Judul: The effect of soil conditioner application and watering interval on water stress resistance and sunflower (Helianthus annuus L.) growth in Regosol Dramaga
Abstrak: Aplikasi Super Absorbent Polymers (SAPs) dapat meningkatkan retensi air dan nutrisi sehingga dapat mengurangi frekuensi air irigasi dan meningkatkan kemampuan tumbuh tanaman. Penelitian ini bertujuan mengetahui pengaruh aplikasi jenis soil conditioner dan interval penyiraman terhadap pertumbuhan tanaman bunga matahari, ketahanan tanaman terhadap cekaman air, dan sifat kimia tanah (N, P, K, Basa-basa), serta mengetahui kombinasi jenis soil conditioner dan interval penyiraman yang optimal untuk pertumbuhan bunga matahari pada Regosol Dramaga. Percobaan disusun menggunakan Rancangan Acak Lengkap faktorial dengan dua faktor, yaitu jenis soil conditioner yang terdiri: dari kontrol (H0), soil conditioner Terracottem (H1), dan hidrogel superabsorben sintesis (H2); interval penyiraman yang terdiri dari: penyiraman 5 hari sekali (P1), penyiraman 10 hari sekali (P2), dan penyiraman 15 hari sekali (P3). Bibit bunga matahari genotipe IPB BM1 berumur dua minggu dipindahkan bersamaan dengan aplikasi soil conditioner ke dalam polibag berisi tanah setara 10 kg BKM. Variabel yang diamati berupa kadar air tanah, pertumbuhan tinggi tanaman, jumlah daun, luas daun, jumlah dan diameter bunga, diameter batang, bobot kering, dan panjang akar. Analisis tanah setelah panen dilakukan dengan mengukur kadar N-total, P-tersedia, Kdd, Cadd, Nadd, dan Mgdd. Hasil percobaan menunjukkan bahwa perlakuan tunggal H1 memiliki kandungan P-tersedia, Kdd, tinggi tanaman, jumlah daun, bobot kering, panjang akar, kadar air dan retensi air yang lebih tinggi dibandingkan H0. Perlakuan tunggal H2 memiliki kandungan P-tersedia, Cadd, Mgdd, tinggi tanaman, diameter batang, panjang akar, kadar air dan retensi air yang lebih tinggi dibandingkan H0. Perlakuan tunggal interval penyiraman menunjukkan kenaikan interval penyiraman berbanding lurus dengan kenaikan P-tersedia setelah panen, penurunan tinggi tanaman, jumlah daun, diameter batang, bobot kering, dan kadar air tanah. Kombinasi soil conditioner H1 dengan interval penyiraman P1 menjadi kombinasi paling optimal untuk meningkatkan hara dan mendukung pertumbuhan tanaman bunga matahari pada Regosol Dramaga., The application of Super Absorbent Polymers (SAPs) can be used to increase water and nutrient retention of soil, so it can reduce the frequency of irrigation and increase plant growth. This study aims to determine the effect of soil conditioner applications and watering intervals on the growth of sunflower plants, plant resistance to water stress, and soil chemical properties (N, P, K, basa-basa), and knowing optimal combination of soil conditioner and watering interval for sunflower growth on Regosol Dramaga. Experiment design used was completely randomized design consisted of two factors, i.e type of soil conditioner that were: without soil conditioner (H0), Terracottem soil conditioner (H1), and synthetic superabsorbent; watering interval that were: watering every 5 days (P1), watering every 10 days (P2), and watering every 15 days (P3). Sunflower seed of IPB BM1 genotype that are two weeks old were transferred together with the application of soil conditioner into polybag containing soil equivalent 10 kg BKM . The observed variabels consist of water content, growth of plant height, number of leaves, leaf area, number of flowers, diameter of flowers, stem diameter, dry weight, and root lenght. Analysis of soil chemical properties after harvest was carried out by measuring the levels of total N, available P, Kdd, Cadd, Nadd, and Mgdd. The results of the experiment showed that treatment H1 contained higher P-available, Kdd, plant
Keyword: soil conditioner, water holding capacity, water stress

Judul: The Effect of Hydrogel Application and Watering Interval on Growth of Sweet Corn Plan on Quartz Sand Planting Media
