Effect of CPPU and Cobalt on the Growth and Productivity of Two Potato Cultivars Under Field Conditions

Field experiment was conducted at the research station, College of Agriculture, University of Anbar, in the Al-Buaytha area located at longitude E43.3265 and latitude N33.4537 for the spring 2023 and autumn 2023 seasons. The aim was to determine the growth and productivity of two potato cultivars under the influence of foliar spray with the growth regulator CPPU and cobalt. The experiment was conducted using a split-split plot design within a randomized complete block design (RCBD) with three factors. The first factor included the cultivars (Rudolf and EL Beida). The second factor foliar spray with the growth regulator CPPU at three concentrations (0, 3, and 6 mg L -1 ). The third factor foliar spray with cobalt at three concentrations (0, 5, and 10 mg L -1 ). In the spring season, treatment with CPPU at 6 mg L -1 enhanced plant traits: tubers per plant (9.82), marketable yield per plant (1.03), yield per plant (1.15), and total marketable yield (54.81). This effect was not observed in the autumn season, where tuber weight average was highest for CPPU-treated Rudolf plants (137.06 g/plant). At a concentration of 10 mg L -1 , cobalt spray significantly increased the number of tubers per plant, at 9.159 tubers plant -1 for the spring season, with an average tuber weight of 134.80 g plant -1 for the autumn season, and a marketable yield of 0.978 kg plant -1 for the spring season. Additionally, the yield per plant was 1.065 kg plant -1 for the spring season, and the total marketable yield was 52.20 tons ha -1 for the spring season.