Role of zinc and potassium sulphate in the yield and productivity characteristics of two types of broccoli Brassica oleracea var.italica

The experiment was carried out in the Mosul Forest Area field of the College of Agriculture and Forestry, University of Mosul, during autumn 2024 and winter 2025, to study the response of the vegetative growth characteristics of two varieties of broccoli (Naxos, Blue Finn) to the effect of three concentrations of zinc sulfate (0, 500,750 mg.L-1) and three levels of potassium sulfate (0,200,400 ton.h-1).The experiment was carried out in the field using a factorial experiment within split plots in the design of complete random segments (RCBD) with three replicates, where the varieties were placed in the main plots and the compatibility between the fertilization treatments by zinc and potassium sulfate in the secondary plots (Sub plots) was repeated for each treatment three times. The study showed that plants of the Blue Finn variety achieved the highest weight of the main heads and the highest total yield of the main heads increased by 1.09% for the two traits when they were not sprayed with zinc sulphate and added 400 ton.h-1 potassium sulfate and the highest significant value for the weight of secondary heads was 121.60 g.Plant-1 at 750 mg.L-1of zinc sulphate, not adding potassium sulphate. The same variety achieved the highest yield per plant for secondary heads when sprayed with 750 mg.L-1 of zinc sulfate and no potassium sulfate added amounted to 445.94 g.Plant-1, while the highest number of secondary heads reached 5.7333 head.Plant-1 when sprayed with 500 mg.L-1 of zinc sulphate and add 400 ton.h-1 of potassium sulphate.