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Scientific Research and Essays Vol. 6(6), pp. 1411-1416, 18 March, 2011 Available online at http://www.academicjournals.org/SRE ISSN 1992-2248 ©2011 Academic Journals

Full Length Research Paper

Tef (Eragrostis tef) based cropping systems in the hot to warm moist valleys of North Shewa, Ethiopia

Adamu Molla* and Kemelew Muhie

Debre Birhan Agricultural Research Center, P. O. Box 112, Debre Birhan, Ethiopia.

Accepted 30 September, 2010

Research on tef (Eragrostis tef (Zucc.) Trotter) in the hot to warm moist valleys of North Shewa of the Amhara regional state has been meager. However, tef is the second most important cereal crop in area coverage in these sub agro-ecologies. Cereal Crops Research Program of Debre Birhan Agricultural Research Center launched informal survey in 2006 while the crops were in the field so as to identify the major tef based cropping systems and production practices for prioritizing research needs. The most important cropping system identified was tef based intercropping. A base crop was found intercropped with sesame, safflower, sesame-safflower, sorghum, gomenzer (Brasica carinata), and sunflower (in descending order of importance). The relative area coverage of sole cropped tef varied from about 4 36%. The component crops intercropped with tef were found to be largely affected by soil type. Seed rates of sesame and safflower as intercrop with tef are determined by the experience of individual farmer on soil type, depth and fertility levels. Other cultural practices also vary according to soil types, onset and duration of rainfall. This paper also outlines priority research directions of tef and its intercrop components. Key words: Cropping system, hot to warm moist valleys, tef, sesame, safflower. INTRODUCTION Tef (Eragrostis tef (Zucc.) Trotter) is a C4, self-pollinated, chasmogamous annual cereal crop indigenous to Ethiopia (Ketema, 1997). It is the second most important cereal crop, next to sorghum, in area coverage in the hot to warm moist valleys (M1-2, M1-3 and M1-4) of North Shewa. Research on tef in these sub agro-ecologies of Ethiopia in general (Ketema, 1997) and in North Shewa of the Amhara Region in particular has been meager. Most of the few available works indicate that tef has been grown mostly as a sole crop. For example, unpublished general survey reports of Sheno Agricultural Research Center in 2002 and 2003 indicated that sole cropping of tef was the dominant cropping system. However, the said general survey results do not reflect the present reality on the ground in which tef is being dominantly grown intercropping with lowland oil crops such as sesame and safflower as revealed by our simple visual observation. Even though it is not specific enough in terms of agro-ecologies and intercrops, the work of Geleta et al. (2002) also indicated that 98.1% of tef fields were interand border-cropped in Shewarobit areas. Under such conflicting reports and observations, it is difficult to design sound research programs of tef in the hot to warm moist valleys. Therefore, this specific informal survey was initiated so as to identify the major tef based cropping systems and production practices for prioritizing research needs.

MATERIALS AND METHODS Using procedures outlined by Byerlee and Collinson (1980), informal survey was conducted in late October 2006 while crops at the reproductive stage were still in the field. The areas covered by the survey include the hot to warm moist valleys (sub agroecologies of M1-2, M1-3 and M1-4) of Shewarobit areas, Jemma and Wonchit River valleys of Merhabietie in the administrative zone of North Shewa. These sub agro-ecologies cover areas with an altitude range of 400 ­ 2000 m above sea level, mean annual rainfall of 250 ­ 1600 mm, growing periods of 120 - 180 days, and mean annual temperature of 16 - 28°C (Anonymous, 1998). The specific areas together with the distances covered in the survey and

*Corresponding author. E-mail: [email protected]

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Table 1. List of surveyed areas including distances and altitudinal ranges covered using tef-based intercropping practices as a bench mark.

Area surveyed Asfachew to Shewarobit Shewarobit to Jeweha Shewarobit to Medina Medina to Sefiberet Medina to Abayatir Jemma River Valley Wonchit River Valley

Distances covered along the road (km) 15 15 20 10 7 19 20

Altitudinal ranges* for tef based sesame or safflower intercropping practices (masl) 1250 ­ 1580 1250 ­ 1340 1250 ­ 1480 1480 ­ 1530 1480 ­ 1500 1430 ­ 1880 1500 ­ 1940

*500 - 1500, 1500 - 2300 and 2300 - 3200 m asl are lowlands, mid-altitude areas and highlands, respectively, according to traditional climatic zonation.

Table 2. Relative area coverage of crops in the surveyed areas in October 2006.

