Tropical and Subtropical Agroecosystems

Tropical and Subtropical Agroecosystems 4 (2004): 85 - 95

GROWTH AND DEVELOPMENT OF RICE UNDER LOW INPUT TECHNOLOGY

Tropical and Subtropical

[CRECIMIENTO Y DESARROLLO DE ARROZ CON TECNOLOGÍA DE BAJOS INSUMOS]

Agroecosystems

P.I. Okocha, B. O. Nuga* and C.O. Muoneke College of Crop and Soil Science, Michael Okpara University of Agriculture, Umudike P.M.B. 7267, Umuahia, Abia State, Nigeria E-mail: [email protected] *Corresponding author

SUMMARY

RESUMEN

The effects of low or high input technology on the vegetative growth and development of seven rice lines were studied in Umudike in Abia and Uyo in Akwa Ibom States, Nigeria. The experiment was laid out in a randomized complete block design with three replications. Data on plant height, number of leaves, total number of tillers per plant, number of productive tillers per plant and grain yield were collected. The results of the study showed that application of 50% of the recommended fertilizer rate produced taller plants at all the growth stages in 2000 and 2001 cropping seasons in Umudike whereas at Uyo, plant height increased with increasing fertilizer rate. Application of 50% or 100% fertilizer rate produced similar number of leaves per plant while 100% fertilizer rate produced more tillers and more grain yield. However, the level of performance between 100% and 50% fertilizer rates was not significantly different (P > 0.05). Therefore, 50% of the recommended fertilizer rate for Umudike and Uyo and one weeding could be adopted as low-input management for low-input rice varieties.

Se estudiaron los efectos de las tecnologías de bajos y altos insumos sobre el crecimiento vegetativo y desarrollo de siete líneas de arroz en los Umudike, Abia y Uyo, Akwa Ibom, Nigeria. El diseño experimental empleado fue de bloques al azar con tres replicas. Se registró la altura de las plantas, número de hojas, número total de hijuelos, número total de hijuelos productivos por planta y producción de grano. Aplicación del 50% del nivel de fertilización recomendado para la zona resultó en plantas más altas en todas las etapas de crecimiento en los ciclos 2000 y 2001 en Umudike, mientras que en Uyo la altura de la planta se incremento con el nivel de fertilización. La aplicación de 50 o 100% resultó en un número similar de hojas por planta mientras que el 100% de fertilizante resultó en más hijuelos and myor producción de grano. Sin embargo el comportamiento de los cultivos entre 50 y 100% de fertilización no fue diferente (P > 0.05). Se recomienda emplear 50% de la dosis de fertilizante recomendada para la zona de Umudike y Uyo y prodría adoptarse conjuntamente con un control de maleza como estrategia de manejo de bajos insumos para el cultivo de arroz.

Key words: Rice, vegetative stage, low-input, high – input management, fertilizer rates.

Palabras clave: Arroz, edad vegetativa, tecnología de bajos insumos, altos insumos, fertilización. increase in production from 1979 to 1989 (Onwueme and Sinha, 1991).

INTRODUCTION The present critical situation in world food supplies, especially in the developing countries, demands that all available agricultural resources should be utilized to the full to maximize food production, through improved agricultural practices: that is better soil management and crop husbandry (Onwueme and Sinha, 1991).

Nigeria is the third most important rice producing country in Africa after Egypt and Madagascar. But the majority of rice farmers in Nigeria are resource–poor, who cultivate rice not for subsistence but as a cash crop. Along with the rice farms, they grow maize, sorghum, millet, cassava, yam, cocoyam etc, for subsistence. The importance of this phenomenon is that labour is shared between the subsistence crop and cash crop farms. Generally no fertilizer is used and weeding, if done at all, is carried out too late to be effective.

