INITIAL GROWTH OF LETTUCE (Lactuca sativa L.) AND ARUGULA (Eruca sativa L.) IN NICKEL-ENRICHED SUBSTRATE

Abstract

Lettuce (Lactuca sativa L.) and arugula (Eruca sativa L.) are highly consumed vegetables owing to their nutritional properties. Nutrients are vital for plant metabolism; hence, to augment productivity and product quality, efforts have been made in the application of micronutrients through seeds. Nickel (Ni) plays a pivotal role in plant germination. Nevertheless, studies related to its usage in fertilization programs remain limited, particularly in vegetable cultivation. In light of the health advantages these vegetables offer and with the goal of affirming the indispensability of this micronutrient in their germination, this research was conducted to assess the initial growth of lettuce and arugula seedlings under varying quantities of nickel sulfate in the substrate. The experiment was carried out using a completely randomized design (CRD) encompassing two vegetable species (lettuce and arugula). Eight treatments, each with four repetitions for every crop, were implemented, incorporating the following doses: control (0.0); 2.5; 5; 10; 20; 40; 80; and 160 mg of Ni kg-1. The rate of emergence was evaluated through daily counting of seedlings that emerged per treatment. One month after seedling emergence, measurements were taken for aboveground height and radicle length. Samples were weighed and subjected to drying in an oven with forced air circulation at 105°C for 72 hours. Subsequently, another weighing was conducted to obtain values for dry mass. The supplementation of nickel at a dose of 70.95 mg of Ni kg-1 of substrate is recommended for lettuce seedling production (resulting in the highest total dry mass). Nickel doses did not exert any influence on the growth of arugula seedlings.