Lower Disease Intensity Research Articles

Pucciniastrum minimum is the causal agent of blueberry leaf rust on different Vaccinium species in Hawke’s Bay, New Zealand

Blueberry leaf rust has become a prevalent disease in New Zealand blueberry production. To identify the pathogen responsible for this disease in the Hawke’s Bay region of New Zealand, leaves showing signs or symptoms of rust infection were collected from three blueberry cultivars (‘Centra Blue’ [Rabbiteye], ‘Georgia Dawn’ [Southern Highbush] and ‘Nui’ [Northern Highbush]) and the pathogen subjected to morphological characterization using both scanning electron and bright-field microscopy. Meanwhile, genomic DNA was extracted from urediniospores of infected leaves collected from cultivar ‘Rahi’ (Rabbiteye) and the Internal Transcribed Spacer (ITS) region was sequenced and compared to the corresponding nucleotide sequence of known rust pathogens. Results from both experiments indicated that Pucciniastrum minimum (syn. Thekopsora minima) was the causal agent of blueberry leaf rust disease in Hawke’s Bay. Next, the level of disease caused by P. minimum was quantified on 23 blueberry cultivars in this region during the 2019 blueberry production season. Here, a total of 20 leaves selected from each cultivar were continually monitored, and the lesion area was calculated using ImageJ based on images taken in the field. Based on this analysis, all leaves were found to be infected by the rust pathogen. However, disease intensity, as a function of the ‘area under the disease progress curve’ (AUDPC) value, was found to be different. This suggests that certain cultivars display a lower disease intensity during the harvest season. Further field assessment covering a whole growing cycle will give a better understanding about blueberry leaf rust infection on these cultivars.

RESISTANCE IN COMMON BEAN(PHASEOLUS VULGARIS L.) TO UROMYCES APPENDICULATUS IN BULGARIA

Common bean rust, caused by Uromycesappendiculatus, is one of the most devastating diseases in common bean. Breeding for resistant cultivars is the most effective and eco-friendly method for disease control. Although there is no targeted breeding program in Bulgaria to create resistant cultivars to the pathogen, periodic screening of the virulent diversity of U. appendiculatus and sources of resistance to the identified races/pathotypes is carried out. During the last twenty years, four investigations were made to estimate virulence diversity in pathogen population. Eleven U. appendiculatus races (20-0, 20-1, 20-2, 20-3, 20-19, 29-0, 29-1, 28-1, 52-3, 20-16 and 20-18) are identified, distributed in Rhodope mountains and North Bulgaria. Chronologically each of the studies was accompanied or followed by a screening for sources of resistance to the pathogen under field conditions. Еach study found different numbers of resistant accessions depending on the virulent potential of the population used. In three of the studies, cultivars that showed resistant phenotype under field conditions were screened against a set of races, distributed in the country in the same time, under greenhouse. Bulgarian cultivar ‘Beslet’ showed resistant reaction under field and greenhouse in all investigation. The resistance of the cultivar to races 20-1 and 20-19 is governed by a single dominant gene. This cultivar can be successfully used in a breeding program for race-specific resistance. Fifty accessions with race-nonspecific resistance, expressed by low disease intensity and resistant/susceptible infection type, are identified in two investigations under field conditions.

Pengaruh Trichoderma harzianum dan Nano Silika Terhadap Penyakit Moler dan Produksi Bawang Merah

<p>Twisted disease is one of the important diseases that can decrease shallot yield.The purpose of this experiment was to examine the effect of the interaction <em>Trichoderma harzianum</em> and nano silica on twisted disease and shallot yield. The research was conducted in Platar, Mangunjiwan, Demak and the Laboratory of Ecology and Plant Production, Faculty of Animal and Agriculture Science, Undip, on April – Agustus 2022. The experimental design used factorial completely randomized design with three replications. The first factor was <em>T. harzianum</em> consisted of three levels (P0 = 0 (control), P1 = 10, and P2 = 20 g plant<sup>-1</sup>). The second factor was nano silica concentration with four levels (S0 = 0, S1 = 1000, S2 = 2000, and S3 = 3000 ppm). The results showed that application of <em>T. harzianum </em>20 g plant<sup>-1</sup> or nano silica 3000 ppm had the lowest disease intensity 2,74 % and 2,48 % observed at 20 days after planting and 11,81 % and 10,81 % observed at 40 DAP. Combination <em>T. harzianum </em>20 g plant<sup>-1</sup> and nano silica 3000 ppm resulted in the highest yield parameters which were tuber diameter (2,370 cm), number of tubers (6 tubers), tuber fresh weight (36,2 g), and tuber dry weight (28,7 g). Treatments of <em>T. harzianum</em> and nano silica did not significantly affect the infection rate and number of leaves, but application of <em>T. harzianum</em> 20 g plant<sup>-1</sup> and nano silica 3000 ppm showed a decrease in twisted disease intensity and the highest shallot yield.</p>

