Effect of foliar application of zinc nanoparticles on growth and yield of grain sorghum (Sorghum bicolor L Moench) under drought conditions

Water stress, can negatively impact the productivity of sorghum. To study the effects of foliar use of zinc nanoparticles on sorghum (Sorghum bicolcr L Moench) varieties production under different water regimes, were studied during the 2022 and 2023 seasons at Tamiya Experiment Station, Fayoum Governorate, Agricultural Research Center, Egypt. The results showed that exposure to increasing irrigations intervals resulted significant reduction in SPAD and Fv/fm values, performance index, 50% flowering and leaf area index, yield and yield characteristics traits across all sorghum varieties tested. Increasing the irrigation period from 10 to 15 and twenty day reduces grain yield by 28.48 & 56.29 and 37.58 and 57.05 %, in both seasons. However, the use of Zn nanoparticles was significantly enhance grain yield, leaf area index, ear length and diameter, weight of 1000 grains and grains ear weight in the sorghum varieties under normal irrigations and increasing water periods. In both seasons, irrigated sorghum plants every 10 days and planted Shandawil 1 variety and sprayed at a level 100 PPM of zinc oxide nanoparticles fertilizer gave significantly the highest grain sorghum yield (2.07 and 1.93 ton/fed.). According to using the relative drought index, with values ranging from 1.13 to 1.23 for Shandawil 1 variety, 0.75 to 0.84 for the Dorado variety under 15 day irrigation intervals, and the values ranging from 0.82 to 0.78 for Shandawil 1 variety, 0.42 to 0.44 for the Dorado variety under 20 day irrigation intervals.