for the identification of the isolate that was the most virulent and caused a disease severity of 85.93%. Under greenhouse and field growing conditions, the efficiency of two bio-agents, Trichoderma asperellum T34 and Saccharomyces cerevisiae AUMC 10203, as well as three doses (50, 25, and 12.5 ppm) of their green-synthesized silver nanoparticles (AgNPs) against purple blotch disease was assessed. For avoiding or treating purple blotch disease in onion plants, it has been demonstrated that the T. asperellum T34 spore suspension was the most effective resulting in a 76% reduction in disease severity. The spore suspension of S. cerevisiae and a 50-ppm dosage of AgNPs were the top contenders for T. asperellum. When compared to the control plants, the plants treated with bio-agents and AgNPs showed a significant decline in disease incidence and disease severity. Additionally, improvements were made to the broadness of inflorescences, the number of flowers and seeds, the weight of seeds per inflorescence, and the seed productivity. Therefore, it is recommended in this study to use T. asperellum T34 spore suspension as a potent bio-agent to manage the symptoms of purple blotch on onions.

Assessment of onion farming practices and purple blotch disease knowledge among farmers in varied agro-ecological zones of Nyeri County, Kenya

Onion (Allium cepa L.) is the second most produced vegetable globally, following tomato and plays a vital role in both cuisines and daily diets. However, the threat of diseases, such as purple blotch caused by Alternaria porri, poses a substantial risk to onion production, particularly in Nyeri County, Kenya. Despite its critical impact on farming, there is a lack of information on farmers' knowledge of purple blotch in this region. This study aimed to assess the onion farming practices and farmers' understanding of purple blotch disease across various agro-ecological zones (AEZs) in Nyeri County. Specifically, the study examines farmers' demographics, cultivated onion varieties, and their knowledge of purple blotch disease. Farms were selected using cluster random sampling. Data were collected from 100 onion farmers through semi-structured questionnaires, and statistical analysis was performed using the chi-square test in Scientific Analysis System (SAS) version 9.4 at α=0.05. The findings revealed that while the Rucet F1 onion variety was popular among the farmers (52%), there is no significant association (X2 (6, 100) = 11.947, p = 0.063) between the choice of variety and AEZs. Similarly, the preferred source of onion seeds, mainly Agroshop (84%), showed insignificant association (X2 (9, 100) = 7.153, p = 0.621) with AEZs. Despite 65% of farmers reporting knowledge about onion diseases, there is no significant association (p > 0.05) between their awareness of purple blotch and AEZs. In conclusion, the study highlights a significant gap in farmers' understanding of purple blotch disease, emphasizing the need for training programs to enhance disease identification skills. Early detection can empower farmers to implement proactive measures, ultimately improving onion productivity. This study recommends diversifying onion varieties for disease resilience, promoting awareness and training on purple blotch identification, engaging women and youths in farming, and fostering collaborative networks for ongoing knowledge exchange and improvement in onion cultivation in Nyeri County.

Efek Antijamur Ekstrak Daun Selasih Liar (Ocimum gratissimum) pada Fusarium oxysporum f. sp. cepae dan Alternaria porri pada Bawang Merah The antifungal properties of clove basil (Ocimum gratissimum L.) extract on Fusarium oxysporum f. sp. Cepae and Alter

The antifungal properties of clove basil (Ocimum gratissimum L.) extract on Fusarium oxysporum f. sp. Cepae and Alternaria porri were evaluated in vitro and in vivo. Thirty grams of the clove basil sterilized leaves were mashed in a sterile mortar, soaked for 24 hr in 100 mL of 96% ethanol as an extractant. The extract was filtered through sterile Whatman No. 1 filter paper and stored at 4°C for subsequent use. Three different concentrations (5, 10, and 15%) were applied using the poisoned food technique. A 4-mm diameter mycelial disc of each tested fungus was inoculated on each amended agar plate. Daily radial growth was recorded for 7 days. For the in vivo test, two different concentrations (15% and 20%) were used. No spray and mancozeb spraying were used as controls. Seed bulbs of shallots were planted in a 25 cm x 25 cm polybag and allowed to be naturally infected by Alternaria porri. The clove basil leaf extract and mancozeb were sprayed onto the plants once a week, starting when the first symptom of the purple blotch disease appeared. The results showed that clove basil leaf extract had good efficacy in inhibiting F. Oxysporum f. sp. Cepae and A. Porri in vitro, with a growth inhibition up to 55%. The extract can also reduce the disease intensity of purple blotch with an infection rate of 0.029, indicating that it has the potential to be developed as a botanical fungicide. Keywords: antifungal effect, Alternaria porri, clove basil, Fusarium oxysporum f. sp. cepae, leaf extract

