Resistance of peanut varieties to phytoplasm. Recently, witches' broom disease on peanut is becoming more important in Indonesia The use of resistant varieties is very potential to overcome the yield loss caused by the disease. Ten peanut varieties were evaluated for their response to phytoplasma using insect vector transmission. Three categories of plant response were observed during the experiment, i.e. moderate resistant (var, Macan, Zebra, and Simpai), susceptible (var. Biawak, Treggiling, Pelanduk, and Kidang), very susceptible (var. Gajah, Tupai, and Banteng). The average seed weight decrease per plant due to the phytoplasma infection was 40.99 - 100%.
Soils containing sclerotia of Sclerotium rolfsii were covered with transparent plastic and exposed to sunlight in an experiment to study the effect of soil solarization on the growth of the fungi and its pathogenicity to peanut. Soil solarization for 3 to 4 weeks significantly suppressed the sclerotial germination up to 44% and reduced hyphal growth and pathogenicity of S. rolfsii placed at 0.5 cm below the soil sulfate, but did not have any gects when the sclerotia were placed at the depth of 15 cm. Among ungerminated sclerotia, 88.0 and 82.7% of them were physically damaged by 3 and 4 weeks of soil solarization, respectively. Some of the damaged sclerotia were colonized by microorganism. The most frequent colonizing microorganisms observed were Asagillus spp, Trichodenna spp., and bacteria. Increased soil temperature as direct effect of soil solarization and the role of some soil microbes might be responsible for the suppression.
Pathogenicity of two species of entomopathogenic agents to subterranean termite Coptotermes gestroi Wasmann (Isoptera: Rhinotermitidae) in laboratory. Pathogenic effcts of two species of entomopathogenic agents, Metarhizium anisopliae and Bacillus thuringiensis A ard B, were trested to subterranean termite Coptotermes gestroi Wasmann in laboratory. Three groups of rhc tcrti~ite tclor.ker:s were each e.xposed to a treated filter paper with one of the entomopathogenic agents for one minute. Twenty-five termite workers and three soldiers were then transferred to a wetfilter paper disk that had been installed in a plastic vial. The test materials were stored in a dark and humid at room temperature for 14 dc~j'.s. Five replicates were provided. Observations were conducted daily to determine termite nlortality urld take out dead termites. Reszllts showed that the fungus M. anisopliae was more pathogenic than Bt. A and B. After being exposed to treated paper with the fungus, all test termites died within 8-10 days. Treatments with B. thuringierisis A and B did not produce high mortality, and seemed to be not different from the control, only causing less than 3% termite mortality until the end of the tests.
Swietenia mahogany Jacq. (Meliaceae) seeds were extracted with methanol. In choice and no-choice leaf disc methods, the crude extract at 5% completely inhibited feeding activity of third instar larvae of the diamondback moth, Plutella xylostella (L.) (Lepidoptera: Yponomeutidae). Fractionation of the extract by combination of counter-current distribution method, silica gel column chromatography and preparative TLC yielded one fraction which strongly inhibited P. xylostella larval feeding activity by 98.3 % at a concentration of 0.2%.
Parasitization of the white rice stem bore< Scirpophaga innotata (Walker) (Lepidoptera: Pyralidae), was studied in Karawang during an outbreak in 1991/1992. The percentage of egg masses parasitized averaged 85.5%, whereas the percentage of individual eggs parasitized 44.2%. Egg masses attacked by parasitoids yielded 1 to 100 wlth arz average of 53.9 borer larvae. A mean of 56.6parasitoid wasps emerged from the parasitized egg masses. Based on the proportion of egg masses parasitized and the number of wasps emerged, the predominant parasitoid was Telenomus rowani Gahan, followed by Trichogramma japonicum Ashmead, and the least was Tetrastichus schoenobii Ferriere. The level of individual egg parasitization was 22.7% for T. japonicum 55.8% for T. rowani, and 92.1% for T. schoenobii. A mean of 66.5 borer larvae survived after attack by T. japonicum, 19.4 lawae by T. rowani, and only 0.8 larvae per egg mass by T. schoenobii. The last mentioned species was the most efJicient and efective parasitoid, and the borer outbreak was considered to be related to the low level of eggparasitization by T. schoenobii.
