Seaweed extracts for agricultural crops have long been used with high success. Their global market value is indeed high primarily due to the manifold benefits derived. Recently, seaweed extracts were applied in seaweed from micropropagation specifically for tissue culture, and also in land-sea-based nurseries and field cultivation, and also disease, epi-endophytes mitigation, as well as improvements for hydrocolloid (carrageenan) qualities. Applications of seaweed extracts were first used to benefit Ulva, Kappaphycus and Eucheuma spp., but more recently the same technology has been tested with other red seaweeds, e.g.,  Eucheumatopsis, Gracilaria and Laurencia as well as the brown seaweed Saccharina. 
This presentation deals mainly with published applications of an extract from the brown seaweed Ascophyllum nodosum to eucheumatoids, i.e., Kappaphycus and Eucheuma spp. This discourse hopefully points the way to further research and innovations on a wider variety of commercially cultivated seaweeds. In particular, work is required to emulate the understanding gained from applications of phycostimulants to land plants and understand the varied modes of actions of various types of extracts, i.e., the algal-based, molecular pathways which determine production, quality  and also mitigate abiotic and biotic stresses such as diseases and epi-endophytes in the eucheumatoids  – all mechanisms which are poorly understood at present, but which are key to future phyconomic sustainability and prosperity.