Produção da rúcula (Eruca sativa) submetida a diferentes níveis de depleção e coberturas de solo

Abstract

The success of vegetables production is basically linked to the water management used in the production system, since the production of these plants practically depends on the moisture content of the soil. Determining the ideal amount and timing of water application is the key to the success of the activity, as rainfall is often not enough to meet the plants demands. In order to increase the efficiency of water use, the use of soil cover is an already consolidated practice, which when associated with drip irrigation provides water savings and promotes the maintenance of soil moisture. Therefore, the aim of this work is to evaluate the influence of four levels of soil water depletion (93.5, 78.0, 65.5 and 51.0% of available water) and plastic coverage on the production and efficiency of irrigation water used for cultivated arugula in two seasons (10 November to 10 December and 22 December to 15 January), in the field. In this way, the following evaluations were performed: fresh and dry mass of the aerial part; number of leaves; plant height; leaf area index and irrigation water use efficiency. The results concerning soil cover for the first growing season were analysed using the Tukey test, with a 5% probability of error, and for the treatments referring to the levels of depletion, regression analysis was performed for both the first and the second growing season. The results of the first growing season determined the level of depletion of 51.0% as the treatment that resulted the highest average values of dry and fresh mass, leaf area index and irrigation water use efficiency, regardless of the soil cover. This same level of depletion still resulted in higher plant height values for the treatments with soil cover and resulted in the highest number of leaves for the treatments without soil cover in the first growing season. For the second growing season, a statistical analysis was performed only for the treatments without soil cover, because the treatments that received the soil cover suffered a severe attack of nematodes, which, associated to the high temperatures of the months of December and January, unviable the production of arugula for treatments with soil cover. Analysing the second growing season for the treatments without soil cover it is possible to observe that the depletion level of 65.5% of available water provided the highest average values of fresh and dry mass, plant height and leaf number. For the variables leaf area index and irrigation water use efficiency, the level of depletion that resulted in the highest values was the treatment with 51.0% of the available water.