Response of vegetative and morphological characteristics of common mesquite (Prosopis juliflora (Swartz) DC.) seedling, under different humidity and light factors

Light and moisture are two important environmental factors that influence seedling growth, therefore the choice of appropriate combinations of these factors is important for afforestation projects. This study aimed to determine the effects of different light and moisture combination treatments on some morphologic and vegetative characteristics of common mesquite (Prosopis juliflora (Swartz) DC.).To this aim, seeds were first collected in consistent region and season. The study was performed as a factorial experiment in a complete randomized design 180 plots distributed in 10 replicates. Two irrigation levels (daily and every other day) and three irradiance levels (full sunlight, 75% and 50% sunlight) were performed in six treatments. Quantitative characteristics of seedlings were measured three times by random sampling (10 seedlings from each treatment). At each measurement time, results showed significant differences in majority of the measured characteristics amongst the six treatments. The best response of vegetative traits and seedling quality index were observed by combining full sunlight and two-day irrigation interval. However, different treatments did not affect shoot/root biomass ratio, yet led to significant differences in seedlings slenderness coefficient. Results also showed that the highest net assimilation rate was observed under full sunlight and daily irrigation treatment. Moreover, the highest relative growth rate was observed in full sunlight treatments. This study concludes that shade is a restricting factor for growthof Prosopis juliflora seedlings, thus they entail full sunlight.