dalam kebanyakan kes, terdapat pokok yang dijangkiti CMV tetapi masih kelihatan sihat. keadaan ini mungkin disebabkan keadaan persekitaran yang tidak menunjukkkan simptom seperti dalam persekitaran bersuhu tinggi.

faktor persekitaran merupakan faktor yang paling banyak mempegnaruhi permulaan dan perkembagan penyakit tumbuhan yang berjangkit. faktor seperti suhu, kelembapan, cahaya, nutrien dan PH tanah banyak mempengaruhi pertumbuhan dan kerentanan perumah, penggandaan dan kegiatan patagen, salingt tindakan antara perumah dan patogen serta keparahan gejala.

makanisme serangan CMV adalah mudah dan cepat. virus ini akan dibaw oleh vektor kepada mana-mana pokok cili. sebahagian besar vektor yang membawa virus ini ialah MYZUS PERSICAE dan APHIS GOSSYPII. CMV akan terus masuk ke dalam urat pokok melalui bahagian yang luka dan bertindak secara agresif di dalamnya. kemudian ia akan menyebar ke seluruh urat pokok dan menampakkan simptom. penyebaran virus ini berlaku antara pokok yang telah dijangkiti. oleh itu kebersihan tangan dan peralatan pertanian di ladang merpukan langkah yang di titikberatkan supaya gejala penularan serangan virus dapat dikurangkan.

pelbagai usaha telah diambil dan sedang giat dijalankan bagi mengatasi maslah virus ini. car yaang paling bias digunakan adalah secara kawalan kimia iaitu merendam biji benih yang akan ditanam di dalam air panas atau larutan natrium fosfat. cara lain adalah dengan menyembur bahan racun yang toksik terhadap virus kepada tanaman. namun usaha mengawl penyakit virus ini, tidak efektif malah kosnya juga amat tinggi.

beberapa pendekatan secara fizikal trut digunakan bagi mengawl jangkitan virus iaitu dengan menggunakan mulche. mulche putih dikatakan dapat mengurangkan populasi afid yang menjadi vektor ( pembawa) kepada virus tersebut. warna mulche menyebabkan vektor tersebut kurang tertarik kepada persekitarannya. selain itu, kaedah jaringan juga berkesan mengawl serangan jangkitan CMV walaupun kosnya sedikit tinggi. petani juga boleh mencabut pokok cili yang telah dijangkiti dan memusnahkannya dengan cara membaakar.

kini dengan adanya kaedah bioteknologi, penghasilan pokok transgenik dapat meningkatkan kualiti pokok cili sedia ada yang telah dikomersialkan. walaubagaimanapun, aplikasi teknik kejuruteraan genetik ini amatlah kurang disebabkan masalah kesukaran dalan penjanaan pokok. untuk itu kaedah yang bersesuaian untuk mengawl serangan virus ini adalah dengan menggunakan variety pokok yang rintang atau tahan penyakit.

penggunakan pokok variety rintang merupakan cara yang paling murah, selamat dan berkesan mengawal penyakit tanaman.petani digalakkan menggunakan variety yang tahan penyakit kerana cara ini selamat dan dapat menjimatkan kos dan tenaga buruh dalam penyemnburan racun.
terdapat beberapa variety cili yang kebanyakannya berasal ari per4ancis dan india yang rintang terhadap penyakit. kaedah penggunaan tenaman rintang ini bukan sahaja dapat diaplikasikan terhadapt penyakit yang disebabkan oleh virus malah bakteria, nematod dan juga kulat.

~pusat penyelidikan hortikultur MARDI Serdang~~

Kursus Cili Fertigasi anjuran Yayasan Kemajuan Sosial Malaysia yang akan bermula awal bulan Julai ini.

Tempat kursus ada 2 pilihan :

1) Stesen Mardi Bertam, Kepala Batas, PP
2) Semeling, Sungai Petani, Kedah (Berdekatan Universiti AIMST)

Hubungi :

04-397 0906 atau 04- 398 5502

Alamat pejabat : 38, Tingkat 3, Jln Todak 2, Bandar Sunway, 13700 Seberang Jaya, PP.

