Morphological Acclimation of Durum Wheat Spikes in Response to Foliar Micronutrient Applications

A cultivation of durum wheat that established in a field with soil poor in micronutrients received foliar applications at the initiation of the dough stage towards biofortifying the spikes with micronutrients. The morphology of the spike is crucial in determining grain yield, and the spikelets, the components of the inflorescence, influence each other. The number and arrangement of these spike components affect spike length, spike weight, spike chaff (the non-grain biomass in the spike), grain number per spike, grain weight per spike, and spikelet number per spike, and all contribute to final grain yield per spike. The spike's developmental program responded to the interventions regarding the morphological traits; this response was analyzed for each spike component, and an acclimation program seemed to be activated by each intervention. Cysteine or methionine has been added as a potential enhancer of the biofortification process, and the application mixtures were coupled with selected surfactants, an organosilicon ethoxylate or an alcohol ethoxylate one, while products with targeted composition for biofortification with micronutrients have also been studied. Their effect on the developmental acclimation program of the treated spike is presented and discussed. The action of this program provided grains of similar weight, regardless of the intervention.