Journal of Applied Biosciences (J. Appl. Biosci.) [ISSN 1997 - 5902]
Volume 10(2): 547 - 553. Published October 7, 2008.
Developing an appropriate technique for evaluating cowpea varieties’ reaction to the parasitic plant Alectra vogelii (Benth.)
Magani I.E.1*, LagokeS.T.O2. and Emechebe A.M3.
*1Department of Crop and Environmental Protection, University of Agriculture, PMB 2373, Makurdi, Nigeria; 2Department of Crop Production, University of Agriculture, Abeokuta, Nigeria; 3International Institute of Tropical Agriculture, PMB 5320, Ibadan, Nigeria
^Corresponding author e–mail:m.enochistifanus@yahoo.com
ABSTRACT
Objective: To develop an appropriate technique for evaluating cowpea varieties’ reaction to the parasitic plant Alectra vogelii (Benth).
Methodology and results: Screen house trials were conducted at Zaria, Nigeria in 2004. Treatments consisted of a factorial combination of eight cowpea varieties, four Alectra seed inoculant density (0, 5, 10, 20 c.c/pot) and three pre – conditioning periods (0, 7 and 14) and (0, 3, 7 and 14) days before crop planting in the first and second trials, respectively. Result indicated that cowpea variety B301 and the derivative of cross with IT84S – 2246 – 4 (IT90K – 76) did not have any attachment of Alectra, while 1T89KD – 245 – 1 had the least Alectra emergence in the two trials. In both trials, variety TVX3236 initiated early emergence of Alectra while delayed emergence was observed with 1T89KD – 245 – 1. Inoculation with 10 c.c/pot of Alectra seeds resulted in higher Alectra infection that 20 c.c/pot. In general, Alectra emergence was earlier in the second trial than the first trial. Alectra emergence increased with Alectra seed density in the first trial while 10 c.c/pot Alectra seed gave the highest number of emerged Alectra in the second trial. Pre – conditioning period prior to cowpea sowing for 14 days initiated early Alectra emergence. The crop dry matter production was negatively correlated to the number of emerged, un – emerged and total number of Alectra plants.
Conclusions and application of findings: This investigation has shown that variety B301 and derivative of its cross with IT84S – 2246 – 4 (IT90K – 76) did not support the emergence of Alectra thus exhibiting resistance. Alectra emergence increased with Alectra seed density up to 10 c.c/pot when compared to other Alectra seed density. Pre – conditioning period had no significant effect on emerged Alectra, but Alectra emergence increased with pre – conditioning period of 7 to 14 days.
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