Sustainable biocontrol of purple blotch disease in Allium cepa L. by biocontrol yeasts, Pichia kluyveri and Filobasidium wieringae

BackgroundPurple blotch disease is a devastating disease, resulting in significant yield losses in onion. Application of synthetic fungicides is a rapid approach for the control of this disease, but extensive use of synthetic fungicides results in resistance development in pathogen. Thus, it is mandatory to explore alternative approaches to overcome the fungicide resistance challenges. The present study focused on a sustainable biocontrolling approach by using biocontrol yeast. The objective was to develop a management strategy that offers an environmentally acceptable alternative to commonly used fungicides.ResultsA total of six pathogenic isolates were obtained from the infected onion leaves, out of all tested isolates, OP-4 recorded as highly virulent with disease incidence (75.2%). Filobasidium wieringae and Pichia kluyveri drastically reduced the in vitro mycelial growth of Alternaria porri (14 and 21 mm, respectively). In the greenhouse experiment, plant inoculated with P. kluyveri suspension was the most effective, resulting in considerable reduction (77.1%) in disease severity, before two days of pathogen inoculation. However, F. wieringae showed a considerable reduction (84.5%) in disease severity when applied in combination with P. kluyveri two days post-inoculation.ConclusionsThese findings highlighted the strong biocontrol potential of P. kluyveri and F. wieringae in managing the purple blotch disease of onion and can reduce the reliance on synthetic fungicides. Further research and field trials should be conducted to optimize the application methods and evaluate the long-term effectiveness of these bioagents.

Test antagonism of several Trichoderma species in suppressing the growth of Alternaria sp. in vitro

Alternaria sp. is a pathogenic fungus that causes purple blotch disease in onion plants. Losses from this disease lead to a decrease in yield by more than 70% and seed damage to 100%. For this reason, a study was conducted to test the antagonistic ability of several Trichoderma species in suppressing the growth of Alternaria sp. in-vitro as an alternative to plant disease control that is safer and more environmentally friendly. Alternaria sp. isolate. derived from onion plants located in Bale Atu, Bukit District, Bener Meriah Regency, Aceh Province. The Trichoderma species used are T. asperellum, T. harzianum, T. virens, and Trichoderma sp. Antagonism testing was carried out using a dual culture method in a 9 cm diameter petri dish. The results showed that, T. asperellum, T. harzianum, T. virens, and Trichoderma sp. able to suppress the growth of Alternaria sp. on observation of 5 HSI. The antagonistic mechanism that occurs is competition against space, nutrition, antibiosis and mycoparasites. The best percentage of resistance occurred in the treatment of T. virens, which was 77.78%. next followed by the inhibitory power of Trichoderma sp. by 72.39%, T. harzianum by 64.80%, and T. asperellum by 60.77%.

Rhizophagus intraradices dan Trichoderma asperellum sebagai Bioprotektan dan Biofertilizer pada Bawang Merah TSS

True shallot seed (TSS) is one of the alternative potential technologies to solve the availability of seed quality on shallot in Indonesia. Another problem in shallot production is infection by purple blotch and twisted disease. This research evaluated the potency of Rhizophagus intraradices and Trichoderma asperellum as bioprotectants and biofertilizer. T. asperellum was mixed in the soil before seedling transplanting, and R. intraradices was applied around the seedling roots at transplanting. The observed parameters were the shallot growth (the plant height, number of leaves, and length of root), plant health (disease incidence and intensity), and bulb resistance to Fusarium solani. The result showed that R. intraradices and T. asperellum increased the resistance of onion bulbs to the pathogen F. solani in the postharvest period, indicated by R. intraradices treatment that had an infection area of 21.99 mm2, followed by T. asperellum treatment 26.63 mm2, and control of 37.66 mm2.
 
 Keywords: Rhizophagus intraradices, Trichoderma asperellum, true shallot seed

Effect of oil cakes and lemongrass essential oil on purple blotch (Alternaria porri) disease of onion (Allium cepa L.)

Effect of oil cakes and lemongrass essential oil on purple blotch (Alternaria porri) disease of onion (Allium cepa L.)