Surveyed areas Jeweha to Asfachew Medina to Sefiberet East of Jemma River West of Jemma River Wonchit Valley

Tef* 52 90 28 35 10

Relative area coverage of crops (%) Sorghum* Other crops 45 3 10 0 72 0 65 0 90 0

*Include intercropped fields of tef, tef being the base crop.

the altitude ranges measured are listed in Table 1. The altitude ranges were determined based on the observed tef based intercropping practices of sesame and safflower altitudinal range coverage in each listed area. According to the traditional climatic zonation, almost all surveyed areas surrounding Shewarobit lie in the lowland classification range of 500 ­ 1500 m, while those of Jemma and Wonchit River valleys lie in the mid altitude classification range of 1500 ­ 2300 m a.s.l. Non-structured check lists were used to talk to key informant farmers and farmers encountered in the field harvesting tef. Depending on the willingness and knowledge of farmers, the depth of talks varied from covering few testing questions to many points of interest. Points of divergent opinions or experiences were raised to many farmers till common understandings were reached. Area coverage of major crops was quantified through discussion with farmers and/or using imaginary grids in such a way that very wide stretch of crops fields were divided into quartiles so as to get approximate estimates during visual observations. While driving, crop field counts were made on both sides of the road covering a radius of at least 500 m in which each component crop of the intercropping was recognizable so as to calculate the relative abundance of each cropping system. Stand counts of main plants of the component crops intercropped with tef was taken from 25 m2 in each field for estimating the population in hectare.

2). Tef is domin ant in the surveyed areas of Shewarobit lowlands as opposed to Jemma and Wonchit Rivers valleys that are dominated by sorghum. Cropping systems Of the total 374 field counts, excluding sole sorghum fields, in areas from Jeweha to Asfachew, 237 were tefbased intercrops, 131 were sole tef, 3 were sole sesame, and 3 were mungbean-sesame intercrops. The relative percentages for 368 fields are presented in Table 3. Only 2 fields were mung bean-sesame intercrops and no field of sole sesame or sole safflower fields were observed in areas from Shewarobit to Medina. Of the total fields covered by tef in Jemma and Wonchit River valleys, tef based sesame intercrops covered more than 95%. For example, of the areas covered by tef in the east of Jemma River, 95, 1 and 4% was covered by tefsesame intercropping, tef-safflower intercropping, and sole tef, respectively; while in west of Jemma River, almost all were occupied by tef-sesame intercrops. Of the areas covered by tef in Wonchit River valley once again almost all were tef-sesame intercrops. In Wonchit River valley, we have also traced one field of tef-sunflower intercropping near Jara River at 1660 masl. However, this was a rare activity for most farmers were not clear with its relative advantage as compared to safflower; few still

RESULTS Relative area coverage of crops The relative area coverage of crops in the surveyed areas as of October 2006 varied among locations (Table

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Table 3. Relative area coverage of tef based cropping systems in areas surrounding Shewarobit as of October 2006.

Cropping systems Tef-sesame intercrop Tef-sesame-safflower intercrop Tef-sorghum intercrop Tef-gomenzer intercrop Tef-safflower intercrop Tef-sesame-safflower-sorghum intercrop Sole cropped tef

Percent of the total 368 fields in Jeweha to Asfachew 60.33 0.27 0.54 0.54 2.72 0.00 35.60

Percent of the total 316 fields in Shewarobit to Medina 59.87 6.05 1.59 0.00 11.15 0.32 21.02

believe that sunflower yields more. Farmers are not producing either sesame or safflower as a sole crop in Jemma and Wonchit River valleys, the tradition being intercropping with tef. Generally, intercropping of sorghum with either sesame or safflower is not common in surveyed areas. Intercropping tef with either gomenzer (Brasica carinata) or sorghum is also a rare practice. Soil types also affect component crop choice in tef based intercrops. Sesame has been widely intercropped with tef on well drained light soils and on stony light soils while tef-safflower intercropping has been dominant on heavy black soils or on deep fertile soils. Cultural practices Plowing Plowing is done by oxen drawn traditional plow called maresha. Be it intercropped or sole cropped, plowing frequency for tef varies from 3 - 6 times in Shewarobit areas while it varies from 2 - 4 in Jemma and Wonchit River valleys even though the common practice is 3 plowings, the sequential operation being in April to June, mid July and the last one from 21 July to 6 August. Light soils as opposed to heavy black soils require more plowing frequency due to high weed pressure. Sowing Sowing dates generally vary from 11 July to 18 August according to soil types and onset of rainfall. Early sowing during 11 - 16 July is the common practice on light soils while sowing during 16 - 31 July is done on heavy black soils. Tef seed is sown soon after plowing on light soil as opposed to plowing followed by sowing and then trampling/packing by livestock/humans on heavy black soils. If intercropped, tef seed is mixed with the component crop seed and is sown at one time. Seed rate Tef seed rate varies from 20 to 28 kg ha

