Response of onion plants to humic acid and mineral fertilizers application [electronic resource].

Includes references.

Two field experiments were carried out in the Experimental Station of National Research Center at Shalakan during the two Successive winter seasons of 200212003 and 2003/2004 to study the effect of the combinations between four levels of humic acid application (0, 2, .. and 6 Liter/fed.) and four levels of mineral fertilizes (0, 50, 75 and 100% of the recommended dose of NPK fertilizers application) on growth, yield and quality of onion. The obtained result clear that: . Vegetative growth of onion plants (plant height, number of leaves / plant, diameter of bulb and nick as well as fresh and dry weight of whole plant), total and exportable bulb yield and its quality (dry weigh% and TSS%) were gradually and significantly increased with increasing the level of humic acid application. However, mtrate accumulation in onion bulbs was decreased by increasing the le\'el of humic acid application. . Data also clear that, vegetative growth of onion plants, total yield and its quality as well as nitrate accumulation in onion bulbs were significantly increased by increasing the level of mineral fertilizers application from 0, SO, 7S up to 1000/. of the recommended dose of NPK application. . As for the interaction treatments, humic acid application at 6 L./fed. combined with adding 7S% of the recommended dose of mineral fertilizers gave the highest yield of onion bulbs with the best quality and reducing nitrate accumulation in onion bulb.

Summary in Arabic.

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