Waktu Pemencaran dan Pengaruh Jenis Air terhadap Perkecambahan Basidiospora Exobasidium Vexans, Penyebab Penyakit Cacar Daun Teh

Blister blight caused by Exobasidium vexans is one of the important diseases in the tea crop. This disease could decrease the production of tea between 20−90%, so that it required a proper and eco-friendly strategy for managing the development of plant disease epidemics. This study was aimed to determine the daily dispersal time of basidiospores of E. vexans, and to study the effect of dew, rain water, and sterile water to the germination of basidiospores of E. vexans. The method used was trapping basidiospores using a spore trap Kiyosawa type on which the object glasses were successively placed for 4 hours at 6:00 a.m., 10:00 a.m., 2:00 p.m., 6:00 p.m., 10.00 p.m., and 2.00 a.m.. The germination of basidiospores was observed with three treatments; i.e. sterile water, rain water and dew. The results revealed that the dispersal of basidiospores of E. vexans mostly occured between 2:00 to 6:00 a.m. Basidiospores of E. vexans could germinate in all kinds of water, but they germinated very well in dew and rain water.IntisariPenyakit cacar daun teh yang disebabkan oleh Exobasidium vexans merupakan salah satu penyakit penting pada tanaman teh. Penyakit ini dapat menurunkan produksi teh antara 20−90%, sehingga perlu ada strategi yang tepat dan dapat diterima lingkungan untuk mengelola perkembangan epideminya. Penelitian ini bertujuan untuk mengetahui waktu pemencaran harian basidiospora E. vexans, dan mengetahui pengaruh embun, air hujan, dan air steril terhadap perkecambahan basidiospora E. vexans. Metode yang digunakan adalah penangkapan basidiospora menggunakan alat spore trap tipe kiyosawa yang dipasang gelas benda pada setiap 4 jam sekali, yaitu pada pukul 06.00, 10.00, 14.00, 18.00, 22.00, dan 02.00. Metode yang dipakai dalam mengamati perkecambahan basidiospora menggunakan tiga perlakuan; embun, air hujan, dan air steril. Hasil penelitian menunjukkan bahwa pemencaran basidiospora E. vexans paling banyak terjadi antara pukul 02.00−06.00. Basidiospora E. vexans dapat berkecambah pada embun, air hujan, dan air steril namun perkecambahan paling baik terjadi pada embun dan air hujan

Identification of the Causal Agent of Cocoa Pod Rot Disease From Various Locations

Cacao (Theboroma cacao L.) is an important estate commodity in Indonesia with high economic value. The interference of cocoa pod rot disease which was affected by Phytophthora palmivora Butl. resulted in the reduction of the quantity and quality of cocoa beans, with losses up to 44%. This research was aimed to figure out the variation in morphology of P. palmivora isolates from cacao. The research was carried out by collecting samples of cocoa pod with rot symptoms in several cacao growing areas in Java, then the pathogen was isolated and cultured on Potato Dextrose Agar (PDA) medium. The observation was performed on morphological characteristics of isolates macroscopically (colony shape) and microscopically (size of sporangium and chlamydospores). All tested isolates showed various colony shape such as stellate, cottony and irregular as well as sporangium varying from obpyriform, globose, ellipsoid, ovoid and distorted with various size between 30.8×21.9–65.5×46.5 µm in range.IntisariKakao (Theboroma cacao L.) merupakan komoditas perkebunan unggulan di Indonesia dengan nilai ekonomi tinggi. Gangguan penyakit busuk buah kakao yang disebabkan oleh Phytophthora palmivora Butl. mengakibatkan penurunan kuantitas dan kualitas biji kakao, dengan kerugian mencapai 44%. Penelitian ini bertujuan untuk mengetahui variasi morfologi isolat P. palmivora asal kakao. Penelitian dilakukan dengan mengambil sampel buah kakao bergejala busuk buah di beberapa area perkebunan kakao di Jawa, kemudian patogen diisolasi dan dikulturkan pada media Potato Dextrose Agar (PDA). Pengamatan dilakukan terhadap karakteristik morfologi isolat secara makroskopis (bentuk koloni) dan mikroskopis (ukuran sporangium dan klamidospora). Semua isolat yang diuji menunjukkan bentuk koloni seperti stellate, cottony, dan irregular serta sporangium yang bervariasi dari obpyriform, globose, ellipsoid, ovoid, dan distorted dengan ukuran bervariasi antara 30,8×21,9−65,5×46,5 µm