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sesame and safflower rates are unknown as individual farmer determines the proportion depending on soil type, soil depth and fertility levels. Seed rate of sesame is higher when intercropped with tef on stony light soils as opposed to that on deep and heavy black soils where seed rate of tef is higher, keeping seed rate of sesame or safflower at lower rate. Since farmers were not able to specify the seed rate of component crops in the tef intercrop, our estimate from eight fields showed that it -1 varies from 17600 to 31200 sesame plants ha and 7600 -1 to 24000 safflower plants ha across soil types. These figures may give a hint for future work. Fertilizer application Farmers believe that fertilizer application on tef, be it sole or intercropped, is unnecessary. Some farmers who tried fertilizer application say that fertilizer together with the hot to warm moist environment enhance vegetative growth at the expense of grain yield. Weeding Twice weeding is a common practice, the first being done in August while the second in September. However, some farmers said that intercropping tef either with sesame or safflower reduces weed pressure resulting in the requirement of only one hand weeding. In Jemma and Wonchit River valleys, few farmers have been using broad leaved weed killer (2, 4D) for the last two years and complained that it killed sesame and safflower in tef intercrops. Nevertheless, they insist that chemical weed control helps much than the income or yield advantages gained from intercropping either sesame or safflower with tef. Thus these farmers are planning to avoid intercropping of these two oil crops with tef for the sake of herbicidal weed control, which still requires one hand weeding for the control of grassy weeds. Crop variety

while those of

Our field observations and discussions with farmers

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revealed that no trace of improved variety of tef and oil crops was under production in the surveyed areas. Early maturing white seeded tef (locally called magna) is almost the only local variety under production. Most farmers rejected the low yielding brown seeded local tef called bunign. Local variety of sesame with brown seeded or mixture of brown and white seeds has almost been the only variety under production. White seeded sesame is rarely produced. Safflower is totally local and no specific local name (as it is generally called soof) for the variety under production. Sesame is largely produced to fulfill home consumption needs while tef and safflower are largely used as cash crops. Harvesting Tef harvesting is done in mid October to mid November and at this time the safflower reaches flowering stage while sesame seed filling stage. Harvesting of sesame is done in late November to mid December while safflower in December to mid January. Rotation As a sole crop or intercropped, the tef is usually rotated with sorghum. Mono-cropping of sorghum for 4 - 5 sequences and of tef as a sole or intercrop for 2 - 3 sequences is the dominant practice of most farmers even though they are aware of yield decline caused by monocropping. DISCUSSION Tef was dominant in the surveyed areas of Shewarobit lowlands because of a shift from sorghum to tef in recent years as sorghum was recurrently hit by an insect pest called sorghum chaffer/packnoda beetle (Pachnoda interrupta). Otherwise, sorghum is preferable to tef for it is higher yielding both in Shewarobit lowlands and in the valleys of Jemma and Wonchit Rivers. The relative area coverage of tef and sorghum also varies according to the timing of the onset of rainfall in the surveyed areas in general. Almost all farmers give priority for sorghum production whenever the rainfall starts early as opposed to high priority for tef on late onset. Moreover, whenever sorghum sown in the small rains of April to May fails, tef gets a priority as a catch crop production. As the areas from Shewarobit to Medina were rugged and more of stony light soils, the dominant cropping system was tef-sesame intercropping as was observed from 316 crop fields, excluding sole sorghum (Table 3). On such soils, tef and safflower are believed to be relatively low yielding. Therefore, to compensate the low yielding nature of tef on stony light soils, higher seed rate

