Judul: Potential Utilization of Hydrolyzed Pineapple Waste Solution as Bioherbicide in Pineapple Plant Cultivation at PT. Great Giant Pineapple, Lampung
Abstrak: Nanas merupakan buah yang cukup diminati masyarakat Indonesia. Tingkat budidaya nanas di Indonesia sudah cukup tinggi. Nanas kebanyakan hanya diambil buahnya sehingga menyisakan limbah berupa kulit dan bonggol dalam jumlah yang cukup besar apabila tidak diolah dan dimanfaatkan secara bijak. Hambatan yang cukup beragam juga membuat produksi nanas menurun. Salah satu hambatan dari budidaya nanas adalah gulma. Gulma mampu menyerap nutrisi yang diberikan ke nanas sehingga mengganggu produktivitas dari tanaman nanas. Bioherbisida dari olahan limbah nanas menjadi salah satu alternatif dalam mengendalikan gulma di budidaya nanas dengan mengusung konsep perusahaan dapat menghemat biaya untuk pembelian herbisida sintetik dan mensubtitusikan dosisnya dengan bioherbisida dari limbah produksi perusahaan. Penelitian ini dilakukan dengan tujuan menguji potensi dari limbah nanas menjadi subtitusi herbisida sintetik yang digunakan oleh perusahaan. Percobaan dilakukan sebanyak 2 kali berupa tahap screening dan aplikasi lahan. Metode yang dilaksanakan adalah dengan mencampurkan herbisida sintetik (Diuron 80WP dan Ametryn 80WP) sebagai herbisida standar perusahaan dengan bioherbisida (Hidrolisat 300 dan Hidrolisat 250) buatan IPB serta asap cair dari limbah nanas yang diolah oleh perusahaan. Hasil pengamatan menunjukan bahwa subtitusi herbisida sintetik dapat menekan pertumbuhan gulma pada fase pre-emergence dan memberikan toksisitas tinggi pada beberapa jenis gulma pada fase early post-emergence, namun pada aplikasi lahan tidak terlalu terlihat dampak herbisida terhadap penekanan gulma maupun toksisitasnya terhadap tanaman nanas. Kata kunci : bioherbisida, gulma, herbisida sintetik, hemat biaya, Pineapple is a fruit that is quite popular in Indonesia. The level of pineapple cultivation in Indonesia is quite high. Most pineapples are only taken as fruit, leaving a large amount of waste in the form of skin and stump if not processed and utilized wisely. Various obstacles also cause pineapple production to decline. One of the obstacles to pineapple cultivation is weeds. Weeds are able to absorb nutrients given to pineapples, thus disrupting the productivity of pineapple plants. Bioherbicide from processed pineapple waste is one alternative in controlling weeds in pineapple cultivation by carrying out the concept that companies can save costs for the purchase of synthetic herbicides and substitute the dose with bioherbicides from company production waste.. This study was conducted with the aim of testing the potential of pineapple waste to be a substitute for synthetic herbicides used by companies. The experiment was conducted twice in the form of screening and land application stages. The method implemented was by mixing synthetic herbicides (Diuron 80WP and Ametryn 80WP) as the company's standard herbicides with bioherbicides (Hydrolysate 300 and Hydrolysate 250) made by IPB and liquid smoke from pineapple waste processed by the company. Observations showed that the substitution of synthetic herbicides can suppress weed growth in the pre-emergence phase and provide high toxicity to several types of weeds in the early post-emergence phase, but in land application the impact of herbicides on weed suppression and toxicity to pineapple plants is not very visible. Keywords: bioherbicide, weeds, synthetic herbicides, cost-effective.