Growth and response of several shallot varieties to its important diseases in Lembang highlands

Disease attacks on shallots (Allium cepa L. var. aggregatum) are one of the main constraints on increasing shallot production. Important diseases that often appear in shallots are purple blotch disease (Alternaria porri), leaf blight (Stemphylium vesicarium), and downy mildew (Peronospora destructor). The diversity of existing varieties is wealth as a substitution for seed sources. The aim of this study was to determine the growth and disease resistance of several shallot varieties grown in Lembang highlands. The research was conducted at the Margahayu Experiment Field of the Indonesian Vegetable Research Institute Lembang, from March to July 2021. The Randomized Block Design (RBD) was used in this study with a treatment consisting of 11 varieties of shallots (Violetta 1 Agrihorti, Violetta 2 Agrihorti, Violetta 3 Agrihorti, Ambassador 1 Agrihorti, Ambassador 2 Agrihorti, Ambassador 3 Agrihorti, Ambassador 4 Agrihorti, Maja Cipanas, Pancasona, Kramat 1, and Sembrani), with 3 replications. The results showed that the growth performance varied between varieties. The Violetta 3 Agrihorti was the highest for plant height, the highest number of tillers was in the Pancasona, and the highest number of leaves was in the Ambassador 3 Agrihorti. Among the eleven shallot varieties tested at high altitudes, none were resistant to the diseases of Alternaria porri, Stemphylium vesicarium, and Peronospora destructor, except for the Pancasona variety which was classified as tolerant (resistance category included in the susceptible category, but has high yield). Meanwhile, for disease resistance, the Violetta 1 Agrihorti is relatively resistant to purple blotch disease, leaf blight, and downy mildew.

Delineation of Purple Blotch Disease Hotspots Caused by Alternaria porri in Key Onion Cultivation Regions of Southern Karnataka, India

Delineation of Purple Blotch Disease Hotspots Caused by Alternaria porri in Key Onion Cultivation Regions of Southern Karnataka, India

Diversity of phyllospheric Actinomycetes in Liliaceae plants and their potential as growth inhibitors of Alternaria porri

Abstract. Wati C, Nawangsih AA, Wahyudi AT, Wiyono S, Munif A. 2023. Diversity of phyllospheric Actinomycetes in Liliaceae plants and their potential as growth inhibitors of Alternaria porri. Biodiversitas 24: 5234-5242. Actinomycetes are microorganisms belonging to a group of Gram-positive bacteria, that have the potential to act as biological control agents against various plant pathogens. Phyllospheric Actinomycetes particularly, can inhibit growth of various microorganisms, such as the fungus Alternaria porri Ell. Cif., which causes purple blotch disease in the shallot plants. These microbes thrive on the surface of leaves, particularly in plants belonging to Liliaceae family. Environmental conditions have been proven to greatly affect their diversity. Present investigation aims to determine diversity of phyllospheric Actinomycetes from Liliaceae plants and their potential to inhibit growth of A. porri. The methods used were to investigate, characterize, and quantify isolates from Liliaceae plants. An antagonistic test was conducted on the isolates to examine the proportion of A. porri fungus growth inhibition. The results showed that plants species Allium fistulosum and A. tuberosum were the most common hosts for phyllospheric actinomycetes. Morphological differences were found in shape, color, elevation, edges, surface, and hyphae size, as well as the type of spore violation. The surface texture of colonies was smooth, rough, powdery, and opaque, usually appearing after 7-12 days of isolation. The isolates also inhibited growth of A. porri, causing the mycelium thins, and a clear zone of inhibition between pathogens and Actinomycetes forms. Isolates BCW9 caused the highest suppression of fungus growth 57.78%. This study is the first experiment to evaluate the diversity of phyllosphere Actinomycetes from Liliaceae plants, which are able to control purple blotch disease caused by A. porri in Indonesia. The phyllospheric Actinomycetes were isolated from the same habitat of A. porri. These investigation show the prospect of phyllospheric Actinomycetes as biocontrol agents against another fungal diseases on leaves of another plants.

Control for purple blotch and anthracnose diseases using biopesticides and local varieties of shallots in the rainy season

Purple blotch and anthracnose disease are the main diseases of shallots. The purpose of this study was to obtain an environmentally friendly technology for controlling purple blotch and anthracnose on shallots during the rainy season. The design used in this research was a split plot design with the main plots of local varieties of shallots (A) namely Sembrani, Bima Brebes and Maja Cipanas. As a sub-plot is the use of fungicides, namely chemical fungicides, chemical fungicides and bio-fungicides are used interchangeably and bio-fungicides are used routinely. The results of research conducted in the rainy season show that Sembrani variety had a significant effect on reducing the severity of purple blotch, anthracnose, and Stemphylium leaf blight disease compared with Bima Brebes and Maja Cipanas varieties. The use of chemical fungicides continuously is comparable to use of chemical fungicides and bio-fungicides which are carried out alternately in suppressing the severity of purple blotch, anthracnose and Stemphylium leaf blight diseases on shallots. Control by using chemical fungicides and bio-fungicides alternately that are can save the use of chemical fungicides by 50% thereby can protect the environment sustainability.

