| Factor | Rate
of transpiration |
| humidity | the higher the humidity of the surroundings, the slower the rate. When the air is wet, diffusion of water vapour out of the leaf is slower. |
| temperature | the higher the
temperature of the surroundings, the faster the rate. Water
evaporates faster at higher temperatures. |
| presence
of light |
the rate is higher in the light
than in the dark. Light
stimulates the opening of the stomata. |
| presence of wind |
the
rate is faster with the presence of wind. Wind carries away
humid air
which is replaced by drier air surrounding the
leaves. |
| Faktor | Kadar transpirasi |
| kelembapan | lebih tinggi kelembapan sekeliling, lebih perlahan kadar transpirasi. Apabila udara sekeliling lembap, peresapan wap air keluar daripada daun lebih perlahan. |
| suhu | lebih tinggi suhu, lebih cepat kadar
transpirasi. Penyejatan air berlaku dengan lebih cepat pada
suhu tinggi. |
| kehadiran cahaya |
kadar transpirasi lebih tinggi dengan kehadiran
cahaya
kerana cahaya
merangsangkan pembukaan liang
stoma. |
| kehadiran angin |
kadar transpirasi
bertambah dengan kehadiran angin. Ini kerana angin
menyingkirkan udara
lembap - yang pula diganti dengan udara kering
di sekeliling daun. |
