Improving growth, quality and increasing yield of onion plants are important goals for growers to
realize the requirements of the market and the consumers. Two field experiments were carried out during two
successive seasons; 2013/2014 and 2014/2015 at a private farm in El-Mahalla El-Kubra district, El- Gharbia
Governorate, Egypt to find out the influence of some growth- stimulants at different rates viz., yeast extract (2, 3and 4
gl-1 ) seaweed extract (3,4 and 5 gl-1) and NAA (0.8, 1.2 and 1.6 gl-1) on vegetative, yield, and its components as well
as bulb storability of onion plants cv. Giza Red. Foliar spray with growth stimulants were applied thrice at 45, 60 and
75 days after transplanting. The design of the experiment was a complete randomized blocks with three replicates. The
results showed that foliar spray of seaweeds extract at 4 or 5 g/l followed by yeast extract 4g/l had the highest
stimulation effect on onion plant growth traits (plant height, number of leaves and leaf fresh weight) total bulb yield and
its components as well as N, P and K content of bulb tissues. Application of seaweed extract (5 g/l) showed the least
weight loss (%) and decay (%) of bulbs compared to the control and other treatments.