Judul: Pengaruh Pupuk Nitrogen dan Jarak Tanam terhadap Pertumbuhan dan Produksi Talas Belitung (Xanthosoma sagittifolium (L.) Schott)
Abstrak: Talas belitung (Xanthosoma sagittifolium (L.) Schott) memiliki potensi untuk dikembangkan sebagai sumber karbohidrat selain beras. Penelitian ini bertujuan mengetahui dosis pupuk nitrogen dan jarak tanam terbaik untuk budi daya talas belitung. Percobaan dilaksanakan di Kebun Percobaan Cikabayan Dramaga, Bogor pada bulan Februari hingga Juni 2016 menggunakan rancangan split plot RKLT dua faktor (jarak tanam sebagai petak utama dan dosis pupuk nitrogen sebagai anak petak) dengan tiga ulangan. Berdasarkan hasil pengamatan dan analisa data, jarak tanam 1 m x 1 m menunjukkan hasil lebih baik terhadap peubah daya tumbuh, jumlah daun hijau, jumlah umbi per tanaman, serta bobot basah umbi per tanaman talas belitung. Perlakuan pupuk nitrogen 100 kg urea ha-1 menunjukkan hasil lebih baik terhadap peubah jumlah daun hijau, tinggi tanaman serta diameter batang talas belitung. Interaksi perlakuan pupuk nitrogen dan jarak tanam tidak memberikan pengaruh nyata terhadap pertumbuhan dan produksi talas belitung
Keyword: jarak tanam, pupuk nitrogen, split plot

Judul: Pengaruh Jarak Tanam dan Dosis Pupuk Kalium Terhadap Pertumbuhan dan Produksi Talas Belitung (Xanthosoma sagittifolium (L.)).
Abstrak: Jarak tanam dan dosis pupuk kalium yang tepat sangat penting diperhatikan dalam budidaya talas belitung. Penelitian ini bertujuan untuk mengetahui pengaruh jarak tanam dan dosis pupuk kalium terhadap pertumbuhan dan produksi talas belitung. Penelitian dilaksanakan di Kebun Percobaan Cikabayan Atas, Departemen Agronomi dan Hortikultura, Institut Pertanian Bogor, pada bulan Februari sampai Agustus 2016 dengan rancangan split plot RKLT tiga ulangan. Faktor pertama adalah jarak tanam yang terdiri dari 2 taraf (J1= 1 m x 1 m ; J2= 1 m x 0,5 m) dan faktor kedua adalah dosis pupuk kalium yang terdiri dari 2 taraf (K1= 100 kg ha-1 KCL ; K2= 150 kg ha-1 KCL). Jarak tanam 1 m x 1 m merupakan jarak tanam terbaik untuk pertumbuhan dan produksi talas belitung. Dosis pupuk 150 kg KCL ha-1 merupakan dosis pupuk terbaik untuk pertumbuhan dan produksi talas belitung. Interaksi perlakuan jarak tanam 1 m x 1 m dan dosis pupuk 100 kg ha-1 KCL merupakan interaksi terbaik, walaupun hanya untuk pertumbuhan talas belitung.
Keyword: Jarak tanam, pertumbuhan, pupuk kalium, produksi, talas belitung

Judul: Categorization in Macaca fascicularis.
Abstrak: Categorization is an ability to group individuals or events into different classes mediated by conceptualized mental images. There are several levels of categorization and within a taxonomy the levels are nested. At the most concrete level of categorization, all or most members of the category shared common physical attributes that differ from other categories. The higher the level of category, the fewer common attributes between members of the group. In addition to humans, the ability to categorize has also been proposed in animals. One example of categorization in animal is species discrimination. Using matching-tosample task, present experiment tested ability of the long-tailed macaque (Macaca fascicularis) in discriminating dichotomous-stimuli of different animals. The species has been shown to be able to see photos as representations of real object so I used facial photos of humans and animals for the stimuli. First, I tested their ability to classify humans and macaques into separate group. Second, I tested their ability to discriminate their conspecific from other macaques. And the last, I tested whether the subjects were able to discriminate non-human animals from humans. In all of these experiments I found that the subjects showed high performance in categorizing objects, even when I discarded details of visual informations, such as color and local shapes. The ability to identify objects with reduced representation of physical properties means the subjects were able to generalize attributes of members of the group. This would indicate that the subjects created a higher level abstraction. On the other hand, in discriminating intrageneric macaque species I found that they were able to extract uniqueness of each species. More over, I also found that the subjects were able to put photos of non-human animals that shared very few similarities in physical percepts into one group. I suggested that the subjects could create a more abstract concept based on non-percepts relations as a basis to put the objects into one category. Thus, I concluded that M. fascicularis were able to perform multiple levels of categorizations.
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