EFFECT OF SELECTED INSECTICIDE ON WHITEFLY (Bemisia tabaci) INFESTING BRINJAL PLANTS 142 Assessment of the Effect of Fungicide and Seed Rate on the Incidence of Leaf Blast (Magnaphorthe Grisea), On the Growth of Foxtail Millet (Setaria Italica (L.) P. BEAUV) in North-eastern Nigeria Z. G. S. Turaki Lake Chad Research Institute Maiduguri, Nigeria B. I. Richard and M. M. Degri Department of Crop Protection, Faculty of Agriculture, P. M. B 1069, University of Maiduguri Borno State, Nigeria Abstract In 2007 a multilocational trial was conducted in a split-plot using randomized complete block University of Maiduguri and Gashua Farm station to assess the effects of fungicide and seed rate on the incidence of leaf blast (Magnaphorte grisea), on the growth and yield of foxtail millet in the Northeastern Nigeria. The results showed that the lowest disease incidence of 20.8% and 0.4% were recorded from 100% recorded significantly (P < 0.05) the highest disease incidence of 80.0% and 64.3% at Maiduguri and Gashua respectively. The highest plant height and panicle length were recorded from plants grown at fungicide seed treatment ranging from 80-100% at seed rate of 5.0kg/ha. The lowest plant height and panicle length were obtained from plants grown from the untreated seed tate of 12.5kg/ha and while the lowest grain yields were recorded from untreated seed rate of 5.0kg/h at Maiduguri and Gashua respectively. Keywords: Incidence, fungicide treatment, leaf blast, seed rate foxtail millet Introduction 1 Foxtail Millet (Setaria italica (L.) p. BEAUV) is the second most widely cultivated species of millet in the world (Zohary and Hopf, 2000). Millet is a very important food grains and economic crop in areas where it is cultivated extensively. It is known by several other names such as Italian millet, German millet, Chinese millet and Hungarian millet (Baker, 2003). The crop is a dwarf millet cultivar newly introduced in Bauchi State and other northern Nigerian Savannah where several millet cultivars are Corresponding author’s Name: B. I. Richard Email address: richybwala@gmail.com used as food and cash crop. According to Nkama et al. (1994), most of the millet grains produced in Nigeria are used for human consumption and for preparing fermented and unfermented breads, weaning food and for production of local alcoholic beverages (Nkama, 1998) Millet generally can adopt to poor nutrient sandy soil in low rainfall areas and it is one of the oldest cultivated crop in sub-Saharan west African (Andrea et al., 2001). In Nigerian savannah where several millet cultivars are grown extensively, plant disease pose a big threat in lowering the yield potential if a necessary and adequate disease control measures are not adopted. Leaf blast of foxtail Asian Journal of Agriculture and Rural Development journal homepage: http://aessweb.com/journal-detail.php?id=5005 mailto:richybwala@gmail.com Asian Journal of Agriculture and Rural Development, 4(2)2014: 142-148 143 millet is a seed borne fungal pathogen of major economic importance and other prominent fungal diseases include Smut (Ustilago crameri), green ear (Sclerospora graminicola) and blight (Cochliobolus setariae) ito et kuribayashi) Drechsler exDastar (Skerman and Riveros, 1990). According to Kato et al. (2001) and Farman, (2002) Leaf blast Foxtail millet has been reported to affect photosynthetic activity and transport of metabolites in the crop. Also Thakur et al. (2002) stated that the incidence of the disease has been quite variable depending on cultivars, season and location. Disease can cause an annual yield lose of 6-8% and up to 55% yield loss has been recorded in some millet fields in Nigeria (Ajayi et al., 1998) Machenzie and Sah (1991) stressed the need for quantitative relationship that relate to the