Views
9 months ago

Spatial distribution and density of Striga hermonthica (Del.) benth infestation associated with cereal production in southern guinea savanna farming systems

Abstract This study describes the distribution patterns of S. hermonthica infestation present in 117 farmers’ fields located in 61 villages in the three major cereal growing areas of Benue and Nasarawa states. A total of 1098 respondents were randomly selected proportionate to the number of households in all the zones. Striga count was taken using a quadrat and farmers’ fields were visually assessed using a five-category ranking (very high density,high density, medium, low, very low density) and recording the geo referenced data. On average, 67.3 and 3.2% of the surveyed area were infested with high and low density of Striga, respectively. The mean number of Striga plants per m2 was greater at Nassarawa State (one to eighteen plants m-2) than Benue State (one to twelve plants m -2). In Benue, the largest percentage of Striga infestation was recorded in Buruku (49.7%) and the lowest was obtained in Guma (38.3%). In Nassarawa, under sorghum cultivation, higher Strigadensties were recorded in Karu and Awe LGA; while Doma, Keana and Obi LGA recorded moderate Striga infestation. In both locations, Striga infestation was highest in sorghum fields; while millet fields recorded the least. About 40% and 35.4% of the farmers reported that new modern farming methods and Striga control copping strategies, respectively are received from Extension agents , during Monthly Technology Review Meeting (MTRM). The study has provided baseline information on the spread of S. hermonthica in the Southern Guinea Savanna of Nigeria and therefore, copping strategies for its control should be intensified.

J. Bio. & Env. Sci. 2014

J. Bio. & Env. Sci. 2014 Striga damage and prevalence and routine crop management practices adopted. Table 2. Coordinate locations and altitudes of S. hermonthica surveyed area in Nassarawa State used in study. State LGA Village Longitude (N) Latitude (E) Altitude (m) Nasarawa Akwanga AnguwanZaria 008.38 o 08.92 o 490 ± 3.96 Nasarawa Akwanga Andaha 008.41 o 09.05 o 514 ± 3.66 Nasarawa Akwanga Gudi 008.26 o 08.90 o 445 ± 3.66 Nasarawa Akwanga Ubbe 008.43 o 08.87 o 404 ± 3.66 Nasarawa Awe Kanje 009.08 o 08.24 o 190 ± 3.35 Nasarawa Doma Doma 008.36 o 08.39 o 159 ± 3.66 Nasarawa Doma Idiya 008.32 o 08.27 o 163 ± 3.35 Nasarawa Doma Ohina 008.36 o 08.31 o 138 ± 3.36 Nasarawa Kaena Aloshi 008.81 o 08.25 o 203 ± 3.35 Nasarawa Kaena Agaza 008.81 o 08.29 o 162 ± 3.35 Nasarawa Karu AnguwanKwano 007.89 o 08.93 o 330 ± 3.66 Nasarawa Karu AnguwanWayo 008.02 o 09.24 o 458 ± 3.35 Nasarawa Karu Gitata 007.95 o 09.14 o 446 ± 3.36 Nasarawa Karu Gunduma 007.89 o 08.97 o 353 ± 3.35 Nasarawa Karu Tattara 007.10 o 09.21 o 482 ± 3.36 Nasarawa Karu Uke 007.72 o 08.91 o 321 ± 3.66 Nasarawa Karu Zango 007.94 o 09.11 o 428 ± 3.96 Nasarawa Keffi AnguwanJaba 007.92 o 08.88 o 345 ± 3.96 Nasarawa Keffi AnguwanNinzo 007.88 o 08.88 o 323 ± 3.35 Nasarawa Keffi Gora 007.77 o 08.88 o 396 ± 3.66 Nasarawa Keffi Sabon-gari 007.82 o 08.86. o 359 ± 3.35 Nasarawa Kokona Garaku 008.15 o 08.86 o 397 ± 3.35 Nasarawa Kokona Sabon-gida 008.02 o 08.85 o 309 ± 3.35 Nasarawa Lafia Akurba 008.57 o 08.53 o 214 ± 3.96 Nasarawa Lafia AkurbaAkoko 008.58 o 08.53 o 220 ± 3.66 Nasarawa Lafia Shabu 008.56 o 08.56 o 161 ± 3.66 Nasarawa Nassarawa Kuvo 007.85 o 08.27 o 162 ± 3.66 Nasarawa Nassarawa Marmara 007.78 o 08.62 o 235 ± 3.35 Nasarawa Nassarawa MarrabaUdege 007.82 o 08.33 o 167 ± 3.66 Nasarawa Nassarawa Nass town 007.72 o 08.56 o 225 ± 3.35 Nasarawa N/Eggon Alizaga 008.59 o 08.67 o 203 ± 3.66 Nasarawa N/Eggon Wulko 008.45 o 08.84 o 420 ± 3.66 Nasarawa Obi Adudu 008.99 o 08.30 o 200 ± 3.66 Nasarawa Obi Agwatashi 008.86 o 08.31 o 217 ± 3.96 Nasarawa Obi Agyragu 008.56 o 08.25 o 192 ± 3.66 Nasarawa Obi Daddare 008.77 o 08.44 o 216 ± 3.35 Nasarawa Obi Obi 008.77 o 08.36 o 170 ± 3.66 Nasarawa Toto Gadabuke 007.24 o 08.42 o 178 ± 4.27 Nasarawa Toto Karmo 007.49 o 08.48 o 192 ± 3.96 Nasarawa Toto Kuru 007.17 o 08.39 o 226 ± 4.27 Nasarawa Toto Yelwa 007.22 o 08.40 o 183 ± 4.27 Nasarawa Wamba Wamba 008.60 o 08.95 o 421 ± 3.35 Nasarawa Wamba Wamba-kurmi 008.57 o 08.94 o 414 ± 3.35 Striga species was identified based on the development and morphological features described by Ramaiahet al., (1983) and Parker and Riches (1993). Striga plant counts were made in maize, sorghum and pearl millet fields. Emerged Striga plant was counted from 1 m x 1 m quadrat from five points diagonally chosen from each field as described by Kim (1994). The coordinates of each surveyed sites were recorded using GPS (Garmin Colorado 400c handheld Global Positioning System). All the measurable data were incorporated into GIS generated model to provide the probability to predict its likely geographical distribution. The spatial distribution in term of the density was classified using five categories, very low, low, medium, high and very high to represent the range of occurrence using the designated map in Arc Map 10. Data were transformed using square root method and analysis was done using first stepwise regression procedures for identifying the most important variables and subsequently general linear model procedures for testing the model (SPSS). 422 | Ibrahim et al.

