Squash Leaf Curl Virus: Species of Begomovirus as the Cause of Butternut Squash Yield Losses in Indonesia

Curling symptom was found in pumpkin plants in Bali, and the PCR detection result using Begomovirus universal primers indicated Begomovirus infection. Further research was conducted to determine the distribution, molecular character of SLCV, and yield loss of the pumpkins. Sampling was carried out at pumpkin plantations in 9 districts in Bali. Detection and identification were carried out using PCR method, followed by cloning and DNA sequencing. DNA band with the measurement of 900 bp was successfully amplified from several pumpkin samples from Denpasar, Gianyar, and Buleleng. Homology analysis of nucleotide sequences using the database in GenBank of SLCV of Balinese isolates showed the highest homology and kinship of 97.3-98.4% and 98.4-99.3% respectively with East Timor isolates from pumpkin plants. The phylogeny analysis showed that SLCV Indonesian isolates were in the same group as Asian isolates. The result of this study is the first report on infection and molecular characterization of SLCV in pumpkin plants in Indonesia. The yield loss caused by curling disease on individual pumpkin plants was 56.3%, and the disease caused a decrease in the quality of harvest fruits. Yield loss estimation caused by the disease in fields with different levels of disease intensity ranged from 10.02 to 25.83%. It was equal to yield loss ranging from IDR 878,400.00 to IDR 10,826,400.00 depending on the disease intensity. It is found that the correlation between curling disease severity and yield loss was high

Karakterisasi Molekuler Papaya ringspot virus tipe P pada Tanaman Mentimun di Jawa

Moleculer Characterization of Papaya ringspot virus type P on Cucumber in JavaInfection of Papaya ringspot virus (PRSV) on cucumber plants showing mosaic symptom was detected using specific antibody.  Further investigation was conducted to determine molecular characters and status of PRSV infecting cucumber in Java.  Infection of PRSV was detected from leaf samples collected from the field using dot immunobinding assay (DIBA).  Disease frequency caused by PRSV infection reached 81.11%, 95.86%, 91.66%, and 92.3% in East Java, Central Java, Yogyakarta, and West Java, respectively.  Characterization of PRSV isolates was conducted by reverse transcription polymerase chain reaction (RT-PCR) using specific primers for PRSV-P and PRSV-W, followed by cloning, and DNA sequencing.  DNA fragment of 470 bp was successfully amplified using specific primers for PRSV-P from several samples from Nganjuk, Brebes, Kulon Progo, and Subang; but no amplification was achieved using specific primers for PRSV-W.  Nucleotide and amino acid analysis showed high homology among PRSV-P isolates from Nganjuk, Brebes, Kulon Progo, and Subang, i.e. 98.6%-99.7% and 99.3%-100%, respectively.  This is an indication of a low genetic variation among PRSV-P from Java. Further phylogenetic analysis indicated that PRSV-P isolate cucumber is in the same cluster with PRSV-P isolate papaya from Bali, Indonesia.  This is the first report of PRSV-P infecting cucumber in Indonesia

Diseases Incidence and Severity of Sweet potato feathery mottle virus in Sweetpotato in Gianyar Regency, Bali

Sweet potato feathery mottle virus (SPFMV) (Potyvirus) was first discovered in Indonesia in 2018. No one has reported information about the incidence and severity of SPFMV disease. Therefore, this study aims to determine the incidence and severity of SPFMV in Gianyar, Bali. The research was carried out directly in the field with observational parameters such as symptoms, incidence and disease severity. Observations were made every week when the plants were 63 to 91 days after planting (DAP). The results showed that SPFMV causes purple ringspot symptoms. The incidence of the disease did not increase when the plants were aged 63 to 91 DAP, while the severity of the disease increased every week. The highest incidence and severity of the disease were 70% and 20.7%. The main cause of SPFMV infection in the field is probably due to the continuous use of stem cuttings from previous crops

Symptom variation and disease severity of Sweet potato leaf curl virus on sweet potato in Gianyar

Sweet potato production fluctuates every year, one of the factors causing the decline in production is the presence of pests and diseases. Sweet potato leaf curl virus (SPLCV) has been reported to infect sweet potatoes in Indonesia in 2022. Until now, there is no information regarding the variation in symptoms and severity of SPLCV disease in sweet potatoes. Therefore, this study aims to analyze the variation in symptoms and severity of SPLCV disease in Gianyar, Bali. The research was carried out directly in the field with observational parameters such as symptoms variation, incidence and disease severity. Observations were made every week when the plants were 63 to 91 days after planting (DAP). The results showed that SPLCV causes a variety of symptoms in the form of mild vein clearing, severe vein clearing, upward vein clearing, and downward vein clearing. The incidence and severity of the disease has increased every week. The incidence and severity of the disease were highest when the plants were 91 HST, namely 73.33% and 40%, respectively. The high incidence and severity of the disease in the field is due to the use of stem cuttings from previous plants which may have been infected with SPLCV and whitefly vectors are always found in the field

The Isolation, Selection and Determination of Endophytic Bacteria from Bamboo, Gamal, Tulsi, and Alamanda