effects of disease and yield losses for development of disease control strategies and crop management plans. Anaso (1996) has pointed out the simulation of various disease conditions which offered a range of data points to predict yield loss in foxtail millet. The use of Chemical and cultural control in combination can effectively lower the disease incidence and severity when ever resistant cultivars are not available even though the use of resistant cultivars has been recommended as the best disease control option, but the genetic improvement is very tedious, slow and takes several years before improved cultivars are introduced for cultivation Richard et al. (2008). Similarly, Richard et al. (2009) reported that seed dressing with Apron star 42ws fungicide controls the early stage of anthracnose and ensure high seedling establishment. Also, Anaso (1989) controlled sorghum downy mildew in Maize by seed dressing with Apron plus 35SD. As a Newly introduced crop in the Nigerian Semi-arid regions there is dearth of information on the crop, diseases and environmental factors. Therefore, the objective of this work was to assess the effects of chemical and seed rate on disease incidence growth and yield loss on foxtail millet due to leaf blast (Setaria italica) in the Northeastern Nigeria. Materials and methods The field experiments were carried out as multi-trials during the 2007 cropping at Maiduguri and Gashua located in the Sudan and Sahel agro-ecological zones respectively. The trail was laid out in a split-plot using randomized complete block design. The varying percentages planting rows of 0%, 20%, 40%, 60%, 80% and 100% sown with Apron Star 42WS treated seeds (2.0g a. i/kg) was laid in the main-plot in order to simulate variable disease incidences, while the variable seed rates of 5.0, 7.5, 10.0 and 12.5 kg/ha was laid in the sub-plots of 5 x 3m replicated four times. There was 0.5m and 1m as spacing between plots and replicates respectively. There was 30cm and 45cm inter- and intra-spacing between plant stands and rows accordingly. An infector rows sown to LCIC 9702 at 4.5m apart was established three weeks earlier. The total land area used was 34.5 x 17m. The first weeding was done at two weeks after sowing (WAS) and the millet were thinned down to two plants per stand. Inorganic fertilizer was applied at the recommended rate of 60.0kg N/ha, 30kg P2O/ha and 30kg K2O/ha for millet in the savannah according to Anon (1989). The experimental plots were kept weed-free throughout the experimental period. Data collection The leaf blast incidence was recorded at fifty days after sowing (DAS) using the formula: Z = K /Y x 100 Where: Z = Disease incidence (%) K= Number of plants infected by leaf blast in the middle rows Y= total number of plants infected and uninfected by the leaf in the middle rows The plant heading was taken at fifty-nine days after sowing and while the plant height panicle lengths were recorded at maturity stage. Asian Journal of Agriculture and Rural Development, 4(2)2014: 142-148 144 Yield The panicles in the middle rows of each plot were cut-off from the main stalk, sundried properly, threshed, winnowed and the grains were weighed separately and converted in kilogram per hectare. All data were subjected into statistical analysis of variance (ANOVA), the means were separated using Duncan’s Multiple Range Test (DMRT). Results and discussions Results in (Table 1) showed that in 2007 cropping season, the effect of fungicide seed treatment levels and seed rates on diseases incidence and grain yield were significant in both Maiduguri and Gashua agro ecological locations. Results revealed that plants grown from the untreated seed (control) significantly had the highest leaf blast incidence of 80.0% and 64.3% at Maiduguri and Gashua