Willy’s Corner

Archive for March, 2008

Mangga merupakan buah tropis musiman yang penting. Buah mangga memiliki kandungan vitamin A dan C yang cukup tinggi, masing-masing sebesar 1.000 IU/100 g bobot segar dan 20 mg/100 g bobot segar (Bradley dalam Sistrunk dan Moore, 1983). Namun demikian, tanaman mangga masih belum banyak diteliti. Perbedaan besar antara kultivar dan daerah produksi di wilayah tropis dan subtropis menyebabkan sulitnya membuat generalisasi fenologi tanaman, pembuahan, kebutuhan hara, perlindungan tanaman dan lain-lain (Verheij, Sukonthasing dan Wongrakpanich, 1992).

Di Asia Tenggara, kebutuhan akan perbaikan penanganan pascapanen dan pemasaran seringkali ditekankan, namun tingkat panen rata-rata yang rendah menunjukkan bahwa tantangan terbesar adalah meningkatkan produksi buah. Perubahan dalam produksi komersial di kebun buah dibarengi dengan kemunculan kebun pembibitan yang menyediakan bahan tanaman seragam dalam jumlah besar, merupakan dasar yang tepat untuk melakukan terobosan dalam produktivitas (Verheij et al., 1992).

Kemajuan lebih jauh seharusnya datang dari studi ritme pertumbuhan dari kultivar unggul di sentra produksi. Studi semacam itu dapat mengungkapkan waktu pembuahan yang tepat, perlindungan tanaman, dan pengatur tumbuh untuk memperbaiki kuantitas dan kualitas pembungaan. Studi detail ritme pertumbuhan pada ranting dan biologi bunga seharusnya memberi gambaran terhadap hambatan pembuahan yang sebenarnya, menuju praktek pemangkasan yang baik serta penyerbukan dan pembentukan buah yang lebih baik (Verheij et al., 1992).

Kesulitan yang dihadapi dalam pemuliaan mangga adalah sedikitnya jumlah benih yang diperoleh, sifat panikula dan bunga yang kompleks, tingkat kesuksesan yang rendah dalam penyerbukan, penurunan kualitas buah yang berlebihan, siklus hidup yang panjang, heterozigositas tanaman dan problema-problema lainnya (Knight dan Schnell dalam Nakasone dan Paull, 1988; Singh dalam Samson, 1980). Pemuliaan mangga bertujuan membentuk kultivar yang berbuah setiap tahun, memiliki ukuran pohon yang rendah, baik untuk ditanam pada daerah tropika basah, memiliki buah yang menarik dengan ukuran yang baik (300-500 g), bebas dari kerusakan internal serta memiliki kualitas yang baik untuk disimpan dan dikonsumsi, tidak berserat, serta tahan terhadap penyakit (antraknosa) dan hama (lalat buah) (Nakasone dan Paull, 1988; Verheij et al., 1992)

Program pemuliaan mangga dilaksanakan secara aktif di berbagai negara di dunia, termasuk India, Amerika, dan Australia (Sauco dalam Nakasone dan Paull, 1988). Di Asia Tenggara, peningkatan produksi mangga telah dihasilkan melalui seleksi di dalam populasi bibit poliembrionik. Program-program yang berbasis hibridisasi juga sedang dilaksanakan (Verheij et al., 1992).

Mangga Arumanis adalah salah satu kultivar terbaik di Pulau Jawa (Bijhouwer dalam Samson, 1980). Kultivar ini memiliki potensi yang sangat baik untuk dikembangkan. Namun demikian, belum banyak perhatian yang diberikan untuk memperbaiki kultivar ini. Masalah utama dalam pemuliaan tanaman buah adalah waktu berbunga dan kematangan buah yang lama, disamping ukuran buah yang beragam. Masalah ini diharapkan dapat diatasi melalui program pemuliaan dengan metode seleksi massa.

Download: Pemuliaan Tanaman Mangga (5402)

About a week ago I created an PHP script for printing a transaction receipt. The receipt contains the quantity and amount of money which are retrieved from MySQL database. The major problem is, the program must allowed the users to output the receipt on the printer.

I write some code utilizing the php_printer.dll, but I found it’s not easy to implement. As I know so far, the program must know which printer is used to print, and the printer must be connected to the server. I haven’t going further with this problem. I just try to find another method to get the users can print the receipt easily.

I tried the simple method utilizing javascript that written by Nicolas and posted at http://www.javascript-page.com/printpage.html. This nice script provide a simple “Print” button or hyperlink that allows users to print the HTML page (it’s including the PHP-generated page, of course). We can use the CSS style to change the appereance of the page so it fits for printing. Wow, what an amazing feature

Suppose you want to establish an one-factor agricultural experiment arranged in Randomized Complete Block Design (RCBD), with five treatments (T1, T2, T3, T4, T5) and three replications (REP #1, #2, #3). You may have a experimental layout like this:

REP #1

REP #2

REP #3

Now you want to place the treatments within the replication/block. As it mention in RCBD’s principles, every block has to consist all of the five treatments, and the treatments within the block must be placed randomly. It is to ensure that every treatment has the same chance to be placed in each plot within the block, in order to eliminate subjectiveness in the experiment. Another RCBD’s principle is, there must be a homogenous condition among the plot, within the block (the difference is only the treatment, of course), and there might be a difference between the block.

