Water stress, nano silica, and digoxin effects on minerals, chlorophyll index, and growth in ryegrass

Water shortage worldwide mandates minimum use of irrigation water with maximumefficiency and productivity in all agricultural crops, landscape plants and turf. The objective inthis experiment was to study the effect of two levels of evapotranspiration-based (ETc) droughtin combination with two levels of nanosilicon dioxide (SiO2; NanSi1=1 mM and NanSi=2 mM),two levels of digoxin (Dig1=0.25 mg.l-1 and Dig2=0.5 mg.l-1) and Dig1 plus NanSi1 onmineral nutrient concentration, chlorophyll index, visual performance of perennial ryegrass(loliumperenne) under climatic conditions of the southwest Idaho in the Intermountain WestRegions of the United States. Clippings with 50% ETc had higher percentage dry weight butlower chlorophyll index and visual rating than those with 75%. Clippings of 75% ETc treatmenthad significantly higher concentrations of nitrogen (N), potassium (K), zinc (Zn) and copper(Cu) but lower sodium (Na), than those of 50% ETc treatment. Considering all mineral nutrientvalues, chlorophyll indices and visual performance ratings, we conclude that application of 75%ETc is sufficient for maintaining a healthy lawn with satisfactory appearance while we can save25% water as compared to application of water at 100%. Root growth was not affected by anyof these treatments. Based on the results of this study, applications of NanSi1 or Dig1, eitherindividually or simultaneously, can slow the process of quality decline in perennial ryegrass turfunder extremely severe drought conditions.