عنوان مقاله [English]
In many sun-loving plants, shading affects their growth characteristics and yield due to the reduction of solar radiation. In order to evaluate effect of different shading levels (0, 25 and 50 percent) on growth and yield of celery (Apium graveolens L.), this experiment was carried out as randomized complete block design with four replications. Results showed that the maximum and minimum length, height and stem number of celery recorded for plants exposed to 50 percent shading and full light intensity, respectively. Leaf area and specific leaf area in plants exposed to full light decreased 330 and 42 percent, respectively in comparison to those received 50 percent shading. The Fv/Fm ratio and leaf stomatal conductance increased with decreasing light intensity. Leaf chlorophyll index, fresh and dry weight of leaf petiole and blade of plants under shade were higher than those grew under full sunlight. The maximum (718g per plant) and minimum total yield (155g per plant) obtained in shading 50 percent and full light intensity, respectively. For conclusion, celeries grown in 50 percent light intensity had better growth and yield.
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