Effects of droplet size and spray interval on root-to-shoot ratio, photosynthesis efficiency, and nutritional quality of aeroponically grown butterhead lettuce

Abstract

The proper selection of the atomizer (droplet size) and nutrient solution spray interval is one of the most important factors to be investigated in aeroponics systems for sustainable agriculture. The aim of this study was to research the effects of four aeroponics atomizing nozzles (one air-assisted; A 1 , two air-less; A 2 and A 3 , and one ultrasonic fogger; A 4 ) with droplet sizes of 11.24 µm, 26.35 µm, 17.38 µm, and 4.89 µm, respectively, four spray intervals (15 min (I 1 ), 30 min (I 2 ), 45 min (I 3 ) and 60 min (I 4 )) at a 5 min of constant spray time by atomizing the Hoagland's nutrient solution on growth, root-to-shoot ratio, photosynthesis characteristics, pigments, and nutritional quality of the aeroponically grown lettuce. The experimental results demonstrated that in A 1 atomizer and I 2 interval, the growth, photosynthesis efficiency, chlorophyll, carotenoids, and nutritional values of the lettuce were significantly higher compared to that grown in A 2 and A 3 atomizers at all spray intervals. The shoot developments were more constrained than root, prominent to the alteration of root-to-shoot ratio (fresh and dry) in the influence of different droplet sizes and spray intervals. Moreover, the plants did not grow well in A 4 atomizer associated with proposed spray intervals. The results disclosed that there was an obvious interaction between droplet sizes (atomizers) and spray intervals for growth, the ratio of root to shoot, photosynthesis efficiency, pigments, and nutritional quality of the aeroponically grown lettuce. This research study increases the awareness of the proper droplet size (atomizer) and the regulation of nutrient solution spray interval for leafy vegetables grown in an aeroponics system.

Kajian Sistem Hidroponik Menggunakan Ultrasonic Atomizer Untuk Pembibitan TSS (True Shallot Seed) Bawang Merah

“…Performa pengabutan larutan nutrsi dilakukan dengan cara membandingkan konsentrasi larutan pada wadah dengan konsentrasi yang dikabutkan oleh modul atomizer dengan menggunakan persamaan (1). Pengukuran performa mengacu pada persentase (%) perbandingan nilai luaran dengan nilai masukan sebuah unit, dalam hal ini konsentrasi larutan nutrisi (Tunio et al, 2022).…”

Metabolic and Developmental Changes in Germination Process of Mung Bean (Vigna radiata (L.) R. Wilczek) Sprouts under Different Water Spraying Interval and Duration

“…In onion, total phenolic contents decreased as spraying duration increased, while total flavonoid contents generally increased [11]. Another research showed that the root length of better-head lettuce increased when the spraying interval is relatively short [13].…”

“…e level of antioxidant and sprout development were primarily affected by the spraying interval and duration [10]. In various plant species, the effects of the spraying interval and duration on the morphological and biochemical changes have been reported earlier [11][12][13]. In onion, total phenolic contents decreased as spraying duration increased, while total flavonoid contents generally increased [11].…”

Analysis of the Factors Affecting the Deposition Coverage of Air-Assisted Electrostatic Spray on Tomato Leaves

“…In electrostatic spraying, the main factors affecting droplet deposition on crop leaf surface are charging voltage, spraying pressure, spraying height, droplet size, etc. [16][17][18].…”