Tanaman padi membutuhkan silika lebih banyak dari pada tanaman lainnya, sementara lahan pertanian di Indonesia banyak yang mengalami leaching unsur hara mikro termasuk Si.Unsur hara Si untuk tanaman padi selama ini hanya didapat dari keberadaannya di lahan sawah dan tidak dilakukan penambahan dari luar, hal ini menyebabkan ketersediaan Si akan terus berkurang dari waktu ke waktu, untuk mengatasi hal tersebut perlu dilakukan pemupukan silika. Penggunaaan pupuk silika dalam bentuk nano lebih menguntungkan bagi tanaman karena lebih reaktif, distribusi lebih merata dan langsung mencapai target, serta hanya dibutuhkan dalam jumlah sedikit. Penelitian ini bertujuan menganalisis pengaruh pemberian pupuk nanosilika terhadap jumlah stomata,kandungan klorofil dan pertumbuhan padi hitam (Oryza sativa L. cv.  Japonica). Penelitian ini dilakukan menggunakan Rancangan Acak Lengkap (RAL) satu faktor, yaitu konsentasi pupuk nanosilika dengan lima taraf perlakuan:0 ml/L; 2,5 ml/L; 5 ml/L; 7,5 ml/L; 10 ml/L.Data yang diperoleh dianalisis menggunakanAnalisys of Variance (ANOVA) dan dilanjutkan dengan uji jarak berganda Duncan’s Multiple Range Test(DMRT) pada taraf kepercayaan 95%. Hasil penelitian menunjukkan bahwa pemberian pupuk nanosilika dengan konsentrasi 7,5 ml/L dapat meningkatkan pertumbuhan yaitu; jumlah stomata sebesar 142 %, tinggi tanaman sebesar 33% dan tebal daun sebesar 100% dibandingkan kontrol. Namun pemberian pupuk nanosilika tidak berpengaruh nyata terhadap jumlah anakan, bobot basah, bobot kering dan kandungan klorofil. Kata kunci: beras hitam, nanosilika, pertumbuhan, stomata, klorofil

Allelopathy is a phenomenon of direct or indirect, beneficial or adverse effects of a plant on its own or another plant through the release of chemicals into the environment. This experiment was carried out to determine the allelopathic effect of Cyperus rotundus L. (purple nutsedge) tuber aqueous extract on seed germination and initial growth of Glycine max L. (soybean) seedlings. The experiment was performed in completely randomized (CRD) design with five replications, using a range of concentrations of aqueous tuber extracts of nutsedge, i.e.: 0%, 5%, 10%, 15%, 20% and 25%. The petri dish experiment showed that with increase of the tuber extract concentration, a significant increase was noted in mean germination time (MGT), significant decreases in germination index (GI), growth tolerance index (GTI), wet weight seedling, dry weight seedling and  length of soybean seedling.

Jatibarang Reservoir is a dam built in Talun Kacang village, Kandri, Gunung Pati, Semarang t with the aim of Water Resources Management and flood control in Semarang City. The presence of Zooplankton in a waters has a close relationship with water quality and its interaction in the environment.The research aimed to find out the distribution and diversity of Zooplankton species in Jatibarang reservoir waters. The method used is Purposive Random Sampling method by dividing the sampling point into 4 research stations, namely Dermaga zone, middle zone, inlet zone, and outlet zone. From the result of this research, we get the type of zooplankton Brachionus sp., Cylops sp., Collotecha sp., Conochilus sp., Daphnia sp., Harringia sp., Rotaria sp., Keratella sp. and species from the Asphlanchnidae (Asphlanchinii) and Trichotriidae Family. The species diversity in Jatibarang reservoirs in each zone is low with abundance between 30-80 ind / L and the equalization and dominance of each low species. The dominant species is Brachionus sp. and Cyclops sp.  Water quality measurement results show the waters of Jatibarang reservoir is good for the life of aquatic biota Keywords: Zooplankton, Jatibarang Reservoir, Diversity.

Pilea microphylla (L.) Liebm. adalah gulma yang diketahui mempunyai kandungan  senyawa fenolik dan flavonoid cukup tinggi, sehingga sering dimanfaatkan sebagai tumbuhan obat. Sampai saat ini penelitian tentang Pilea microphylla (L.) Liebm. sebagian besar dilakukan  pada aspek fitokimia, sedangkan aspekpertumbuhan dan  perkembangan anatomi masih jarang dilakukan. Penelitian ini bertujuan untuk mengetahui perkembangan anatomi organ batang, akar, dan daun Pilea microphylla (L.) Liebm. dengan membandingkan ukuran sel pada organ batang, akar serta daun muda dan dewasa. Sampel organ diambil secara acak, pembuatan preparat anatomi organ dengan metode parafin dan replika sedang pengukuran sel menggunakan fotomikrograf. Hasil penelitian menunjukkan pertumbuhan batang, akar dan daun Pilea microphylla (L.) Liebm. ditunjukkan dengan terjadinya penambahan diameter  batang dan diameter lumen xilem batang, penambahan diameter akar dan diameter lumen xilem akar, penambahan lebar daun  dan kerapatan stoma. Kata kunci:  Pilea microphylla (L.) Liebm.,  pertumbuhan, xilem, anatomi.

The siam weed (Chromolaena odorata L.) has allelochemical compounds capable in inhibiting the growth of surrounding plants so that it has the potential as a natural herbicide to control various weeds including autoallelopathic weeds. This study aims to examine the effect of siam weed leaf extract at different concentrations on germination and initial growth of the Siam weed seed. The study used a Completely Randomized Design of one factor in the form of extract concentrations of 0%, 5%, 10%, 15%, and 20%. Germination method was carried out on petri dish and observations are carried out every 24 hours, and the treatment was stopped after 100% germination occurred at least in one petri dish. Each treatment was done with five replications — parameters measured as a percentage of germination and germination rate, initial germination including hypocotyl length, radicula length, and fresh weight. Data were analyzed by Analysis of Variance (ANOVA) and continued with Duncan’s Multiple Range Test (DMRT) at 95% confidence level. The results of this study showed that the Siam weed extract inhibited germination and initial growth of the Siam weed seed sprout, the higher concentration of the Siam weed extract the highest, inhibition of germination and initial growth of the Siam weed seed.