PEMANFAATAN LIMBAH SAGU SEBAGAI PENGENDALIAN GULMA PADA LADA PERDU

ABSTRAK<br />Limbah sagu di samping dapat dimanfaatkan sebagai sumber bahan<br />organik juga potensial digunakan sebagai amelioran dan herbisida nabati.<br />Penelitian bertujuan untuk mengetahui pengaruh limbah sagu dan cara<br />penyiangan gulma terhadap populasi gulma dan pertumbuhan lada<br />perdu. Penelitian dilaksanakan di Kebun Percobaan (KP) Institut Pertanian<br />Bogor (IPB) dan Laboratorium Balai Penelitian Tanaman Obat dan<br />Aromatik Balittro) dari bulan Mei 2003 sampai April 2004. Penelitian<br />menggunakan rancangan petak terbagi yang disusun secara faktorial. Cara<br />penyiangan gulma (S) sebagai petak utama dan komposisi limbah sagu<br />(L) sebagai anak petak. Susunan perlakuan sebagai berikut: S 1 =<br />penyiangan bersih dan S 2 = penyiangan terbatas. Komposisi limbah<br />sagu terdiri dari L 0 = tanpa bahan organik; L 1 = 100% limbah sagu, L 2<br />= 100% limbah sagu, dekomposisi 1 bulan, L 3 = 100% limbah sagu<br />dekomposisi 2 bulan; L 4 = 75% limbah sagu + 25% kompos; L 5 = 75%<br />limbah sagu + 25% kompos, dekomposisi 1 bulan; L 6 = 75% limbah<br />sagu + 25% kompos, dekomposisi 2 bulan; L 7 = 50% limbah sagu +<br />50% kompos; L 8 = 50% limbah sagu + 50% kompos, dekomposisi 1<br />bulan; L 9 = 50% limbah sagu + 50% kompos, dekomposisi 2 bulan;<br />L 10 = 25% limbah sagu + 75% kompos; L 11 = 25% limbah sagu + 75%<br />kompos, dekomposisi 1 bulan; dan L 12 = 25% limbah sagu + 75%<br />kompos, dekomposisi 2 bulan. Hasil penelitian menunjukkan bahwa<br />kandungan limbah sagu 75% limbah sagu + 25% kompos dekomposisi<br />2 bulan meningkatkan pertumbuhan dan produktivitas lada perdu.<br />Limbah sagu dengan 100% dalam bentuk segar dan dekomposisi<br />sampai 2 bulan efektif dalam menekan populasi gulma.<br />Kata kunci: Limbah sagu, gulma, lada perdu<br />ABSTRACT<br />The use of sago palm waste in controlling weed on<br />dwarf pepper<br />Sago palm waste can be used as a source of organic matter;<br />in addition, it can also be used as ameliorant and natural<br />herbicide. The objective of the research was to find out the<br />effect of sago palm waste and weeding method on the growth of<br />dwarf pepper and weed population. The research was conducted<br />at the experimental garden of the Bogor Agriculture Institute and<br />the Indonesian Medicinal and Aromatic Crops Research Institute<br />from May 2003 to April 2004. The research was arranged<br />factorially in split-plot design. The main plot was weeding<br />methods (S) and a composition of sago palm waste (L) as the sub<br />plot. The treatments were as follows: S 1 = clean weeding and S 2<br />= limited weeding. The composition of sago waste were Lo =<br />non organic matter; L 1 = 100% sago waste; L 2 = 100% sago<br />waste of one month decomposition; L 3 = 100% sago waste of two<br />months decomposition ; L 4 = 75% sago waste + 25% compost; L 5<br />= 75% sago waste + 25% compost of one month decomposition;<br />L 6 = 75% sago waste + 25% compost of two months<br />decomposition; L 7 = 50% sago waste + 50% compost; L 8 = 50%<br />sago waste 50% compost of one month decomposition; L 9 = 50%<br />sago waste + 50% compost of 2 months decomposition; L 10 =<br />25% sago waste + 75% compost’ L 11 = 25% sago waste + 75%<br />compost of one month decomposition; and L 12 = 25% sago waste<br />+ 75% compost of two months decomposition. The result showed<br />that the composition of 75% sago waste + 25% compost of two<br />months decomposition increase the growth and productivity of<br />dwarf pepper. The fresh (75 - 100%) sago palm waste of one<br />month decomposition was effective in decreasing weed<br />population.<br />Key words : Sago palm waste, weed, bushy black pepper

On the Temperature Stability of NaI(T1) Scintillators

ABSTRACTThe temperature stability of NaI(T1) scintillators is studied for crystals with various Tl+ impurity content. It is shown that supersaturation of the T1+ ions and regulation of solid solution decomposition increase the light output at elevated temperatures. An explanation of this phenomenon is proposed.

Synthesis of 3(2-haloethyl)aryltriazenes and study of their reactions in aqueous solution

Several 1-aryl-3-(2-haloethyl)triazenes have been synthesized and characterized spectroscopically as well as by their esterification of 3,5-dinitrobenzoic acid. Their rates of decomposition in aqueous media at pH7 were determined polarographically employing the electrochemically active triazene moiety. In two selected cases the rates of decomposition increase markedly with lowered pH in the range 9.3 to 4.65. The products of aqueous decomposition, both volatile and involatile, were identified and quantitated by gc and gc–ms. Discrimination between alternative decomposition pathways was possible by the preparation and use of selectively deuterated triazenes. The data are consistent with initial protonation of the triazene and generation therefrom of a 2-haloethyl cation (or its kinetic equivalent) which is subject to rearrangements detected by deuterium scrambling. A second competing pathway involves cyclization of the triazene to a 1-aryl-1,2,3-triazoline intermediate which is then subject to nucleophilic opening at two sites with attendant loss of nitrogen. The effects of structural changes in the triazenes on their modes of decomposition and generation of electrophiles should assist in the interpretation of their antitumor effects.

The thermal decomposition of t-alkyl N-arylcarbamates. I. The effect of ring substituents

A series of t-butyl N-arylcarbamates in which the aryl group is a phenyl or a meta- or para-substituted phenyl ring has been prepared. Decomposition of these compounds in diphenyl ether at 177.5 °C has shown that the reaction is essentially first order, yielding carbon dioxide, isobutylene, and the corresponding amine. The rates of decomposition increase with increasing electronegativity of the substituent on the aromatic nucleus, and give a Hammett plot with a slope of 0.54. A cyclic mechanism is proposed for the decomposition reaction.

THERMAL DECOMPOSITION OF MOLECULAR COMPLEXES: IV. FURTHER STUDIES OF THE β-QUINOL CLATHRATES

The endothermal decomposition of 18 β-quinol clathrates has been studied by thermo-analysis, calorimetry, and X-ray diffraction, and the decomposition process shown to be[Formula: see text]For those symmetrical guest molecules (M) which do not distort the β-quinol cavities from their normal dimensions, both temperatures and enthalpies of clathrate decomposition increase with increasing volume of the guest molecule. For those unsymmetrical guest species which require distortion of the cavities along their c-axis, temperatures and enthalpies of decomposition tend to decrease as the initial distortion required to accommodate the guest increases. Thermal stability of β-quinol clathrates is thus strongly influenced both by the size and shape of the guest molecule.The mechanism of thermal decomposition is suggested to involve a combination of the loss of stabilizing guest–wall interactions, together with increased thermal motion of the interpenetrating networks of hydrogen-bonded quinol molecules.