EFFECTS OF PEARL MILLET (Pennisetum glaucum L.)–COWPEA (Vigna unguiculata L.) INTERCROP ON Striga hermonthica (DEL.) BENTH, YIELD COMPONENTS AND GRAIN YIELD IN THE SUDAN SAVANNAH ZONE OF GHANA

Abstract

Field experiment was conducted on naturally Striga hermonthica infested field in the Kassena-Nankana East District of the Upper East Region during the 2018 cropping season. This was to investigate effects of Striga tolerant pearl millet varieties intercropped with cowpea on S. hermonthica, crop yield and yield components. The study was a 4 x 3 factorial experiment consisting of four pearl millet varieties (Akad-kom, Kaanati, Naad kohblug and Waapp naara) and three cropping patterns (Sole millet, Millet-cowpea (1:1) and millet-cowpea (2:1) laid out in a Randomized Complete Block Design with three replications. Results showed that Naad kohblug gave the highest plant height of 171 cm whilst Waapp naara gave the shortest at 9 WAP. Highest leaf area index was obtained with Naad kohblug (5.5) whilst Waapp naara gave the lowest leaf area index of 2.6 at 9 WAP. Grain yields of Akad-kom (1892 kg/ha) was the highest with millet-cowpea (1:1) as the best cropping pattern. S. hermonthica emergence and shoot biomass was highest with Waapp naara variety, which also gave the lowest grain yields (1778 kg/ha) and 1000 grain weight (8.3 g). Millet-cowpea (1:1) cropping pattern had the lowest Striga numbers and shoot biomass. Longest panicle length was obtained by Naad kohblug (31.1cm). Shortest days to 50% heading were found in Kaanati (40) and Akad-kom (42). Naad kohblug variety and MC (1:1) cropping pattern gave best total LER of 1.44 and 1.41 respectively. Grain yield was negatively correlated with Striga count (r = -0.42). Millet-cowpea (1:1) cropping pattern exhibited suicidal germination of Striga seeds, enhanced soil fertility and promoted Striga seed bank depletion of 46%. Resource poor farmers in Striga endemic areas could plant Akad-kom and Naad kohblug varieties as sole crops or intercropped with cowpea (1:1) to manage Striga hermonthica and maximize grain yields.