Physiological Study on Jerusalem Artichoke Plants (Helianthus Tuberosus L.) Under Two Types of Soils

Two field experiments were carried out on Jerusalem artichoke crop during two successive seasons of 2016 and 2017 at Soil Salinity Laboratory Research, Agricultural Research Center, Alexandria Governorate, Egypt. Each experiment included sixteen treatments representing the combination of two types of soils; i.e., clay and calcareous, two trimming treatments; i.e., without trimming (T0) and trimming (T1) [removing of flowering buds before opening with 10-20 cm from ends of vegetative branches], and four fertilization treatments; i.e., 75 kg nitrogen/feddan + Halex-2 (F1), 75 kg nitrogen/feddan + yeast extract (F2), 75 kg nitrogen/feddan + Halex-2 + yeast extract (F3) and 100 kg nitrogen/feddan (F4).The experimental layout was presented as a split-split-plot in a randomized complete blocks design with three replicates. Two types of soil were assigned in the main plots; two trimming treatments were allocated to the sub-plots and four fertilization treatments which were, randomly, distributed in the sub-sub-plots. Planting Jerusalem artichoke tubers in clay soil encouraged each of the vegetative growth, yield and its component characters compared to planting in calcareous soil. Un-trimming Jerusalem artichoke growing plants resulted in positive effects on the vegetative characters, tubers' yield and its components traits compared to trimming treatment. Adding moderate amount of nitrogen fertilizer (75 kg N/ fed.) combined with Halex-2 plus yeast extract yielded statistically equal results if 100 kg N/fed. was added to the growing plants for most studied characters especially the economic ones. Maturity date trait did not affect with any of the applied treatments on Jerusalem artichoke growing plants. It turned out from the obtained results that a quarter of nitrogen fertilizer quantity could be saved by adding a mixture of bio-stimulants (Halex-2 + yeast extract) to the growing plants, in addition to un-trimming the ends of branching whether the cultivation was in clay or calcareous soils.