Effects of irrigation on production and quality of marigold and basil in different weather conditions

Abstract

Irrigation improves the water regime of soil creating favorable conditions for growing plants. Frequent oscillations of weather conditions in the region, first of all the amount and distribution of precipitation, are the reason why irrigation is needed in plant production. The aim of the study was to detect the effect of irrigation on the yield and quality of marigold (Calendula officinalis L.) and basil (Ocimum basilicum L.). The experiments were conducted at the experimental field of the Institute of Field and Vegetable Crops. Irrigation was scheduled on the basis of the water balance method. Daily evapotranspiration (ETd) was computed from the reference evapotranspiration (ETo) and crop coefficient (kc) in May, June, July and August of 0.5, 0.6, 1.1 and 1.0, respectively. ETo was calculated using Hargreaves equation. The irrigation depth was restricted to the soil depth of 0.3 m. In other words, irrigation started when readily available water in the soil layer of 0.3 m was completely depleted by plants. The irrigation rate was 30 mm (30 l-1 m-2) while the amount of water added by irrigation during the season was 120 mm in 2016 and 300 mm in 2017. According to the results, the yield of fresh herb of all two plants under irrigation was higher compared to non-irrigated, control variant. As well essential oil and carotenoids, the main indicators of the quality of investigation plants were also affected by irrigation.