scholarly journals Efektivitas Nanoemulsi Minyak Serai Wangi Terhadap Phytophthora palmivora Butl. Patogen Busuk Buah Kakao

2020 ◽  
Vol 7 (3) ◽  
pp. 127
Author(s):  
Rita Harni ◽  
Khaerati Khaerati ◽  
Rita Noveriza ◽  
Sri Yuliani
Keyword(s):  
Dry Weight ◽  
Phytophthora Palmivora ◽  
Inhibition Rate ◽  
Citronella Oil ◽  
Randomized Design ◽  
Black Pod ◽  
Black Pod Disease ◽  
And Inversion ◽  
Significant Disease

<p><em>Black pod disease caused by </em>Phytophthora palmivora<em> is a significant disease on cocoa crops worldwide. Citronella and geraniol are two dominant substances of citronella oil that have fungicidal activity, which is potentially used to control black pod disease. However, those two substances are relatively unstable form volatile. To improve stability can be done using nanotechnology. The study aimed to analyze the effectiveness of citronella-oil-nanoemulsions formulas on the growth of </em>P. palmivora<em> in vitro and on cocoa pods.  Eight nano formulas were prepared at the Postharvest Center in Bogor; however, the effectiveness was conducted at the Indonesian Industrial and Beverage Crops Research Institute in Sukabumi. The nano formula was prepared following spontaneous, simultaneous, and inversion methods.  The experiments were designed in a completely randomized design, with five replications.  Eight treatments were evaluated, i.e., the inversion formulas (F1, F2, F5 &amp; F7), spontaneous (F3, F6 &amp; F8), and simultaneous (F4). Two concentration levels of the formula were tested, i.e., 0.5% for in vitro and 1.0% in cacao pods. The variables observed were the inhibition rate of formula, bioassay, concentration, and inhibition rate on cacao pods. The nanoemulsion formulas of citronella oil could inhibit 23.13%–77.78% of the growth of </em>P. palmivora<em>. Formula F5 was the best, which inhibited 77.78% growth in vitro and 31.60% in cacao pods. The nanoemulsions of citronella oil affected the growth rate, fresh weight, and dry weight of </em>P. palmivora<em>. For better effectiveness of the formula on cocoa pods, the concentration should be increased.</em></p>

scholarly journals Phytophthora theobromicola sp. nov.: A New Species Causing Black Pod Disease on Cacao in Brazil

2021 ◽  
Vol 12 ◽  
Author(s):  
Jennifer Decloquement ◽  
Roberto Ramos-Sobrinho ◽  
Samuel Galvão Elias ◽  
Dahyana Santos Britto ◽  
Alina Sandra Puig ◽  
...  
Keyword(s):  
New Species ◽  
Growth Rates ◽  
Mycelial Growth ◽  
Elongation Factor ◽  
Limiting Factors ◽  
Phytophthora Palmivora ◽  
Black Pod ◽  
Black Pod Disease ◽  
A New Species

Black pod disease, caused by Phytophthora species, is among the main limiting factors of cacao (Theobroma cacao L.) production. High incidence levels of black pod disease have been reported in Brazil, being induced by Phytophthora capsici, Phytophthora citrophthora, Phytophthora heveae, and Phytophthora palmivora. To assess the diversity of Phytophthora species affecting cacao in Brazil, 40 new isolates were obtained from cacao pods exhibiting symptoms of black pod disease collected in different smallholder farms in 2017. Further, ten cacao-infecting isolates morphologically identified as P. citrophthora and P. palmivora were molecularly characterized. The genomic regions beta-tubulin, elongation factor 1 alpha, heat shock protein 90, and internal transcribed spacer, and the mitochondrially encoded cytochrome c oxidase I and II genes were PCR-amplified and Sanger-sequenced from the cacao-infecting Phytophthora isolates. The morphological characterization and evaluation of the mycelial growth rates for the Phytophthora isolates were performed in vitro. Based on the molecular analysis and morphological comparisons, 19 isolates were identified as P. palmivora (clade 4). Interestingly, 31 isolates grouped together in the phylogenetic tree and were placed apart from previously known species in Phytophthora clade 2. Therefore, these isolates are considered as a new species herein referred to as Phytophthora theobromicola sp. nov., which produced papillate, semipapillate, and persistent sporangia on simple sporangiophores. The P. palmivora isolates were identified as A1 mating type by pairing each isolate with known A1 and A2 tester strains of P. capsici, but no oogonia/antheridia were observed when P. theobromicola was paired with the different tester strains. The P. theobromicola and P. citrophthora isolates showed higher mycelial growth rates, when compared to P. palmivora, on different media at 10, 15, and 20°C, but similar values were observed when grown on clarified CA media at 25 and 30°C. The pathogenicity tests carried out on pods of four cacao clones (CCN51, PS1319, Cepec2004, and CP49) showed significant variability among the isolates of both Phytophthora species, with P. theobromicola inducing higher rates of necrotic lesion expansion, when compared to P. palmivora. Here, two Phytophthora species were found associated with black pod disease in the state of Bahia, Brazil, and the previously undescribed P. theobromicola seems to be prevalent in field conditions. This is the first report of P. theobromicola on T. cacao. Also, these findings are crucial to improve the disease control strategies, and for the development of cacao materials genetically resistant to Phytophthora.