In Africa, there has been both a rapid increase in rice consumption and production. For example there were increases in both area and production of 47 and 30% as compared to the average of the period 1961-65 to 1979, and a further 15% increase in area and 20% 85

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hydrometer method of Bouyoucos (1951); soil pH was determined using the glass electrode pH meter both in H2O and KCl; organic carbon was by Walkley and Black (1934) method; available P was by the Bray 2 extractant method (Bray and Kurtz, 1945); total nitrogen was determined through micro kjeldahl method (Bremner, 1965). Exchangeable cations were determined by extracting the cations with 1 N ammonium acetate buffered at pH 7. Exchangeable acidity was determined by the titration method (Juo, 1979).

Rice is grown under such widely differing conditions that it is difficult to define the climate that is most suitable for its development. One of the main reasons for this wide range of climatic conditions is the large diversity of rice cultivars (Onwueme and Sinha, 1991). Rice has been bred and selected for dependable yields under low management levels; such rice should be tolerant to variations in water levels in the field and should compete reasonably well with weeds. It should also endure low soil fertility conditions and fairly resistant to insect and disease attacks (Onwueme and Sinha, 1991). If high-yielding varieties are screened under upland conditions using low input management it would ensure adaptability of selected materials to local conditions as well as a high yield potential (Maurya and O’Toole, 1986).

Seven rice lines selected on the basis of their excellent performance under low-input management conditions between 1995 and 1999 were used in this study in 2000 and 2001. These were laid out in a randomized complete block design with three replications. The plot size was 4 x 3 m with a spacing of 20 x 20 cm. In both years 5 –6 rice seeds were direct seeded into one hole.

Thirty six advanced rice breeding lines as composed by the West Africa Rice Development Association (WARDA) were screened from 1995 under low-input management conditions. By 1999, seven lines were selected.

The entries were tested using a factorial combination with four fertilizer (NPK) levels which included: 100% NPK (which is the recommended fertilizer rate for the zone), 50%, 25% and 0% of the recommended rates.

The general objective of this research work was to develop a protocol for the cultivation of low-input rice varieties in southeastern Nigeria and the main objective is to establish the effect of low-input management on the growth and development of rice at the vegetative stage.

High input management was taken to be 100% of the recommended fertilizer rate for the zone, which is 80 kg N/ha, 30 kg P2O5/ha and 30 kg K2O/ha (WARDA, 1995) and two weedings, two weeks after germination and booting stage just before fertilizer application. The fertilizer was applied in two split applications (a basal of 60 kg N/ha, 30 kg P2O5/ha and 30 kg K2O/ha, two weeks after germination, using NPK 20:10:10 and top dressed with urea at the rate of 20 kg N/ha at the booting stage). Low-input management was taken to be the use of either 0%, 25% or 50% of recommended fertilizer rate for the zone and only one hand weeding at four weeks after germination. A sampling size of five plants per plot was taken at random for analysis of data. Data collected included plant height at maximum tillering, booting and maturity stages, number of leaves at maximum tillering and booting stage, total tiller number at maximum tillering, booting and maturity stages, number of productive tillers and grain yield.

MATERIALS AND METHODS The experiments were carried out in two locations viz: Umudike in Abia State and Uyo in Akwa Ibom State, both in the humid forest zone of south eastern Nigeria. In Umudike, the experiment was sited at the Michael Okpara University of Agriculture research farm (05º 29´ N, 07º 33´ E, 122 m above sea level). In Uyo, the experiment was located at the National Cereals Research Institute (NCRI) research farm, (05º 30´ N, 7º 05´ E, 100 m above sea level). The total rainfalls and mean temperatures in 2000 and 2001 were 1681 mm and 2190 mm, 27º C and 27.5º C in Umudike; 1664 mm and 2177 mm, and 26.8º C and 26.8º C in Uyo, respectively. The soils of the two study areas are of the coastal plain sand geological formation usually referred to as “acid sands” (Ofomata, 1975; Ojanuga et al, 1981). Soil samples were collected from the experimental sites before treatments were applied. Each soil sample consisted of composite of 3 cores collected from a depth of 0-15 cm.