Parasitoid Telur pada Hama Kubis Plutella xylostella (L.) (Lepidoptera : Yponomeutidae)
Egg parasitoids of the diamonback mont, Plutella xylostella (L.) (Lepidoptera : Yponomeutidae) have never been reported in Indonesia. In this study, eggs of P.xylostella were collected from cabbage planation in Cisarua-Bogor, Ciloto-Cianjur, Cikole-Lembang (West Java), Tawangmangu (Central Java), and Malang (East Java). Three species of parasitoids were colleted from all areas, Trichogrammatoidea armigera Nagaraja emerged from eggs colledted from Cisarua-Bogor, Cikole-Lembang, and Ciloto-Cianjur, and Trichogramma flandersi Nagaraja and Nagarkatti (Hymenoptera : Trichogrammatidae) was only found from the eggs collected from Tawangmangu. The morphological character of the parasitoids are discussed
Ketahanan Beberapa Varietas Kedelai Terhadap Nematoda Puru Akar (Meloidogyne incognita)
Resistance of 19 soybean varieties to the root-knot nematode (Meloidogyne incognita) was evaluated in the green-house. One-week old seeding in a plastic bag containing 4 liters soil of Segunung Andosol type, was infested with 500 second stage juveniles (L2) per 1000 cm cubic of soil. The experiment was arranged in a completely randomiz-ed design with three replication. Based on the reproductive index of M.incognita, two varieties (Wilis and Ringgit) were moderately resistant, 14 varieties were slightly resistant and three varieties (Muria, Malabar, and Lakon) were susceptible to M.incognita. The productive index of M.incognita on the varieties that were moderately resistant, slightly, and susceptible were 12.75 - 23.65, 25.48 - 42.88, and 50.99 -58.83 % respectively
Selection of Coconut Resistance to the Nutfall Disease (Phytophthorapalmivora Butler) The objective of this research was to select the coconut resistance to nutfall phytophthora disease. Using wounding inoculation method, detachedhits of 11 coconut populations at Pakuwon Coconut Cropping Pattern Research Station were inoculated with Phytophthora palmivora Co5 isolate. Based on the dhease lesion size at seven days after inoculation, Genjah Salak (GSK) coconutpopulation was more resistant than the other coconutpopulations and showed individual resistance variation to the disease. From 238 GSK coconut trees selected, 226 (95%) trees were resistant and 12 (5%) trees were susceptible.
Morphological Variation of the Asian Honeybee Apis cerana (F.) (Hymenoptera: Apidae) in West Java. The diversity of Asian honeybee Apis cerana (F.) (Hymenoptera: Apidae) occupying low and high altitude habitats in West Java was studied using morphological analysis, based on the length of proboscis, hindleg, front wing, tergites, and sternites. All morphological characters measured were signifcantly longer in high altitude bees compareded to those of low altitude bees (p < 0.05), except proboscis. Dendogram analysis showed that bees from those two altitudes were separated, whereas the result of principal component analysis indicated that both belong to the same group (P < 0.05).
A farmer survey, to determine the way potato farmers perceived the leafininer fly and methods they employed to control the pest, was conducted in ten highland vegetable production centers in five provinces jhm June to September 1998. The total number of potato farmers interviewed was 309. The study revealed that the farmers were familiar with the leafininer as a new pest that have caused heavy damage since 3-6 years ago. However, only few farmers (5.5%) were knowledgeable that L. huidobrensis was an exotic pest. Most farmers (>75%) reported that leafininer infestation caused more than 40% yield losses, and the crops have to be harvested 2-4 weeks earlier than was the nomal practice. All respondents applied insecticides to control the leafininer twice a week. Insecticides mostly used were pyrethmids and organophosphates. Selection of pesticides was based on farmer's own experiences, other farmers experiences, and based on suggestion jhm pesticide kiosk's owners. Although insecticides were used intensively, most farmers (72%) were dissatisfied with the efficacy of control. Biological control with parasitoids may pegom satisfatorily only if it B accompanied by minimizing insecticide use.
