Commercial Extract From the Brown Seaweed Ascophyllum Nodosum (Acadian®) Improves Early Establishment and Helps Resist Water Stress in Vegetable and Flower Seedlings

Many vegetable and ornamental bedding plant crops are grown in plug trays and cell packs under greenhouse conditions prior to transplantation into the field or landscape. The development of a large, healthy root system is important for young seedlings to help withstand the inevitable transplantation shock. Commercial extracts of Ascophyllum, are known to improve root development of horticultural plants as well as to help alleviate some symptoms typically associated with abiotic stresses such as drought. Greenhouse experiments in Cornwallis, Nova Scotia were designed to test the effects of Acadian^® seaweed extract on root development in lettuce, melon, tomato, pepper, celery, petunia, pansy and cosmos. Acadian^® treatments, in combination with 10-52-10 N-P-K fertilizer, were applied as a drench and compared to plants which received only 10-52-10 as control. The roots and leaves of plants from each treatment were examined with WinRhizo^® root and WinFolia^® leaf image analysis systems. Time lapse videos were also used to record results. Replicated trials showed significant improvements in root length, surface area, volume and leaf area when the Acadian^® was applied in combination with fertilizer. Further studies examined the effects of this commercial seaweed extract on water stress in pepper, lettuce, tomato, petunia and pansy. Results showed that plants treated with Acadian^® plus fertilizer were more water stress tolerant than those treated with fertilizer only. The application of Acadian^® extended the time before the plants began to succumb to water stress compared to fertilizer treated controls. These results suggest that applications of the Ascophyllum-based, commercial extract improves early root and shoot development and provides protection against water stress under the conditions tested. All of these positive attributes have important commercial applications, particularly for greenhouse operators and suppliers of bedding plants.