Statistical analyses of data were carried out using analysis of variance (ANOVA) as described by Gomez and Gomez (1984). Mean separation was carried out using Duncan’s New Multiple Range Test (Duncan, 1955). RESULTS AND DISCUSSION Soil characteristics Table 1 shows some of the physical and chemical properties of the soils of the study areas. The pH

The bulked soil samples for each site were processed and analyzed. Particles size analysis was performed by 86


appropriate fertilizer recommendation is therefore an essential tool for ameliorating the present nutrient imbalance under such conditions (Adediran and Banjoko, 1995). Most of the exchangeable bases are present in low amounts. The implication is that crops grown on these soils will respond well to lime which will improve the pH thereby preventing the fixing of some of the essential nutrients needed for good crop growth and development.

values of the soils were low varying between 4.3–4.6 in H2O and 4.0–4.1 in KCl indicating strongly acidic reaction. The total N was moderately low and medium in Umudike and Uyo respectively while the exchangeable K was very low at both sites. The available P was very high at the study sites unlike the organic carbon, which was low at both sites thus justifying the need for the application of N fertilizer. The application of P through NPK fertilizer likely increased P accumulation in the soil. Soil test with

Table 1: Physico-chemical properties of the soils of the study sites at Umudike and Uyo Soil properties Sand (%) Clay (%) Silt (%) Texture pH (H2O) pH (KCl) Available P (µg g-1) Total N (%) Ogranic C (%) Ca (meq 100-1 g soil) Mg (meq 100-1 g soil) K (meq 100-1 g soil) Na (meq 100-1 g soil) Exchageable Acidity (meq 100-1 g soil) ECEC (meq 100-1 g soil) Fe (ppm) Mn (ppm) Zn (ppm) Cu (ppm)

Umudike 75.2 6.4 18.4 Loamy sand 4.3 4.0 64.47 0.14 0.68 0.67 0.33 0.08 0.14 0.05

Uyo 79.2 3.4 17.4 Loamy sand 4.6 4.1 91.61 0.19 0.92 0.57 0.38 0.08 0.14 0.05

1.27 16.34 18.89 1.34 0.97

1.22 26.36 20.19 1.28 0.54

plant is a varietal characteristic and is not influenced by the management levels. The number of leaves per plant ranged between 3.3–4.3 at maximum tillering and between 4.0–6.0 at the booting stage. Similarly, there was no main effect of rice lines, fertilizer level or rice line x fertilizer level interaction effect on the number of tillers at all the stages of growth (Figure 3). However, high coefficient of variation was recorded for the tillering ability, which ranged from 35.8% at the maximum tillering to 33.0% at both the booting and maturity stages. Tall plant height at the early growth stages and high number of leaves per plant could serve as measures of good plant vigour and high (good) weed competitiveness, which would be very desirable to the resource –poor farmers. Seedling vigor is generally considered essential in upland rice for good stand establishment and ability to compete with weed growth (Chang et al, 1972, Chaudhary and Rao, 1982).

Umudike Location Growth characteristics At maximum tillering stage in Umudike, Suakoko 8 and TOX 3084– 136–1-3-1-2 were taller than the other rice lines in 2000 and 2001 (Figure 1). The trend was similar at the booting stage in 2000 and at the booting and maturity stages in 2001. However, IR 54 was the shortest of the rice lines at the maturity stage in 2001. Application of 50% of the recommended NPK fertilizer rate produced taller plants at all the growth stages in 2000 and 2001 cropping seasons, while 25% fertilizer level was consistent in the production of the shortest plants, especially in IR 54. The rice lines did not show any significant (P>0.05) responses to fertilizer levels on number of leaves per plant at all the growth stages in 2000 and 2001 (Figure 2). This would mean that the number of leaves per

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Rice lines TOX 3084-136-1-3-1-2 SUAKOKO 8 IR 54 TOX 3154-17-1-3-2-2 BG 90-2 TOX 3118-47-1-1-2 ITA 324 2000 At maximum tillering

Plant height (cm)

Plant height (cm)

100

2001 At maximum tillering

80 60 40 20 0 0

25

50

100 80 60 40 20 0 0

100

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Plant height (cm)