Pola Agihan dan Intensitas Penyakit Busuk Pangkal Batang Lada di Provinsi Sulawesi Tenggara

The success of foot rot disease control is largely dependent on information data of pepper cultivation conditions, distribution pattern of the disease, and the magnitude of the intensity of the disease. This study aimed to determine the condition of pepper cultivation, distribution pattern of pepper foot rot disease, the development of disease symptoms, and intensity of pepper foot rot disease in Southeast Sulawesi. Data cultivation conditions, distribution of the disease, progression of symptoms, and the intensity of the disease were obtained by means of surveys in pepper plantations and interviews with pepper farmers. The results showed that the pepper plantations in Southeast Sulawesi were cultivated on flat to hilly topography, and the cultivation method was very conventional but herbicide use was very intensive. The development of wilt symptoms on pepper plants was very quick in dry weather but slow in the wet. Pepper foot rot disease has patch distribution. The highest intensity of the pepper foot rot disease was in less weedy plantations with intensive use of herbicides. The intensity of the pepper foot rot disease in Southeast Sulawesi was 61,2% with the spread in each district namely South Konawe at 53,8%, Konawe at 63,7% and Kolaka by 61,2%

Deteksi Dan Penghitungan Kerapatan Inokulum Phytophthora Capsici Dalam Tanah Dengan Menggunakan Umpan Daun Lada

Phytophthora capsiciis a causal agent for footrot disease in pepper and classified as a soil-borne pathogen. The inoculums of P. capsici in the soilis difficultto detect. The dynamics of P. capsici population in the soil is frequently and rapidly fluctuates and hard to detect, causing the pathogen to produce disease rapidly. The aimsof this research were todetect the pathogen P.capsici using black pepper leaf baiting and to quantify the inoculum of the pathogen P.capsici in the soil belonging to several disease intensities of the black pepper foot rot in the field. The first experiment: detecting the pathogen P. capsici using black pepper leaf baiting in the soil artificially infested using several sporangia, anda second experiment: quantification of propagul of the P.capsici in various categories of intensity on the black pepper foot rot disease in the field. The research results showed that the black pepper leaf baiting could be used to detect the existence of the propagul of P.capsiciin the soil artificially infested in various densities of sporangia. The increase in disease intensity occurred in parallel with the greater density of P. capsici inocula in soil. The density of P. capsici inocula in the soil tended to decline when the disease intensity reached the highest level

The Roles of Arbuscular Mycorrhizal Fungi in the Intensity of the Foot Rot Disease on Pepper Plant From the Infected Soil

Pepper (Piper nigrum L.) is an important spice plant of Indonesia. In Bangka Belitung Province, the main pepper producer, pepper has been the most commonly cultivated commodity. However, the production has declined from time to time. One of the causes of the decline is Pepper Fot Rot, caused by Phytophthora capsici. The rapid spread and development of the disease is mainly due to utilization of diseased plant materials for pepper cuttings and infested or diseased plantation soil. The materials used in this research included the infected soil taken from the infectedpepper plantation at Bangka Island with disease intensity of pepper foot rot 60%, inoculum of Arbuscular Mycorrhizal fungi in the zeolite medium, compost, and pepper seedling from Natar variety. This research was done by planting pepper seedling on infected soil and observing plant height, disease intensity, and infection of AM fungi on the roots. The results showed that soil from diseased pepper plants harbored high population of plant pathogens inoculum and caused the death of 9 week-old cuttings and retarded growth of the survivors. Sterilization of the infected soil with hot water vapor for 3 hours still could not control the pathogen. Good growth was observed on one node cutting planted in sterile soil amended with arbuscular mycorrhizal fungi

