Optimal nutrient solution and dose for the yield of nuclear seed potatoes under aeroponics

Authors: SILVA FILHO, JAIME BARR - University Of California, Riverside; FONTES, PAULO - Universidade Federal De Vicosa; Ferreira, Jorge; CECON, PAULO - Universidade Federal De Vicosa; CRUTCHFIELD, ELIZABETH - University Of California, Riverside

Submitted to: Agronomy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/9/2022
Publication Date: 11/11/2022
Citation: Silva Filho, J., Fontes, P., Ferreira, J.F., Cecon, P., Crutchfield, E. 2022. Optimal nutrient solution and dose for the yield of nuclear seed potatoes under aeroponics. Agronomy. 12(11). Article 2820. https://doi.org/10.3390/agronomy12112820.
DOI: https://doi.org/10.3390/agronomy12112820

Interpretive Summary: The aeroponic production of seed potatoes is a booming alternative for arid and semi-arid areas where fresh water is scarce and soilborne diseases and nematodes preclude the production of certified propagation materials. However, the salinity effect of widely used nutrient solutions has not been evaluated in salt-sensitive crops such as potato. Salt-sensitive crops can suffer 50% or higher yield reduction when irrigation water salinity surpasses the crop salinity threshold. Our study established 1) the best of two nutrient solutions (Otazú vs. modified Furlani) at 20, 50, 100, and 150% of the crop-recommended dose for seed-potato production, 2) growth indexes to diagnose plant N status, and 3) a prognosis for the aeroponic yield of nuclear seed potatoes based on the best growth indexes. The 4th-leaf indexes correlated with yield parameters indicating that they can be used to prognosticate the final potato minituber yield. Our results suggest that the following parameters can diagnose the N status in potato plants: 4th leaf area, length, and dry weight, SPAD, and 4th leaf area. Although both nutrient solutions had a similar nitrogen concentration, Otazú’s nutrient solution at 100% of the recommended nitrogen dose for potato had lower salinity than the modified Furlani’s solution and was the best to produce nuclear seed potatoes. Our results will help seed-potato breeders and producers choose nutrient solutions of low salinity to accommodate salt-sensitive crops such as potatoes.

Technical Abstract: The aeroponic production of certified seed potatoes is a booming alternative for arid and semi-arid areas where fresh water is scarce and soil-borne diseases and nematodes preclude field production. Although widely used in aeroponics, nutrient-solution salinity effects have not been evaluated in potatoes. This study aimed to (1) establish the best of two nutrient solutions (Otazú vs. modified Furlani) at 20, 50, 100, and 150% of the crop-recommended dose for seed-potato production, (2) evaluate growth indexes to diagnose plant-N status, and (3) establish a prognosis for the yield of nuclear seed potatoes under aeroponics. At 21 days after transplanting, there was a significant correlation between the nitrate-N petiole-sap test and some of the parameters measured. The 4th leaf indexes correlated with yield parameters indicating that they can be used to prognosticate the final minituber yield. The best parameters to diagnose the N status in potato plants were: 4th leaf area, length, and dry weight (Otazú’s), SPAD, and 4th leaf area (modified Furlani’s). Although both nutrient solutions had similar nitrogen concentrations, Otazú’s nutrient solution at 100% of the recommended nitrogen dose had lower salinity than the modified Furlani’s solution and was the best to produce nuclear seed potatoes.