Abstrak: Pasir merupakan salah satu media tumbuh tanaman yang memiliki kemampuan menahan air rendah, kapasitas tukar kation rendah dan kandungan unsur-unsur hara yang rendah hingga sangat rendah. Salah satu alternatif agar media tanam pasir dapat menyediakan air dalam jangka waktu tertentu adalah dengan menggunakan bahan pembenah tanah berupa hidrogel. Hidrogel dikenal sebagai zat yang dapat memperbaiki sifat fisik dan mampu menyediakan air secara perlahan untuk tanaman. Tujuan penelitian ini adalah mengetahui pengaruh aplikasi hidrogel dan interval penyiraman terhadap pertumbuhan tanaman jagung dan ketersediaan air pada media tanam pasir kuarsa. Percobaan dilakukan di rumah kaca menggunakan Rancangan Acak Lengkap (RAL) dua faktorial. Faktor pertama adalah aplikasi hidrogel dengan 4 taraf perlakuan, yaitu: tanpa hidrogel, 10 g hidrogel/5 kg pasir, 20 g hidrogel/5 kg pasir dan 40 g hidrogel/5 kg pasir. Faktor kedua adalah interval penyiraman dengan 3 taraf perlakuan, yaitu: penyiraman dengan interval 5 hari sekali, 10 hari sekali dan 15 hari sekali. Jagung digunakan sebagai tanaman uji. Parameter yang diamati berupa tinggi tanaman, jumlah daun, bobot basah dan bobot kering tanaman, bobot basah dan bobot kering akar, panjang akar, air tersedia dan hara pada pasir setelah tanam. Hasil penelitian menunjukkan penggunaan hidrogel memberikan pengaruh positif dan nyata terhadap pertumbuhan tanaman jagung dan air tersedia pasir kuarsa. Tinggi tanaman, jumlah daun, bobot basah dan bobot kering tanaman, bobot basah dan bobot kering akar serta panjang akar menunjukkan nilai yang paling tinggi pada dosis hidrogel 20 g dan 40 g hidrogel/5 kg pasir. Air tersedia setelah tanam paling tinggi terdapat pada perlakuan 40 g hidrogel/5 kg pasir. Interval penyiraman yang optimal untuk pertumbuhan tanaman jagung yaitu penyiraman 5 hari sekali dan 10 hari sekali., Sand is one of the plants growing media that has low capability to retain water, low cation exchange capacity and low to very low nutrient content. One alternative in order to provide water availability for certain period of time is to use hydrogels. Hydrogel is substance that can improve soil physical properties and is able to provide water to plants slowly. The purpose of this study was to determine the effect of hydrogel application and watering intervals on corn plant growth and water availability in quartz sand planting media. The experiment was conducted in a greenhouse using a two-factorial Completely Randomized Design (CRD). The first factor is the application of hydrogel with 4 levels of treatment, namely: without hydrogel, 10 g/kg of sand, 20 g/5 kg of sand and 40 g/5 kg of sand. The second factor is the watering interval with 3 levels of treatment, namely: watering at intervals of once every 5 days, once every 10 days and once every 15 days. Corn is used as a test crop. The observed parameters were plant height, number of leaves, fresh and dry weight of the plant, fresh and dry weight of roots, length of roots, moisture and nutrient content in the sand. The results showed that the use of hydrogel had a positive and noticeable influence on the growth of corn plants and the moisture content of quartz sand. Plant height, number of leaves, fresh and dry weight of the
Keyword: Hidrogel, Jagung, Pasir, Penyiraman, Corn, Hydrogel, Sand, Watering

Judul: Posisi Filogenetik Kura-Kura Carettochelys Insculpta  (Reptillia: Testudinata)
Abstrak: Carettochelys insculpta is an endemic freshwater turtle of southern Papua and northern Australia. Phylogenetic position of this turtle is remain unresolved until now. Most of the research conducted show close relationships of C. insculpta and members of Trionychidae family. However, some of the research show distance between C. insculpta and members of Trionychidae family. This research is conducted to analyze phylogenetic relationship between C. insculpta and other members of Testudinata using 12S rRNA, 16S rRNA, and both gene as markers. DNA samples were obtained from three different organisms of C. insculpta. Two species used as outgroups were Alligator mississippiensis and Iguana iguana. Phylogenetic analysis was carried out using Neighbor-Joining method with Felsenstein 1981 (F81) modeltest. A polytomy tree of Testudinata was produced by using 12S rRNA gene. However, analysis using 16S rRNA and both genes as markers confirmed that C. insculpta was located between the Chelonidae and the Trionychidae family.
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