scholarly journals Pengaruh Formula Fungisida Nabati Minyak Cengkeh dan Serai Wangi terhadap Penyakit Busuk Buah Kakao

2014 ◽  
Vol 1 (1) ◽  
pp. 41 ◽  
Author(s):  
Rita Harni ◽  
Efi Taufiq ◽  
Widi Amaria
Keyword(s):  
Salicylic Acid ◽  
Seed Weight ◽  
Block Design ◽  
Disease Suppression ◽  
Phytophthora Palmivora ◽  
Clove Oil ◽  
Phenolic Contents ◽  
Citronella Oil ◽  
Black Pod ◽  
Black Pod Disease

<p>Penyakit utama busuk buah kakao disebabkan oleh Phytophthora palmivora dapat menurunkan hasil 20%-30%. Pengendalian penyakit<br />dengan fungisida nabati saat ini banyak dikembangkan, dengan tujuan mengurangi dampak negatif dari fungisida sintetik. Fungisida<br />nabati yang digunakan adalah minyak cengkeh dan serai wangi karena mudah didapat dan bersifat fungisidal. Penelitian bertujuan<br />menganalisis pengaruh formula fungisida nabati minyak cengkeh dan serai wangi terhadap perkembangan penyakit busuk buah kakao<br />(BBK) yang disebabkan oleh Phytophthora palmivora. Penelitian dilaksanakan di kebun petani Kabupaten Mamuju, Sulawesi Barat,<br />menggunakan rancangan acak kelompok 7 perlakuan, 4 ulangan. Setiap perlakuan diamati 20 buah kakao berukuran 8-10 cm.<br />Perlakuan yang diuji adalah 1) minyak cengkeh+serai wangi, 2) minyak cengkeh+asam salisilat, 3) minyak cengkeh+silikon, 4) serai<br />wangi+asam salisilat, 5) serai wangi+silikon, 6) fungisida sintetik sebagai pembanding, dan 7) kontrol. Larutan formula (5ml/liter)<br />disemprotkan pada buah setiap 2 minggu sekali sampai buah masak atau dipanen. Parameter yang diamati adalah persentase serangan,<br />intensitas serangan, kadar senyawa fenol, dan bobot biji kakao. Hasil penelitian menunjukkan bahwa formula fungisida nabati<br />cengkeh dan serai wangi yang diperkaya dengan asam salisilat dan silikon dapat menekan intensitas serangan penyakit busuk buah<br />kakao sebesar 20,48%-65,62%, tidak berbeda nyata dengan fungisida sintetik (73,15%). Besarnya tingkat penekanan penyakit sejalan<br />dengan kandungan senyawa fenol pada kuit buah kakao. Semakin tinggi kadar fenol pada kulit buah, maka semakin tinggi penekanan<br />penyakit busuk buah kakao. Penggunaan formula fungisida nabati dapat menekan kehilangan produksi kakao 23,94%-43,02%.<br />Formula terbaik dan dapat dianjurkan untuk pengendalian penyakit busuk buah kakao adalah minyak cengkeh+serai wangi,<br />cengkeh+asam salisilat, dan serai wangi+silikon.</p><p>Kata Kunci: Kakao, Phytophthora palmivora, busuk buah kakao, fungisida nabati</p><p>Black pod disease caused by Phytophthora palmivora is a major disease on cacao crops, which can cause yield losses until 20%-30%. Disease<br />control using botanical fungicide such as the use of clove and citronella oil, which have fungicidal effect, have been developed to reduce the negative<br />impact of synthetic fungicide residues. The objectives of this study was to analyze the effect of clove and citronella oil as botanical fungicide formula<br />on the development of black pod disease and seed weight of cocoa in the field. The study was carried out at farmer’s fields in Mamuju District, West<br />Sulawesi using a randomized block design with 4 replications and 7 treatment. In each treatment was observed 20 cacao pods with size 8-10 cm. The<br />treatments were 1) clove + citronella oil, 2) clove oil + salicylic acid, 3) clove oil + silicone, 4) citronella + salicylic acid, 5) citronella + silicone,<br />6) synthetic fungicides as a comparison treatment, and 7) control. The botanical formula was applied by spraying onto the entire surface of pod with<br />a concentration of 5 ml/litre every 2 weeks. Observations were include the percentage of attacks, intensity of the attack, the levels of phenolic<br />compounds, and seed weight of cacao. The results showed that the formula of botanical fungicide containing clove and citronella oil enriched with<br />salicylic acid and silicon can suppress disease attack of black pod (20.48%-65.62%), which was not significantly different from synthetic fungicide<br />(73.15%). The level of disease suppression in line with phenolic compounds of cocoa husk. In which, high phenolic contents can reduce black pod<br />disease at a higher level . The use of botanical fungicides formula can suppress the yield loss until 23.94% to 43.02%. The best formulas that can<br />be recommended in suppressing intensity of black pod disease were clove oil + citronella, clove oil + salicylic acid, and citronella + silicon.</p>

