Articles
Growth and yield responses of Amaranthus cruentus, Corchorus olitorius and Vigna unguiculata to nitrogen application under drip irrigated commercial production
Article number
1253_40
Pages
303 – 310
Language
English
Abstract
Amaranthus spp. (pig weed), Corchorus olitorius (Jews mallow) and Vigna unguiculata (cowpea) are amongst the major African leafy (ALVs) vegetables of importance in South Africa.
The aim of the study was to evaluate growth, physiology and yield responses of the three ALVs to nitrogen fertilizer application rates.
Field trials were conducted at the Agricultural Research Council Vegetable and Ornamental Plant Institute, South Africa over two summer seasons, 2011/2012 and 2012/2013. The trials were laid out in a randomized complete block design with three replications in 2011/2012 and nine replications in 2012/2013. The treatments were three nitrogen levels, viz. 0, 44 and 88 kg N ha‑1 for the 2011/12 season and four levels viz. 0, 50, 100 and 125 kg N ha‑1 for the 2012/13 season.
Parameters measured included chlorophyll content index (CCI), chlorophyll fluorescence (CF), stomatal conductance (SC), leaf number, leaf area index (LAI) and fresh mass.
The application of nitrogen at 44 kg N ha‑1 (2011/12) and 100 kg N ha‑1 (2012/13) resulted in significantly (P<0.05) higher growth in terms of leaf number, LAI, increased CCI, increased biomass and yield of A. cruentus and C. olitorius. A further increase of nitrogen above 44 kg N ha‑1 and 100 kg N ha‑1 had diminishing returns.
In V. unguiculata, the application of 50 kg N ha‑1 significantly (P<0.05) increased leaf number.
Fresh mass yield was significantly reduced by applying nitrogen.
In C. olitorius and A. cruentus, higher leaf quality parameters (CCI, plant height, leaf number, biomass per plant, LAI and yield) following nitrogen application at 44 kg N ha‑1 (2011/12) and 100 kg N ha‑1 (2012/13) indicate that ALVs can perform better with nitrogen fertilization.
In V. unguiculata, 50 kg N ha‑1 improved leaf number; however, this did not translate to any fresh yield advantage implying that the optimum rate for nitrogen application might be lower than 50 kg N ha‑1.
The aim of the study was to evaluate growth, physiology and yield responses of the three ALVs to nitrogen fertilizer application rates.
Field trials were conducted at the Agricultural Research Council Vegetable and Ornamental Plant Institute, South Africa over two summer seasons, 2011/2012 and 2012/2013. The trials were laid out in a randomized complete block design with three replications in 2011/2012 and nine replications in 2012/2013. The treatments were three nitrogen levels, viz. 0, 44 and 88 kg N ha‑1 for the 2011/12 season and four levels viz. 0, 50, 100 and 125 kg N ha‑1 for the 2012/13 season.
Parameters measured included chlorophyll content index (CCI), chlorophyll fluorescence (CF), stomatal conductance (SC), leaf number, leaf area index (LAI) and fresh mass.
The application of nitrogen at 44 kg N ha‑1 (2011/12) and 100 kg N ha‑1 (2012/13) resulted in significantly (P<0.05) higher growth in terms of leaf number, LAI, increased CCI, increased biomass and yield of A. cruentus and C. olitorius. A further increase of nitrogen above 44 kg N ha‑1 and 100 kg N ha‑1 had diminishing returns.
In V. unguiculata, the application of 50 kg N ha‑1 significantly (P<0.05) increased leaf number.
Fresh mass yield was significantly reduced by applying nitrogen.
In C. olitorius and A. cruentus, higher leaf quality parameters (CCI, plant height, leaf number, biomass per plant, LAI and yield) following nitrogen application at 44 kg N ha‑1 (2011/12) and 100 kg N ha‑1 (2012/13) indicate that ALVs can perform better with nitrogen fertilization.
In V. unguiculata, 50 kg N ha‑1 improved leaf number; however, this did not translate to any fresh yield advantage implying that the optimum rate for nitrogen application might be lower than 50 kg N ha‑1.
Authors
I. Maseko, T. Mabhaudhi, Y.G. Beletse, N. Nogemane, C.P. Du Plooy, A.T. Modi
Keywords
African leafy vegetables, nitrogen, yield, quality
Online Articles (60)