International Journal of Scientific Research in Environmental Sciences (IJSRES), 1(5), pp. 71-77, 2013 Available online at http://www.ijsrpub.com/ijsres ISSN: 2322-4983; ©2013 IJSRPUB http://dx.doi.org/10.12983/ijsres-2013-p071-077

Full Length Research Paper Incorporation of Melon Shell at Different Stages of Land Preparation in the Management of Striga hermonthica (Del.) Benth in Maize (Zea mays L.) Liman Rabba Muhammad, Mathew Ahmed* Department of Crop Production Technology, College of Agriculture, P.M.B. 109, Mokwa, Niger State *Corresponding Author: [email protected] Received 19 March 2013; Accepted 10 April 2013

Abstract. A trial was conducted in 2010 and 2011 wet seasons at Mokwa to evaluate the effects of melon shell incorporated into the soil at different stages of land preparation in the management of Striga hermonthica in two maize varieties. Mokwa lies on longitude (090 181N and 050 041E) in the Southern Guinea Savanna of Nigeria. The experiment was laid out in Randomized Complete Block Design (RCBD). It consisted of two maize varieties, Early White Maturity (EWM) and Oba Super II factorially combined with three different stages of land preparation. The data collected includes days to first Striga shoot emergence, Striga shoot count at 9 and 12 WAS, syndrome reaction score, plant height at 3, 6 and 9 WAS and grains yield (Kg/ha). The data collected were subjected to analysis of variance (ANOVA) and means were partitioned using least significant different at 5% level of probability. The results indicated that Oba Super II (resistant) variety generally supported less Striga infestation and Striga shoot count comparable to treatments combination of Early White Maturity (Susceptible) variety. Also Oba Super II maize variety planted with incorporation of melon shell two days before ridging significantly had taller plant height than Early White Maturity variety only in 2010 wet season. Generally, Oba Super II (resistant) variety treated with melon shell at different stages of land preparation significantly recorded higher grain yield in 2011 wet season than the Early White Maize variety. Key words: Organic manure, Land preparation, Striga management

produces large quantities of residual biomass for soil improvement and weed suppression (Pesch and Pieterse, 1982; Olaniya et al., 1990). Muriethi et al. (2003) reported that incorporation of GMCC promotes greater yields of maize presumably due to increased N supply to the soil and reduced loss of N by volatilization. Esilaba et al. (2000) reported that combined application of 40 kg N ha-1 and 30 t ha-1 manure (FYM) significantly reduced Striga emergence. The objective of this study therefore, was to determine the influence of time of incorporating melon shell into the soil for Striga hermonthica control under field condition.

1. INTRODUCTION The parasitic witchweed (Striga hermonthica (Del.) Benth.) is a major constraint to cereal (Maize, sorghum, millet and upland rice) production in Africa sub-Sahara. It is the most economic important Striga spp. The extent to which it damages its host even before it is visible above ground, is one of the characteristics that make it the most serious of all parasitic weeds. Johnson et al. (1997) showed that parasitization of 17 shoots of Striga per square meter reduced rice grain yield by about 5%. Effective control of Striga has been difficult to achieve through conventional hand or mechanical weeding as the parasite exert its greatest damage before its emergence above ground. The situation is further compounded by increased demographic pressure on land use leading to monocropping. Available literature indicates different methods that are applied on the control of Striga, for example manipulation of sowing date and transplanting (Gbehounou et al., 2004), soaking of host seed in Parkia biglobosa extract (Kolo et al., 2005), and crop rotation (Oswald and Ransom, 2001). Furthermore, the incorporation of green manure cover crop (GMCC) as well as leguminous cover crop residues, as a low input technology in traditional cropping systems, reduces germination of Striga seeds and

2. MATERIALS AND METHODS The study was conducted on fields with track history of natural high infestation of Striga hermonthica at Niger State College of Agriculture, Mokwa (090 181N and 500 41E) Teaching and Research Farm situated in Southern Guinea Savanna agro-ecological zone of Nigeria. The area has an annual rainfall of 1100 – 1500 mm and temperature range of 28 – 300C with a relative humidity of 80% in the morning, 40% in the afternoon and later increase to 70% in the evening. The soil is sandy-loam with pH of 6 – 8. The ridges were manually constructed 75 cm apart with hand hoe on 6th June and 24th July 2010 and 2011 respectively

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Liman Rabba Muhammad and Mathew Ahmed Incorporation of Melon Shell at Different Stages of Land Preparation in the Management of Striga hermonthica (Del.) Benth in Maize (Zea mays L.)

after land clearing. The plots consisted of four (4) ridges each 4 m long at 75 cm apart. The seeds were treated with Apron plus (20% W/W thiamethosam, metaloxym and difenoxonzole) just prior to sowing at the rate of one sachet of chemical (10 g) to 3 kg of seed. This was done to prevent the seeds from soil borne diseases and insect pests attack. The treatments were randomly laid out in randomized complete block design (RCBD), consisting of two maize varieties:

Early white maturity (EWM) which is susceptible to Striga and Oba Super II which is known to be resistant to Striga, combined with time of incorporating the melon shell into the soil i.e. two days before ridging, during ridging, placement of manure after land preparation as well as no application (control) replicated three times in each year.