Genetic diversity of native cultivated cacao accessions (Theobroma cacao L.) in Nicaragua

2012 ◽  
Vol 10 (3) ◽  
pp. 254-257
Author(s):  
Erwin Aragon ◽  
Claudia Rivera ◽  
Helena Korpelainen ◽  
Aldo Rojas ◽  
Paula Elomaa ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Theobroma Cacao ◽  
Phytophthora Palmivora ◽  
Genetic Composition ◽  
Breeding Programmes ◽  
Black Pod ◽  
Black Pod Disease ◽  
Parental Lines ◽  
Resistant Genotypes ◽  
Theobroma Cacao L

A total of 60 farmers' cacao accessions (Theobroma cacao L.) from Nicaragua were investigated using microsatellite markers to reveal their genetic composition and to identify potentially resistant genotypes against the black pod disease caused by Phytophthora palmivora. These accessions were compared with 21 breeders' accessions maintained locally, two Criollo accessions from Costa Rica and two accessions from Ecuador. The analyses showed a low level of differentiation among groups of farmers' accessions (FST = 0.06) and that six Nicaraguan accessions were genetically closely related to the two Criollo accessions used as a reference. In addition, seven distinct genotypes were found to have allelic composition that may indicate linkage to resistance alleles, thus being potential parental lines in future breeding programmes.

scholarly journals Growth Inhibition of Cocoa Pod Rot Fungus Phytophthora palmivora byPseudomonas fluorescence and Bacillus subtilis bacteria

2013 ◽  
Vol 29 (2) ◽  
Author(s):  
Sakti Widyanta Pratama ◽  
Sri Sukamto ◽  
Lis Nur Asyiah ◽  
Yeni Vida Ervina
Keyword(s):  
Bacillus Subtilis ◽  
Fungal Growth ◽  
Petri Dish ◽  
Phytophthora Palmivora ◽  
Fungal Treatment ◽  
Pure Cultures ◽  
Black Pod ◽  
Black Pod Disease ◽  
First Time ◽  
Important Disease

Black pod disease caused by Phytophthora palmivorafungus is one of the important diseases on cocoa crop. Pod rot is the most important disease because it may cause loss of cocoa pod. Until now, the fungal pathogen of cocoa black pod disease is still a crucial problem and there is no fungicide that is really effective against the disease. One alternative to control the cocoa black pod disease is by using biological agents as biofungicide, including utilizing Pseudomonas fluorescenceand Bacillus subtilis bacteria. The research was done by isolation of P. palmivora from infected pods of Kaliwining Experimental Station to obtain pure cultures of fungus and by multiplication of P. fluorescence and B. subtilis. Antagonist test was performed by inoculating P. palmivora into a petri dish in a distance of 3 cm from the edge. P. fluorescenceand B. Subtilis were inoculated into petridishes in three days after the fungal treatment. Control was inoculated with isolate of P. palmivora only. Fungal growth was measured everyday by measuring radius of fungal colonies first time 24 hours after inoculation. Growth of Phytophthora palmivora in the two treatmens were used to calculate the percentage of inhibition. The results of this study indicated that P. fluorescence and B. subtiliswere able to inhibit fungal growth of P. palmivora. Both bacterial antagonists had the same effectiveness in inhibiting the growth of P. palmivora fungus based on the percentage of inhibition and effectiveness criteria. Based on the results of translucent zones indicated that B. subtiliswas more powerfull in inhibiting growth of P. Palmivora compared to P. fluorescence. Key words: Black pod disease of cocoa, biological control, Phytophthora palmivora, Pseudomonas fluorescence, Bacillus subtilis

scholarly journals Symbiotic and endophytic fungi as biocontrols against cocoa (Theobroma cacao L.) phytopathogens

