Wednesday, August 20, 2008
MENGENAL SIRIH-SIRIH HEBAT
Vascular Streak Dieback disease of cocoa (II) Diagnosis on cutting
PENAMPILAN EKSOTIS SANG NAGA DI POT
The good news is that planting flower bulbs is fast, easy, and nearly foolproof.
Hookeri Hijau Mini
Determination of minimum plot size of Robusta coffe field experiment
Manfaat dan kepopulerannya buah lemon
Study on growth characteristics of Robusta coffe generated from seddling, grafting and cuttings
Harmonia octomaculata (F). as a predator of Leucaena psyllied
Efficiency of ornamental plants cultivation.
TaBuLamPot : Solusi Pas di Lahan Terbatas
Lima SyaratAgar tanaman dalam pot rajin berbuah, Lily dan Joesi sama-sama menyebut sejumlah syarat yang harus dipenuhi. Paling tidak ada lima syarat tumbuh atau faktor yang jadi pertimbangan.Pertama, pemilihan jenis tanaman yang sesuai dengan ketinggian tempat. Kedua, pemilihan bibit tanaman. Diikuti pemilihan media tanam dan pot. Lalu pemupukan yang efektif dan terakhir, pengendalian hama dan penyakit tanaman.Pengetahuan asal-usul tanaman harus sudah nyantol di otak sebelum memutuskan menanam suatu bibit tanaman buah dengan teknik pot. Ini penting. ”Jangan sampai stroberi dan apel yang merupakan tanaman di daerah dingin, ditanam di dataran rendah. Wah, mana mau berbuah dia,” kata Joesi memberi perumpamaan. Umumnya, semua jenis tanaman buah hanya dapat berbunga dan berbuah dengan baik bila ditanam di daerah berketinggian sekitar 400 m dpl.Pemilihan bibit juga tak kalah penting. Bibit yang baik tentu akan menghasilkan – secara kualitas dan kuantitas – pertumbuhan dan perkembangan tanaman yang jempolan. ”Saya menganjurkan untuk memilih bibit tanaman buah yang jelas asal-usulnya. Artinya, bibit dibeli dari penangkar tanaman yang baik dan terpercaya,” ucap Lily.Urusan bibit selesai, langkah berikut menyiapkan media tanam dan pot. Kata Joesi, media tanam yang digunakan untuk tanaman buah dalam pot sebaiknya memenuhi syarat minimal, yaitu mengandung tanah sebesar 50 %, pasir 20 % dan bahan organik 30 %.Dari syarat minimal tadi, bisa diterjermahkan menjadi berbagai macam komposisi bahan dasar sebagai media tanaman buah dalam pot. Bahan dasar untuk media tanam terdiri atas tanah, pupuk kandang, kompos, pupuk kimiawi dan bahan lain sebagai tambahan.Pemilihan pot yang tepat menjadi modal awal bagi pertumbuhan tanaman. Pot yang digunakan bisa dipilih dengan memanfaatkan kaleng biskuit bekas, sisa galon air mineral, ember tak terpakai, drum bekas senyawa kimia dan lainnya. Agar menghindari kontaminasi zat, Lily menyarankan membeli wadah yang sudah dicuci. Wadah favorit tetap dipegang belahan drum bekas. Wadah ini mampu menampung seluruh sistem pengakaran.Pemupukan harus dilakukan dengan dosis tertentu. Kelebihan dan kekurangan dosis tentu berdampak buruk bagi tanaman itu. Jenis pupuk yang bisa dipilih memang beragam. Yang pasti, tanaman buah butuh unsur hara makro, seperti N, P, K dan unsur hara mikro macam Ca, Mg dan S. Unsur hara mineral itu merupakan sumber nutrisi bagi pertumbuhan dan perkembangan tanaman. Cermati pula waktu dan cara pemupukan.Langkah terakhir, pengawasan terhadap hama dan penyakit tanaman. Faktor pengganggu ini jangan sampai mengacaukan mimpi Anda untuk memanen buah. Bayangkan betapa kecewanya hati ini saat mengetahui pertumbuhan tanaman buah terhambat oleh hama dan penyakit.Pada tanaman buah juga dikenal teknik pemangkasan. Tujuannya, kata Joesi, untuk menjaga kesehatan dan meningkatkan