The response of onion plants Allium cepa L. to foliar spray with different concentrations of seaweed extract (Algaren)

The experiment was carried out in the General Commission for Scientific Agricultural Research in the nursery of Al-Adaway in 2014 and 2015 seasons to study the effect of foliar spraying with seaweed extract (Algaren, Seaweeds and Seaweed Products) on local red onion growth and the yield of dry bulbs and produce of seeds. Spray treatments: (control/distilled water, 5, 10, and 15 ml/l Algaren) were applied four times during the season. The complete randomized block design was used with four replicates per treatment. The results showed that spraying the onion plants emerged from bulblets (Resulting from seed cultivation( with Algaren extract has improved the vegetative growth, which was reflected on both productivity indicators diameter and weight bulb , and has also increased the hardness of the bulb and its content of dry matter; the treatment of 15 ml/l was significantly superior in dry bulb yield and bulb’s dry matter content (3.5 kg/ m2,21.3 %) comparing to the control (2.1 kg/m2, 19.5 %). Spraying with Algaren showed positive effect in improving flowering growth indicators of onion plants cultivated for seed production. that was reflected on increasing the seed production indicators, plants treated with 15 ml/l were significantly superior in average number of seeds in both capsule and umbel also in plant productivity of seeds (4.9 seed/capsule 3454 seed/ umbel, 33.5 g/per plant, respectively). Comparing to the rest of the treatments and the control (4.0 seed/umbel, 2172 seed/capsule, 23.6 g/per plant). In conclusion, spraying with Algaren has promising and positive effects on increasing vegetative growth, bulb and seed production