The purpose of review is to determine the benefits and mechanisms of secondary metabolites from weed, the advantages and disadvantages of natural pesticides from weed, identification of secondary metabolites from weed, procedures for making natural pesticides from weeds, and policy implications of natural pesticides from weed in controlling plant pests. The results of review showed that the potency of secondary metabolites from weeds can be multiple as natural pesticides. The advantages of natural pesticides from weeds included: (1) secondary metabolites from weeds that are organic and not toxic, (2) weeds are easily obtained from the field and do not require expensive costs, (3) several mechanisms of secondary metabolites from weed not found in the mechanism of synthetic pesticides, (4) weeds have more than one secondary metabolite of with multiple benefits in controlling pests, (5) does not cause toxication in crops, (6) can be combined with integrated pest control, (7) can be applied in an individual scale and farmer groups, and (8) do not cause pests, bacteria, nematodes, fungi, and other pests to become resistant. The weed phytochemical screening is needed to make precise pest controlling. Policies that carried out in the application of natural pesticides from weeds are: farmers are expected to extract and apply pesticides from weeds, and Ministry of Agriculture collaborates with university or research institutions in secondary metabolites from weed testing, and forming farmer groups to producing and creating patent of natural pesticides from weeds.Keywords: Natural pesticides • Secondary metabolite • Weed.Sari. Tujuan kajian ilmiah ini adalah untuk mengetahui manfaat dan mekanisme metabolit sekunder gulma, kelebihan dan kekurangan pestisida nabati gulma, identifikasi metabolit sekunder gulma, prosedur pembuatan pestisida nabati dari gulma, dan implikasi kebijakan dari pestisida nabati gulma dalam mengendalikan organisme pengganggu tanaman. Hasil kajian menunjukkan potensi senyawa metabolit sekunder dari gulma dapat berfungsi ganda sebagai pestisida nabati. Kelebihan pestisida nabati dari gulma antara lain: (1) metabolit sekunder gulma bersifat organik dan tidak bersifat racun, (2) gulma yang digunakan mudah diperoleh dari lapangan dan tidak membutuhkan biaya yang mahal, (3) beberapa mekanisme metabolit sekunder gulma tidak ditemui dalam mekanisme kerja pestisida sintetis, (4) memiliki lebih dari satu metabolit sekunder setiap spesies gulma yang manfaatnya ganda dalam mengendalikan OPT, (5) tidak menimbulkan keracunan pada tanaman budidaya, (6) dapat dikombinasi dengan pengendalian hama terpadu, (7) dapat diterapkan dalam skala perorangan maupun kelompok tani, dan (8) tidak menyebabkan hama, bakteri, nematoda, jamur dan OPT lainnya menjadi resisten. Pengujian skrining fitokimia dari gulma diperlukan agar tepat sasaran dalam mengendalikan OPT. Kebijakan yang dilakukan dalam penerapan pestisida nabati dari gulma, antara lain: petani diharapkan dapat mengekstrak dan mengaplikasikan metabolit sekunder gulma, ser...

<p>Secondary metabolites from <em>Mikania micrantha</em> could be expected to control barnyardgrass (<em>Echinochloa crus-galli</em>) characteristics and have an effect on lowland rice. This research was aimed to screening of secondary metabolites in <em>M. micrantha</em> extract, obtaining the greater extract concentration in suppressing the barnyardgrass growth, and determine the impact on the lowland rice characteristics. This method used was Randomized Completely Block Design in non-factorial within the concentration rates of <em>M. micrantha</em> extract using ethanol 96% (0%; 20%; 40%; 60%; 80%; 100%, and herbicide 2,4-D dimethylamine at the dose of 1 l ha^-1 as a comparison). Lowland rice and barnyardgrass characteristics were analyzed using F-test and followed by DMRT at 5% with SPSS software. The result showed that <em>M. micrantha</em> had secondary metabolites include alkaloids, flavonoids, and tannins. The concentration at 20 to 100% significantly decreased the fresh- and dry-weight of barnyardgrass with the highest suppressing found in 60% concentration by 65.91% and 67.92%, respectively compared to un-sprayed. The concentrations at 20% and 60% were classified as inhibiting the growth biomass of barnyardgrass. The concentrations at 20%, 60%, and 80% can still encourage the tillers growth of lowland rice. An extract concentration of <em>M. micrantha</em> at 20% can be applied to inhibit the growth of barnyardgrass biomass and stimulate the lowland rice tillers.</p>

This study aimed to identify the optimum rice stem cutting size combined with the application of Seprint liquid organic fertilizer (SLOF) to promote the growth and yield of ratoon rice. This research was conducted in a greenhouse at the Faculty of Agriculture, University of Muhammadiyah Sumatera Utara, North Sumatra Province, Indonesia, from January to August 2018. The experiment was set up as a completely randomized design factorial with four replications. The first factor consisted of the cutting sizes of the rice stem (R1 = 5 cm, R2 = 10 cm, and R3 = 15 cm) and the second factor involved the SLOF dosage (S1 = 5 mL L −1 , S2 = 10 mL L −1 , and S3 = 15 mL L −1 ). The parameters were analyzed using analysis of variance (ANOVA), and the means were determined by Duncan’s multiple range test (DMRT). The results showed that the R2 treatment significantly increased the ratoon rice height at 10 to 30 days after cutting (DAC), the number of tillers at 40 to 60 DAC, the number of productive tillers, and the yield per hectare. The S2 and S3 applications at significantly increased the yield per hill and ratoon rice height at 20 DAC. The R2S1 and R2S2 combination treatments significantly increased the number of filled grains per panicle and the ratoon rice height at 10 DAC. Cutting the stems at 10 cm combined with various dosages of SLOF resulted in greater growth and yield of ratoon rice for achieving an adequate food supply.

Eleusine indica population at oil palm estate in the Asahan Regency has never been reported to being resistant to glyphosate and paraquat. This research was aimed to the resistance classification of E. indica population to glyphosate from one of oil palm estate in the Asahan Regency and to find out of glyphosateresistant Eleusine (GRE) biotype has been also resistant to paraquat. This research was conducted on Weed Research Center Land, Faculty of Agriculture, Universitas Sumatera Utara, Medan from September 2017 until May 2018. Single resistance evaluation of E. indica population was performed using glyphosate at the dose 720 g a.i.ha-1. However the multiple resistance of GRE biotype was performed using paraquat at rates of 0, 50, 100, 200, and 400 g a.i.ha-1 and glyphosate at rates of 0, 720, 1440, 2880, and 5760 g a.i.ha-1. Susceptible-population (ESU-0) was taken at ball field of Politeknik Negeri Medan (Medan City) as a comparison. The data were analyzed by ANOVA and followed by Duncan test at level 5% using IBM SPSS Statistics software. The results showed that E. indica populations from one of oil palm estate in the Asahan Regency had survival of 81.48% (classified as glyphosate-resistant) and the dry weight of 24.35 g. Glyphosate at the dose 2880 g a.i.ha-1 and paraquat at the dose 200 g a.i.ha-1 were effectively (100%) controlled survival, tillers.pot-1 , fresh weight.pot-1 , dry weight.pot-1 and mortality of GRE biotype. The resistance index value of GRE biotype to glyphosate and paraquat of 4.91-and 1.26-fold, respectively compared to susceptible plants.

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