Impact Of Arbuscular Mycorrhizae And Gogo Rice Interaction Against Rice Blas Disease (Prycularia oryzae)

Gogo rice productivity is lower than lowland rice because one of the factors of the production gap is the control of plant-disturbing organisms. One of the diseases that attack rice plants is Blast disease, it is necessary to control efforts by utilizing micro organisms such as mycorrhizae vesicular-arbuscular (MVA). The purpose is to study the role of MVA on the growth and development of three gogo rice varieties and the level of infection intensity of blast disease (Pyricularia oryzae CAF). This research used a Randomized Block Design with the treatments were No MVA with Varieties IR-64, MVA Inoculation with Varieties IR-64, No MVA with Membrano, MVA Inoculation with Membranos, No MVA with Pelita I-1, Inoculation of MVA with Varieties of lamp I-1. The mycorrhizae treatment increased the uptake of P nutrients which was seen in plant height, dry weight yield, percentage of root associations and speed of flower formation. The mycorrhizae treatment showed a relatively low intensity of blast disease. In relation to plant resistance, mycorrhizae can suppress pathogens that cause Pyricularia oryzae CAF so that these plants have low disease intensity. Conclusion: Mycorrhizae increased the plant height, trunk and time of flower formation and P nutrient uptake, an average of 0.26 percent in leaf tissue. Mycorrhizae increased the resistance of gogo rice plants from Pyricularia oryzae CAF attack. The membramo variety showed the best growth and yields.

Orta Anadolu Bölgesinde çilek ekiliş alanlarında görülen fungal hastalıkların tespiti, yaygın olarak yetiştirilen çeşitlerin önemli patojenlere karşı çeşit reaksiyonlarının belirlenmesi

Strawberry diseases, occurring in Central Anatolia region of Turkey was studied in the years 2013-2016 in the strawberry growing areas of Bartın, Kayseri, Konya, and Zonguldak provinces. Totally 515.5 da strawberry fields in the above mentioned provinces were visited and plants showing disease symptoms were counted and their percentages were determined. Foliage and root diseases were determined by using 383 samples collected from various fields. Seventeen fungal pathogens: namely Alternaria alternata (Fr.) Keissler, Boeremia exigua (Desmazières) Aveskamp, Gruyter & Verkley, Mycosphaerella fragariae (Tul.) Lindau., Colletotrichum acutatum J.H. Simmonds, Colletotrichum gleosporoides (Penz.) Penz., Botrytis cinerea (de Bary) Whetzel, Lasiodiplodia theobromae (Pat.) Griffon & Maubl., Diaporthe actinidae N.F. Sommer & Beraha., Diaporthe eres Nitschke, Didymella americana Saccardo ex Saccardo, Didymella pomorum (Thümen) Aveskamp, Gruyter & Verkley, Diplodia seriata de Notaris, Macrophomina phaseolina (Tassi) Goidanich, Peyronellae prosopidis, Phytophthora cactorum (Lebert & Cohn) J.Schröter, Phytophthora plurivora Jung & Burgess., Phytophthora kelmania were identified. A. alternata, was the most frequently isolated fungus and was obtained from 41.94% of the plant samples while root rot diseases caused by various fungi occurred on 38.13% of the fields. Reactions of twelve strawberry cultivars; (Festival, Kabarla, Sweetann, Alison, Osmanlı, Kara çilek, Tüylü, Sabrina, Rubigem, San Andreas, Albion, Festival, Monterey) were tested against the three most widespread pathogen; A. alternata, M. phaseolina and L. theobromae. With the 86% disease severity, Kabarla was found the most susceptible cv. against A. alternata while Tüylü was the most susceptible cv. against M. phaseolina and L. theobromae. Only one variety, Osmanlı, showed low disease intensity against three of the pathogens.