Biorational Approaches for Purple Blotch Disease of Garlic (Allium sativum L.) Incited by Alternaria porri (Ellis) Cif

Garlic (Allium sativum L.) is the second most important bulb crop after onion. It is a major spice crop. Garlic is attacked by many diseases, one of which is Purple blotch. This study was aimed to determine the effect of botanicals and bio-agent on purple blotch disease of garlic caused by Alternaria porri. The research work was undertaken at Central Research Farm (CRF) Sam Higginbottom University of Agriculture, Technology and Sciences, SHUATS, Naini, Prayagraj during Rabi in 2022-23. A randomized block design with eight treatments was employed including T0 (Control - untreated) , T1 ( Azoxystrobin @0.1% as treated check), T2 (Trichoderma harzianum @10g/litre) , T3 (Lantana camara leaf extract @10%), T4 (Azadirachta indica leaf extract @10%), T5 (Henna leaf extract @2% + Licorice root extract @2% + Rosemary leaf extract @2% ), T6 (Licorice root extract @10%) and T7 (Neem cake @50g/m2). The treatments led to significant decrease in purple blotch severity in garlic.The results revealed that among the treatments, T7 showed minimum disease intensity (4.33, 18.74 and 26.35%) at 30, 60 and 90 days after sowing (DAS) respectively; while maximum disease intensity was recorded in T0 (10.42, 25.52 and 34.68%). T7 also recorded maximum plant height (24.02, 34.01 and 45.71cm) at 30, 60 and 90 DAS, respectively and highest yield of 4.46t/ha. Maximum number of leaves were recorded with T3 (5.53, 7.5 and 9.4) at 30, 60 and 90 DAS respectively. Fungicide usage is increasing day by day that can lead to negative effect on human and soil health in the long run, so there is need to find effective and economic alternatives preferably some bio-agents and botanicals.

Exploration of Indigenous Actinomycetes as Biocontrol Agents of Purple Blotch Diseases at Onion

Purple blotch disease caused by Alternaria porri is an essential disease in shallot plants. Actinomycetes microorganisms have potential as A. porri biological control agents because they produce bioactive compounds. The research aimed to select actinomycetes isolates that can suppress the growth of A. porri, stimulate growth, and increase the production of shallots. The study consisted of four stages: isolation, selection, characterization, and identification of potential actinomycetes isolates. The isolation results obtained 35 indigenous isolates, and as many as 16 isolates were successfully selected based on the results of the biosafety test. The antagonism test showed that 12 isolates produced suppression to A. porri by 4.87–63.77%. From 16 selected isolates, 13 isolates could produce chitinase enzymes with a chitinolytic index of 0.61-2.58. Nine selected isolates: AMSN23, AMSN10 AMBP7, AMSP10, AMSR21, AMTE2, AMDK6, AMTD 14, and AMPL24, could dissolve phosphate and produce Indole Acetic Acid (IAA) with a concentration of 34.82–85.98 ppm, but only six isolates were able to fix nitrogen. In the results of the 16S rRNA gene sequence, nine isolates were selected and potentially identified as Streptomyces rameus, S. lydicus, S. panaciradicis, S. seoulensis,S. fuscichromogenes, Streptomyces sp, S. nigrescens, S. viridaris, and S. griseus

Study of Streptomyces spp. to control purple blotch disease caused by Alternaria porri in shallot plant

Alternaria porri is a fungal pathogen that causes purple blotch on shallots, this fungus can cause crop yield loss of 3 – 57%. A. porri was obtained from the Sumber Brantas onion farm and then isolated by planting infected tissue. Streptomyces spp. is a filamentous bacterium that is abundant in the soil and can be used as a biological agent, decomposer and plant growth promote. Streptomyces spp. was obtained one isolate from shallot land location in Pare, Kediri, East Java (BMP: Bawang Merah Pare) and three isolates from Sidera, Palu, Central Sulawesi (BMS: Bawang Merah Sidera) (BMS1, BMS2, BMS3). The purpose of this study was to determine the efficacy of Streptomyces spp. to control A porri consist of in vitro and In vivo antagonist test. Antagonist test was carried out by dual culture method and the Streptomyces spp. which can inhibit the development of A porri would be used antagonist test in vivo. The study was designed using a Factorial Complete Randomized Design with two factors, candidate isolates of biological control agents and concentrations of Streptomyces spp. be diluted into 5%, 10%, and 15%, it will applied on shallot plant Bauji variety. The results of the In vitro test shown the highest inhibition zone from BMP 17.75% while BMS1 13.75%, BMS2 8,75%, and 8.50%. in vivo test shown lowest disease severity value in BMP 15% concentration was 1.13% while diseases severity of BMS1 was 1.27%, and BMS2 was 1.80%. Therefore, Streptomyces spp. has potency as an alternative pesticide for sustainable agriculture.