P/S: Dengan kerjasama NCER (Koridor Utara).

Perjumpaan pertama pd 3/7/2010 di Bandar Sunway, Seberang Jaya.

REBUTlah peluang ini, tanpa bayaran (PERCUMA).

Saya dapat maklumat ini dari banner di persimpangan jalan Semeling - Sg Petani. Alhamdulillah saya sendiri telah daftarkan diri utk kursus ini.

Kursus ini berterusan, 4 jam seminggu. Jika tidak berkerja, mungkin kursus ini lebih intensif. Cuba tanya mereka utk keterangan lanjut.

Sekadar Berkongsi maklumat. Sharing is Caring.

Kepetingan PH:

Different dissolved salts are taken up less effectively as pH varies from low (acid) to high (alkali) A good point to aim for is between 5.8-6.8, if pH rises much above 7.5 then problems can occur.The graph plots the total nutrient available at increasing pH values. It peaks at around 6.5, both side of which the total available drops.
A plant's ability to take up nutrients is determined by pH and temperature. If your soil is too acid or too alcaline then the plant will struggle to extract what it needs. This in turn leads to deficiency symptoms


Kepentingan Suhu:

Maintain the nutrient solution at about 24-27 deg C.

Kepentingan EC:

Nutrient manufacturers publish the preferred concentrations and EC readings for their products on the packaging. Usually 1.5-2.5 millisiemens or 15-25 CF is the target, less than this will result in deficiencies, more than 30 CF and the plant will also deteriorate
A word of caution though, it is easy to over fertilize and burn the roots, especially with younger plants.

Algae

Even if you aim to grow a single type of plant hydroponically you usually end up growing two, your favorite crop and algae. Algae are an unwelcome addition as it uses nutrient, can clog pipes and pumps, can harbor pests and looks a mess. Algae are one of the oldest waterborne plants on the planet and it has become supremely well adapted to taking any advantage it can to grow. Hydroponic systems are perfect for algae, lots of liquid nutrient, oxygen, warmth and light. Limiting light is the best way to prevent its growth. Black plastic components should be used where possible, if not then light should be excluded by covering. Dustbin liners are good for this and when cardboard or polystyrene sheet is placed inside it make an adaptable material for boxing in nutrient sumps or covering exposed substrate.

Aeration

Many systems include an air pump and air stone to aerate the nutrient solution. This action is used in simple aeroponics systems to provide a fine spray as the bubbles burst at the surface. In all other systems it's used to provide circulation of the nutrient within the holding container, helping to keep it fresh. Oxygen is poorly adsorbed by water, the larger the surface area between the two the better. As the bubbles add very little to the total area, they add very little oxygen directly. Far greater is that added at the surface of the solution where the area is large. Bubbles help by causing a gentle flow in the solution, as they rise the surrounding liquid also rises. This flow moves the lower part of the solution to the surface where it can take up oxygen. This movement can also be used directly in some pot-based systems to move nutrient up onto the substrate through a tube, replacing the pump. In continuous flow systems there is often no need for anything other than the returning nutrient to increase surface flow. In other systems it's possible to divert some of the flow from the pump to cause currents in the solution by splitting the outlet into two pipes using a T-piece and a valve to balance the output

Fertilizer is an important component of any operation. However, rising raw material costs have put all crop inputs under close scrutiny. Fertigation systems boost fertilizer use efficiency, allowing growers to tailor fertilizer applications to both crop growth and the environment. However, there are still areas where small economies can be made, helping to increase the dollar return on the fertilizer investment.

For larger operations, solid fertilizer sources are a less expensive alternative to the commonly used liquid formulations. The solubility of these fertilizers does vary greatly. When switching to a solid fertilizer source, avoid problems in the nurse tanks by ensuring that ample water is added to the stock solution.

Urea Ammonium Nitrate (UAN) is often considerably less expensive than Calcium Ammonium Nitrate. It also contains more nitrogen on a per volume basis (28% vs. 17%) allowing for lower application rates.