2017 ◽  
Vol 43 (2) ◽  
pp. 87-93 ◽  
Author(s):  
Raquel Amanda Villamizar-Gallardo ◽  
Oscar Orlando Ortíz-Rodriguez ◽  
Jhon Wilmer Escobar
Keyword(s):  
Theobroma Cacao ◽  
Trichoderma Viride ◽  
Phytophthora Palmivora ◽  
Mycotoxigenic Fungi ◽  
Black Pod ◽  
Antagonistic Potential ◽  
Native Strains ◽  
Biological Methods ◽  
Theobroma Cacao L

ABSTRACT Cocoa (Theobroma cacao L.) is a tropical tree, seriously affected by fungal diseases. To control several pathogens, biological methods are prescribed since they are friendly to the environment and easy to use. The main objective of this study was to assess the biocontrol effect of two native strains, Trichoderma viride and Botryosphaeria quercum, on phytopathogens such as Phytophthora palmivora and Moniliophtora roreri, causal agents of black pod and frosty pod rot diseases, respectively. In addition, biocontrolers were faced on potential mycotoxigenic fungi such as Aspergills flavus and Fusarium solani, which are very common on cocoa. The Bio-Control Index (BCI) was calculated to determine the in vitro biocontrol effect against the four phytopathogens. Results indicated that the best biocontrol agent of phytopathogens was B. quercum, showing BCI of 82.3%, 80.7%, 63.3% and 59.7% for each tested phytopathogen, respectively. Competition for substrate was the dominant biocontrol strategy. As to the origin of strains, those coming from the Department Norte de Santander and Santander showed the highest average inhibition percentage. This study provides an initial screening to the endophytic and antagonistic potential of fungi, specifically those capable of colonizing cocoa pods and soils. Thus, these strains can be used as an efficient biological control alternative against several known phytopathogens of cocoa in the field.

scholarly journals Evaluation of different growth hormones mediated callus induction and regeneration as well as the effect of colchicines, ethyl methanesulfonate (EMS) and gamma radiation on some traits of Impatiens walleriana

Genetika ◽  
2021 ◽  
Vol 53 (1) ◽  
pp. 379-391
Author(s):  
Sedigheh Sharafi ◽  
Pejman Azadi ◽  
Maryam Jafarkhani Kermani ◽  
Vahid Abdossi ◽  
Ali Eskandri
Keyword(s):  
Dry Weight ◽  
Control Treatment ◽  
Lower Survival Rate ◽  
Randomized Design ◽  
Effective System ◽  
Number Of Leaves ◽  
Impatiens Walleriana ◽  
The Impact ◽  
Disease Free

Impatiens is an ornamental member of family Balsaminaceae. This plant mostly propagated by vegetative technique, which generally time wasting process. It is often multiplicities via seed but is barricaded by F1 seed sterility. In vitro culture of Impatiens walleriana has much significant function in fast proliferation with useful features and elicitation of healthful and disease-free plants. This experiment was conducted to investigate the impact of medium and different hormones on in vitro propagation of Impatiens walleriana by using a completely randomized design. MS medium was prepared along with various concentrations of BAP, TDZ and ZEA. Callus was induced and grew well in media supplemented with 0.5 mg/l NAA + 1 mg/l BAP. In order to indirect propagation, explants were cultured in same media containing BAP, ZEA and TDZ in combination with NAA. These treatments have ability to organogenesis. The results revealed that the control treatment had the lowest effect on traits including shoot percentage, number of shoots, number of leaves, shoot length, fresh and dry weight, and it lead to maximum proliferations in medium supplemented with 0.5 mg/l NAA + 1 mg/l BAP. The highest root length and rooting percentage was observed in 0.5 mg/l IBA + 0.5 mg/l BAP. In addition, the effect of mutation agents was studied. Aseptic samples were treated with ?- irradiation, Ethyl Methane Sulfonate and colchicines at growth chamber. Treatments with 30 and 60 grey respectively had the lower survival rate, growth rate and polyploidy while colchicines with 0.1 and 0.2 had the highest rats. Regarding to these, the present technique illustrate an effective system for in vitro reproduction of Impatiens walleriana by hypocotyls cultures. In addition, colchicines proved to be effective in induction of polyploidy in this plantlet.

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