Vegetative Growth, Yield, and Quality of Onion as Influenced by Nitrogen Rates and Natural Stimulators

Abstract

O EXPLORE the influence of varied nitrogen rates and foliar spraying of natural stimulants on vegetative growth, yield, and onion quality. This experiment was carried out over the two seasons 2019-2020 and 2020-2021 to investigate nitrogen fertilizer at rates: 144, 216, and 288 kg N ha -1 and natural stimulant treatments (yeast extract, fulvic acid, amino acids, and seaweed extract). As well as control. The results clearly demonstrated that raising the nitrogen rate from 144 to 288 kg N ha -1 significantly enhanced the leaves number of plant -1 , fresh plant weight (g), average bulb weight (g), marketable bulb yield (t ha-1), double bulbs%, bulb diameter, TSS%, dry matter%, N%, P%, K%, carbohydrate% and protein content%. Foliar spraying with natural stimulators (yeast extract, fulvic acid, amino acids, seaweed extract) significantly increased plant height (cm), number of leaves/plant, fresh plant weight (g), neck diameter (cm), bulb diameter (cm), bulbing ratio, average bulb weight (g), marketable bulb yield (t ha-1), culls bulb yield (t ha-1), double bulbs%, bulb diameter, TSS%, dry matter%, N%, P%, K%, carbohydrate% and protein content%, during both seasons. The nitrogen at rate of 288 kg N ha -1 combined with amino acids spraying appeared the highest mean values of average bulb weight (g) during the 1 st season and marketable yield during the two seasons. The highest value of dry matter% was achieved by fertilizing by 216 kg N ha -1 when spraying with fulvic acids during both seasons.

Effect of Potassium Humate, Phosphorus and Copper on Onion Quantitative and Qualitative Yield

“…In Egypt, onion (Allium cepa L.) is one of the most important vegetable crops either for export or local market [14,15]. Onion is one of the commercial vegetable crops having high nutritional value, as it contains oil (20.4%), protein (24.8%), fibre (22.4%), potassium (1010 mg 100 g -1 ) and calcium (175.0 mg 100 g -1 ) [16].…”