Basil Performance Evaluation in Aquaponics

Abstract

<jats:p>Basil (<jats:italic>Ocimum</jats:italic> sp.) is a fast-growing, high-value cash crop for aquaponics. Plant suitability evaluation in tropical conditions is critical to recommend new cultivars, increasing grower portfolio and minimizing the production risks associated with untested selections. Two trials were conducted to identify suitable basil cultivars for tropical outdoor aquaponics production using the University of the Virgin Islands (UVI) Commercial Aquaponics System in the U.S. Virgin islands. We evaluated five basil cultivars in Summer 2015 (Genovese, Lemon, Purple Ruffles, Red Rubin, and Spicy Globe), and seven cultivars in Fall 2015 (Cinnamon, Genovese, Lemon, Purple Ruffles, Red Rubin, Spicy Globe, and Thai). In both trials, 3-week-old seedlings were transplanted in net pots at a density of 1.5 plants/ft<jats:sup>2</jats:sup> (16.15 plants/m<jats:sup>2</jats:sup>). The 6-inch portions and upper portions of the canopy were harvested as a salable product and the resultant material (leaves and stems) considered as total yield per square meter. In the summer, yield was higher in ‘Genovese’ (14.91 kg·m<jats:sup>−2</jats:sup>) and ‘Spicy Globe’ (13.99 kg·m<jats:sup>−2</jats:sup>); ‘Purple Ruffles’ resulted in the lowest yield (4.18 kg·m<jats:sup>−2</jats:sup>). Leaf anthocyanin was greater for the red cultivars Red Rubin [28.35 anthocyanin content index (ACI)] and Purple Ruffles (34.36 ACI) compared with the other cultivars. Chlorophyll content was the highest in ‘Genovese’ [48.59 chlorophyll content index (CCI)]. In the fall, ‘Cinnamon’ (6.60 kg·m<jats:sup>−2</jats:sup>), ‘Genovese’ (6.70 kg·m<jats:sup>−2</jats:sup>), and ‘Spicy Globe’ (6.35 kg·m<jats:sup>−2</jats:sup>) showed the highest yield and ‘Purple Ruffles’ the lowest (1.68 kg·m<jats:sup>−2</jats:sup>). Leaf anthocyanin differed in all cultivars, with the higher values in Purple Ruffles (80.5 ACI) and Red Rubin (36.5 ACI). Chlorophyll content was a response of plant growth and cultivar, with values increasing over time and ranging from 12.06 (Lemon) to 17.99 CCI (Cinnamon). Plant growth index (PGI) was higher than that of other cultivars in Genovese and Lemon on day 58 (summer), and higher in Cinnamon on day 87 (fall). Yield was greater during the summer, which was calculated from May to August, in comparison with the fall, calculated from September to November. Yield declined for the fourth harvest in the summer, indicating that growers may need to end production after the third harvest and replant the crop. The results of this experiment indicate that basil has potential as a specialty, short-season, and high-value crop in the UVI Commercial Aquaponics System. Of the cultivars tested, Genovese and Spicy Globe were the highest yielding cultivars within the environmental and geographical conditions of this study for two consecutive seasons (summer and fall).</jats:p>

Canopy Size and Light Use Efficiency Explain Growth Differences between Lettuce and Mizuna in Vertical Farms

“…The ACI of both species did indeed increase with increasing PPFD ( Figure 4 B). However, the ACI of both crops was much lower than those previously reported for red leaf basil (ACI of 28–81) [ 26 ] and pak choi (ACI of 35–65) [ 27 ]. Consistent with the low ACI, we did not observe any red coloration on leaves of mizuna or lettuce, with increasing PPFD.…”

Basil (Ocimum basilicum) Cultivation in Decoupled Aquaponics with Three Hydro-Components (Grow Pipes, Raft, Gravel) and African Catfish (Clarias gariepinus) Production in Northern Germany

“…Under coupled aquaponics conditions outdoors in the Caribbean (UVI-commercial-aquaponics-system), the mean plant weight of basil was lower under batch (286.5 g) and staggered (244.7 g) plant cultivation with Nile tilapia (O. niloticus) [64]. Higher plant yield of Genovese sweet basil was reported in the same system with tilapia in the summer with calculated 923 g per plant (16.15 plants/m 2 with yield of 14.91 kg/m 2 ), whereas the harvest in fall with approximately 415 g per plant (16.15 plants/m 2 with yield of 6.70 kg/m 2 ) corresponded to wet weights of plants in our gravel bed and was higher than plant weights in grow-pipe and raft subsystems [52]. Compared to commercial greenhouse O. basilicum production, our plants performed well in terms of yield, especially since no fluid fertilizer was added.…”

“…Electrical conductivity (EC) seemed to be optimal as conducted for basil hydroponic greenhouse production with 1600 µS/cm [47], though the EC can be even higher (2800 µS/cm) [49]. In aquaponics generally, lower conductivity values are described, ranging from 300-600 µS/cm [50], and in commercial outdoor coupled aquaponics, conductivity levels were reported between 0.8 mS/cm [51] and 0.65-0.69 dS/m [52] with the production of Nile tilapia (Oreochromis niloticus) and basil cultivation.…”

Analysis of application of aquaponic system as a model of the circular economy: A review

“…E.g., leafy vegetables are the most common type of plant grown in these systems because they grow well in concentrated water with nitrogen, have a short growth period, do not require a large number of nutrients and are generally in great demand in the world (Bailey and Ferrarezi, 2017). Commercial producers most often grow the following plant species: basil (Ferrarezi and Bailey, 2019), various types of lettuce, tomato, kale, paprika, and cucumber.…”