A farmer survey, to determine the way potato farmers perceived the leafininer fly and methods they employed to control the pest, was conducted in ten highland vegetable production centers in five provinces jhm June to September 1998. The total number of potato farmers interviewed was 309. The study revealed that the farmers were familiar with the leafininer as a new pest that have caused heavy damage since 3-6 years ago. However, only few farmers (5.5%) were knowledgeable that L. huidobrensis was an exotic pest. Most farmers (&gt;75%) reported that leafininer infestation caused more than 40% yield losses, and the crops have to be harvested 2-4 weeks earlier than was the nomal practice. All respondents applied insecticides to control the leafininer twice a week. Insecticides mostly used were pyrethmids and organophosphates. Selection of pesticides was based on farmer's own experiences, other farmers experiences, and based on suggestion jhm pesticide kiosk's owners. Although insecticides were used intensively, most farmers (72%) were dissatisfied with the efficacy of control. Biological control with parasitoids may pegom satisfatorily only if it B accompanied by minimizing insecticide use.
Geminivirus infecting pepper: symptom variation and transmission study Infection of geminiviruses has been reported to cause signz3cantyield loss on various crops. Polymerase chain reaction was able to detect geminivirus infection on pepper samples around Bogor and Cipanas, West Java. Symptom variation and transmission of the geminivirus infectingpepper was studied using five solanaceae plants with three dzgerent transmission mannec i.e. mechanical inoculation, side grafirng, and insect vector. The transmission study showed that mechanical inoculation was not able to transmit the eminivirus, while side grafting and insect vector, Bemisia tabaci, caused infection with symptoms varies from yellow mosaic, leaf curl leaf distortion, to stunting of the plant. Higher infection was observed on pepper var. Hot Chilli through B. tabaci (8009) and side grafting (71.4%) than those on chilli pepper and tomato. DNA fiagment of - 1.7 kb was amplified wing PCRfim those plants showing symptoms, but no DNA fiagment was observedfrom symptomless eggplant and tobacco var. White Burley. Thus it can be concluded that the last two kina3 ofplants were resistant to the geminivirus infectingpepper.
Critical Period of Tomato toAlternariasokuri (Ell. & G. Martin) Sor. infection and its determinant. Determination of critical period (susceptible period) of plant is one of the strategies in Integrated Pest Management (LPM), because it can reduce or minimize pesticide use. Study about the critical penendo of tomato was cam'ed out in the field of Bangbayang village, in the Cicwug district of Sukubumi. Tomato plant cultivar Zntan at dzremnt age (50, 60, 70 and 80 &ys after sowing [DAS] were inoculated with 15 ml of Id s p o ~ l suspension of Alternaria solani per plant, that have been added with Agristick 2% and llveen 80 2%. Observation that was conducted include disease severity, the height of plant, dry weight of plant biomass and total Jiuit production. Leaves of diferent age (50, 60, 70, 80 DAS) at d@rent part of plant (lower, middle and upper canopy) were analyzedfor totalprotein by Auto Analyzer ZZMethod, totalphenol by Follin- Denis Method and total sugar content by L u ~ h o o rMl ethod. The result showed that the older plant have the higher disease severity. The same trend can be seenjkm the age of leaves i.e. leaves fLom the lower part ofplants (olakr) am more susceptible than the middle and upper leaves. The critical period of the plant is at the age of 50 - 60 DAS. TotalJiuit production is not determined by disease severity, instead it is more determined by the age of plant infected. l%em is a tendency that the interaction among total protein and phenol content efect the susceptibility of the plant to the pathogen as can be seen the following regression equation: Y = 167 - 3.1 9 X2 - 22.58 X3 (R= 0.76).
