Judul: Allelopathic Potential of Asystasia gangetica (L.) T.  Anderson from Various Populations on the Growth and Production of Sweet Corn (Zea mays L.)
Abstrak: Asystasia gangetica L. (T.) Anderson merupakan gulma invasif pada lahan perkebunan yang menghasilkan senyawa alelopati. Pengaruh senyawa alelopati A. gangetica terhadap pertumbuhan dan produksi tanaman kelapa sawit menghasilkan masih belum banyak dilaporkan. Penelitian bertujuan mempelajari potensi senyawa alelopati gulma A. gangetica dari berbagai populasi terhadap pertumbuhan dan produksi tanaman uji jagung manis. Penelitian dilakukan pada Maret hingga September 2022 di Agribusiness and Technology Park IPB. Penelitian menggunakan Rancangan Kelompok Lengkap Teracak (RKLT) dengan enam perlakuan dan empat ulangan. Perlakuan yang diuji yaitu populasi gulma A. gangetica 0, 1, 2, 4, 8, dan 16 individu per pot. Satuan percobaan berupa pot berukuran 25 cm – 19 cm (diameter – tinggi) dengan isi media 3 kg. Biji gulma diperoleh dari Kebun Percobaan Leuwikopo IPB. Biji A. gangetica ditanam di pot dan pada umur dua bulan setelah tanam dipotong setinggi 5 cm dari permukaan media. Benih jagung manis ditanam satu minggu setelah pemotongan gulma A. gangetica. Hasil penelitian menunjukkan bahwa perlakuan 16 populasi gulma A. gangetica menekan pertumbuhan jagung manis meliputi tinggi tanaman, panjang daun, lebar daun, jumlah daun, diameter batang, kehijauan warna daun, bobot per tongkol berkelobot dan tanpa kelobot, diameter tongkol, serta derajat kemanisan. Perlakuan populasi gulma A. gangetica tidak mempengaruhi indeks luas daun, panjang tongkol, bobot kering biomassa, bobot kering tajuk dan bobot kering akar saat panen. Populasi gulma A. gangetica yang semakin tinggi terbukti menghasilkan senyawa alelopati yang lebih banyak sehingga menekan pertumbuhan vegetatif dan hasil panen tanaman uji jagung manis.
Keyword: indole-3-carboxaldehyde, secondary metabolites, suppression, weeds

Judul: Allelopathic Potential of Asystasia gangetica (L.) T. Anderson at Various Populations in Suppressing the Growth and Production of Mustard Greens (Brassica juncea L.)
Abstrak: Asystasia gangetica (L.) T. Anderson direkomendasikan sebagai tumbuhan penutup tanah pada tanaman kelapa sawit menghasilkan, namun memiliki senyawa alelopati yang berpotensi menghambat pertumbuhan tanaman. Penelitian bertujuan mengetahui potensi alelopati gulma A. gangetica pada berbagai populasi terhadap pertumbuhan dan produksi caisim. Tanaman caisim digunakan sebagai tanaman uji. Penelitian dilakukan pada Maret hingga Juli 2022 di Agribusiness and Technology Park, IPB. Penelitian ini menggunakan rancangan acak kelompok (RAK) dengan 6 perlakuan dan 4 ulangan. Perlakuan yang diuji yaitu populasi A. gangetica 0, 1, 2, 4, 8, 16 individu per pot. Satuan percobaan berupa pot berukuran 20 cm – 13 cm (diameter – tinggi) dengan isi media tanam 2 kg. Biji A. gangetica ditanam di pot dan pada umur 2 bulan setelah tanaman dipotong setinggi 5 cm dari permukaan media. Caisim ditanam satu minggu setelah pemotongan gulma A. gangetica. Hasil penelitian menunjukkan bahwa perlakuan populasi 1 sampai 16 gulma A. gangetica per pot menekan pertumbuhan vegetatif tanaman caisim. Produksi segar, produksi kering, bobot basah akar, dan bobot kering akar pada perlakuan populasi 16 gulma A. gangetica berturut-turut berkurang sebesar 54,9%, 55,5%, 60,5% dan 54,2% terhadap kontrol. Perlakuan populasi gulma A. gangetica tidak mempengaruhi warna dan kandungan klorofil daun saat panen., Asystasia gangetica (L.) T. Anderson is recommended as a ground cover for mature oil palms, but has allelopathic compounds that have the potential to inhibit plant growth. The aim of the research was to study allelopathic potential of A. gangetica in various populations on the growth and production of mustard greens. Mustard greens was used as a test plant. The research was conducted from March to July 2022 at the Agribusiness and Technology Park, IPB. This study used a randomized complete block design (RCBD) with 6 treatments and 4 replications. The tested treatment i.e. A. gangetica 0, 1, 2, 4, 8, 16 individuals per pot. The experimental unit was a pot measured 20 cm – 13 cm (diameter – height) with 2 kg of media content. A. gangetica seeds were planted in pots and at the age of 2 months after the plants were cut to a height of 5 cm from the surface of the media. Mustard greens was planted one week after A. gangetica was cut. The results showed that the treatment of populations of 1 to 16 A. gangetica per pot suppressed the vegetative growth of mustard greens. Production fresh weight, production dry weight, root fresh weight, and root dry weight in the treatment population of 16 of A. gangetica reduced by 54.9%, 55.5%, 60.5% and 54.2% respectively, compared with control. The A. gangetica populations treatment did not affect the color and chlorophyll content of the leaves at harvest.
Keyword: competition, HPLC, indole-3-carboxaldehyde, secondary metabolites

Judul: Persamaan Korteweg-de Vries Orde Tinggi untuk Menggambarkan Gerak Gelombang Internal
Abstrak: The ocean can be considered of layers of fluid that each layer has a constant density. Internal waves are waves occur in the interface of every'two layers with different density. Because it occures underneath the surface of the ocean, it is invisible. One of internal waves is internal solitary waves. One of formulation that can describe intemal waves movement is KdV equation. KdV equation is derived from governing equations of ideal fluid in Lagrange formulation using asymptotic method. On this thesis, KdV equation is derived in higher order and then its solution is derived by using internal solitary waves assumption. An example of a two-layer fluid is a case will be used. By using Mathematica6 software, for this case will be obtained the coefficients in lower and higher order explicitly and the corresponding between coefficients and relative lower layer depths and fluid depths, the corresponding between coefficients and relative densities, and also observed the different between solitary waves in lower and higher order.
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