Jurnal Hama dan Penyakit Tumbuhan Tropika

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

Tue, 02 Jul 2024 00:00:00 +0000

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 bionematicide from Purpureocillium lilacinum in controlling root-knot nematodes (Meloidogyne spp.)

Sat, 29 Jun 2024 00:00:00 +0000

This research aimed to study the efficacy of the fungus Purpureocillium lilacinum as a bionematicide to control root-knot nematodes (RKN). Two steps of experiments were carried out in this study. The first experiment involved the application of various levels of bionematicide doses to control RKN on tomato plants. The second experiment tested the application of bionematicide (both as a single application and in combination with bromelain compost) to control RKN on guava cv. Kristal. A carbofuran nematicide was applied following the company’s recommendation in this second experiment for comparison. The results of the first trial showed that the application of P. lilacinum bionematicide at doses ranging from 20–40 g per plant or 7–13 g per kg of soil was effective in reducing the J-2 RKN population in the soil and roots, as well as mitigating damage to plant roots. In the second experiment, it was shown that the application of P. lilacinum bionematicide, either alone or mixed with bromelain compost, was more effective than the application of carbofuran nematicide in reducing the J-2 RKN population in the soil and roots, as well as in minimizing root damage to guava seedlings. Additionally, the application of bionematicides mixed with compost proved more effective than their single application in reducing plant root damage. Furthermore, apart from being able to control nematode populations and plant damage, P. lilacinum bionematicide could stimulate plant growth.

Diversity and community structure of predators in surjan (polyculture) and lembaran (monoculture) paddy fields

Dina Wahyu Trisnawati, Ihsan Nurkomar, Andri Antono, Era Puspitasari — Thu, 13 Jun 2024 00:00:00 +0000

Predator diversity decreases because of low ecosystem quality in modern agriculture that applies monoculture systems. However, polyculture systems in paddy fields can improve biodiversity, including pests, natural enemies, and microorganisms. Surjan is a local polyculture farming practice that originated in Yogyakarta. This farming practice consists of raised beds for cultivating palawija or horticultural crops and sunken beds for rice cultivation. Surjan farming may have an impact on predatory diversity and abundance, although this has not been studied. To address this issue, research was carried out to investigate the diversity, abundance, and structure of the community of predators in the paddy fields of surjan (polyculture) and lembaran (monoculture). The field experiment was conducted in three pairs, surjan and lembaran, in Panjatan District, Kulon Progo Regency, Yogyakarta Special Region, Indonesia. In each field, five random plots arranged in a cross pattern were used to collect a sample of predators. Several traps, including sweeping, pitfall traps, yellow adhesive traps, and yellow pan traps, were used to determine the abundance and diversity of predators. Results showed that species diversity, abundance, species composition, and biodiversity index in surjan farming were significantly improved compared to lembaran farming. Ceratopogonidae and Formicidae were the most abundant families in both surjan and lembaran farming, although they are more abundant in surjan. It can be concluded from the study that surjan farming could improve ecosystem quality by implementing predators for pest management.

The effect of tobacco leaf extract dosage on the development of virus disease in curly chili

Haryuni , Sapto Priyadi — Fri, 15 Mar 2024 00:00:00 +0000

Curly chili is a horticultural product with high nutritional value, greatly demanded as a distinctive complement or flavoring for dishes due to its unique taste and aroma. Despite the increasing demand for chilies, production has not followed suit, mainly due to disruption caused by viruses transmitted by Bemisia tabaci and Thrips sp. This study aimed to investigate the effect of tobacco extract on the growth and development of viral diseases in curly chili. Conducted at Kwangsang Village, Jumapolo District, Karanganyar Regency, from September to December 2021, the research was designed using a completely randomized block design, with treatment doses of tobacco extract at 0 mL/L, 1 mL/L, 2 mL/L, 3 mL/L, and 4 mL/L, labeled J0, J1, J2, J3, and J4, respectively. The results indicated that the variabels, i.e. plant height, number of leaves, number of fruits, and fruit weight per plant, were significantly affected by the tobacco extract. Similarly, the disease incidence and severity of viral infection were significantly influenced by the tobacco extract application. The yield decrease in curly chili was attributed to virus infection by Bemisia tabaci and Thrips sp., which caused chlorosis and mosaic symptoms on the leaves. Although the affected plants did not die, they experienced a yield reduction. The application of tobacco extract significantly reduced the percentage of incidence and severityof virus infection on curly chili. The highest disease incidence was 35.42% (J0) and disease severity was 70.92% (J0), while the lowest disease incidence was 14.58% (J4) and disease severity was 20.58% (J4).

Molecular identification of Trichoderma sp. Margodadi isolate and its potential against Phytophthora capsici causing foot rot of black pepper

Joko Prasetyo, Nur Baitullah Juniar, Rusdi Evizal, Tri Maryono, Cipta Ginting — Fri, 15 Mar 2024 00:00:00 +0000

Trichoderma has the potential to suppress fungal pathogens and thus control plant diseases, including Phytophthora foot rot, which is the most devastating disease of black pepper in Lampung. Identification of a microorganism can not only rely on its morphological characteristics, but it is also necessary to identify it molecularly at the species level. This research was aimed at identifying the fungus Trichoderma sp. Margodadi isolates at the species level and to know the potential of Trichoderma sp. Margodadi isolates and their secondary metabolites to control P. capsici. This research was conducted from March to November 2021 at the Laboratory of Plant Disease, Department of Plant Protection, and the Laboratory of Agricultural Biotechnology, Faculty of Agriculture, University of Lampung. Identification of Trichoderma was done by morphological characteristics and molecular methods. The ability of Trichoderma to suppress P. capsici was tested by dual culture. The effect of secondary metabolites on the growth of P. capsici was determined in vitro at concentrations of 0% (control), 10%, 20%, 30%, and 40%. The experimental design used was a completely randomized design consisting of five treatments repeated five times. The data obtained from the test were analyzed using ANOVA, followed by the LSD test at 5%. The results of this study showed that Trichoderma sp. Margodadi isolate had a close relationship with Trichoderma asperellum and had the ability as an antagonist to inhibit the growth of P. capsici up to 47.23%, and the secondary metabolites produced could inhibit the growth of P. capsici up to 72.53% with the best concentration of 40%.