Effects of Acidity and Aluminium Toxicity on faba bean

It is important to study the factors which inhibit the cultivation of major crops which serve as a source of food and feed, with various other medicinal values as well. One of these factors is soil degradation and infertility which could be due to high amounts of toxic elements or unfavourable pH conditions. Faba bean is one such crop and is widely affected by the acidity and aluminium toxicity in soil. In this study, an effort has been made to observe the varying tolerance of faba bean accessions and understand the underlying mechanisms used by them under stress conditions. The accessions selected were Aurora, Babylon and Kassa. Each accession was subjected to three treatments and were grown in pH 7 (control), pH 4.5 (acid treatment) and pH 4.5 + Al3+ (aluminium treatment). The pH of peat for acidic treatment was reduced to 4.5 using Sulphuric acid (H2SO4) and for aluminium treatment, Aluminium sulphate (Al2(SO4)3) was added in addition to the acid. At 16 Day after Sowing (DAS) and 30 DAS the physiological data was collected which comprised of chlorophyll concentration (SPAD value), stomatal conductance, leaf temperature and photosynthesis rate. At 35 DAS, the experiment terminated and the shoot data (fresh and dry weights of leaves and stem; and leaf area) of each plant was recorded. Then the root data (tap root length, quality and quantity of nodules and photographs of roots) was taken for each plant. ICP samples for peat, shoot and shoot were also analysed. The data collected were subjected to analysis of variance using R version 4.0.3. (means separated by 5% significance level). From the plant data, Aurora was found to be tolerant. Kassa was sensitive (especially the roots) and Babylon was sensitive to both acid and aluminium treatments. The ICP results provided the reason for this tolerance pattern and a higher concentration of elements needed for plant growth such as P and S were found to be higher in aluminium and acid treatments