J. Bio. & Env. Sci. 2014 Results and discussion In total, 117 farmers’ fields were sampled during August, September, October and November 2010, comprising maize, sorghum and millet crop fields in Benue and Nasarawa state (Tables 1 and 2). The geo reference coordinates of the locations are as shown (Fig.s 1 and 2). In Benue state S. hermonthica infestation comprised 42.3% of the maize fields and was the second most endemic by Striga after sorghum (53.5%) (Table 3). Similarly, in Nasarawa state, sorghum fields (56.7%) > maize (39.9%) > millet (6.56%) of crop infested fields were recorded (Table 4). The incidence of Striga infestation in the sorghum – based cropping system is quite apparent. Sorghum is believed to have evolved with Striga hermonthica and tends to be associated with it for a longer time than other crops such as maize or millet. This is mainly because most of the sorghum varieties grown by farmers are local land races that mature late and produce after – harvest sprouts on which the Striga plants continue to parasitize and produce seeds. This constituted about 12.6% of the total area of infestation of S. hermonthica in millet fields (Table 3). In Nasarawa state S. hermonthica is recorded from almost every field of sorghum (61.1%). The maize and millet field infestation covered 39.9% and 6.56% respectively (Table 4). Table 3. Geospatial Distribution of area of Striga infestation of the crop fields across the survey location of Benue zone B. Cropping System Buruku n= 3 Gboko n= 9 Guma n= 6 Survey location Gwer n= 12 % of field infested Gwer west n= 3 Makurdi n= 12 Tarka n= 9 Overall mean n= 8 Maize fields n= 22 58.3 41.7 47.2 38.6 45.2 31.2 33.9 42.3 Sorghum fields n= 27 65.0 52.9 60.3 55.1 46.8 44.2 50.2 53.5 Millet fields n= 5 Overall 25.8 - 28.8 21.3 - - 12 12.6 mean 49.7 31.5 45.4 38.3 30.7 25.1 32.0 36.1 Table 4. Geospatial distribution of area of Striga infestation of the crop fields across the survey location in Nasarawa state. Cropping Akwanga Awe system n= 12 n= 3 Maize fields n= 37 Sorghum fields n= 59 Millet fields n= 21 Overall mean n = 117 Doma n= 9 Keana n= 6 Karu n= 21 Keffi n= 12 Survey location Kokona n= 6 % of field sampled Nasarawa Lafia N/eggon n= 9 n= 6 n= 12 Obi n= 15 Toto n= 12 Wamba n= 6 Overall mean n= 117 23.7 - 51.2 61.8 42.3 45.2 50.2 46.5 39.8 47.9 52.3 57.8 - 39.9 55.3 67.3 54.0 67.3 59.5 53.7 51.3 47.0 42.3 65.0 61.7 63.3 49.3 56.7 7.0 11.3 8.0 8.0 5.0 5.0 6.9 4.1 3.8 9.2 3.2 4.8 7.0 6.56 28.7 26.2 37.7 45.7 35.6 34.6 36.1 32.5 28.6 40.7 39.1 42.0 18.8 34.4 423 | Ibrahim et al.

Reaction of cowpea (Vigna unguiculata (L.) Walp) varieties to Alectra vogelii (Benth) as influenced by botanicals (plant materials) in the Northern Guinea Savanna of Nigeria
Effectiveness of parkia (Parkia biglobosa) products for the control of Striga genesrioides in the southern guinea savanah
Evaluation of okra (Abelmoschus esculentus L. Moench) cultivars for dry season production in the Southern Guinea Savanna ecology of Nigeria
Bio – efficacy of Aqueous Plant Extracts and Cyperdicot on Insect Pests Infestation, Growth and Yield of Sweet Pepper (Capsicum annum L.) in the Dry Savanna of Nigeria
Diversity and spatial distribution of stem borers and their natural enemies on off season sorghum, Sorghum bicolour (L.) Moench (Poaceae), in the Sudano-sahelian zone of Cameroon - IJAAR
Diversity and spatial distribution of stem borers and their natural enemies on off season sorghum, Sorghum bicolour (L.) Moench (Poaceae), in the Sudano-sahelian zone of Cameroon