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close this bookConsultancy report on first extension staff training in horticulture. (1998)
close this folderBasic understanding of horticulture
close this folderReview of effects of physical factors of the environment on horticultural crops
View the document(introduction...)
View the documentTemperature
View the documentLight
View the documentRainfall
View the documentWind
View the documentSoils
View the documentBiotic factors

Light

Photosynthesis uses light. Light intensity and duration are important for crop growth and development. Low light causes plants to be spindly, small leaves, bud blades, poor pollination and poor fruit quality.

Plants differ in light requirements. An example was given for horticultural crops.

- Light affects pollen viability and fruit set.
- Certain seed require light to break dormancy e.g. lettuce.
- Some horticultural crops are sensitive to protoperiod.
Examples were given.
- Short day plants flower rapidly when the days get shorter.
- Long day plants flower when days are longer.
- Short days hasten tuber formation in potatoes, root enlargement in sweet potatoes.
- Long days and high temperatures keep plants in staminate (phase) in Cucurbits.

Light intensity and duration are important for crop growth and development:

- Photosynthesis uses light

- Low light causes plants to be long and this (spindly), small leaves, bud blades, poor pollination and poor fruit quality.

- Photosynthesis is stopped at high light intensity depending on species.

- Plants differ in light requirements.

- Certain seeds require light and break dormancy.

- Some plants are sensitive to photoperiod or day length.

- Short day plants flower rapidly when the days get shorter.

- Long day plants flower when days are longer.

- Short days hasten tuber formation in potato, root enlargement in sweet potatoes.

- Long days and high temps keep plants in staminate (phase) in cucurbits.