120 100 80 60 40 20 0 25

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120 100 80 60 40 20 0 25

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0

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At booting

0

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120 100 80 60 40 20 0 0

Fertilizer levels (%)

25

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Fig. 1: Effects of NPK fertilizer levels (%) and rice lines on rice plant heights (cm) at different stages of growth in 2000 and 2001 at Umudike

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Rice lines



6 5 4 3 2 1 0

No. of leaves

No. of leaves

TOX 3084-136-1-3-1-2 SUAKOKO 8 IR 54 TOX 3154-17-1-3-2-2 BG 90-2 TOX 3118-47-1-1-2 ITA 324

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6 5 4 3 2 1 0

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No. of leaves

At booting

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At booting

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50



Fig. 2: Effects of NPK fertilizer levels (%) and rice lines on rice number of leaves per plant at different stages of growth in 2000 and 2001 at Umudike

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Total no. of tillers/plant

Rice lines

20 15 10 5 0 0

2000 At booting 15 10 5 0 25

50

100

10 8 6 4 2 0 25

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20 15 10 5 0 0

25

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At maturity

At maturity

0


20

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20 15 10 5 0 0

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Fig. 3: Effects of NPK fertilizer levels (%) and rice lines on total number of tillers at different stages of growth in 2000 and 2001 at Umudike

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in plant height at 50% fertilizer rate which was not significant (P>0.05).

Productive tillers and grain yield There was no significant difference (P>0.05) in the number of productive tillers and grain yield for the lines in both 2000 and 2001 cropping seasons (Table 2). The number of productive tillers varied from 3.83 in Suakoko 8 to 5.58 in IR54 in 2000 and from 6.70 in BG 90-2 to 12.80 in Suakoko 8 in 2001. The grain yield on the other hand ranged from 0.93 t/ha in BG 90-2 to 1.49 t/ha in TOX 3154-17-1-3-2-2 in 2000 and from 0.85 t/ha in BG 90-2 to 1.23 t/ha in TOX 315417-1-3-2-2 in 2001. The highest grain yield was reached with the 50% fertilizer rates in both 2000 and 2001 while the lowest yields were with for the 0% and 100% fertilizer rates, which were not significantly different. Uyo Location

There was no significant rice line effect on the number of leaves per plant at the booting stage in 2000 cropping season (Figure 5). Application of 50% or 100% fertilizer rate produced similar number of leaves per plant, which was significantly (P < 0.05) higher than for 0% and 25% fertilizer levels. There was, however, no significant difference (P > 0.05) between the number of leaves for 0% and 25% fertilizer levels. In 2001, Suakoko 8 produced the highest number of leaves at the maximum tillering stage at all the various fertilizer levels but at the booting stage its leaf production the lowest with 50% and 100% fertilizer levels, exceeding only TOX 3154-17-1-3-2-2. At the maximum tillering stage, the number of leaves per stand dropped at 25% fertilizer level for most of the rice lines but rose again at 50 and 100% fertilizer levels.

Growth characteristic In 2000, Suakoko 8 produced the tallest plant at 50% and 100% fertilizer levels at both the booting and maturity stages while IR 54 produced the shortest plants at all fertilizer levels (Figure 4). In 2001, plant height also followed the same trend at Uyo as for Umudike, with Suakoko 8 again producing the tallest plants at the maximum tillering, booting and maturity stages while IR 54 also had the shortest plants at all the stages. Plant height increased as fertilizer levels increased upto 100% level, although there was a drop

In 2000, the highest total number of tillers was with the 100% fertilizer level, which was followed by 50% while 0 and 25% fertilizer levels had the least but similar number of tillers at the booting stage (Fig. 6). Similar trend was observed at the maturity as well as at the booting stage but the increase from 50% to 100% fertilizer level was less pronounced than at the booting stage. At both stages, there was no significant rice line effect on total number of tillers per stand.