Utilization of Arbuscular Micorrhizal Fungi to Control Fusarium Wilt of Tomatoes

Tomato is a vegetable crop which is preferred by the Indonesian people. The problem encountered in tomato production is Fusarium wilt which is known as devastating disease. Studies have been done to solve the problem but effective and inexpensive control technique is still questioned. This study aimed to ascertain the ability of Arbuscular Mycorrhizal (AM) fungi as biological control agent in reducing tomato Fusarium wilt. Research was arranged in a completely randomized design (CRD) consisting of 5 treatments and 10 replications. The treatments were untreated plants, Fusarium oxysporum f.sp. lycopersici inoculated plants, AM fungi inoculated plants, AM fungi + F. oxysporum f.sp. lycopersici inoculated plants, F. oxysporum f.sp. lycopersici + benomyl inoculated plants. The results showed that plants which were inoculated with AM fungi had better growth compared to those which were not inoculated with AM fungi. Moreover, plants which were inoculated with AM fungi showed lower disease intensity compared to untreated plant and inoculated plant with F. oxysporum f.sp. lycopersici + benomyl application. Orthogonal contrast analysis showed plants treated with AM fungi significantly perform better growth and resistance towards infection compared with other treatments. Thus, it concluded that AM fungi had the potency as biological control agent. INTISARITomat merupakan tanaman sayuran yang banyak digemari masyarakat Indonesia. Salah satu pengganggu utama pada tomat adalah penyakit layu Fusarium yang disebabkan oleh Fusarium oxysporum f.sp. lycopersici dan menimbulkan masalah yang serius. Kerugian yang ditimbulkan oleh penyakit tersebut sangat besar sehingga perlu dicari cara pengendalian yang murah, efektif, dan aman. Penelitian yang bertujuan untuk mengetahui kemampuan jamur mikoriza arbuskular (JMA) sebagai agens pengendali hayati dalam menekan penyakit layu Fusarium pada tomat ini dilakukan dengan Rancangan Acak Lengkap (RAL) yang terdiri atas 5 perlakuan dan 10 ulangan. Perlakuan meliputi kontrol, inokulasi F. oxysporum f.sp. lycopersici, inokulasi JMA, inokulasi JMA dan F. oxysporum f.sp. lycopersici, inokulasi F. oxysporum f.sp. lycopersici dan aplikasi fungisida benomil. Hasil penelitian menunjukkan bahwa tomat yang diinokulasi JMA memiliki pertumbuhan yang lebih baik dibandingkan yang tidak diinokulasi JMA. Intensitas penyakit pada tomat yang diinokulasi JMA lebih rendah, baik dibandingkan dengan kontrol maupun dengan perlakuan F. oxysporum f.sp. lycopersici dan aplikasi fungisida. Hasil analisis kontras orthogonal menunjukkan bahwa tomat bermikoriza berbeda nyata bila dibandingkan dengan yang tidak diinokulasi JMA maupun yang diaplikasi benomil. Terjadi peningkatan pertumbuhan tomat dan penekanan intensitas penyakit layu Fusarium, sehingga JMA berpotensi sebagai agens pengendali hayati (APH)

Epidemi Penyakit Busuk Pangkal Batang Lada Pada Kondisi Lingkungan Yang Bervariasi

Foot rot disease epidemic on black pepper in variety of environmental conditions. The foot rot disease on black pepper caused by Phytophthora capsici Leonian, is often destructive to farmers of black pepper. This research aims to study the infection rate and the pattern of development of the black pepper foot rot disease in various condition of the environment. The research was conducted in the areas of black pepper cultivation in the Ultisol and Entisol soils. In each location plots were set with few (75%) weeds. Variable observed was disease incidence. The data were used to analyze model of development of the black pepper foot rot disease and infection rate. Results of the research showed that the model of development of the black pepper foot rot disease was not affected by soil type, but the type of soil affected the infection rate. At the pepper plantation with abundance of weeds, the disease development followes Gompertz model. At the plantation with few weeds, however the disease developed in a logistic model. The rate of disease infection on the black pepper plant with abundant weeds lower compared with those with few weeds