Abstract
This study consummated in the open field at the nursery of Hort. Res. Inst., A.R.C., Giza, Egypt during 2020 and 2021 seasons to explore the response of Jatropha curcas plants to EM (effective microorganisms) which was applied as soil drench at 3 ml/L, 5 times with one month interval. Plants cultured in 25-cm-diameter plastic pots filled with sand only as control (T1), sand + plant compost 10 % mixture (T2), T2 + EM (T3), sand + plant compost 20 % mixture (T4), T4 + EM (T5), sand + plant compost 30 % mixture (T6) and T6+ EM (T7). The obtained results showed that means of the different growth parameters ;expressed as: plant height, number of leaves / plant , leaf area , root length , as well as fresh and dry weights of stem, leaves and roots were ascending increased as the ratio of compost was increased in the soil especially with EM treatments compared to means of control in most cases of the two seasons, otherwise stem diameter trait, which progressively increased with the middle ratio of compost (20 %) and compost (20 %) + EM followed by the highest one (30 %) and (30%) + EM reached to the lowest values of compost (10 %) and (10 %) + EM over control in the first and second season. A similar trend was also obtained regarding the leaf content of chlorophyll a, b, carotenoids beside the percentages of N and total carbohydrates which were recorded the highest values with sand + compost (30%) subsequent sand + compost (20%) and sand + compost (10%) individually or with EM. Whereas, the leaf contents of P% and K% significantly increased in sand + compost (20%), (30 %) and then (10%) whether with EM or without. Hence, it can be recommended to drench EM (3 ml/l) in sand soil mixed with plant compost (30 %) in which J. curcas plants are grown to keep good growth and the best quality plant.