Synergistic Action of PGPR and Biofungicide with Active Ingredient of Cladosporium clasporioides to Control White Rust on Chrysanthemum

The application of antagonist microbes to control significant diseases on crops is an essential issue in the eco-friendly and sustainable agriculture of the chrysanthemum production system. The application of antagonist consortiums is expected to synergistically suppress the pathogen more effectively than a single microbe, thus increasing the marketable flower yield. The research is carried out to evaluate the single and combined application of antagonists C. ladosporioides and PGPRs, B. subtilis, and P. flourescens to control white rust in Chrysanthemum. The results show that there is no cumulative effect from the combination of biofungicide and the PGPR on disease suppression, disease incidence, and plant growth improvement than single antagonist treatments. Compared to synthetic fungicide, biofungicide and the PGPR treatments give higher parasitism intensity, though the values were negligible among the treatments. The lowest disease intensity is recorded from synthetic fungicide treatment. The improvement of flower quality due to biofungicide, PGPR, and synthetic fungicide treatments was found only on the longer vase life than untreated plants. Observation on the compatibility of antagonists with PGPRs are still needed to increase the effectiveness in controlling white rust in Chrysanthemum.

Efficacy of different fungicides for leaf blight (Alternaria triticina) management in wheat

A. triticina, a seedborne pathogen, can cause major damage to susceptible wheat varieties under wet or humid conditions. Considering the importance of leaf blight of wheat caused by Alternaria triticina,the field study was conducted using different fungicides. The different fungicides like, Mancozeb 75% WP, Propineb 70% WP, Hexaconazole 5% SC, Propiconazole 25 % EC, Azoxystrobin 11% + Tebuconazole 18.30% SC and Hexaconazole 4% + Zineb 68% WP tested as foliar spray under field conditions the lower disease intensity (15.79 %) was recorded in foliar application of Propiconazole 25 % EC (500 ppm) followed by Hexaconazole 4 % + Zineb 68 % WP (18.44 %) at 1000 ppm. The maximum grain yield (3831 kg/ha) was also recorded in foliar spray of Propiconazole 25 % EC which was at par with Hexaconazole 4 % + Zineb 68 % WP and Hexaconazole 5 % SC.

Dissecting the susceptibility/resistance mechanism of Vitis vinifera for the future control of downy mildew

The Eurasian grapevine (Vitis vinifera), a species cultivated worldwide for high-quality wine production, is extremely susceptible to the agent of downy mildew, Plasmopara viticola. Nevertheless, germplasm from Georgia (Southern Caucasus, the first grapevine domestication centre), characterized by a high genetic variability, showed resistance traits to P. viticola. The cultivar Mgaloblishvili exhibited the most promising phenotype in terms of resistance against P. viticola. Its defence response results in: i) low disease intensity; ii) low sporulation; iii) damaged mycelium; iv) production of antimicrobial compounds such as volatile organic compounds (VOCs), whose effectiveness on the pathogen was evaluated by leafdisc assays. At the transcriptomic level, its resistance mechanism is determined by the differential expression of both resistance and susceptible genes. The resistance genes are related to: i) pathogen recognition through PAMP, DAMP and effector receptors; ii) ethylene signalling pathway; iii) synthesis of antimicrobial compounds (VOCs) and fungal wall degrading enzymes; iv) development of structural barriers (cell wall reinforcement). The first putative susceptible gene was the transcription factor VviLBDIf7 gene, whose validation was carried out by dsRNA (double-stranded RNA) assay. In this work, these unique results on plant-pathogen interaction are reviewed with the aim of developing new strategies to control the disease.

