Response of Broccoli to Mulching and Foliar Application of Licorice Root Extract and their Effects on Yield and Macronutrient Contents

The research was done in the vegetables research farm at the College of Agricultural Engineering Sciences at University of Dohuk, Kurdistan region of Iraq, during the growing season in (2021-2022). The reason behind the study was to investigate the response of two cultivars of Broccoli (Brassica oleracea var. italica.) Ajjasi and Wisdom cv. to different types of mulching (without, black plastic and straw) and also the different concentrations levels of licorice root extract (0, 6, 12 and18g.L-1) on productivity and some nutrients content of Broccoli curd. The results showed that Wisdom cultivar performed better than Ajjassi in terms of early yield and nutrients content. Throughout the research season, both cultivars were considerably improved in all examined attributes. Additionally, it was shown that all features in both cultivars were noticeably enhanced in plastic mulch. There was an observed increase in the majority of features of the interactions between licorice root extract and straw. Early yield in Wisdom cultivar was meaningfully different from Ajjasi (27.814 and 24.138) ton. ha-1 respectively. Most of the measurements were greatly influenced by black plastic mulch, while the best overall outcome was achieved in black plastic mulch and 18g.L-1 concentration of licorice root extract in Ajjassi cultivar. In both cultivars, there were noticeable changes in the nutrient’s contents of (Nitrogen, phosphorus, potassium %). In general, the combination among treatments was significantly enhanced in the all studied traits.