Endophytic bacteria have many benefits, including increasing plant growth by producing phytohormones, increasing the production of mineral absorption, nitrogen fixation, reducing damage due to weather changes and increasing plant resistance to disease. Based on the above, it is necessary to select endophytic bacteria from various plants to be used as biocontrol agents. This study aims to obtain endophytic bacterial isolates that have the potential as biocontrol agents and plant growth supporters from bamboo shoots, Gamal, Tulsi, Lotus, and Alamanda. This research method includes sampling, endophytic bacteria isolation, hypersensitive, hemolysis, phosphate solvent, chitinolytic, proteolytic, and antagonist tests. Isolation of endophytic bacteria in 5 plants using 22 plant parts had a diversity of isolates. The isolated plant parts produced 1 to 7 isolates that had different morphology. The total isolates obtained were 59 isolates. In antagonistic observations, there was one isolate of endophytic bacteria that showed a clear zone when tested together with S. rolfsii, namely the isolate with code A24 from allamanda flower. From the data obtained, it is known that the endophytic bacterial isolates had an effect on inhibiting the growth of the pathogenic fungus S. roflsii, the endophytic bacterial isolates Consortium, A21 and the endophytic bacterial isolates A22 had no incidence of disease, while the bacterial isolates T00 (Bx) with an average disease incidence of 40% and 30% disease intensity. Meanwhile isolates A23, A24 and A25 had an average disease incidence ranging from 13.3%-26.6%, while controls had the highest disease incidence, namely 53.3% and disease intensity 66.6%

Biology and the Statistic Demographic of Aphis Glycines Matsumura (Hemiptera: Aphididae) on the Soybean with Plant Growth Promoting Rhizobacteria (PGPR) Treatment

A correction has been published:Erratum to “Biology and the Statistic Demographic of Aphis glycines Matsumura (Hemiptera: Aphididae) on the Soybean with Plant Growth Promoting Rhizobacteria (PGPR) Treatment” [Jurnal Perlindungan Tanaman Indonesia, 24(1), 54 ̶ 60]Plant Growth Promoting Rhizobacteria (PGPR) applied to different plants may suppress pests population developments. This research was to study the capability of a commercial PGPR product contained Bacillus polymyxa and Pseudomonas fluorescens in suppressing population developments of Aphis glycines Matsumura (Hemiptera: Aphididae). The biology and demographic statistics of A. glycines reared on soybean with and without the PGPR applications were compared. The PGPR suspensions of 5 g formulation per liter water were used to soak soybean seed for 15 minutes and to water soybean plant 2 weeks after transplanting. Cohorts of 65 first instar A. glycines of each treatment were observed daily and individual mortality, molting, and fecundity were recorded until the last individual dead. Second instar stadium of A. glycines reared on treated plant lasted longer than those reared on untreated plant, i.e. 1.4 and 1.1 days, respectively. These resulted on a longer life cycle for A. glycines reared on treated plant than on untreated plant, i.e. 4.9 and 4.5 days, respectively. In turn, it caused the A. glycines population to experienceslower growth on treated plants than on untreated plants. The values of A. glycines GRR, Ro, rm, T and DT on treated plants were 71.834, 57.780, 0.557, 7.287 and 1.245, consecutively; whilst that of untreated plants were 104.861, 63.326, 0.586, 7.084 and 1.184, respectively

Isolasi cendawan endofit pada tanaman padi serta potensinya sebagai pemacu pertumbuhan tanaman

Cendawan endofit banyak mendapat perhatian karena potensinya dalam memacu pertumbuhan dan kemampuannya dalam meningkatkan ketahanan tanaman terhadap penyakit dan hama tanaman. Penelitian ini bertujuan mengisolasi cendawan endofit pada tanaman padi di Bali dan menguji potensinya sebagai pemacu pertumbuhan tanaman. Isolasi bakteri endofit dilakukan dengan metode sterilisasi permukaan dengan alkohol dan natrium hipoklorit pada medium PDA. Lebih dari 15 isolat cendawan endofit berhasil diisolasi dan dikoleksi dari beberapa bagain tanaman padi. Isolat tersebut diseleksi untuk melihat kemampuan antibiosisnya terhadap cendawan patogen secara in vitro dan memacu pertumbuhan tanaman. Hasil seleksi menunjukkan cendawan endofit non pathogen yang memacu pertumbuhan tanaman yaitu 3 isolat asal pelepah, 3 isolat asal batang, dan 1 isolat asal daun padi. Hasil identifikasi cendawan endofit menunjukkan bahwa isolate asal pelepah dan batang padi dinamakan Phoma sp, sedangkan asal daun padi dinamakan Acremonium. Hal ini mengindikasikan bahwa beberapa cendawan endofit non patogen asal padi berpotensi sebagai pemacu pertumbuhan tanaman

Screening of Endophytic Bacteria Isolated from Mimosa pudica in Bali Island

This study aims to determine the screening of endophytic bacteria isolatd from Mimosa pudica in Bali Island. This research was conducted from September 2020 to January 2021 at the Plant Disease Laboratory, Faculty of Agriculture, Udayana University, Denpasar. Isolation of endophytic bacteria was carried out by taking a sample of the root of the shy daughter plant which was then washed and dried on a tissue.. Hypersensitivity test followed Klement and Goodman (1967) by growing bacteria in a petri dish containing 100% TSA and NA.Tests were carried out by growing endophytic bacteria in 100% NA and TSA media.  Isolation of the roots of the Mimusa pudica plant resulted in 43 isolates. The resulting isolates then passed the hypersensitive test so that 27 isolates were selected. A total of 27 isolates were then tested for hemolysis on blood agar. The final results obtained were 12 endophytic bacterial isolates which were then used in the next practicum. The results showed that the endophytic bacterial isolates were not able to inhibit the fusarium sp. and Phytophthora sp., when using the inhibition percentage formula. This is because the average diameter of the pathogenic fungi colonies in the control treatment (R1) with the average diameter of the pathogenic fungi colonies in the endophytic treatment (R2) has the same size, so that when calculated by the percentage inhibition formula it results in the number 0 which means no. there is a zone of inhibition