RESISTANCE IN COMMON BEAN TO UROMYCES APPENDICULATUS UNDER FIELD AND GREENHOUSE CONDITIONS

Bean rust, caused by Uromyces appendiculatus, is a major disease in common bean which occurs annually in The Rhodope Mountains and sporadic in the plains of Bulgaria. The present study aims to find sources of resistance in common bean to the pathogen for using in a breeding program. The reaction of fifty-five Phaseolus vulgaris accessions to the pathogen was monitored under field condition. Infection type, disease intensity and area under the disease progress curve were calculated. Twelve common bean cultivars were inoculated with eight pathotypes of races 20-2, 20-16, and 20-18 in the greenhouse, and infection type was estimated. Twelve accessions had an immune reaction, eight accessions had resistant a reaction, two accessions had a middle resistant reaction, and seven accessions had a susceptible reaction to U. appendiculatus population in both field estimations. Five cultivars showed resistant phenotype to the eight pathotypes in the greenhouse, four of which were resistant in the field (Abritus, Beslet, Trakiya, and Prelom). Five cultivars had a susceptible or resistant reaction to the pathotypes of the same race, resulting from different interaction between resistant genes in the host and virulent genes in the pathogen. Nine accessions showed race-nonspecific resistance in the field expressed in low disease intensity and susceptible/resistant phenotype.

Evaluation of Botanicals to Manage Leaf Spots (Passalora arachidicola and Passalora personatum) of Groundnut (Arachis hypogaea L.) in Zoba Hamelmalo Region of Eritrea

Groundnut (Arachis hypogaea L.) is grown globally and it is affected by many widespread diseases and infestations in all the groundnut growing areas. In Eritrea, leaf spot diseases are prevalent that is caused by fungi (Passalora arachidicola and P. personata) and results great losses. Botanical pesticides play an important role to control fungal infections due to their non-phytotoxic and eco-friendly nature. This study intended to evaluate the efficacy of selected botanicals viz., Neem (Azadirachta indica), Melia (Melia azadirach), Lantana (Lantana camara), Datura (Datura metel) and Marigold (Tagetes patula) on plant height, intensity of leaf spots disease and yield of groundnut in Hamelmalo zoba, Eritrea, during 2017-2018. Extract of neem leaves (5.66, 14.10 and 25.38%) showed high significance in plant height after 20, 40 and 60 days, respectively, as compared to untreated control (21.07%) and mancozeb (treated control). The lowest disease intensity was recorded in the application of neem extract (15%w/v) at different days after sowing. However, mancozeb (2 g/liter) was the most effective and followed by Neem greater than Melia greater than Lantana showed improvement in plant growth and maximum reduction in disease intensity. The highest reduction rate in ‘disease incidence’ and ‘disease severity’ was found in Neem extract application (63.11 and 40.29) after mancozeb (56.52 and 36.18) at 95 DAS at 5% significant level. Among the botanicals, plants treated with Neem extract was observed with highest number of pods (89.45) and yield (98.10 q/ha) followed by Melia (5% w/v) i.e. 87.59 and 95.02 respectively.

Evaluation of Bush Type Common Bean (Phaseolus vulgaris L.) Genotypes for Morphological Characters and Anthracnose under Cold Arid Ladakh Conditions

In the present study 25 bush type common bean genotypes were evaluated for their adaptability, performance of yield, maturity and anthracnose disease. Among 25 genotypes, ten were red in colour, five were brown in colour, four genotypes were white, two purple and one each was black, pink, yellow and chocolate in colour. For seed shape, 16 genotypes were kidney shaped, 3 were oval, cylindrical and cuboidal. For seed coat pattern, 19 genotypes were plain and 6 were mottled. Seed size revealed that out of 25 genotypes, 6 were large, 17 were medium and two were small. Out of 25 genotypes, 14 were having green colour pods, 10 were yellow and one light green in colour. The pod curvature revealed that 15 genotypes were having medium pod curvature, 7 were curved and 3 genotypes were having straight pod curvature. WB-185 was earliest to flower, whereas WB-956 was earliest to maturity. Highest pod length was recorded in WB-185where as lowest was recorded in local Ladakh and WB-257. Maximum seeds per pod were recorded in genotype WB-185 whereas minimum seeds per pods were recorded in WB-956. Highest plant height was recorded in genotype WB-1690. Highest value for 100 seed weight was recorded in WB-966 and lowest value was recorded in WB-6. Highest yield per plant was recorded in WB-185 and lowest yield per plant was recorded in WB-1129. Analysis of variance revealed that the genotypes exhibited significant variability for all the traits. Screening of genotypes against anthracnose revealed that maximum disease incidence was shown by WB-1690 followed by WB-257, WB-1643, WB-956 and WB-1129. Maximum disease intensity was shown by WB-1690 while lowest disease intensity was recorded in WB-719.