locations, while those grown from the highest fungicide level of 100% recorded the lowest disease incidence of 20.8% and 10.4% at Maiduguri and Gashua respectively (Table 1). Similarly, the effect of different seed rates on disease incidence showed that plants grown from the highest seed rate of 12.5kg/ha recorded significantly the highest disease incidence of 51.6% and 39.7% at Maiduguri and Gashua, while the lowest leaf blast incidence of 41.0% and 28.2% were obtained from the plants grown from the lowest seed rate of 5.0kg/hg at Maiduguri and Gashua locations respectively. The result also indicates that the disease incidence increased significantly with each successive increase in seed rate and decrease with each successive increase in fungicide level at both locations. Table 1: Effect of fungicide seed treatment and seed rates on leaf blast incidence of foxtail millet at Maiduguri and Gashua locations during the 2007 cropping season Treatments Disease Incidence Maiduguri Gashua Fungicide rates (%) Leaf blast (%) Leaf blast (%) 0 80.0a 64.3a 20 60.3b 49.6b 40 50.2c 36.1c 60 39.1d 26.4d 80 27.7e 18.2e 100 20.8f 10.4f SE ± 1.07 1.10 Seed Rates (kg/ha) 5.0 41.0d 28.2d 7.5 44.7c 32.5c 10.0 48.1b 36.1b 12.5 51.6a 39.7a SE ± 0.61 0.65 Interaction F x Sr ** * Means in the same column followed by similar letter (s) are not significantly different at 5% probability level of the Duncan’s Multiple Range Test (DMRT). The results in (Table 2) showed that the effect of fungicide levels and seed rates on plant height and panicle length of foxtail millet were highly significant at Maiduguri and Gashua agro-ecological locations in 2007 cropping season, but the heading days was not significantly different at both locations in the same season. The results of 2007 indicated that the highest plant height and panicle length of 44.9cm and 6.2cm; 42.9cm and 6.1cm which were not significantly different from each other was recorded on the plants grown from the Asian Journal of Agriculture and Rural Development, 4(2)2014: 142-148 145 highest fungicide level of 100% and 80% respectively at Maiduguri. Similarly, the highest plant height of 45.0cm and panicle length of 7.2cm were recorded from foxtail millet grown from seed treated with the highest level 100% fungicide at Gashua. The untreated (0%) plant had the lowest plant height and panicle length of 27.8cm and 4.9cm; 34.3cm and 5.4cm at both Maiduguri and Gashua locations respectively. Also, results in Table 2 showed that at the two locations, plants grown from the lowest seed rate of 5.0kg/ha significantly had the highest plant height and panicle length. Based on this rate, the highest plant height and panicle length of 42.6cm and 6.1cm were recorded at Maiduguri agro ecological location, while the highest plant height and panicle length of 44.7cm and 6.5cm were obtained at Gashua agro ecological locations. This was followed by the plants grown at the seed rate of 7.5kg/ha. This result indicated that an increase in seed rate with corresponding increase in the plant population resulted to a highly significant decrease in the plant height and panicle length which could be due to competition for light, space, water and nutrients. Results on grain yield in 2007 (Table 2) showed highly significant differences in relation to levels of fungicide seed treatment and seed rates in the two locations. At Maiduguri location, the results revealed that the highest grain yields of 1334.0kg/ha and 1337.0 kg/ha were recorded on plants grown at 100% fungicide level and seed rate of 10.0kg/ha respectively. Also results showed that at Gashua location, the highest grain yields of 1248.0 kg/ha and 981.0 kg/ha were obtained on plants grown from fungicide seed treatment level and seed rate similar to those of Maiduguri. On the same