In this plot, I’d like to demonstrate how to random the treatments using Excel. In a case like this, of course, we can use the random number (usually found on appendix in statistical books), or using a set of cards, or another tools we like. But, I found that Excel has a interesting feature to do this.

1. First, open the blank worksheet in Excel.
2. We need two columns here. In column A, we want to place the treatment number, and in column B, we want to place the random number. Give a title on every column. In A1 cell, type “TRTMENT”, and in B1, type “RANDOM”
3. Next, fill in the TRTMENT column. In A2..A6, write a treatment number (T1, T2, …, T5).
4. Generate a random number in B2. Write “=RAND()” (without “) in B2 to generate a random number between 0 and 1. Copy the function to the B3..B6. Simply copy and paste to do this. You’ll see the random number like 0.31902, 0.57968, etc. in B2..B6.
5. Click on B1 cell (it contains the title of RANDOM column). Click on the sort button (A->Z) to sort by the RANDOM column. Alternatively, click Data > Sort. On the “Sort by” field, select “RANDOM”, and then click “OK”. You’ll find the number of treatments has been randomized.
6. Write the number of treatments to REP #1 on your layout. And then, randomize again (repeat step 5) to fill REP #2 and REP #3.

Below is an example of the plotting result.

REP #1

REP #2

REP #3

Well done

This evening I’ve got a great mail from my students’ mailing list. It’s a story explained by some images that shows us how precious the life is. I searched in Google for a while to find the original source, but I couldn’t find it. So, I write the source as the second of original mailing list provided it, that is jurnal_01 mailing list, while I also couldn’t access the first mailing list, iai_family.

The message I’ve got from this mail is that we must have a “big hope” and “big goal” in this life. That is, we must have a big motivation to do the hard works, and always remember that Allah SWT never forget to give everything we need. We must not to be hopeless, regardless of the others’ activities in their life. We must realize that Allah SWT knows everything about us, and really knows which is the best for us.

For your convinience, I was made the PowerPoint version, completed with Indonesian translation which was taken from the mailing list. With that version, I also can show it in a part of my hours in class Of course, I want to share it with you too. Click on the download link below. Enjoy!

Download: Life is Precious (424)

In this post I just want to share my experience and view about being a junior plant breeding lecturer. I think it’s a very good job. The plant breeding itself is the combination of science and art which is manipulate genetic constitution of a plant population to get a new and better variety. Although this field is not my “real” hobby, but I have learned many things about it in my S1 and S2 study.

In this semester, I have the job as a lab assistant of the Fundamentals of Plant Breeding course. It’s a course gived by our department/major, Agronomy and Horticulture, especially by the Genetics and Plant Breeding division. Now it has been taken by 200+ undergraduate students, from our major and the major of Plant Protection. Wow, what a big number of students. The question is, how can we do the management and arrangement of the topics (and field :-)), to provide good quality of laboratory class for the students? I know that the research station do not have a large area for this activity, because the other labs/research activities also conducted at this site. The field area for this lab is about 2000 sq meters. I’m lucky that the lab’s coordinator for this course had worked hard for organizing it.

The lab topics in this semester are: (1) hybridization, (2) estimation of variation, (3) selection. Some crops will be used to explain the topics, those are: sweet corn, long bean, pepper, and soybean. Now I have to study to give a good explanatory to the students, filling in my schedule. I have passed the first meeting without my voice in the explanatory session, but I still have a chance to do better next time.

The picture above is the “Praktikum DasPMT in action”. The students were planting the sweet corn at IPB Research Station, Cikabayan, Darmaga, on Feb 29, 2008. There are 20 groups of students; each group contains 10 students. For this activity, they had 4 x 5 sq meters of field area, to plant the sweet corn with the distance of 80 cm (between row) x 25 cm (within row). Because they had taken the Fundamentals of Agronomy class before this semester, they already have a practice in planting. With manual technique and tools, they had finished their work in about one and half hour.

It’s interesting for me for using Photobucket as a drum to put my photos. On this morning I’ve registered on that site. The registration process is really simple. First it asked me to fill in username and password, and the next page only requested me to fill some personal identity.

Next, the screen bring me to upload my photos. I’ve been started with three photos I took with Nikon Coolpix L14 camera at 5 megapixel, which the size varies between about 650-960 kb. I want to check photobucket’s capabilities to resizing my upload, so I didn’t resize it before uploading.

After the uploading process finished, it asked me to give the title, description, and tags of the photos. After I filled in it, my photos was saved and it give us some properties to use the photos, they are: Email & IM, Direct Link, HTML Code and IMG code. Wow, amazing!

Now I try to insert one photo in this post. I just clicked the “Insert/edit image” button in the WordPress’ Write feature. Next, I paste the “Direct Link” URL, give the image description, set the resolution into 320 x 240 pixels, set the border into 1 and vertical & horizontal margins into 10, respectively. Suddenly… the photo appeared For the best position of the photo, I move it into the top-left of this post by simply cut-and-paste.

Thanks for the Photobucket.