Critical Period of Tomato toAlternariasokuri (Ell. &amp; G. Martin) Sor. infection and its determinant. Determination of critical period (susceptible period) of plant is one of the strategies in Integrated Pest Management (LPM), because it can reduce or minimize pesticide use. Study about the critical penendo of tomato was cam'ed out in the field of Bangbayang village, in the Cicwug district of Sukubumi. Tomato plant cultivar Zntan at dzremnt age (50, 60, 70 and 80 &amp;ys after sowing [DAS] were inoculated with 15 ml of Id s p o ~ l suspension of Alternaria solani per plant, that have been added with Agristick 2% and llveen 80 2%. Observation that was conducted include disease severity, the height of plant, dry weight of plant biomass and total Jiuit production. Leaves of diferent age (50, 60, 70, 80 DAS) at d@rent part of plant (lower, middle and upper canopy) were analyzedfor totalprotein by Auto Analyzer ZZMethod, totalphenol by Follin- Denis Method and total sugar content by L u ~ h o o rMl ethod. The result showed that the older plant have the higher disease severity. The same trend can be seenjkm the age of leaves i.e. leaves fLom the lower part ofplants (olakr) am more susceptible than the middle and upper leaves. The critical period of the plant is at the age of 50 - 60 DAS. TotalJiuit production is not determined by disease severity, instead it is more determined by the age of plant infected. l%em is a tendency that the interaction among total protein and phenol content efect the susceptibility of the plant to the pathogen as can be seen the following regression equation: Y = 167 - 3.1 9 X2 - 22.58 X3 (R= 0.76).
Pratylenchus brachyurus (Godh) Filipjev. & Stekhoven is one of the importantplantparasitic nematodes that attacked root of patchouli and the causal of mot necrosis, growth retardation, reddish or yellowish leaf: A greenhouse study was conducted to evaluate the level of resistant of six patchouli cultivars, those were wide planted in Sumatera against P. brachyurus, and to determine the effect of population level of the nematodes on three dzrerent resistance patchouli. Six patchouli cultivars were inoculated with 200 nematodes& soil. Based on reproduction index the cultivar of Seulimum Putih, Pidie and Sidikalang known as susceptible ones Tapaktuan and Seulimum Merah was moderate resistant and Girilaya was resistant. Furthermore, the effect of population levels of P. brachyurus (0, 100, 200 and 800 nematodes& soil) on three patchouli cultivars showed that 200 nematodeskg soil population caused significant effect on reduced shoot and weight root and plant height on susceptible cultivars, howevec on the moderat resistant and resistant cultivar the signifcance effect occurred at 800 nematodeslkg soil. The reproduction factors on three patchouli cultivars were decreased with the increased of population nematodes level. me oil and chlorophyll content have been decreased on the infectedpatchouli cultivars atfive month afCer inoculation.
Biological and molecular variability among PStV (peanut stripe virus) strains isolated from various peanut growing areas in Indonesia was studied based on their pathogenicity and coat protein genes. Six strains of PStV causing different types of symptoms on peanut leaves were used to study biological and molecular variability among these strains. Biological variability of the PStV strains was evaluated based on their pathogenicity on peanut cultivars, Gajah and Landak. While analysis of the coat protein gene was used to study the molecular variability of PStV strains. Based on their pathogenicity, six PStV strains could be grouped into three groups, medium, strong, and very strong strains. Analysis of a coat protein gene showed the variability of the PStV strains were 0-2.1percent based on nucleotide sequence and 0-1.4percent based on predicted amino acid sequence. There was no correlation between biological and molecular variability.