trend, results in (Table 2) also indicates that at Maiduguri location, higher grain yield of 1236.0 kg/ha was recorded on plants grown from 80% fungicide seed treatment level which was not significantly different from the grain yields obtained at 100% fungicide seed treatment level at Gashua location. The lowest grain yields of 307.0 kg/ha and 264.0 kg/ha were recorded from the untreated plants (%) at Maiduguri and Gashua locations respectively (Table 2) in 2007. Also, the results of the same year showed that the lowest grain yields of 430.0 kg/ha and 414.0 kg/ha were obtained from the plants grown from the lowest seed rate of 5.0 kg/ha at Maiduguri and Gashua zones respectively. In light of this, the work has obviously found that the optimum attainable grain yield of foxtail millet if possible within the fungicide seed treatment of 80-100% and seed rate of 10kg/ha which also agreed with Emechebe et al. (1994) which stated that seed dressing with effective chemical is a viable option for disease control and maximum yield production for the peasant farmers in the West African Sudan Savannah. Anaso et al. (1989) state that seed dressing with Apron plus 35SD controlled downy mildew in maize. Similarly, Richard et al. (2009) also stated that seed dressing with Apron star 42WS at the rate of 2.5 product a.i.kg/ha lowered the incidence and severity of sorghum Anthracnose. Table 2: Effects of fungicide seed treatment levels and seed rates on heading, plant height and panicle length of foxtail millet at Maiduguri and Gashua during the 2007 cropping season Treatments Heading (days) Plant height (cm) Panicle length (cm) Grain yield (kg/ha) Heading (days) Plant height (cm) Panicle length (cm) Grain yield (kg/ha) Fungicide rate (%)[Fr] Maiduguri Gashua 0 57.2 27.8d 4.9e 307d 57.1 34.3e 5.4c 264e 20 57.3 32.2c 5.4d 734c 56.8 36.2d 5.8c 590d 40 27.8 36.2b 5.7c 820c 57.1 37.8cd 5.8c 614d 60 57.7 38.5b 5.8b 980b 57.5 38.7c 6.1c 780c 80 58.3 42.9a 6.1a 1236a 57.3 41.2b 6.4b 1065b 100 58.2 44.9a 6.2a 1334a 57.7 45.0a 7.2a 1248a Asian Journal of Agriculture and Rural Development, 4(2)2014: 142-148 146 SE ± 0.59 0.92 0.04 47.4 0.29 0.61 0.26 43.4 Seed Rate (kg/ha) 5.0 58.6 42.6a 6.1a 430d 57.3 44.7a 6.5a 414d 7.5 57.8 37.7b 5.9b 867c 57.3 38.9b 6.2a 760c 10.0 57.3 36.3b 5.6c 1337a 57.3 38.1b 6.1b 981a 12.5 57.3 31.7c 5.2d 973b 57.1 33.6c 5.6b 886b SE ± 0.44 0.63 0.03 30.2 0.21 0.53 0.18 29.7 Interaction F x Sr NS * ** ** NS * * ** Means in the same column followed by similar letter(s) are not significantly different at 5% probability level of the Duncan’s Multiple Range Test (DMRT) Results in (Tables 3) showed that the effects of interaction between the seed treatment fungicide levels and seed rates on the incidence of leaf blast and grain yield were significantly different at both Maiduguri and Gashua locations during 2007. Results obtained from the Maiduguri location proved that plants grown from the untreated seeds at the seed rate of 12.5kg/ha significantly had the highest disease incidence of 90.5 while those plants treated with 100% fungicide at seed rate of 5.0 kg/ha recorded the lowest leaf blast incidence of 13.0% in the same season (Table 3).similarly, results in (Table 3) showed that the highest disease incidence of 74.1% was recorded on the untreated plant (0%) under the seed rate of 12.5kg/ha while the lowest disease incidence of 5.6% was obtained on plants grown from 100% level of fungicide seed treatment under the lowest seed rate of 5.0 kg/ha at Gashua location. Higher grain yields (Table 3) of 1805.0 kg/ha, 1812 kg/ha and 1636 kg/ha which were not significantly different from each other were obtained under the same seed rate of 10.0 kg/ha at fungicide seed treatment levels of 100%, 80% and 60% Maiduguri respectively, while the lowest grain yield