Abstract
Weed problem appears to be the most deleterious factor causing between 25 and 60% reduction in potential yield of cowpea. Field trials were therefore conducted to study the effect of inter-row spacing and period of weed interference on growth and yield of cowpea (Vigna unguiculata (L) Walp) at the Teaching and Research Farm of the Federal University of Agriculture, Abeokuta (07° 15'; 03° 25' E) in South Western Nigeria during the early and late wet seasons of 2009. The experiment consisted of eight main plots of weed interference which included initial weed removal for 3, 6, 9, and 12 weeks after sowing (WAS) and subsequently weed –infested until harvest as well as initial weed infestation for corresponding periods and thereafter kept weed free until harvest. There were also sub-plot treatments of three inter-row spacing of 60, 75, and 90 cm. All treatments in different combinations were laid out in a split-plot design with three replications. In both trials, the use of inter-row spacing of 60 cm resulted in significant reduction in weed growth as evident in lower weed dry matter production and subsequent higher cowpea pod and grain yields than those of 75 and 90 cm inter-row spacing. Initial weed infestation of up to 3 WAS did not have any adverse effect on crop growth and cowpea grain yields provided the weeds were subsequently removed. On the other hand, cowpea grain yield loss was not significantly averted by keeping the crop weed free for only 3 WAS without subsequent weed removal. In this study, initial weed-infestation for 6 WAS and beyond significantly depressed various crop growth parameter and cowpea grain yield compared with the crop kept weed free throughout its life cycle. In order to obtain optimum yields similar to that of the weed free cowpea field, it was required to keep the crop weed free for 6 WAS and beyond. However, frequent weeding beyond 9 weeks after sowing did not improve cowpea yield significantly and as a matter of fact it may even result in reduction of cowpea grain yield due to mechanical damage of hoe weeding. The practical implication of this finding is that early weeding starting from 3 WAS is very crucial for cowpea production while the critical period of weed removal for optimum yield in cowpea is between 3 and 9 WAS in the forest-savannah transitional zone of south Western Nigeria.
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Claims 8
Claim · model-written summary
60 cm spacing reduced weed dry matter relative to 75 and 90 cm.
- Taxon
- cowpea
Vigna unguiculatat0 - Treatment
- inter-row spacing of 60 cme0
- Interactor
- weede0weed
- Outcome
- weed dry matter productione0
- Direction
- lowere0
- Comparator
- 75 and 90 cm inter-row spacinge0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the use of inter-row spacing of 60 cm resulted in significant reduction in weed growth as evident in lower weed dry matter production and subsequent higher cowpea pod and grain yields than those of 75 and 90 cm inter-row spacing”
t0“Cowpea”
Claim · model-written summary
60 cm spacing increased cowpea pod and grain yields relative to 75 and 90 cm.
- Taxon
- cowpeaVigna unguiculatae0
- Treatment
- inter-row spacing of 60 cme0
- Interactor
- weede0weed
- Outcome
- cowpea pod and grain yieldse0
- Direction
- highere0
- Comparator
- 75 and 90 cm inter-row spacinge0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the use of inter-row spacing of 60 cm resulted in significant reduction in weed growth as evident in lower weed dry matter production and subsequent higher cowpea pod and grain yields than those of 75 and 90 cm inter-row spacing”
Claim · model-written summary
Weed infestation through 3 weeks after sowing followed by removal did not adversely affect crop growth or cowpea grain yield.
- Taxon
- cowpeaVigna unguiculatae0
- Treatment
- Initial weed infestation of up to 3 WASe0
- Interactor
- weedse0weed
- Outcome
- crop growth and cowpea grain yieldse0
- Direction
- did not have any adverse effecte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Initial weed infestation of up to 3 WAS did not have any adverse effect on crop growth and cowpea grain yields provided the weeds were subsequently removed”
Claim · model-written summary
Keeping cowpea weed free for only 3 weeks without later removal did not significantly avert grain yield loss.
- Taxon
- cowpeaVigna unguiculatae0
- Treatment
- keeping the crop weed free for only 3 WAS without subsequent weed removale0
- Outcome
- cowpea grain yield losse0
- Direction
- not significantly avertede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“cowpea grain yield loss was not significantly averted by keeping the crop weed free for only 3 WAS without subsequent weed removal”
Claim · model-written summary
Initial weed infestation for at least 6 weeks depressed cowpea growth parameters and grain yield versus weed free plants.
- Taxon
- cowpeaVigna unguiculatat0
- Treatment
- initial weed-infestation for 6 WAS and beyonde0
- Outcome
- various crop growth parameter and cowpea grain yielde0
- Direction
- depressede0
- Comparator
- the crop kept weed free throughout its life cyclee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“initial weed-infestation for 6 WAS and beyond significantly depressed various crop growth parameter and cowpea grain yield compared with the crop kept weed free throughout its life cycle”
t0“Cowpea”
Claim · model-written summary
Keeping the crop weed free for 6 weeks and beyond was required for optimum yield similar to a weed free field.
- Taxon
- cowpeaVigna unguiculatat0
- Outcome
- keep the crop weed free for 6 WAS and beyonde0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“it was required to keep the crop weed free for 6 WAS and beyond”
t0“Cowpea”
Claim · model-written summary
Weeding beyond 9 weeks did not significantly improve cowpea yield and may reduce it through hoe damage.
- Taxon
- cowpeaVigna unguiculatae0
- Treatment
- frequent weeding beyond 9 weeks after sowinge0
- Outcome
- cowpea yielde0
- Direction
- did not improvee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“frequent weeding beyond 9 weeks after sowing did not improve cowpea yield significantly and as a matter of fact it may even result in reduction of cowpea grain yield due to mechanical damage of hoe weeding”
Claim · model-written summary
The critical period for weed removal for optimum cowpea yield was 3 to 9 weeks after sowing.
- Taxon
- cowpeaVigna unguiculatae0
- Outcome
- weed removal for optimum yielde0
- Value
- between 3 and 9 WASe0
- Setting
- forest-savannah transitional zone of south Western Nigeriae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the critical period of weed removal for optimum yield in cowpea is between 3 and 9 WAS in the forest-savannah transitional zone of south Western Nigeria”
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