It has been known that phytoplasma inducing witches broom disease can infect various kind of leguminous plants in Indonesia, among others soybean. Information on the resistance of various kind of soybean varieties to the phytoplasma is still limited. Experiments were conducted to eveluate the resistance of ten soybean varieties/lines to the phytoplasma. The evaluation was carried out by inoculation method through Orosius argentatus Evans, with two days of acquisition feeding period, ten days latent period and two days inoculation feeding period. Observation was conducted on the presence of phytoplasma, incubation period, symptom and number & weight of seed. The result indicated that line Malang 3474 was resistant, Sindiro and Sriono were tolerant, while the other tested varieties/lines, i.e. Galunggung, Orba, Ringgit, Wilis, Malang 2999, Malang 2805 and Sicinang were susceptible
The research was conducted in sub-district of Ciledug (Cirebon) with the objectives to study the infexiation and larvaal population development id onion armyworm. Spodoptera exigua (Habner) (Lepidoptera: Noctuidae), on shallots grown in lowland. Monitoring of egg masses and leaf damage were made at 3-4 days internal while of larvae at 1 week internal. Outbreak took place during the dry season of August-October 1995 when population density reached 0.8 egg mass and 23 larvae per hill, and subsequently all hills were heavily damaged. Throughout the rainy season of December 1995-February 1996, egg masses and larvae were difficult to find. Result of hand-picking showed that larval population during dry season was 78 times higher than those of rainy season. Larvae exhibited body color vartations. During the epidemics 80 percent of the larvae were dark whereas,during the endemics only 10 percent, the rest were light green. Level of egg parasitization was 0,9 percent coused by Tricogramma xp. (Hymenoptera; Trichogrammatidae) and telenomus sp. (hy menoptera; sceltonidae ), and larval parasitization 5.7 percent coused by Microplitis sp. (Hymenoptera; Braconidae), Euplectrus sp. and stenomesius sp (Hymeno[tera; Eulophidae), and Peribaea sp. (Diptera; Tachinidae). Low level of parasitization together with the abundance of food supply and dry season were believed to be the main foctors contributing to the population outbreaks. Hand-picking of egg masses and larvae conducted regularly, as practiced by the farmer group in the village of Dukuh wringin (Brebes(, should be adopted as a key activity for mitigating S. exigua infestation during dry season; and therefore, this practice should disseminated to farmers in other areas.
Laboratory and greenhouse experiments were carried out during April-October 1996 to investigate the response of three soybean varieties to the combined infestation ofMeloidogyne incognita (Kofoid & White) Chitwood and three root-gall nematode colonizing fungi (MCF). The experiments were done in a factorial completely randomized design with three replications. Treatments in laboratory test were combination of three soybean varieties, i.e. Black soybean (VI)' Wilis (V z) and Lokon (V,J, two initial population densities of M. incognita, i.e. 0 and 300/200 ml growth medium, and three MCF species, i.e. Paecilomyces sp., Gliocladium catenulatum, and Trichoderma viride. The greenhouse treatments were the combination of three soybean varieties (Vb V2, V3), three initial population densities ofM. incognita (0, 1000, and 2000/4 I growth medium), and three MCF species. Result of laboratory tests showed that the combination ofM. incognita and three MCF species significantly reduced the damage levelofM. incognita and root weight loss. Reduction of shoot weight loss occurred only in slightly resistant and susceptible varieties in combination with PaeciIomyces sp. and G. catenulatum. Combination ofT. viride and M. incognita on three soybean varieties showed synergistic interaction. Result of greenhouse tests showed that all of the MCF isolates significantly reduced the damage level and the final population ofM. incognita. However, only Paecilomyces sp. could reduce the root weight loss, relative plant growth rate, and harvested seeds. These reducing effects were achieved on Lokon variety only, that is susceptible to M. incognita. There was no synergistic interaction between M. incognita and T. viride in the greenhouse test, even though the root colonization frequency of Trichoderma sp. on the susceptible variety was rather high.
Laboratory and greenhouse experiments were carried out during April-October 1996 to investigate the response of three soybean varieties to the combined infestation ofMeloidogyne incognita (Kofoid &amp; White) Chitwood and three root-gall nematode colonizing fungi (MCF). The experiments were done in a factorial completely randomized design with three replications. Treatments in laboratory test were combination of three soybean varieties, i.e. Black soybean (VI)' Wilis (V z) and Lokon (V,J, two initial population densities of M. incognita, i.e. 0 and 300/200 ml growth medium, and three MCF species, i.e. Paecilomyces sp., Gliocladium catenulatum, and Trichoderma viride. The greenhouse treatments were the combination of three soybean varieties (Vb V2, V3), three initial population densities ofM. incognita (0, 1000, and 2000/4 I growth medium), and three MCF species. Result of laboratory tests showed that the combination ofM. incognita and three MCF species significantly reduced the damage levelofM. incognita and root weight loss. Reduction of shoot weight loss occurred only in slightly resistant and susceptible varieties in combination with PaeciIomyces sp. and G. catenulatum. Combination ofT. viride and M. incognita on three soybean varieties showed synergistic interaction. Result of greenhouse tests showed that all of the MCF isolates significantly reduced the damage level and the final population ofM. incognita. However, only Paecilomyces sp. could reduce the root weight loss, relative plant growth rate, and harvested seeds. These reducing effects were achieved on Lokon variety only, that is susceptible to M. incognita. There was no synergistic interaction between M. incognita and T. viride in the greenhouse test, even though the root colonization frequency of Trichoderma sp. on the susceptible variety was rather high.
