Use of Biostimulants: Towards Sustainable Approach to Enhance Durum Wheat Performances

The use of biostimulant (BS) holds a promising and environmental-friendly innovation to address current needs of sustainable agriculture. The aim of the present study is twofold: (i) assess the potential of durum wheat seed coating with microbial BS ('Panoramix', Koppert), a mix of Bacillus spp., Trichoderma spp., and endomycorrhiza, compared to two chemical products ('Spectro' and 'Mycoseeds') through germination bioassay, pot and field trials under semi-arid conditions, and (ii) identify the most effective method of BS supply ('seed coating', 'foliar spray', and 'seed coating + foliar spray') under field conditions. For this purpose, three modern durum wheat cultivars were tested. 'Panoramix' was the most efficient treatment and enhanced all germination (germination rate, and coleoptile and radicle length), physiological (relative water content, chlorophyll content, and leaf area), and agro-morphological (plant height, biomass, seed number per spike, thousand kernel weight, and grain yield) attributes. Unexpectedly, the individual application of 'Panoramix' showed better performance than the combined treatment 'Panoramix + Spectro'. Considering the physiological and agro-morphological traits, the combined method 'seed coating + foliar spray' displayed the best results. Principal component analysis confirmed the superiority of 'Panoramix' treatment or 'seed coating + foliar spray' method. Among tested durum wheat cultivars, 'Salim' performed better especially under 'Panoramix' treatment, but in some case 'Karim' valorized better this BS showing the highest increase rates. Based on these study outcomes, 'Panoramix' might be used as promising sustainable approach to stimulate durum wheat performance.