Early growth of chickpea (Cicer arientinum L.) under various environmental conditions: A dissertation submitted in partial fulfilment of the requirements for the degree of Bachelor of Horticultural Science (Honours) at Lincoln University

Abstract

Three experiments were conducted to examine the early growth and nodulation responses of Kabuli chickpea to: a) Low 'starter dose' nitrogen (0, 15, and 30 kgN/ha) under increasing water stressed conditions, with different inoculation methods (dipped roots, solution, solid peat) (trial 1); b) Increasing nitrate concentrations (0, 1, 2.5, 5 Mol NO₃- m⁻³) with different inoculation rates (0, 1x, 4x) under non-water-stressed conditions (trial 2); c) Applied nitrogen (0-90 kgN/ha) with increasing inoculation rates (field trial). Water stress had increasingly negative effects on all plant DW components, except for increasing root DW by 27%, 18 DAS. At final harvest (49 DAS), shoot, root, nodule, and DWs were reduced 65, 20, and 73% respectively. Root:shoot was consistently greater in stressed plants (70, 53, and 84%, at 18, 34 and 49 DAS). Interactions between nitrogen and irrigation (affecting plant and root DWs, 18 DAS) implied that reduced early growth due to mild water stress may be partially offset by nitrogen fertiliser through greater root (but not shoot) growth. However, at 34 DAS), water-stressed total plant DW did not respond to nitrogen, whereas total plant DWs of fully irrigated plants increased by =38% at both 15 and 30 kgN/ha. Inoculation method had little effect. Shoot DW's were increased with increasing nitrogen concentration (11 and 16 % at 15 and 30 kgN/ha, 49 DAS; 41, 85 and 148%, at 1, 2.5, and 5 Mol NO₃- m⁻³, 43 DAS). Rootshoot decreased with increasing nitrogen concentration at all harvests, except at 43 DAS.