AMALAN PENANAMAN UMUM - Faktor Keadaan Persekitaran / GENERAL CULTURAL PRACTICES - Environment Conditions Required

Faktor-faktor ini merangkumi 1) Cahaya 2) Suhu 3) Kelembapan Relatif (RH) 4) KarbonDioksida 5) Kitaran Udara dan 6) Oksigen
Kita akan mulakan dengan faktor Cahaya dahulu.

1) Cahaya: 2 faktor yang penting dan boleh dipengaruhi oleh struktur rumah berpelindung terhadap tanaman di dalamnya ialah:

• Kualiti: Ia merujuk kepada gelombang cahaya tersebut (sebagaiman yang disebutkan tentang cahaya spektrum di dalam matapelajaran Fizik iaitu faktor PAR ( Aktif radiasi untuk Fotosintesis ) iaitu biru, kuning, oren & merah.
• Kuantiti: Ia dipengaruhi oleh tempoh lamanya waktu siang dan juga sudut matahari (ia ketara di negara-negara bermusim).
  

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These factors includes 1) Light 2) Temperature 3) Relative Humidity (RH) 4) Carbon Dioxide 5) Air Circulation and 6) Oxygen. First we will cover - Light: Two factors are important and can be affected by greenhouse structures and coverings . NOTE: Both of these vary with plant species.

• Quality: Refers to wavelengths of light. (Remember in physics: light spectrum) Visible light = 390-760 nm: blue at the low end, red at the high end. PAR (photosynthetically active radiation) = between 400 and 700 nm (blue, yellow, orange and red… but not green)NOTE: This varies slightly for each plant species.
• Quantity: Is affected by both day length and sun angle (changes with season): Day Length & Sun Angle.
  

The quantity (amount) of light reaching the Earth’s surface is therefore higher in Summer than it is in Winter.
For tomatoes in the desert southwest or other high light areas:

1. During the Winter or times of low light the quantity of light available is enough to support 3 – 4 fruit/cluster.
2. During Spring/Summer/Fall the quantity of light may be too high and shading may be needed. 4 – 5 fruit/cluster is typical.