The experiment was conducted in a plastic house of the vegetable research field Horticulture Department, College of Agriculture, University of Dohuk, Iraq, to study the effect of seaweed extracts (seaforce and seamino) with concentrations (0.0, 1.5ml/L) for both extracts and exposure to low temperature (7±1)οC for three durations (0, 5 and 10) days on the flowering and yield of two cucumber (Cucumis sativus L.) cultivars. The extracts were sprayed three times on seven days intervals. Seeds were sown on February 22th, 2011. The seedlings were exposed to low temperature after expansion of cotyledon leaves. The experiment was arranged in a factorial experiment within split-split plot in a randomized complete block design with four replicates. The results showed that treatment with both extracts significantly enhanced number of female flowers and fruit setting percentage. The dual interaction between factors (seaforce + seamino) + cultivar and (seaforce + seamino) + temperature exposure for (5) days were significant on flowering characters. The triple interaction (seaforce + seamino) + low temperature exposure for (5) days + Karol cultivar increased flowering characters, and for yield characters its showed that (seaforce + seamino) significantly increased cucumber yield (number of fruit per plant, fruit weight, yield per plant, yield.m2and total yield).
