GROWTH AND YIELD RESPONSE OF FOUR NEWLY- BRED COWPEA VARIETIES (VIGNA UNGUICULATA (L.) WALP) TO ALECTRA VOGELII (BENTH) INOCULATION AND NPK FERTILIZER APPLICATION
GROWTH AND YIELD RESPONSE OF FOUR NEWLY- BRED COWPEA VARIETIES (VIGNA UNGUICULATA (L.) WALP) TO ALECTRA VOGELII (BENTH) INOCULATION AND NPK FERTILIZER APPLICATION
No Thumbnail Available
Date
2018-07
Authors
OKEH, Miriam Onyinyechi
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Cowpea (vigna unguiculata) is an important source of protein and income for farmers in Africa but its production has been constrained by Alectra vogelii Benth, a parasitic weed which attaches itself to the root of cowpea plants and diverts the assimilate from cowpea roots to itself. Therefore, two pot trials were conducted in the Horticultural Garden of the Department of Agronomy and under a Screen house in the Department of Soil Science, Institute for Agricultural Research, Ahmadu Bello University, Zaria to evaluate the Growth and Yield Response of Four Newly-bred Cowpea (Vigna unguiculata (L.) Walp) Varieties to Alectra vogelii Inoculation and NPK Fertilizer (15:15:15) Application. The trial consist of four cowpea varieties (IT08K-125-107, IT06K-128, IT07K-303-1, IT07K-299-6) obtained from International Institute of Tropical Agriculture, Kano Substation and four levels of NPK fertilizer (0, 100, 200 and 400 kgNPK/ha). The treatments were applied with Alectra vogelii (0 kgNPK/ha + Alectra) and without Alectra vogelii inoculation (0 kgNPK/ha + zero Alectra). The experiments were designed in a completely randomized design in three replications and with six (6) pots to represent each replicate. Growth and yield parameters such as plant height, shoot fresh weight, root fresh weight, number of root nodules, leaf area index, pod weight, pod length, 100 seed weight, number of pods per plant and grain yield were evaluated. Generally, NPK fertilizer application significantly improved vegetative growth and yield of the cowpea varieties with 400 kgNPK/ha giving the best growth and yield. Fertilizer application at 400 kgNPK/ha significantly enhanced plant height (23.72 cm), shoot fresh weight (71.48 g) and leaf area index (1.22) when compared with the control (18.65 cm, 14. 92g and 0.17 respectively) at 9 WAS in Trial 1. Alectra inoculation significantly reduced root fresh weight (0.90 g) and root nodules (40.77) of cowpea plants inoculated with Alectra when compared with the Alectra uninoculated cowpea plants (1.00 g and 46.58 respectively) at 7 WAS in Trial II. Highest grain yield per plot was observed under cowpea variety IT07K-303-1
viii
in Trial I (75.95 g) and Trial II (70.15 g) while the lowest grain yield was observed under cowpea variety IT08K-125-107 in Trial I (58.11 g) and Trial II (49.39 g). The best grain yield (68.49 g) was due to the application of 400 kgNPK/ha fertilizer when compared with the untreated control (59.98 g) in Trial I. Number of pods/plant, pod length, and seed weight per pod of cowpea plants were significantly reduced due to Alectra inoculation when compared with the uninoculated cowpea plants in Trial I. Cowpea variety IT07K-303-1 was observed to have supported the highest number of Alectra vogelii shoots per plot (2.00) and cowpea variety IT06K-128 supported the lowest number of Alectra vogelii shoots per plot (0.29) in Trial II. In conclusion, the study showed that, application of NPK fertilizer enhanced vegetative growth and yield parameters of the cowpea varieties. Alectra vogelii inoculation generally reduced most of the vegetative growth parameters and consequently yield parameters. Cowpea variety IT07K-303-1 was tolerant to Alectra vogelii. Therefore, cowpea variety IT07K-303-1 and 400 kgNPK/ha fertilizer rate can be recommended for effective control of Alectra vogelii and improved cowpea yield.
Description
A THESIS SUBMITTED TO THE SCHOOL OF POSTGRADUATE STUDIES, AHMADU BELLO UNIVERSITY, ZARIA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE AWARD OF MASTER OF SCIENCE DEGREE IN BIOLOGY DEPARTMENT OF BIOLOGY, FACULTY OF LIFE SCIENCES, AHMADU BELLO UNIVERSITY, ZARIA, NIGERIA
Keywords
GROWTH,, YIELD RESPONSE,, NEWLY- BRED COWPEA VARIETIES (VIGNA UNGUICULATA (L.)WALP),, TO ALECTRA VOGELII (BENTH),, INOCULATION,, NPK FERTILIZER APPLICATION,