Effect of using the nano-organic fertilizer Optimus Plus in three saline solutions on the growth of date palm offshoots (Phoenix dactylifera L., Al-Zamli cultivar)

Abstract

The research was conducted to determine the effect of using nano organic fertilizer on increasing the tolerance of date palms (Phoenix dactylifera L.) of the Al-Zamili variety in one of the orchards of Basra Governorate during the 2023-2024 growing season. Twenty-four young offshoots were selected that were as similar and homogeneous as possible in growth and free from pests and diseases. The offshoots were divided into two groups: the first group consisted of 12 offshoots without spraying with nano organic fertilizer and 12 offshoots with spraying with nano organic fertilizer. Irrigation was carried out with four saline solutions (0, 5, 10, and 15 dS/L) mixed with the irrigation water. The offshoots were sprayed with Optimus Plus nano bio-fertilizer at a concentration of 2.75 ml L⁻¹. The results indicated that spraying the Optimus Plus nano-organic fertilizer at the above concentration led to a significant increase in the leaf content of nitrogen, phosphorus, potassium, and total chlorophyll, recording the highest values ​​of 2.012%, 2.441 g/kg⁻¹, 7.931 g/kg⁻¹, and 19.776 mg/100 g⁻¹, respectively, compared to without spraying the nano-organic fertilizer. Irrigation water quality also had a significant effect on the leaf content of nitrogen, phosphorus, potassium, and total chlorophyll, with the 0.5 dS/m⁻¹ irrigation treatment significantly outperforming, recording the highest values ​​of (2.477 and 1.795)%, (2.230 and 2.245) g/kg⁻¹, (7.465 and 7.455) g/kg⁻¹, and (24.448 and 17.775) mg/100 g⁻¹, respectively. Regarding the interaction between the factors The interaction between nano-organic fertilizer and irrigation water quality was significant. The 0 and 5 dS/m¹ irrigation treatments with nano-organic fertilizer significantly increased leaf nitrogen, phosphorus, potassium, and total chlorophyll content. The 0 and 5 dS/m¹ irrigation treatments with nano-organic fertilizer application showed significantly higher levels, recording 2.470, 2.475%, 2.74%, 2.750%, 8.800, and 8.790 g/kg¹, and 24.750 and 24.450 mg/100 g¹, respectively. The study also revealed that the treatment without fertilizer application had a higher proline content in the leaves compared to the treatment with nano-organic fertilizer application, reaching a maximum of 0.835 µg/g¹. The 15 dS/m¹ irrigation treatment also recorded a higher value of 0.835 µg/g¹. These results indicate that the interaction between nano-organic fertilizer and irrigation water resulted in higher levels of the amino acid proline. The study showed that spraying the nano organic fertilizer onto palm seedlings under saline stress conditions can lead to increased nutrient absorption, increased tolerance to saline stress, and encouragement of vegetative growth. The results also showed that the interaction between the two factors in the study gave a significant advantage in most of the mentioned traits.