Influences of Nitrogen, Magnesium and Soil Moisture Contents and their Interactions on Yield Quality and Tolerance Indices of Rosemary (Rosmarinus officinalis L.)

Abstract

The present study was carried out in the glasshouse of the Department of Biology, College of Science, Salahaddin UniversityErbil, and laboratories of Research Center in Erbil Polytechnic University, from April 21st, 2019 to July 26th, 2020, to determine the effects of foliar application of nitrogen (N1:100, N2:200, and N3:300 kg. h-1) and magnesium (Mg1:0.0, Mg 2:30, and Mg3:60 kg. h-1) applied under two different soil moisture contents (SM1:100% field capacity (FC) and SM2: 60% FC) on some physiological properties and yield quality of rosemary plants (Rosmarinus officinalis L.). A factorial experiment was laid out according to a completely randomized design with four replications. Two cuttings were taken from the rosemary shoots (in March, and July, 2020). Results showed that SM2 decreased phenolic compounds in cut 1 (cut 1), dry matter percent in leaves in cut 2 and relative nitrogen yield in cut 1, cut 2 & cut 1+2. N3 increased dry matter in leaves & shoots in cut2 significantly, proline, phenolic compounds in leaves, stress tolerance index (STI), modified stress tolerance index 1(MSTIK1), & modified stress tolerance index 2 (MSTIK2). The interaction treatment SM2Mg2 increased the proline content in dry leaves. The proline content was increased by the triple interactions SM2N3Mg2 and SM2N3Mg3.