of 176.0 kg/ha was recorded from the untreated plant under seed rate of 5.0 kg/ha at Maiduguri location. In contrary, at Gashua location, the highest grain yield of 1599 kg/ha and 1460 kg/ha; 1444 kg/ha and 1326 kg/ha were obtained at fungicide levels 100% and 80%; and at seed rates of 10.0 kg/ha and 12.0 kg/ha respectively. In the two agro-ecological locations, result revealed that the disease incidence and the resultant yield loss were higher at Maiduguri than Gashua location. This could be due to favourable humid environment which might have favoured spore sporulation and dispersal with resultant high disease incidence and yield reduction. This finding also agree with Kato et al. (2000), Eto et al. (2001) and Farman (2002), who reported that leaf blast affect photosynthetic activity and transport of metabolites in the crop. Table 3: Effect of Interaction between Fungicide seed treatment levels and seed rates on leaf blast incidence and grain yield of foxtail millet at Maiduguri and Gashua locations during the 2007 cropping season Fungicide Rate (%) INCIDENCE OF BLAST (%) 5.0 7.5 10.0 12.5 5.0 7.5 10.0 12.5 Maiduguri Seed Rates (kg/ha) Gashua 0 72.5c 75.7c 81.3b 90.5a 57.9d 59.8c 68.2b 74.1a 20 56.4ef 60.0de 62.3d 62.4d 46.0f 49.2ef 50.7de 52.4de 40 46.7hi 49.8hi 50.5gh 53.7fg 28.9ij 36.4gh 38.5gh 40.7g 60 33.9kl 35.5k 41.8j 56.3ij 19.9kl 24.3jk 27.7j 33.6hi 80 23.6mn 29.9mn 29.4lm 30.8klm 13.8m 14.7m 19.7l 24.5jkl 100 13.0p 20.30o 23.1bo 26.8no 5.6n 10.8m 12.0m 13.1m SE ± 1.48 Grain Yield (kg/ha) Asian Journal of Agriculture and Rural Development, 4(2)2014: 142-148 147 0 176m 266lm 433kl 355lm 199k 290jk 327jk 241k 20 302lm 733ij 1065efg 837hij 375jk 494hij 778d-g 712efg 40 321lm 794hij 1271cde 893ghi 398jk 606ghi 800d-g 652fgh 60 418kl 856g-j 1636ab 1010fgh 415ijk 841c-f 941cd 924cde 80 631jk 1190def 1812a 1312cd 468hij 1022c 1444ab 132b 100 730ij 1366cd 1805a 1434bc 626f-i 1309b 1599a 1460ab SE ± 74.02 Means in the same column followed by letter(s) are not significantly different at 5% probability level of the Duncan’s Multiple Range Test (DMRT) The results (Table 4) of the combined analysis of the two agro-ecological locations in 2007 showed that the average (mean) and ranges of heading days, plant height and panicle length are 57.5 (56.5 – 59.5 days), 38.0cm (25.2 – 53.5cm) and 5.9cm (4.2 – 7.5) respectively. On the same trend, results also revealed that the average (mean) and ranges of leaf blast incidence and yield are 40.2% (5.6 – 90.5) and 831.0 kg/ha (176 – 1812 kg/ha) (Table 4). This results agree with Skerman and Riveros (1990) which reported that the leaf blast is among the major three diseases of foxtail millet and also that the yield of the crop ranges from 800 – 900 kg/ha with flowering date ranging from 56 – 52 days in the Sudan Savanna. Table 4: Combine analysis of the effects of fungicide levels and seed rates on heading days, plant height, plant length, leaf blast, incidence and grain yield at Maiduguri and Gashua agro ecological locations in 2007 cropping season Heading (days) Plant height (cm) Panicle length (cm) Leaf blast incidence (%) Grain yield (kg/ha) Means 57.5 38.0 5.9 40.2 831.0 Range 56 – 59.5 25.2 – 53.5 4.2 – 7.5 5.6 – 90.5 176 – 1812 CV (%) 3.00 7.65 11.26 8.57 20.67 This work shows that an appropriate Apron star seed dressing fungicide level and appropriate seed rate can lower the incidence of leaf blast, increase plant height, panicle length and reduce yield loss. Therefore, this result will immensely serve as first-hand vital information to the farmers for the effective management of foxtail millet diseases in Nigerian Savannah and other parts of the Semi-arid regions. References Ajayi, O., Owonubi, J. J., Uyovbisere E. O., & Zarat, A. B. (1998). 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