Paper presented at the 52nd CFCS Annual Meeting, Guadeloupe, July 10-16, 2016 Aerated system A concrete brick trough was constructed under greenhouse conditions and was filled with water in which several air stones, connected to a pump, were immersed. These air stones served to continuously aerate the water within the trough. Two (2) gallon buckets were filled with different layers of planting mediums, namely; Promix, Promix-Soil, PromixSharp Sand, Sharp Sand-Promix, Promix-Sharp Sand-Promix, Sharp Sand-Promix-Sharp Sand. Two holes were drilled in each bucket approximately 4 inches below the top of the bucket, in order to allow water to flow into it. Watercress planting material was sourced from a nearby market place, leaves were trimmed and the stalks were cut into 4-5 inch pieces. Six stalks of watercress were secured into the planting material of each bucket. Each week, Blaukorn fertilizer (12:12:17) was applied in accordance with the farmer’s rate, at 0.12grams for each 415.5cm2 bucket. On a daily basis, pH, temperature, electrical conductivity and total dissolved solids were measured and recorded. Additionally, every 2 weeks, number of stems, stem length, number of leaves and dry and fresh weights were measured and recorded. Figure 2. Photo displaying the continuously aerated system for watercress production utilizing different planting media under shade conditions
Results and discussion Days after planting 17 25 32 45 Average Days after planting 17 25 32 45 Average Days after planting 17 25 32 45 Average Days after planting 17 25 32 45 Average
Average fresh weight for full sunlight condition (g) 7.38 0.00 5.85 6.54 4.94
Average fresh weight for shaded condition (g) 10.30 6.71 8.23 22.30 11.89
Average dry weight for full sunlight condition (g) 0.80 0.00 0.55 0.59 0.49
Average dry weight for shaded condition (g) 0.77 0.47 0.62 1.45 0.83
Average stem length for full sunlight condition (cm) 18.10 0.00 11.53 13.10 10.68
Average stem length for shaded condition (cm) 16.73 17.87 17.70 18.10 17.60
Average number of leaves for full sunlight condition 35 0 17 9 15
Average number of leaves for shaded condition 20 16 18 13 17
Table 1: Data from full sunlight conditions versus shaded conditions
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