produksi. Pemangkasan juga mampu menjaga kelembaban tanaman sehingga tak mudah terserang hama dan penyakit.Berdasar umur tanaman, pemangkasan terbagi menjadi tiga, yaitu pemangkasan pada pembibitan, pemangkasan tanaman yang belum menghasilkan dan pemangkasan tanaman yang sudah menghasilkan. Sedang dilihat dari tujuannya, pemangkasan dibedakan menjadi empat, yaitu pemangkasan bentuk, pemeliharaan, produksi dan peremajaan.Bagi sebagian pehobi, tanaman buah dalam pot bisa jadi lahan bisnis yang menarik. Dengan perawatan yang cermat, tanaman buah dalam pot mampu menyedot perhatian siapa saja.Tajuk tanaman yang tak terlalu tinggi dengan disusupi gerombol buah di ujung cabang, apalagi saat dicicipi buahnya, terasa manis dan segar, siapa yang tak kepincut. Jadi jangan heran bila ada tanaman buah dalam pot yang mampu mencapai seharga tiga juta rupiah. Wow! Jambu biji termasuk salah satu jenis tanaman buah yang mudah ditanam dan berbuah dengan teknik tanbulampot.
Friday, August 08, 2008
Interactions among Factors Regulating Phenological Development and Acclimation Rate Determine Low-temperature Tolerance in Wheat
Background and Aims Exposure to low temperatures (LT) produces innumerable changes in morphological, biochemical and physiological characteristics of plants, with the result that it has been difficult to separate cause and effect adjustments to LT. Phenotypic studies have shown that the LT-induced protective mechanisms in cereals are developmentally regulated and involve an acclimation process that can be stopped, reversed and restarted. The present study was initiated to separate the developmental factors determining duration from those responsible for rate of acclimation, to provide the opportunity for a more in depth analysis of the critical mechanisms that regulate LT tolerance in wheat (Triticum aestivum).
• Methods The non-hardy spring wheat cultivar ‘Manitou’ and the very cold-hardy winter wheat cultivar ‘Norstar’ were used to produce reciprocal near-isogenic lines (NILs) in which the vrn-A1 (winter) alleles of ‘Norstar’ were inserted into the non-hardy ‘Manitou’ genetic background and the Vrn-A1 (spring) alleles of ‘Manitou’ were inserted in the hardy ‘Norstar’ genetic background so that the effects of duration and rate of LT acclimation could be quantified.
• Key Results Comparison of the acclimation curves of the NILs and their parents grown at 2, 6 and 10 °C established that the full expression of LT-induced genetic systems was revealed only under genotypically dependent optimum combinations of time and temperature. Both duration and rate of acclimation were found to contribute significantly to the 13·8 °C difference in lowest survival temperature between ‘Norstar’ and ‘Manitou’.
• Conclusions Duration of LT acclimation was dependent upon the rate of phenological development, which, in turn, was determined by acclimation temperatures and vernalization requirements. Rate of acclimation was faster for genotypes with the ‘Norstar’ genetic background but the ability to sustain a high rate of acclimation was dependent upon the length of the vegetative stage. Complex time/temperature relationships and unexplained genetic interactions indicated that detailed functional genomic or phenomic analyses of natural allelic variation will be required to identify the critical genetic components of a highly integrated system, which is regulated by environmentally responsive, complex pathways.
