Effect of nitrogen and some weed control methods on yield and quality of onion in a newly reclaimed soil

الملخص EN

Two field experiments were carried out during the two successive winter seasons of 2014/2015 and 2015/2016, at the Farm of the Faculty of Agriculture, New Valley University, to study the effect of four rates of mineral nitrogen fertilizer, i.e., 0, 178.60, 357.14 and 535.71 kg N ha-1and three weed control methods, i.e., unweeding, hand weeding and chemical herbicides, i.e.,bentazon (Basagran® 48% AS) and clethodium (Select super® 12.5% EC) at the recommended rates (1.19 L/238L/ha and 0.595 L/238L/ha, respectively)on yieldandbulb quality of onion cv.

Giza 6.

The obtained results showed that the interaction from mineral nitrogen at the highest rate (535.71 kg N ha-1) and hand weeding methodsignificantly increased the percentages of bulbs ranged from 6-8 cm in diameter, doubles,bulbfreshweight (g), bulb diameter and length (cm),bulb dry matter(%), bulb quality such as vitamin C concentration, percentages of sulfur volatile oil, total soluble solids (TSS), crude protein and total carbohydratesin onion bulb.

On the other hand, the percentages of bulbs ranged from 3.5-6 cm in diameter, bolters and pickleswere the highest with the interaction between unfertilized and unweeding plants in both growing seasons.

In this regard, the interaction between the highest rate of nitrogen ha-1and hand weedingmethodsignificantly increased yield ha-1.In addition,thehighest values ofyielddue to the interaction between the highest rate of nitrogen ha-1and hand weedingmethodwere12.59 and 13.51 ton ha-1, when compared to the interaction between unfertilized and unweeding plants(4.29 and 4.19 ton ha-1) in both growing seasons, respectively.