Regardless of the fertilizer source, rate selection and dilution is critical. To avoid fertilizer injury, aim for a fertilizer concentration of 1-2% of the total water volume. Do not exceed concentrations of more than 5%.

Plan to inject the fertilizer over 1-2 hours at the end of the irrigation cycle. Studies have shown that fertigating at the beginning of the cycle may cause the fertilizer to move below the crop's rooting zone where it is less available for crop uptake. Be sure to run the system long enough to properly flush the fertilizer from the drip lines after the injection period.

Always check for fertilizer compatibility. DO NOT mix fertilizer solutions containing calcium with solutions containing phosphates or sulphates. Table below outlines the compatibilities of the most common fertilizer sources. When using a new fertilizer source, do a jar test to ensure there are no incompatibilities. Mix the fertilizer solutions with a sample of the irrigation water and allow it to sit for 1-2 hours. If the products are incompatible, precipitates will form or the sample will become cloudy.

Fertigation Fertilizer Compatibility Chart
Urea, Ammonium Nitrate, Ammonium Sulphate, CN, PN, Potassium Chloride, SOP, Ammonium Phosphate, Fe/Zn/Cu/Mn Sulphate, Fe/Zn/Cu/Mn Chelate, Mag Sulphate, Phosphoric Acid, Sulphuric Acid, Nitric Acid

Urea => Urea
Ammonium Nitrate => Urea, Ammonium Nitrate
Ammonium Sulphate => Urea, Ammonium Nitrate, Ammonium Sulphate
Calcium Nitrate => Urea, Ammonium Nitrate; x = Ammonium Sulphate
Potassium Nitrate => Urea, Ammonium Nitrate, Ammonium Sulphate, CN
Potassium Chloride => Urea, Ammonium Nitrate, Ammonium Sulphate, CN, PN
Potassium Sulphate @ SOP => Urea, Ammonium Nitrate, PN; R= Ammonium Sulphate, Potassium Chloride; x = CN;
Ammonium Phosphate =>Urea, Ammonium Nitrate, Ammonium Sulphate, PN, Potassium Chloride, SOP Ammonium Phosphate; x = CN;
Fe/ Zn/ Cu/ Mn Sulphate =>Urea, Ammonium Nitrate, Ammonium Sulphate, PN, Potassium Chloride; R = SOP; x = CN, Ammonium Phosphate
Fe/ Zn/ Cu/ Mn Chelate => Urea, Ammonium Nitrate, Ammonium Sulphate, PN, Potassium Chloride, SOP; R = CN, Ammonium Phosphate;
Magnesium Sulphate (MgS) => Urea, Ammonium Nitrate, Ammonium Sulphate,PN, Potassium Chloride,Fe/Zn/Cu/Mn Sulphate, Fe/Zn/Cu/Mn Chelate; R = SOP; x = CN, Ammonium Phosphate
Phosphoric Acid => Urea, Ammonium Nitrate, Ammonium Sulphate, PN, Potassium Chloride, SOP, Ammonium Phosphate, Fe/Zn/Cu/Mn Sulphate, Magnesium Sulphate, R = Fe/Zn/Cu/Mn Chelate, x = CN
Sulphuric Acid => Urea, Ammonium Nitrate, Ammonium Sulphate,PN, Potassium Chloride,SOP, Ammonium Phosphate, Fe/Zn/Cu/Mn Sulphate, Fe/Zn/Cu/Mn Chelate, Mag Sulphate, Phosphoric Acid , R = SOP; x = CN
Nitric Acid => Urea, Ammonium Nitrate, Ammonium Sulphate, CN, PN, Potassium Chloride, SOP, Ammonium Phosphate, Fe/Zn/Cu/Mn Sulphate, Mag Sulphate, Phosphoric Acid, Sulphuric Acid, x = Fe/Zn/Cu/Mn Chelate

PN = Potassium Nitrate
CN = Calcium Nitrate
SOP = Potassium Sulfate @ Sulfate of Potash
Legend:
=> compatible; x = incompatible; R = reduced compatibility