Introduction: Maize downy mildew (MDM) is considered as a major problem in all maize growing areas in Indonesia including the Province of Lampung. Objectives: The objectives of this study were (i) to identify the species of Peronosclerospora causing maize downy mildew (MDM) in Lampung, (ii) to determine the influence of varieties on the intensity of downy mildew and (iii) to determine the efficacy of metalaxyl to control MDM on some maize varieties. Methodology: To identify Peronosclerospora causing MDM, the pathogens were observed under light microscope and scanning electron microscope. Maize varieties response against pathogens and efficacy metalaxyl were studied in the field with the test plants exposed to plants showing MDM symptoms as the sources of inocula to mimic natural conditions. Results: Peronosclerospora sorghi, P. maydis, and P. philippinensis were found to cause MDM in Lampung. On both varieties Pioneer 27 (P-27) and NK-22, AUDPC on F1 plants was greater than that on F2 plants. On P-27, the production of F2 was higher than that of F1 plants, but there was not significant difference in production between F1 and F2 of NK-22 variety. Seed treatment using metalaxyl was not effective to control downy mildew of maize. Conclusion: Three species of Peronosclerospora were identified as disease-causing pathogen of MDM in Lampung, but these results were tentatively pending for further studies through molecular techniques. F1 plants were more susceptible than F2 plants to MDM in both P-27 and NK-22. Metalaxyl was not effective in controlling MDM.

Epidemic Components of Sugarcane Root and Basal Stem Rot In South Sumatra Root and basal stem rot disease is one of new disease that currently was became a emerging problem on sugarcane plantations in Lampung and South Sumatra. The research was aimed to study the model of disease progression, AUDPC, infection rate (r), and the influence of weather and soil condition (physical and chemical properties of soil) on the development of sugarcane root and basal stem rot disease. The research was conducted on sugar cane plantation in South Sumatra. The disease incidence in three varieties was observed weekly in the field which had infected plant in previous year.. The data were analyzed to develop model of the disease progression, AUDPC, and the rate of root and basal stem rot disease. Weekly weather data was acquired from weather station of Sultan Mahmud Badaruddin Airport, Palembang. Soil sample was taken from three disease category i.e moderate (disease incidence 25,1% - 50%), severe (disease incidence 50,1% - 75%), and healthy (no disease). The results showed that the disease develops following monomolecular and logistic models. The AUPDC and infection rate (r) in the monomolecular model were lower than in the logistic model. The direct effect coefficient of rainfall and relative humidity (RH) on the disease were positive (1.27 and 0.46 respectively), contrary the temperature and duration of irradiation which had a negative coefficient (-0.33 and -0.45 respectively). Meanwhile, K availability and permeability give a positive effect on the disease, while the total N and Fe availability give a negative effect on the disease.

Salah satu penyebab rendahnya produksi kedelai nasional adalah adanya serangan penyebab penyakit rebah kecambah. Pengendalian yang dapat dilakukan adalah dengan menggunakan agen antagonis. Penelitian ini bertujuan mengetahui kemampuan Trichoderma sp. dan filtratnya dalam menekan pertumbuhan Sclerotium rolfsii secara in vitro. Pengujian terdiri atas uji antagonisme dengan metode kultur ganda dan uji filtrat Trichoderma sp. terhadap pertumbuhan S. rolfsii. Percobaan disusun dalam Rancangan Acak Lengkap (RAL) dengan lima ulangan. Data yang diperoleh dianalisis dengan sidik ragam dan dilanjutkan dengan uji BNT pada taraf nyata 5%. Hasil penelitian menunjukkan bahwa Trichoderma sp. dan filtratnya mampu menekan pertumbuhan S. rolfsii secara in vitro. Isolat Trichoderma sp. yang kemampuan penghambatannya paling tinggi adalah isolat Trichoderma harzianum.

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