Relative Growth Rates and Root Colonization of Mycorrhiza-Inoculated Corchorus olitorius L. Cultivars as a Measure of Crop Productivity

Mycorrhizae utilization is an integral part of the strategy for adapting to climate change in semi-arid regions. A controlled experiment was conducted at the University of Limpopo, South Africa, to determine the effects of arbuscular mycorrhiza fungi (AMF) and soil type on crop growth and root colonization of Jew’s mallow. Treatments comprised two levels of mycorrhiza (with and without), two soil sources (Ofcolaco and Syferkuil), and three Jew’s mallow cultivars (“Amugbadu”, “Oniyaya”, and a landrace). The results revealed that the Amugbadu cultivar produced the highest Mycorrhizal growth response (MGR) in Syferkuil soil, whereas the Oniyaya cultivar was the highest in Ofcolaco soil. MGR in Ofcolaco soil was six times higher than in Syferkuil soil. AMF-inoculated Amugbadu consistently resulted in the highest crop growth rate (CGR) in Ofcolaco soil. The inoculated landrace was superior in CGR, compared to the uninoculated landrace in Syferkuil soil. Approximately 71.23–75.86% of the Jew’s mallow roots were colonized by AMF in both soil sources, with inoculated “Amugbadu” producing the highest root colonization. The landrace root colonization was inferior in both soil sources. Our results indicate that incorporating AMF in Jew’s mallow could improve root colonization, growth rate, and productivity in the semi-arid regions of South Africa, depending on soil type.