This study was conducted during the summer seasons of 2022 and 2023 at the Research Farm of the Agricultural Research Station in Gemmeiza, affiliated with the Agricultural Research Center located in Gharbia Governorate ,Egypt. This is to study the effect of the interaction between fertilizing Jerusalem artichoke plants with three forms of nitrogen
fertilization (100% of the recommended rate (RR) in mineral nitrogen (MN), which is equivalent to 90 nitrogen units/fed.), 100% RR in organic nitrogen (ON), which is equivalent to 10 tons per fed. of farmyard manure (FYM) fertilizer, MN at 50% RR, which is equivalent to 45 nitrogen units/fed. + ON at 50% RR, which is equivalent to 5 tons per fed. FYM and spraying with all of boron (B) at a concentration of 50 ppm and calcium (CaCl2) at a concentration of 150 ppm), beside spraying
with water ( control treatment) on the growth, yield and quality of Jerusalem artichoke tubers of the Fuseau variety grown under clay soil conditions. The interaction between MN at 50 %RR (45 kg N/fed.) +ON at 50 %RR (5 ton FYM/fed.) and spraying with CaCl2 at 150 ppm increased plant height , number of branches /plant , both fresh and dry weight of
shoots/plant , the concentrations of chlorophyll a , chlorophyll b, total chlorophyll (a+b) in leaf tissues, N, P and K contents and its uptake by shoots at of Jerusalem at 135 days after planting , number of tubers/ plant , average tuber weight , yield / plant , total yield /fed. as well as nitrogen use efficiency (NUE) in both seasons. Furthermore , the interaction between MN at 50 %RR +ON at 50 %RR and spraying with B at 50 ppm or CaCl2 at 150 ppm increased total carbohydrates ,inulin and B concentration in tuber in both season. In this regard, the yield its components, and NUE of the fertilization treatment were MN at 100% RR, and spraying with CaCl2 at 150 ppm gave a yield and its components, and the nitrogen use efficiency equal to the interaction treatment between MN at 50% RR. +ON at 50% RR and foliar spraying with CaCl2 150 ppm.