Maize (Zea mays sp) is one of the most important basic grains in our diets, and requires high levels pf nitrogen and phosphorus for optimum growth. However, phosphorus is problematic due to its high reactivity in the soil matrix, meaning that it is fixed in a very short time and inaccesible to plants. The lupinus genus, and more specifically, Lupinus albus through its root clusters, or proteoid roots, have the ability to solubilize portions of phosphorus when it is found in a limited environment. The objetive of the current study was to evaluate the effect of lupinus montanus under phosphorus stress conditions intercropped with maize, utilizing sandy soils with calcium phosphate bands. Materials and Methods: Work was conducted in growth chambers using rhizotrons, which allowed the authors to observed the growth and root behavior of both species (Lupinus monatnus and maize), The SAS 9.0 program was used for the statistical Analysis and ANOVA and tukey test were perfomed. Results : The phosphorus analysis in the plant tissue indicated that is concentration in maize was slightly higher in intercropping conditions than in monoculture planting. Conclusion: From this, we calculated that lupinus montanus is capable of solubilizing portions of phosphorus making available for other crops.; likewise, we also observed that proteoid structures did not develop, leaving the study open for other wild species.

Citron watermelon (Citrullus lanatus var. citroides) is an extremely drought-tolerant cucurbit crop widely grown in sub-Saharan Africa in arid and semi-arid environments characterized by drought. The species is a C3 xerophyte used for multiple purposes, including intercropping with maize and has a deep taproot system. The deep taproot system plays a key role in the species’ adaptation to dry conditions. Understanding root system development of this crop could be useful in identifying traits for breeding water-use efficient and drought-tolerant varieties. This study compared root system architecture of citron watermelon accessions under water-stress conditions. Nine selected and drought-tolerant citron watermelon accessions were grown under non-stress (NS) and water stress (WS) conditions using the root rhizotron procedure in a glasshouse. The following root system architecture (RSA) traits were measured, namely: root system width (RSW), root system depth (RSD), convex hull area (CHA), total root length (TRL), root branch count (RBC), total root volume (TRV), leaf area (LA), leaf number (LN), first seminal root length (FSRL), seminal root angle (SRA), root dry mass (RDM), shoot dry mass (SDM), root–shoot mass ratio (RSM), root mass ratio (RMR), shoot mass ratio (SMR) and root tissue density (RTD). The data collected on RSA traits were subjected to the analysis of variance (ANOVA), correlation and principal component analyses. ANOVA revealed a significant (p < 0.05) accession × water stress interaction effect for studied RSA traits. Under WS, RDM exhibited significant and positive correlations with RSM (r = 0.65), RMR (r = 0.66), RSD (r = 0.66), TRL (r = 0.60), RBC (r = 0.72), FSRL (r = 0.73) and LN (r = 0.70). Principal component analysis revealed high loading scores for the following RSA traits: RSW (0.89), RSD (0.97), TRL (0.99), TRV (0.90), TRL (0.99), RMR (0.96) and RDM (0.76). In conclusion, the study has shown that the identified RSA traits could be useful in crop improvement programmes for citron watermelon genotypes with enhanced drought adaptation for improved yield performance under drought-prone environments.