Judul: Analisis Iklim dan Dinamika Populasi Hama Penggerek Batang Padi Kuning di Indramayu dengan Menggunakan Model Simulasi Dymex 3.0
Abstrak: Scirpophaga incertulas known as the Yellow rice stem borer (PBK) is one of the most attacking pests of rice plants in Indramayu region. One of the factors that influence the presence of this pest is the climatic factor, that were rainfall, maximum and minimum temperature, maximum and minimum Relative humadity. The purpose of this study was to analyze the influence of climate on the population dynamics of Yellow rice stem borer in the district of Indramayu. Life cycle model and estimation of pest populations using simulation models Dymex 3.0. Simulations were performed for four years from 2009-2012. Results of simulation models have been able to give a fairly good prediction. Model simulations also indicate that the pest population peaks occurred in the dry months with low rainfall intensity and pest population decreases as a result of high rainfall washed away by rain. This is also supported by the value of the coefficient of determination (R2) between the validation results of outcomes population of model Dymex and observations by 64%. Different climatic influences on the development and the presence of pests PBK. Temperature and rainfall are the most important factor in the progression and mortality of pest PBK
Keyword: Climate, Dymex, Scirpophaga incertulas

Judul: Pemodelan Fenologi Populasi Penggerek Batang Padi Kuning Scirpophaga incertulas (Walker) Berbasis Pengaruh Iklim
Abstrak: West Java province is the highest of rice production area in Indonesia, contributing an average of national rice production about 17.4% in 2009 to 2012. Rice production can be maintained or enhanced if we have a great capability to protect rice from pests’ infestation. In 1995, the population of rice white stem borer (WSB) Scirpophaga innotata (Walker) decreased, while the population of the rice yellow stem borer (YSB) Scirpophaga incertulas (Walker) increased to 30%. Since 1995, YSB was more dominant than WSB, with population of more than 90%. Based on the report from Directorate of Food Crop Protection, some areas in the West Java in particular of North Coastal region has a total area of high annual infestation compared to other regions, reaching ± 10 to 12 thousand ha. High infestation of YSB is suspected as a result from transition of rice varieties. Furthermore, climatic might have strong influence on population dynamics of rice stem borer. Understanding relationship between climatic factors and life cycle and population dynamics of YSB is important for long- and short term management strategies, as control measures to reduce production and economic losses. This research utilized DYMEX software and aims to develop a population dynamic model of YSB and to assess model's ability to predict abundance and population peak of YSB under climate change scenario SRES A1FI and B1. Modeling the YSB requires two major components: climate parameter and lower developmental threshold temperatures (To) to describe life cycle of YSB from the egg, larva, pupa, and adult stages. DYMEX also describe development, mortality, transfer of individuals from one to the next life stages, fecundity and reproduction of YSB. The coefficient of determination (R2) of calibration models between predictions and observations showed a strong positive correlation of 0.72. Model validation could well predict the peak population, with R2 of 0.42. The simulations showed that the trend of population peaks occur at high rainfall i.e. in March to April, July to September, and November to December. The model predicted YSB population in the Sukamandi and Pusaka Negara reaches 3 generations per year, while in Kuningan 2 generations per year. Decrease in the population will affect the number generations of YSB in the three regions. Simulation models under climate change scenarios SRES A1FI and B1 showed differences in the sensitivities. Trend of YSB population is increasing in the regions Pusaka Negara and Kuningan and decreasing in region Sukamandi. Under changing climate, environment conditions in Pusaka Negara and Kuningan become more suitable for the proliferation YSB, allowing an increase in the number of generations per year. The level of model accuracy can still be improved by exploring more variables to include interactions between YSB and host plant (paddy) and the natural predators parasitism against the YSB. This makes model becomes more complex but may reflect better condition of YSB populations in the field. Further model improvement could be facilitated by be integrating DYMEX and CLIMEX software to determine the distribution of species in relation to climatic conditions. This models integration can simulate regional risks and determine whether a site could potentially be
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Judul: Hydroxyapatite-Chitosan Composite Coating on Stainless Steel 316 to Improve Corrosion Resistance
Abstrak: Metals that were used in bone implantation should have good corrosion resistance that were not easily corroded when implanted into the body. Metal corrosion resistance of stainless steel 316 can be enhanced through the metal coating by hydroxyapatite-chitosan composite with composition ratio of hydroxyapatite (gram) and chitosan 3% (mL) 0.2:0, 0.2:0.1, 0.2:0.5, 0.2:1.0, and 0.2:1.5. Besides improving the corrosion resistance of metal, the presence of chitosan also maintain the position of hydroxyapatite on metal surfaces. Corrosion resistance increases with increasing amount of chitosan added and the best composition of hydroxyapatite-chitosan composite was 0.2:1.0.
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