Keyword: bioherbicide, weeds, synthetic herbicides, cost-effective

Judul: Improvement of Soil Chemical Properties and Pineapple Plant Growth by Ultilizing Bromelain Waste Fiber and Chopped Bamboo
Abstrak: Permasalahan yang dihadapi oleh PT Great Giant Pineapple pada lahan 88C2 dalam budidaya nanas adalah terjadinya pemadatan tanah (soil compaction) dan rendahnya sifat kimia tanah. Limbah ekstraksi bromelain dan cacahan bambu merupakan bahan organik yang mengandung lignin tinggi sehingga diharapkan akan mempunyai residence time yang lebih panjang. Bahan ini diharapkan dapat memberikan pengaruh terhadap kimia tanah di lapangan sehingga dapat meningkatkan pertumbuhan akar nanas yang selanjutnya dapat meningkatkan produksi nanas. Penelitian ini merupakan percobaan faktorial dua faktor (petak utama) yang ditempatkan dalam rancangan petak terpisah (split plot). Faktor pertama jenis bahan organik organik terdiri dari dua taraf: limbah ekstraksi ekstraksi bromelain dan bambu cacah, merupakan petak utama, faktor kedua dosis bahan organik terdiri dari lima taraf: 0, 20, 40, 60, dan 80 ton ha-1 dan merupakan anak petak. Data diolah dengan menggunakan aplikasi minitab dan parameter yang berpengaruh nyata diolah lebih lanjut dengan Duncan Multiple Range Test (DMRT.) Parameter yang diamati adalah sifat kimia tanah, kadar hara tanaman, dan pertumbuhan vegetatif tanaman. Hasil percobaan menunjukkan bahwa kondisi kesuburan tanah awal rendah. Setelah aplikasi, bahan organik berpengaruh nyata terhadap pH H2O, C-Organik, Fe tersedia, Zn tersedia, Al-dd dan KTK, sedangkan dosis bahan organik berpengaruh nyata terhadap P tersedia. Bahan organik berpengaruh nyata terhadap kadar hara P, namun tingkat kecukupan hara N dan Ca masih rendah. Jenis bahan organik berpengaruh nyata terhadap lebar daun dan indeks tanaman. Dosis bahan organik berpengaruh nyata terhadap lebar daun dan indeks tanaman., The problem faced by PT Great Giant Pineapple's in 88C2 land in pineapple cultivation is soil compaction and low soil chemical properties. Bromelain extraction waste and chopped bamboo are organic materials that contain high lignin so they are expected to have a longer residence time. This material is expected to have an influence on improving the chemical properties of the soil in the field so that it can increase the growth of pineapple root which can further increase pineapple production. This study is a two-factor factorial experiment (main plot) placed in a split plot design. The first factor of the type of organic organic matter consists of two levels: bromelain extraction waste fiber and chopped bamboo, is the main plot, the second factor is the dose of organic matter consists of five levels: 0, 20, 40, 60, and 80 tons of ha-1 and is a child plot. The data was processed with variance analysis and the parameters of real effect were further processed with the Duncan Multiple Range Test (DMRT.) The observed parameters are the chemical properties of the soil, the nutrient content of plants, and the vegetative growth of plants. The results of the experiment showed that the conditions of early soil fertility were low. After application, organic matter has a marked effect on pH H2O, C-Organic, Fe available, Zn available, exchangeable Al and KTK, while the dose of organic matter has a noticeable effect on P available. Organic matter has a significant effect on P nutrient levels, but the level of adequacy of N and Ca nutrients is still low. This type of organic matter has a noticeable effect on the width of the
Keyword: Pineapple, Bromelain, Bamboo

Judul: Penentuan Nilai Eigen dan Vektor Eigen dari Matriks Tridiagonal 2-Toeplitz dengan Pendekatan Polinomial Chebyshev
Abstrak: The eigenvalues and eigenvectors of a matrix can be determined by finding its characteristic polynomials. The characteristic polynomials of a tridiagonal 2-Toeplitz matrix is shown to be closely connected to polynomials which satisfy the Chebyshev recurrence relationship. If the order of the matrix is odd, then the eigenvalues are found explicitly in terms of the Chebyshev zeros and the eigenvectors are found in terms of the polynomials satisfying the recurrence relationship. For even ordered matrices, the situation is more complicated. The problem in these cases is that although the Chebyshev recurrence formula is still applied, its initial values are not generating Chebyshev polynomials
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