Effectiveness of the Ageratum (Ageratum conyzoides) Leaf Extract as Botanical Fungicide Against Twisted Disease of Shallot

Rianosa R, Hartal H, Setyowati N. 2020. Effectiveness of the Ageratum (Ageratum conyzoides) leaf extract as botanical fungicide against moler diseases of shallot. Jurnal Lahan Suboptimal: Journal of Suboptimal Lands 9(1): 1-10. Moler is a major disease of onion caused by Fusarium oxysporum f. sp. cepae. Application of synthetic fungicides in the long-term has a negative effect to the environment. Weed leaves of Ageratum (Ageratum conyzoides) have potential to be an anti-fungal, anti-bacterial as well as anti-cancer. This study aimed to determine the best concentration of Ageratum leaf extract to control twisted disease and to compare the effectiveness of botanical fungicide and synthetic fungicide. The research was conducted in June - September 2018 at the Plant Protection Laboratory and greenhouse, University of Bengkulu. The experiment was consists of five Ageratum leaf extract concentrations as a botanical fungicide (i.e. 1%, 2%, 3%, 4%, and 5%), and synthetic fungicide namely mancozeb and metil tiofanat and control treatment (in sterile soil with no fungicide treatment). The experiment used Completely Randomized Design (CRD) with a single factor. Ageratum leaf extract was obtained through the maceration method using ethanol 96%. The application of fungicide was carried out on shallot bulbs before planting. The results showed botanical fungicides from Ageratum leaf extract were effective against twisted disease of shallots, concentration 4% of Ageratum leaf extract resulted in a longer incubation period and lower disease intensity compared to other concentrations, and the effectiveness of Ageratum leaf extract at a concentration of 4% was comparable to that of mancozeb to control twisted disease. Application of both synthetic and botanical fungicide resulted in a higher yield of shallot. Therefore, Ageratum leaf extract has potential as a substitution of synthetic fungicides to control twisted disease of shallots.

Assessment of yield loss caused by powdery mildew disease in mungbean

An experiment was conducted at the Instructional Farm of Agronomy, College of Agriculture, JAU, Junagadh during Kharif, 2015. The yield loss caused by powdery mildew disease was recorded on three treatments i.e. application of propiconazole @ 0.025%, water sprays and untreated control under field conditions. Out of three treatments, lower disease intensity (18.5%) and higher seed yield (1242 kg/ha) was recorded in protected plots as compared to untreated control plots where disease intensity was 68.0% and seed yield was 709 kg/ha. With the application of propiconazole, 42.9% seed yield could be saved with the reduction of disease intensity by 72.8%. Whereas, the application of water saved 5.7% seed yield with reduction of disease intensity by 13.8%.

Response of oat grain yield and quality to nitrogen fertilizer and fungicides

AbstractRecently agronomists and producers have expressed interest in combining higher nitrogen (N) rates with a fungicide application even when disease intensity is low. The objective of this study was to evaluate the effect of fungicide application and N rates on grain yield and oat quality (Avena sativa L.). The experimental design was a split plot with fungicide (none, pyraclostrobin, propiconazole + trifloxystrobin) as the main plot, and eight N rates as sub‐plots (5, 20, 40, 60, 80, 100, 120, and 140 kg ha−1). This study was conducted in 2012 and 2013 at two locations in Saskatchewan, Melfort and Indian Head. Disease intensity was very low for crown rust (Puccinia coronata) and low‐to‐moderate for all other foliar diseases, and with no large effect on grain yield and quality. No interaction between fungicide and N was observed. A curvilinear increase in grain yield occurred as the N rate increased from 5 to 140 kg ha−1. Increasing the N rate caused a small linear decrease in test weight. At a low oat price, $130 t−1, the N rate that maximized economic return was sensitive to N fertilizer price. As the crop price increased the optimum N rate was100 kg ha−1. In conclusion, our results indicate that using an N rate of 100 kg ha−1 provided the most consistent economic returns when the crop price is between $162 and $194 t−1. There is no beneficial interaction between fungicide and N for growers using higher N rates at low disease intensity and resistant genotypes.

