The researchers studied how applying zinc nano-chelate to wheat plants at different growth stages affects their growth and yield. They found that applying zinc nano-chelate to the soil and leaves during the grain filling stage increased chlorophyll content by 72-77% and biomass by 54%. Foliar application of zinc nano-chelate also led to a 66% increase in ear yield. These results suggest that agronomic biofortification with zinc can improve wheat phenology and yield.