Yields and protein content of two cowpea varieties grown under different production practices in Limpopo province, South Africa

A three-factorial field experiment was carried out at the University of Limpopo experimental Research farm during two planting seasons (2005/06 and 2006/07) to examine the effect of cowpea-leaf removalon cowpea performance. Three treatment factors namely cowpea varieties (Pan 311 and Red Caloona), cropping systems (sole and intercropping) and cowpea-leaf pruning regimes (pruned and un-pruned) were combined and arranged in a randomized complete block design (RCBD). Sole cowpea and sweet corn treatments were included and all treatments replicated four times. Fully expanded cowpea leaves on all cowpea plants in the two middle rows were harvested once at seven weeks after seed sowingprior to flowering. Growth and yield component data were collected from component crops while the protein content of harvested leaves and green pods as well as those of grains and the fodders at harvest were determined. The results of the study revealed that cowpea leaf protein content ranged from 24.1 to 28.1% and 26.0 to 30.7% for Red Caloona and Pan 311, respectively. The protein content of green cowpea pods obtained from Pan 311 cowpea variety ranged from 18.8 to 25.1% while that of Red Caloona varied between 17.9 and 20.7%. Similarly, the protein content of the fodder obtained after grain harvest varied between 9.3 and 9.4% and 9.9 and 12.3%, respectively for Pan 311 and Red Caloonaduring the two seasons. The protein content of cowpea grain obtained from intercropped plots (23.7 to 26.3%) was similar to that from sole plots (23.7 to 25.7%). In 2005/06, grain yield was 1704 kg ha-1 and1480 kg ha-1 respectively for Pan 311 and Red Caloona while 1291 and 512 kg ha-1 were obtained for Pan 311and Red Caloona, respectively in 2006/07. There was a significant season x varietal effects on podand seed protein content. These results reveal that Pan 311 would be better suited for both vegetable and grain production purposes for human consumption while Red Caloona would better serve as a fodder crop for animal production. The results also show that neither cropping system nor cowpea leaf pruning did have consequential effects on the nutritional value of cowpea plant parts and grains

Influence of long-term crop residue and fertilizer application on some chemical properties of an alfisol under arid environment

The distribution patterns of some soil chemical properties of an alfisol were investigated following a long term (1983 – 1996, fourteen years) crop residues and fertilizer application in an arid environment. The investigation involved five treatment combinations: Control (-CR-F); Crop residue with no fertilizer addition (CR); no crop residue plus fertilizer addition (F), Crop residue plus fertilizer addition (CF+F) and fallow. The pH, exchangeable Ca, Mg, and acidity as well as effective cation exchange capacity (ECEC) had irregular distribution pattern down the soil depth in all the treatments. Fertilizer application without crop residue addition (-CR+F) as well as continuous crop cultivation (-CR-F) had increased contents of soil total N, available, P, exchangeable Ca and acidity with increasing soil depth. Crop residue addition with (+CR+F) and without fertilizer application (+CR-F) and fallow resulted in reduced soil acidity. However, crop residue addition with fertilizer application (+CR+F) as well as depth of sampling significantly (

Assessment of variable application rates of biological amendment substances on establishment and growth characteristics of maize plants

Good plant establishment and excellent vigour constitute essential  pre-requisites for successful grain production. The sowing of good viable seeds could contribute to increased productivity and ultimately lead to minimal seed cost and high return on investment. These are however dependent on such factors as the possible effects of pre- and post-seed sowing soil amendments. Hence, a greenhouse experiment was  conducted in 2008 to assess the effects of variable rates (50, 75 and 100% of the recommended rates) of industrial manufactured biological amendment substances (IMBAS) (Biozone, Crop care, Gromor, Growmax, K-humate, Lanbac, Molcast, Montys and Promis) on the establishment and growth characteristics of maize seedlings. Inorganic NPK fertilizer and unamended control treatments were included as standards. Results obtained revealed a significant IMBAS as well as IMBAS x rates interaction effects on plant height, number of leaves, total biomass and leaf area. The percent plant emergence in K-humate, Montys and Promis treatments at 50% recommended rate were significantly decreased relative to the standard treatments. Application of most of the IMBAS at 100% of the recommended rate generally decreased plant establishment and phenological characteristics of maize. The study underpins the relevance of in-depth and accurate agronomic evaluation of industrially manufactured growth enhancement materials prior to recommendation for use by farmers.Keywords: Industrial manufactured biological amendment substances, maize phenology, plant vigour, seedling emergence, soil amendment