AUTHOR=Farqani Ali Al , Cheng Lailiang , Robinson Terence L. , Fazio Gennaro 

TITLE=Effect of solution pH on root architecture of four apple rootstocks grown in an aeroponics nutrient misting system

JOURNAL=Frontiers in Plant Science

VOLUME=Volume 15 - 2024

YEAR=2024

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2024.1351679

DOI=10.3389/fpls.2024.1351679

ISSN=1664-462X

ABSTRACT=The pH level of the solu�on in the rhizosphere is an important factor that determines the availability and mobility of nutrients for plant uptake. Solu�on pH may also affect root distribu�on and architecture of apple rootstocks. In this study, we evaluated the effect of solu�on pH on root system development of apple rootstocks using an aeroponics system that was designed and made at Cornell AgriTech Geneva, USA. Four Geneva® apple rootstocks (G.210, G.214, G.41, G.890)  were grown in an aeroponic system under nutrient solu�on mis�ng featuring con�nuously adjusted pH levels to three pH treatments (5.5, 6.5 and 8.0). Root development was monitored for 30 days and evaluated regularly for distribu�on and root mass. Images of developed roots grown in the aeroponic system were collected at the end of the experiment using a high-resolu�on camera and analyzed using GiA Roots® so�ware which generates root architecture parameter values in a semi-automated fashion. The resul�ng root architecture analysis showed that Geneva® rootstocks were significantly different by two architecture parameters. The length to width ra�o analysis represented by two GiA Roots parameters (Minor to Major Ellipse Ra�o and Network Width to Depth Ra�o) showed that G.210 was flater when compared to G.890 which had a greater tendency to grow downward. Rootstocks G.214 and G.41 displayed similar growth values. The solu�on pH affected most root architecture parameter measurements where overall root growth was higher at pH 8 compared to pH 5.5 and 6.5 which showed similar growth. In general, average root width tended to decrease with higher pH values. While there were no significant differences in leaf nutrient concentra�ons of P, K, Ca, Mg, S, B, Zn, Cu, and Fe within the four rootstocks, the pH level of the solu�on had a significant effect on P, Ca, and Mn. This research is the first of its kind inves�ga�ng the effect of pH on root architecture in a soil free (aeroponic) environment and may have implica�ons for apple root behavior in field condi�ons where pH levels are different.