كليدواژه :
شدت تشعشع , كشاورزي , ماده خشك تاج خروس , redroot pigweed (Amaranthus retroflexus L.) , كيفيت نور
چكيده لاتين :
In order to study the effects of light intensity and quality on the rate of development and thy matter distribution of redroot pigweed (Arnaranthus retroflexus L.), which is an important weed in the most parts of summer crop fields, and experiment was conducted at the University of Guelph, Canada. Controlled environment conditions were used for simulating different light treatment, that may occur in a natural crop-weed system. Different light treatments were three combinations of low and high PPED and R/FR levels. Some quantitative and morphological traits such as total dry matter, branch number, plant height, leaf area and allocated dry matter percent to each parts of plant were measured. Also reproductive development stages like as initiation of floral primordium, initiation of flowering and initiation of seed set were determined. The results showed that low PPED significantly decreased total dry matter, branch number, plant height, leaf area and rate of leaf appearance. Physiological indices such as LAR and SLA also were significantly increased by low PPFD. However, results were different under low PPFD and R/FR treatment. The initiation of floral primordium was delayed at low PPED with high R/FR in comparison to full sunlight treatment. This delay was partly compensated by Low PPFD and R/FʹR. Remarkable increment of plant height and allocation of more dry matter into the main stem under low PPFD and R/FR treatment indicates the role of spectral light quality in growth and development of redroot pigweed and confirms itʹs high adaptation ability under crop-weed interference.