Key words: Low-temperature tolerance, Vrn-A1, near-isogenic lines, developmental regulation, vernalization, cold acclimation, Triticum aestivum, wheat
D. B. FOWLER* and A. E. LIMIN, E-mail Brian.Fowler@usask.ca
The control of flowering in time and space
The transition to flowering is one of the most important developmental decisions made by plants. Classical studies have highlighted the importance of photoperiod in controlling flowering time. More recently, the identification of mutants specifically affected in the photoperiod pathway in the model system Arabidopsis thaliana has enabled the flowering time pathways to be placed in a molecular context. This review highlights recent advances in understanding how photoperiod signals (perceived in the leaves) act at the apex of the plant where the floral stimulus is perceived. The photoperiod pathway acts predominantly through the gene CONSTANS to activate the small signalling molecule FT. While FT transcription is induced in the leaves, it is essential that FT protein is present at the apex of the plant. FT at the apex interacts with the transcription factor FD to induce flowering. Key words: Arabidopsis, FD, florigen, flowering, FTKatja E. Jaeger, Alexander Graf and Philip A. Wigge.E-mail: philip.wigge@bbsrc.ac.uk
The Yellow Rose of... Wheatfield
Yellow roses give you a warmth you do not get from any other color. I look forward to them the same way I long for the first daffodils every spring. Living in the north, it's a sign that the cold of winter is gone... at least for a while. It's that warm spot on the carpet when the first ray of sun comes through the window in the morning. You know. The one the cat always sits on. In this article in my 'Roses of Color'[1] series, I'm back to what I have in my garden... both those that I planted last year when the garden was new and those that I have ordered for this year. I would like to share the reasons for my choices. Of course, they may not work for your climate as well as I hope they will in my zone 6a garden. But it will give you an idea of the process I go through to choose my roses. By Jan Recchio (grampapa)July 12, 2008
But why are the palm and cycad societies almost ALL men?
Here are a few of my uneducated theories: To me the draw for women seems to be the flowers. Men are completely content growing plants which either never flower, or the flowers are insignificant or uninteresting. Women are attracted to color- particularly bright colors, while men seem to like mostly greens and blues (more masculine colors?). Women like little plants while men like big ones. Women like potted plants while men seem to be more apt to grow plants in the ground (now THAT is a total generalization... and I am not even sure if it's at all accurate- plenty of women have huge in-ground rose gardens and other flower gardens). Women like delicate, soft plants, while men like the thicker, spinier and bulkier items. Women are much more content with annuals and don't seem to mind starting over every year (seem to even like it that way)... while men seem to prefer plants that live for centuries. On the other hand, women tend to like to grow plants that are more likely to survive and look good, while men seem less upset when things don't go well, or their plants are the type that look dead half the time. And women seem to spend far less on plants than men do. Copyright © 2000-2008 Dave's Garden.com.
Flower primordium formation at the Arabidopsis shoot apex: quantitative analysis of surface geometry and growth
Geometry changes, especially surface expansion, accompanying flower primordium formation are investigated at the reproductive shoot apex of Arabidopsis with the aid of a non-invasive replica method and a 3-D reconstruction algorithm. The observed changes are characteristic enough to differentiate the early development of flower primordium in Arabidopsis into distinct stages. Primordium formation starts from the fast and anisotropic growth at the periphery of the shoot apical meristem, with the maximum extension in the meridional direction. Surprisingly, the primordium first becomes a shallow crease, and it is only later that this shape changes into a bulge. The bulge is formed from the shallow crease due to slower and less anisotropic growth than at the onset of primordium formation. It is proposed that the shallow crease is the first axil, i.e. the axil of a putative rudimentary bract subtending the flower primordium proper, while the flower primordium proper is the bulge formed at the bottom of this axil. At the adaxial side of the bulge, the second axil (a narrow and deep crease) is formed setting the boundary between the flower primordium proper and the shoot apical meristem. Surface growth, leading to the formation of the second axil, is slow and anisotropic. This is similar to the previously described growth pattern at the boundary of the leaf primordium in Anagallis. Key words: Arabidopsis, flower primordium, reproductive shoot apex, surface curvature, surface growth Dorota Kwiatkowska. E-mail: dkwiat@us.edu.pl/dorotak@biol.uni.wroc.pl