Possibility of overcoming salinity disadvantages on Lettuce plants using Humic Acid and Mycorrhiza

الملخص EN

Two pot experiments were carried out during the two successive winter seasons of 2019 and 2020, in a private farm at Ahmed Rami village, El-Bostan area, EL- Beheira Governorate, Egypt.

The main purpose of this work is to investigate the effect of humic acid and inoculation with mycorrhiza under different salinity levels on the growth and chemical properties of Crisp head lettuce, iceberg, (Lactuca sativa var.

capitata L.

'Calmar').

The goal is to expand lettuce cultivation in areas irrigated with high salinity concentration water.

This experiment included 24 treatments which were the combinations between four salinity levels (tap water, 2.0, 4.0 and 6.0 mS/cm), and six treatments; i.e., five ameliorative treatments (mycorrhiza), (humic acid at 1.5 g / L), (humic acid at 3.0 g / L), (humic acid at 1.5 g / L + mycorrhiza), (humic acid at 3.0 g / L + mycorrhiza) in addition to the treatment of distilled water as a control treatment.

The experimental layout was a split-plot system in a randomized complete blocks design, whereas the salinity levels were arranged in the main plots and the soil application treatments of humic acid and mycorrhiza were randomly distributed in the sub-plots.

The obtained results, generally, showed, that all values of the tested characters decreased with increasing salinity levels.

The reduction rate on any character varied depending on the imposed level of salinity stress.

Application of humic acid and /or mycorrhiza revealed significant effect in improving all studied characters as compared to the control treatment, in both seasons.

Application of humic acid at 3.0 g / L + mycorrhiza achieved the highest average values of leaves number, head weight, total fresh weight, head dry weight, root length, root fresh weight, root dry weight, nitrogen, phosphorus, potassium, calcium, protein, total chlorophyll and potassium / sodium ratio and reduced sodium contents compare to the other treatments in both seasons.

The combined treatment of humic acid at 3.0 g / L + mycorrhiza with tap water salinity level gave the highest mean values of the most tested characters.

The conclusion of this research suggested the possibility of utilizing the combination between humic acid and mycorrhiza to enhance growth of lettuce plants and minimize the damaging effect of salinity.