Jurnal Hama dan Penyakit Tumbuhan Tropika

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%.

The changes of chili leaf structure by Geminivirus infection

Wed, 13 Mar 2024 00:00:00 +0000

The Geminivirus in chili plants is a significant problem in chili cultivation. Symptoms of Geminivirus infection are quite easy to find in chili plants because the symptoms are quite typical: mosaic, yellowing, small leaves, leaf lamina malformation, and stunting. The visual changes in leaf morphology are due to the leaf tissue structure, such as the upper and lower epidermis and the mesophyll tissue, including the palisade and sponge. There is little information about changes in the structure of chili plants infected with the Geminivirus. Therefore, this study aims to add information about changes in the leaf tissue structure of chili plants infected with the Geminivirus. The structural changes observed were palisades. Long palisades were less preferred by whiteflies, so the incidence of geminivirus disease was lower. This information is a reference for assembling chili plants with better structural resistance. The method used was a cross-section of chili leaves, double staining, and observation with a light microscope. Observations on mild symptoms showed epidermal cells shrinking. Some parts of palisade leaves were composed of two layers with shortened cells and tend to be oval. The symptom is that the upper epidermal cells were shrunken, and the palisade also tends to shorten. Severe symptoms of the epidermis on the leaves were curly, shriveled, thinned, and even dying; the palisade is shortened and sometimes looks irregular/tight. Changes in the leaf tissue of chili plants infected with the Geminivirus cause changes at the ultra-structural, cell, or tissue level, depending on the type of virus attack and the attack level.

The population dynamics of Spodoptera frugiperda after its invasion in Lampung Province, Indonesia

Wed, 13 Mar 2024 00:00:00 +0000

Spodoptera frugiperda is an invasive pest that attacks maize throughout Indonesia. As an invasive pest, the population of S. frugiperda continues to increase exponentially, leading to outbreaks. Both internal factors (biology) and external factors (weather, host, and natural enemies) can affect the growth rate of pest populations. This research was conducted to assess the population dynamics of S. frugiperda based on the extent of its infestation and damage to maize post-invasion in Lampung Province. Observations were made in maize fields in 15 districts of Lampung Province from 2019 to 2022. Damage intensity was calculated based on the leaf damage scale. Weather data from 2019 to 2022 was obtained from the Lampung Province Central Statistics Agency. The research results indicate that upon the initial introduction of S. frugiperda to Lampung Province, the population increased exponentially, as observed based on the level of infestation and damage to maize. There was an outbreak from late 2019 to early 2020, and after that, there was a population decline. The population increase coincided with the early rainy season, which is associated with the beginning of the maize planting season. Although the level of damage to the maize is considered slight, S. frugiperda can cause anywhere between 21.94% to 51.38% of damage.

Biochemical changes in some banana cultivars infected by Banana bunchy top virus

Ruth Feti Rahayuniati, Ruly Eko Kusuma Kurniawan, Nurtiati — Mon, 04 Mar 2024 00:00:00 +0000

Bunchy top is one of the major diseases on bananas that caused economic losses. This study aimed to determine changes in protein content, the concentration of phenolic compounds, the amount of chlorophyll, and sugar content in several Banana bunchy top virus (BBTV)-infected banana cultivars. The research involved the artificial inoculation, extraction, and biochemical analysis of banana seedlings from the cultivars Mas, Cavendish, Kepok, and Raja. Inoculation was performed using the vector Pentalonia sp.. A factorial complete randomized design (CRD) was used as the experimental design. Each experimental unit consisted of 5 repetitions. Protein, phenol, chlorophyll, and sugar content measurements were performed using a UV-Vis spectrophotometer. Test samples were in the form of fresh leaves from BBTV-infected and non-BBTV-infected plants. Regression analysis and tests for significance were performed to determine the biochemical changes that occurred after testing. The results showed that the average levels of phenols, chlorophyll, protein, and total sugars in BBTV-infected plants were significantly altered. The chlorophyll content decreased from 82–87% in Mas, Cavendish, and Raja cultivars. Total plant phenol in all BBTV-infected cultivars increased by 69.2 to 348.3 ppm. Specificity was evident in the change in protein concentration, which increased by 95 ppm and 84.5 ppm in the Mas and Cavendish cultivars, respectively. This contrasts with the Kepok and Raja cultivars, which decreased by 660.5 ppm and 113.6 ppm, respectively. Sugar levels increased from 3133.9 to 3298.6 ppm in all BBTV-infected breeds. According to the data, BBTV infection has been shown to cause physiological and biochemical changes in Mas, Cavendish, Kepok, and Raja.