Table 1: Striga shoot count as influenced by the effect of melon shell incorporated into the soil at different stages of land preparation at Mokwa during 2010 and 2011 wet season. Treatment Early white + incorporation two days before ridging Early white + incorporation during ridging Early white + placement of manure after land preparation Early white + no application Oba Super II + incorporation two days before ridging Oba Super II + incorporation during ridging Oba Super II + placement of manure after land preparation Oba Super II + no application LSD (0.05)

9 WAS 12.7a 9.0b 7.0bc 15.3a 5.0bc 6.0bc 5.7c 4.9c 3.6

2010 12 WAS 8.3 6.7 6.7 8.0 5.3 4.0 4.0 5.3 NS

9 WAS 9.0a 7.7a 8.0a 9.3a 4.3b 5.0b 5.0b 5.0b 2.4

2011 12 WAS 6.7a 7.0a 7.0a 7.7a 4.3b 3.7b 4.3b 4.7b 1.26

Mean(s) followed by the same letter (s) within the column are not significantly different at 5% probability, WAS- week after sowing, NS- not significantly different and LSD- Least significant difference.

Table 2: Number of days to first Striga shoot emergence and number of flowering stage at harvest as influenced by the effect of melon shell incorporated into the soil at different stages of land preparation at Mokwa during 2010 and 2011 wet season. Treatment Early white + incorporation two days before ridging Early white + incorporation during ridging Early white + placement of manure after land preparation Early white + no application Oba Super II + incorporation two days before ridging Oba Super II + incorporation during ridging Oba Super II + placement of manure after land preparation Oba Super II + no application LSD (0.05)

2010 53.7a 50.3b 56.3a 51.7a 61.0a 60.3a 60.0a 52.0a 8.3

NDFS 2011 58.0bc 55.3bc 58.3bc 52.0c 69.3a 67.3a 66.7a 61.7b 7.3

2010 14.0a 10.7a 13.3a 13.3a 8.0b 9.7ab 9.3ab 8.0b 4.2

NFSH 2011 15.0a 13.3a 10.0b 15.3a 7.3c 6.3c 7.3c 7.3c 1.9

Mean(s) followed by the same letter (s) within the column are not significantly different at 5% probability, NS- not significantly different, LSD- Least significant difference, NDFS- number of days to first Striga and NFSH- number of flowering stage at harvest.

Table 3: Maize crop reaction score as influenced by the effect of melon shell incorporated into the soil at different stages of land preparation at Mokwa during 2010 and 2011 wet season. Treatment Early white + incorporation two days before ridging Early white + incorporation during ridging Early white + placement of manure after land preparation Early white + no application Oba Super II + incorporation two days before ridging Oba Super II + incorporation during ridging Oba Super II + placement of manure after land preparation Oba Super II + no application LSD (0.05)

6 WAS 2.0 1.7 1.0 1.3 1.7 1.0 1.0 1.3 NS

2010 9 WAS 2.0b 2.0b 3.3a 3.7a 2.0b 2.3a 2.7a 2.7a 1.1

6 WAS 1.3 1.7 1.3 1.3 1.3 1.2 1.2 1.3 NS

2011 9 WAS 1.2 1.2 1.2 1.3 1.2 1.1 1.7 1.2 NS

Mean(s) followed by the same letter (s) within the column are not significantly different at 5% probability, WAS- week after sowing, NS- not significantly different, LSD- Least significant difference,

Three maize seeds were sown per hill at 50 cm x 75 cm on 15th June and 30th July 2010 and 2011 respectively, the plant were thinned to two plant per stand at two weeks after sowing (WAS). Compound fertilizer (NPK 20:10:10) was applied at 3 WAS at the

rate of 60 kg N, 30 kg P and 30 kg K in a single dose since high rates would reduce Striga hermonthica growth. Manual hoe weeding was carried out at three weeks after sowing and hand pulling of weeds other

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International Journal of Scientific Research in Environmental Sciences (IJSRES), 1(5), pp. 71-77, 2013

than Striga hermonthica was adopted at 5 and 8 WAS in order to avoid damage to Striga shoots. Data were taken on days to Striga shoot emergence, Striga shoot density per m2, number of Striga shoot flowering at harvest, visual maize damage score (on a scale of 1 – 10, where 1 indicated no plant damage by Striga, 5 was average damage and 10 was severe maize damage) at 6 and 9 WAS, vigour score at 6 and 9 WAS, maize plant height at 3, 6 and 9 WAS and maize grain yield per ha. The data were subjected to analysis using Minitab 14. The treatments compared using the least significant difference at 5% level of probability.

3. RESULTS Early white maturity (EWM) of maize variety planted with incorporation of melon shell two days before ridging and without melon shell application were significantly (p