Table 2: Effects of NPK fertilizer levels and rice lines on productive tillers and grain yield of rice at Umudike and Uyo in 2000 and 2001 cropping seasons No. of productive tillers Umudike Uyo 2000 2001 2000 2001 4.67 8.50 5.05c 11.3 4.10 9.20 6.43bc 11.7 5.24 9.80 7.10b 13.7 3.86 10.70 10.52a 15.0 0.415 0.930 0.051 0.68

NPK fertilizer levels (%) 0 25 50 100 Se Rice lines TOX 3084-136-1-3-1-2 4.42 9.20 7.00 SUAKOKO-8 3.83 12.80 7.75 IR 54 5.58 10.40 8.33 TOX 3154-17-1-3-2-2 4.42 8.50 6.08 BG 90-2 4.58 6.70 6.72 TOX 3118-47-1-1-2 4.00 9.10 7.42 ITA 324 4.42 10.00 7.42 Se 0.548 1.23 0.672 Within each location and for each year, fertilizer means with differerent

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Grain yield (t/ha) Umudike Uyo 2000 2001 2000 2001 0.81c 0.60b 0.39c 1.09c 1.18b 0.93b 0.56bc 1.48bc 1.72a 1.46a 0.83b 1.69bc 1.15bc 0.92b 1.63a 1.97a 0.149 0.127 0.108 0.173

12.6 1.40 0.99 0.75 11.8 1.40 0.65 0.57 12.5 1.22 1.23 0.77 11.6 1.49 1.02 1.07 13.6 0.93 0.85 0.85 13.8 1.08 0.94 0.80 14.8 0.98 1.15 1.15 0.90 0.198 0.168 0.143 the same letter (s) are not significantly (P >

1.78 1.47 1.31 1.70 1.49 1.67 1.49 0.229 0.05)

Okocha et al., 2004


Rice lines Plant height (cm)


80 60 40 20 0 0

25

100 80 60 40 20 0 0

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50

120 100 80 60 40 20 0 0

100

Plant height (cm)

Plant height (cm)

120 100 80 60 40 20 0 25

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At maturity

At maturity

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100

At booting Plant height (cm)

Plant height (cm)

2000 At booting

50

100

120 100 80 60 40 20 0 0


25

50


Fig. 4: Effects of NPK fertilizer levels (%) and rice lines on plant height (cm) at different stages of growth in 2000 and 2001 at Uyo

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100



Number of leaves/plant

Rice lines TOX 3084-136-1-3-1-2 SUAKOKO 8 IR 54 TOX 3154-17-1-3-2-2 BG 90-2 TOX 3118-47-1-1-2 ITA 324

60 50 40 30 20 10 0

2000 At booting



0

32 28 24 20 16 12 8 4 0 0

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50

100

25

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At booting 120 100 80 60 40 20 0 0

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Fertilizer level (%)


Fig. 5: Effects of NPK fertilizer levels (%) and rice lines on number of leaves per plant at different stages of growth in 2000 and 2001 at Uyo

In 2001, Suakoko 8 produced the highest total number of tillers at 50 and 100% fertilizer levels than the other rice lines (Fig. 6). But at the booting and maturity stages, there was no difference between rice lines, although there was a rise in the number of tillers at 100% fertilizer level for BG 90-2.

from 6.08 in TOX 3154-17-1-3-2-2 to 8.33 in IR 54 in 2000 while it varied from 11.60 in TOX 3154-17-1-32-2 to 14.80 in ITA 324 in 2001. On the other hand the grain yield varied from 0.57 t/ha in Suakoko 8 to 1.15 t/ha in ITA 324 in 2000 and from 1.13 t/ha in IR 54 to 1.78 t/ha in TOX 3154-17-1-3-2-2 in 2001.

Productive tillers and grain yield.

In general, plant height, number of leaves per plant and tillering ability are genotypic (varietal) characteristics and do vary from one variety to another. The higher the level of fertilizer rate, particularly N, the more luxuriant the plant would be. Consequently, the tallest plants were produced by 50 and 100% fertilizer levels. In both Umudike and Uyo, Suakoko 8 produced the tallest plants while IR 54 produced the shortest plants in 2000 and 2001.