Potency of biofertilizer to control damping off disease and stimulate plant growth on Japansche Citroen Seedling

Damping off is one of the diseases caused by soil-borne pathogens resulting in the death of seedling in a short time. Control of this disease is quite difficult. The study aimed to examine the potential of biofertilizers and the time of application to damping off disease intensity and plant growth on Japansche citroen seedling. This study used a Factorial Completely Randomized Design with two factors: 1). Biofertilizer namely AzzoFor (P1), liquid biofertilizer (P2), a secondary metabolite of Trichoderma asperellum (P3), the mixture of three biofertilizers (P4), and control (P5), 2). The time of application, namely the treatment of biofertilizers first then followed by the inoculation of F. oxysporum. (A1) and the treatment of F. oxysporu first followed by treatment of biofertilizer (A2). The results showed that the lowest disease intensity was found in A1P3 treatment (0%), while in control reached 41.3%. The treatment of A1P2, A2P1, A2P2 and A2P4 showed the same disease intensity. The highest disease control effectiveness found in A1P2, A1P3, A2P1, A2P2 and A2P4 treatments and this was significantly different compared to A1P4, A2P3 and control treatments. The most significant percentage of seeds germinate at 21 DAS was shown in A1P1 treatment (26.7%) and A2P3 treatment (25.3%), while after 28 DAS, it was in A2P4 treatment (73.3%). The lowest plant height at 28 DAS was A1P4 treatment and control. Biofertilizer is useful for controlling the damping-off disease if applied separately.

Integrated management of anthracnose disease of bottle gourd

The anthracnose of bottle gourd incited by Colletotrichum lagenarium (Syn.C. orbiculare) is emerging as a major disease of bottle gourd in Konkan region. The fungal growth on solid medium was robust, compact with distinct zonation at specific distance. Initially the growth was olivaceous grey to green which gradually turned black with a pinkish tinge at maturity. Mycelium was septate, hyaline and branched about 2-5 μm in diameter. Conidia were hyaline, single celled measuring about 12 - 14 X 4 - 4.5 μm and guttulate with single oil globule. The disease appeared in the form minute, irregular yellow spots on leaves. These spots enlarged into brown necrotic lesions surrounded by yellow halo. Under field conditions, Benomyl (0.25%) was found to be the most effective fungicide with PDI of 28.00 per cent. The highest yield 19.43t/ha was recorded from Propiconazole (0.1%) with highest ICBR of 0.63. in case of integrated management of the disease, seed treatment with T. viride + three sprays with Propiconazole (0.1%) was the best treatment in integrated management with the lowest disease intensity (24.35%). The maximum yield (20.71t/ha) was recorded from seed treatment with T. viride + three sprays of Propiconazole (0.1%) with ICBR of 0.80.

Combined Application of Bio-PF and Synthetic Fungicide Suppress Soil Borne Disease Caused by Cylindrocladium sp. in Leather Leaf

An evaluation of formulated Bio-PF with the active ingredient of Pseudomonas fluorescens to reduce synthetic fungicide usage in controlling soil borne disease in leather leaf fern under different shelters was studied. The research was conducted at the experimental field of the Indonesian Ornamental Crops Research Institute (IOCRI) from January to December 2015. Different concentrations of Bio-PF were singly and/nor alternately applied with two different synthetic fungicides were applied on leather leaf plants under UV plastic + 70% black-net and 70% black-net shelters. The results showed that the average disease intensity was higher in 70% black-net shelter. Weekly alternate-application of Bio-PF 5 + Carbendazim & Mancozeb and single Carbendazim & Mancozeb gave lower disease intensity than other treatments with the highest percentage of suppression. These two treatments also improved yield in terms of number and proportion of the preferred grade of harvested leaves. Combined Bio-PF 5 + Carbendazim & Mancozeb gave longer vase life and the application reduced synthetic fungicide usage in controlling the respected disease. In term of synthetic fungicides, Carbendazim & Mancozeb gave more consistent effects on disease suppression, plant growth and foliage production than Asilbensolar & Mancozeb.

