Retno Peni Sancayaningsih

Systemic inducing resistance against late blight by applying antagonist Trichoderma Viride

Biological control by Phytophthora infestans (Mont.) de Bary, a pathogen causing late blight disease on potatoes, has attracted scholars as an environmentally alternative preference to chemical pesticide. Some species of Trichoderma spp. has proven to be capable of triggering resistance mechanism of plant against fungal pathogens. The aim of this research was to analyze the effect of Trichoderma viride SP1 suspension to induced systemic resistance on potato plant as showing glucanase activity and total phenol content. The method used was Completely Randomized Design with six treatments and seven times repeated. Variables observed were total phenol content and total crop. The result showed that glucanase activity and total phenol content in plants treated with Trichoderma viride and fungicide (1587 μg/g and 1934 μg/g) significantly increased. In addition, T. viride enhanced induced systemic resistance on potato plant and increased potato yield.

Sasi : Traditional Conservation to Protect Population of Mangrove Crabs ( Scylla serrata (Forskal, 1775)) in Mangrove Area of Leksula Village of Buru Selatan District, Indonesia

Excessively high frequency of mangrove crabs (Scylla serrata) catching activity caused the decrease in their natural population. The study aimed at investigating the population structure and estimation of the catching result of crabs in the sasi and non-sasi mangroves in Leksula village. The observed crabs were caught using traditional crab catching tool called bubu. The data included the number of crabs by sex, carapace length, and body weight, and physicochemical parameter of air, substrate, and litter were measured. The results of the study showed that the substrate texture in the sasi location was clay-sandy and clay with high carbon and organic matter contents, while the substrate texture in the non-sasi location was sandy and sandy-clay with low carbon and organic matter contents. The population structure of the crabs in the sasi location was dominated by the subadult crabs. There were 63.1% of the crabs caught which are immature. The carapace length of the male crabs was in the range of 52.2 mm to 116.7 mm, while the female crabs were in the range of 34.2–114.6 mm. The growth pattern of the crabs in the sasi location was positive allometric. The male-female ratio was 1:1.06. The population structure of the crabs in the non-sasi could not be analyzed because of limited data. The estimation of the crab catching result in the sasi location was 1.85 crabs/trip and in the non-sasi location was 0.08 crabs/trip. The implementation of the sasi resulted in better crab catching result.