The number of productive tillers and grain yield were each not significantly (P > 0.05) influenced by rice lines in both 2000 and 2001 but 100% fertilizer level produced significantly (P < 0.05) the highest grain yield followed by the 50% application while the least grain yield was recorded for 0 and 25% fertilizer levels (Table 2). The number of productive tillers ranged 93

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Rice lines

30 25 20 15 10 5 0 0


2000 At booting 25 20 15 10 5 0 0

25

50

100

20 15 10 5 0 0

25

50

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100

At booting 40 35 30 25 20 15 10 5 0 0

25

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At maturity

At maturity


Total no of tillers/plant



100


25 20 15 10 5 0 0

25

50


Fig. 6: Effects of NPK fertilizer levels (%) and rice lines on total number of tillers at different stages of growth in 2000 and 2001 at Uyo

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100


Duncan, D.B. 1955. Multiple range and multiple F tests. Biometrica, 11: 1-42.

CONCLUSION The performance of the selected rice lines under both low and high input management levels has confirmed the fact that it is possible to select low input rice from the present varieties. The 50% fertilizer level with one weeding was recommended as the low input management option for the rice crio in both locations.

Gomez, K.A. and A.A. Gomez. 1984. Statistical Procedures for Agricultural Research (2nd ed.). John Wiley and Sons, New York, 680 pp.

REFERENCES

Juo, A.S.R. 1979. Selected Methods for Plant Analysis.International Institute of Tropical Agriculture Manual No. 1.

Adeniran, J.A. and Banjoko,V.A. 1995. Response of maize to N,P and ak fertilizers in the zones of Nigeria. Communication in Soil Science and Plant Analysis, 26 (3 & 4): 593-606.

Maurya, D.M. and J.C. O’Toole, 1986. Screening upland rice for drought tolerance. In: Progress in Upland Rice Research. A Proceeding. of the 1985 Jakarata Conference. IRRI. Philippines. PP. 245-261.

Bouyoucos, G.H. 1951. A recalibration of the hydrometer for making mechanical analysis of soil. Agronomy Journal, 43: 434-438.

Ofomata, G.E.K. 1975. Landform regoins. In: Nigeria in Maps – Eastern States. Ethiope Publishing House, Benei City, Nigeria, pp. 33-37.

Bray, R.H. and Kurtz, L.H. 1945. Determination of total organic and available forms of phosphorus in soils. Soil Science, 59: 39-45.

Ojanuga, A.G. Lekwa, G and Akamigbo, F.O.R. 1981. Survey, classification and genesis of acid sands. In: Acid sands of Southern Nigeria Soil Science Society of Nigeria Special Publication. Monograph No. 1: 1-18.

Bremner, J.M. 1965. Total nitrogen. In: C.A. Black (ed). Methods of Soil Analysis. Part II. American Society of Agronomy. Madison, WI, Agronomy Monograph, 9: 1149-1178.

Onwueme, I.C. and T.D. Sinha. 1991. Field Crop Production in Tropical Africa. Principles and Practice. The Technical Centre for Agricultural and Rural Co-operation (CTA), Wageningen, Netherlands. 480 pp.

Chang, T.T, G. Loresto and O.Tagumpay, 1972. Agronomic and growth characteristics of upland and lowland varieties. In: Rice Breeding, International Rice Research Institute, Los Banos, Philippines, pp.656 – 661.

Walkley, A. and Black, L.A. 1934. An examination of the Degtjareff method for determining soil organic matter and a proposed modification of the chromic acid titration method. Soil Science, 37: 29-38.

Chaudhury, D. and M.J.B.K. Rao. 1982. Evaluating rice for drought tolerance using field screening and multiplication testing. In: Drought Resistance in Crops with Emphasis on Rice. International Rice Research Institute. Los Banos, Philippines. pp. 245263.

West

Africa Rice Deevlopment Association (WARDA). 1995. Growing Irrigated Low land/Swamp Rice in Nigeria. WARDA Rice Research Programme, IITA, Ibadan, Nigeria.

Submitted June 10, 2004 -- Accepted August 15, 2004

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