Evaluation of Biological and Chemical Fungicides to Control White Rust in Chrysanthemum Grown Under Open Condition

The effort to reduce chemicals has become an important issue in floriculture agribusiness. The chemicals included fungicides for white rust control in chrysanthemum. The combined application of synthetic fungicide with biological agent and botanical fungicide were expected not only to reduce synthetic fungicide application, but also suppressed the white rust attacks. The research was conducted at the Indonesian Ornamental Crops Research Institute (IOCRI). A factorial randomized complete blocked experiment was designed to facilitate combined applications of hexaconazol-50 (SFH-50), antagonist microbe Corynebacterium sp. (Cor-5) and formulated botanical fungicide CEES 50EC (ES-50). The results showed that the combined SFH-50 with Cor-5 and ES-50 merely affected the disease intensity, yet less on white rust incidence, period of disease emergence, plant growth, flower production and quality. All combined applications of SFH-50 with Cor-5 and ES-50 showed lower disease intensity than single SFH-50. Higher suppressions were detected on 1 ml/l SFH-50 + 5 ml/l Cor-5-3 and 1 ml/l SFH-50 + 2 ml/l ES-50-3. The use of antagonist microbe and botanical fungicide singly or in combination with synthetic fungicide could reduce with the higher affectivity than single synthetic fungicide application.

Optimizing management of cercospora leaf spot (Cercospora beticola) of sugarbeet in the wake of fungicide resistance

Cercospora leaf spot (CLS), caused by Cercospora beticola, is the most detrimental disease of sugar beet in temperate climates. In the Great Lakes region, CLS was well managed by pyraclostrobin-based programmes using the decision support tool BEETcast™. Due to C. beticola resistance to pyraclostrobin in the region, other groups of fungicides were evaluated. Field experiments were conducted at six sites from 2013 to 2015 in Pain Court (PC) and Ridgetown (RT), Ontario. BEETcast™ application schedules for prothioconazole and mancozeb as well as carrier volume (115 and 235 L ha−1) were compared with label-based (calendar) applications. When disease intensity was high, the conservative calendar application schedule reduced the standardized area under the disease progress curve (sAUDPC) by an average of 84% compared with all BEETcast™ schedules, and the BEETcast™ 50/35 schedule (235 L ha−1) reduced sAUDPC by 48% compared with the 55/50 schedules. However, there were fewer differences among application schedules at sites with low or moderate disease intensity. BEETcast™ application schedules reduced the number of fungicide applications by 34–55%. All application schedules increased sucrose (%) and recoverable white sugar (RWS) to an equivalent level, but none of the schedules increased profit margin compared with the non-treated control. Using a carrier volume of 235 L ha−1 reduced sAUDPC by 28% compared with 115 L ha−1 at one site when disease severity exceeded 95% in non-treated control plots. Thus, management recommendations should consider that CLS severity is reduced by application schedules using a shortened interval and appropriate carrier volume, but this does not necessarily result in higher beet or sucrose yield or increases in profit margin.

The effectiveness of fungi Gliocladium fimbriatum and Trichoderma viride to control fusarium wilt disease of tomatoes (Lycopersicum esculentum)

Tomato (Lycopersicum esculentum) is a horticultural commodity with high economic value. However, serious disease management is needed to get good production with better fruit quality. Wilt disease caused by Fusarium is constraining tomato production. This study was aimed to measure the effectiveness the use of Gliocladium fimbriatum and Trichoderma viride to control fusariumwilt disease. This study was conducted in Food Crop and Holticultural Plant Protection Institute of West Papua and Laboratory of Plant Diseases of Agricultural Faculty, Papua University, Manokwari. This study was designed using factorial complete randomized design consisting of two treatment factors and repeated three times. The experiment findings indicated that servo variety was better compared to other tested varieties as indicated by better plant height, low fusarium wilt disease intensity, and higher fruits quantity and weight. Trichoderma and Gliocladium were capable of controlling the development of fusarium wilt disease in tomatoes plant, but the effectiveness of Trichoderma (53.68%) was better controlling the pathogen compared to Gliocladium (48.89%). Interaction between the treatments of Servo variety and fungi Trichoderma resulted in better effect both to lower disease intensity and higher fruits quantity and weight.