A survey on the· occurrence of downy mildew and fusarium wilt on melon was conducted in Bogor and Sukabumi regions, from May 1983 to December 1984, which comprise of one wet season and one dry season. The areas surveyed were melon plantations in the districts of Cisarua, Cipayung, Ciawi, Caringin (Bogor region) and Parungkuda(Sukabumi region). The two diseases are considered as an important factor in melon production, because it could cause heavy losses. It was found that all farmer in the areas surveyed planted the same variety, Sky Rocket 221, which was imported from Taiwan. The average infection intensities of downy mildew in the areas surveyed were not significantly different in both seasons, i.e., 24.56% in the wet season and 20.40% in the dry season. However, the average infection intensity of fusarium wilt was higher in the dry season (6.47%) than in the wet season (0.58%). The possible causes of the infection differences are discussed.
The tidal swamp lands in Indonesia are potential areas for increasing food production especially rice. About 250.000 hectares of the swampy areas in suamtra and Kalimantan have been developed for rice production. Tidal swamp land has many interconnecting natural habitats wgich are economically and scientifically important. Agronomic activities in rice fields might have detrimental effects on other habitats. Therefore, agrochemicals especially pesticides for pest control, have to be carefully applied based on sound ecological approach. A Kind of pest management model is presented which consits of compatible combination of cultural control, use of resistant varieties, sanitation, and chemical control with environmentally least toxic pesticides if it is needed base on pest population count.
TKV-0 was identifled as the causal agent of a disease of Aranda Wendy Scott in Jakarta. Bioasssay showed that the virus prduced 10-1 lesirms m Cassia occidentalis, Chenopodium amzranticolor, Gornphrena ~l obosa , and Nicotiana glutinoaa . Observation of the "dig methoda preparation of diseaaed plant sap under the electron microscope indicated that the virus particles were rod-shaped and right with a length of about 300 mm.
A number of legume species were inoculated with Phakopsora pachyrhizi Syd. the causal agent of soybean rust. The species showing rust symptom were Pachyrhizus erosus, Crotalaria juncea, Glycine max var. si Nyonya, Vigna unguiculata, Phaseolus vulgaris (green bean), P. radiatus (mung bean), P. aureus, Psophocarpus tetragonolobus, Vigna umbellata and Calopogonium mucunoides.
Mycorrhizae are symbiotic structure developed by the roots of plants and fungal mycelia. These mycorrhizae are often necessary for the growth of forest trees. This study was undertaken to determine the effect of the application of nitrogen and phosporus on the development of mycorrhizae in pinus merkusii. Andosol, collected in puncak, and latosol, collected in Darmaga, were used in this experiment. A seedling, transplanted into a pot containing 490 gr of dried soil, served as an experimental unit. Nitrogen ((NH4)2SO4) was applied at o ppm, 60 ppm, 120 ppm,
Penyakit Daun Phyllosticta dan Penyakit Layu pada Cengkeh di Daerah Lampung
Sejak tahun 1977 di Kecamatan Pekalongan, Kabupaten Lampung Tengah telah timbul penyakit daun pada cengkeh yang cukup mengkhawatirkan, karena dapat mengakibatkan gugur daun dan tanaman mati sebelum waktunya. Penyakit ini pernah ditemukan juga di Bengkulu dan Bogor. Di desa Atarlebar, Kecamatan Wonosobo, Kabupaten Lampung Selatan, lebih kurang 80% dari 106.000 pohon cengkeh telah mati akibat penyakit layu. Hasil pemeriksaan di lapang dan di laboratorium menunjukkan bahwa Phyllosticta sp. selalu berasosiasi dengan bercak-bercak pada daun cengkeh di Pekalongan, sedangkan bakteri Pseudomonas solanacearum ditemukan pada akar tanaman sakit di Atarlebar. Penyakit layu yang sama ditemukan pula di SumateraBarat dan di Bogor