Journal of Applied Biosciences (J. Appl. Biosci.) [ISSN 1997 - 5902]
Volume 48: 3316 - 3321. Published December 29, 2011.
Correlation analysis of tuber yield and yield related characters in two cassava (Manihot esculenta Crantz) morphological-types grown under nine weed management systems in the Guinea savanna zone of Nigeria
1Agahiu, A. E; *2Baiyeri, K. P. and R. O. Ogbuji2
1Department of Crop Production, Kogi State Univeristy, Anyigba, Kogi State, Nigeria
2Department of Crop Science, University of Nigeria, Nsukka, Enugu State, Nigeria.
ABSTRACT
Objective: The interplay of weed management options and temporal environment on correlative responses of two cassava morphotypes were studied with the aim of elucidating growth and yield correlation patterns under weed management and temporal environment.
Methodology and results: The two cassava morphological types ‘NR 8082’ (short with profuse branching) and ‘TMS 30555’ (tall and non-branching) were subjected to nine different weed management options in a split plot design replicated three times. Data on weed biomass, cassava growth and yield parameters were subjected to multiple correlation analyses. Results revealed that weed dry matter had significant negative correlation with plant height (r = - 0.975**), plant girth (r = - 0.796**), tuber diameter (r = - 0.841**), tuber weight (r = - 0.929**), and average whole plant biomass yield (r = -0.921**) in 2008 cropping season for the branching cultivar. In 2009, a similar correlative response trend was also obtained, weed dry matter showed highly significant negative correlation with plant height (r = -0.984**), plant girth (r = -0.789**), tuber diameter (r = -0.822**), tuber weight (r = -0.911**), and average whole plant biomass yield (r = -0.901**). For the non-branching cultivar, weed dry matter also demonstrated strong and significant negative relationship with the following growth and yield parameters: plant height (r = --0.910**), plant girth (r = -0.763**), tuber diameter (r = -0.805**), tuber weight (r = -0.864**), and average whole plant biomass yield (r = -0.860**) in 2008. In 2009, the data revealed strong and significant negative relationship between weed dry matter and plant parameters as follows: plant height (r = --0.966**), plant girth (r = -0.772**), tuber diameter (r = -0.898**), tuber weight (r = -0.940**), and average whole plant biomass yield (r = -0.928**). Conclusion and application: Irrespective of cultivar or cropping year, plant height was significantly and positively correlated with average tuber weight and average whole total plant biomass yield (in most cases, with r-values > 0.90**). The correlative responses obtained for the two cultivars expectedly suggest that weed interference limits genetic productive potentials of the crop. The implication is that weed management strategies will indirectly enhance genetic expression of the cultivar thereby improving yield.
Key words: Cassava morphological-types, correlative responses, weed biomass, tuber yield.
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