Impact of different irrigation & trace metals treatments on onion (Allium cepa L.) plant growth cultivated in rural and urban soils

Abstract

AbstractThe present research attempts to evaluate the response of Allium cepa L. to different irrigation treatments and to indicate the optimum scheme along with plant growth, throughout a pot experiment during Spring 2021. The experimental procedure consisted of two different soil types, three treatments of irrigation and two levels of Cu and Zn (low and high), in four replications each. Irrigation events started when the lower allowable limit (LAL) reached a defined percentage of filed capacity (FC): 40% FC, 60% FC, and 75% FC and an irrigation event occurred with irrigation doses (Dn) equal to 60% FC, 40% FC, and 25% FC, respectively, to reach the value of FC. According to the results, the minimum yield was achieved by both soil types when Cu and Zn solution concentration and water stress were at their highest levels, although light texture soil (loamy sand—LS) allowed for superior growth. The optimum scheme was: the lower concentration of Cu and Zn solution along with LAL equal to 60% FC at the loamy sand soil. The outcomes suggest that frequent short irrigation doses at light-texture soils can result in yield response indicators when planted in pots. Furthermore, the influence of Cu and Zn cations at low concentrations can be advantageous for onions because Cu cations provide protection against fungal diseases, while Zn cations serve as nutrient support reducing the risk of metals deficiency.