of sesame that naturally performs well on such soils is practiced. Thus, tef-sesame intercropping was also found to cover more than 95% of the fields covered by tef on light soils in Jemma and Wonchit River valleys. Sesame production on heavy black soil is very limited because of its susceptibility to waterlogging. Keneni and Woyessa (1992) also reported that sesame requires freely drained soils. Safflower on heavy black soil is believed to produce higher seed and oil yields with better quality than on light soils. That is why tef-safflower intercropping was found dominant on plain lands of heavy black soil in Medina to Sefiberet. Generally, in the surveyed areas of hot to warm moist valleys, the major driving force for intercropping sesame and safflower with tef is largely the need for additional yield and income. Farmers believe that intercropping of sorghum with either sesame or safflower is not common because of early maturity of sesame that makes harvesting difficult due to shattering and the thorny nature of safflower makes weeding difficult in sorghum. Moreover, sorghum does not leave space in time for these two oil crops that are under the shadows of sorghum throughout their growing period causing yield penalty. Sometimes people are confused when they see some sorghum plants in tef field, considering it as intercropping. Such occasions occur when tef is sown as a catch crop on failed sorghum fields, in which some sorghum plants survive and continue to grow without the intention of individual farmers. Intercropping tef with either gomenzer or sorghum is also a rare practice for most farmers believe that these two crops are more competitive, especially in height, resulting in low yield of tef. However, experiences elsewhere indicate that yields of sesame were increased when it was intercropped with short and early maturing varieties of sorghum in southeast Tanzania (Taylor, 1986); and a yield advantage from intercropping of sunflower with mustard was also reported by Putnam and Allan (1992). In the surveyed areas of our case, the sorghum varieties are tall and late maturing and therefore are expected to be more competitive than complementary with sesame and safflower when intercropped; it calls for research into identifying sorghum varieties complementary in the utilization of below and above ground resources. Farmers in the surveyed areas practice more plowing frequency on light soils than on heavy black soils for the main reason that weed pressure is high on light soils. Even though our result disagrees with the one reported by Ketema (1997) indicating that heavy clay soils need more plowing frequency than loam or sandy soils, there is agreement that fields with high weed populations receive more plowings than those with fewer weeds. Experiences elsewhere in Ethiopia also shows that plowing frequency for tef varies from 3 to 12 depending on the onset of rainfall and its seasonal duration, crop variety, soil type, effect on soil erosion, strength of draft power animals, and fertility status of soil (Yadeta et al.,

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2001). Be it sole or intercropped, fertilizer application for tef production is a rare practice even though it has been -1 recommended to apply 41/20 kg N/P ha in low rainfall areas such as the hot to warm moist valleys. Farmers usually use higher proportion of fertilizer urea than DAP and that may be the reason why they observed enhanced vegetative growth being aggravated by the hot to warm moist environment resulting in low grain yield. This practice has been depleting the soil for a long time now and needs a prioritized research to improve the productivity of tef as a sole crop and intercropped. Two conflicting ideas are there with regard to weed control in tef-based intercropping with sesame or safflower. Those who advocate tef intercropping with either sesame or safflower say that weed pressure is lower in intercropping and therefore one hand weeding is enough as opposed to sole cropped tef that requires twice hand weeding. Those who are against tef intercropping with either sesame or safflower at Jemma and Wonchit River valleys say that intercropping hinders the use of broad leafed weed killer herbicides like 2,4-D for it kills sesame and safflower; and use of broad leafed weed killer on sole cropped tef has more monetary advantage than can be obtained from tef even though sole cropped tef still needs one hand weeding to control grassy weeds. These conflicting interests call for immediate research so as to reach a data based decision. Moreover, the ever increasing demand for sesame as an export crop is a compelling reason to give priority for maintaining production of sesame as an intercrop with tef, in addition to production stability that is provided by this cropping system in the face of unpredictable rainfall in its amount and distribution. Early maturity of tef for harvesting in mid October to mid November leaves space for the late maturing sesame and safflower to maximize utilization of underground resources such as water and nutrients. One of the most important factors affecting both crop yield and yield stability is drought/moisture stress (Lynam et al., 1986; Fageria et al., 1997). Drought occurs not only in arid and semi-arid regions but also in humid regions because of uneven distribution of rainfall. Sanders and de Hollanda (1979) and Norman et al. (1981) cited by Lynam et al. (1986), reported that in regions where water is limited, intercropping was found extremely widespread among smallholder farmers. With regard to crop variety, early maturing white seeded tef (locally called magna) is almost the only local variety under production for it fits well to the rainfall distribution pattern in the surveyed areas. Most of the farming community rejected brown seeded local tef called bunign due to its early maturity which gave low yield as compared to magna. Thus bunign matures in the last week of September before rain ceases completely and hence liable to shattering that results in yield loss. As opposed to the widely produced local variety with brown seeds or mixture of brown and white seeds, white seeded

sesame is rarely produced for its low productivity and low demand in the local market. CONCLUSIONS AND RECOMMENDATIONS The dominant tef based cropping system is tef-sesame followed by tef-safflower intercropping. Soil types, depth and fertility status determine the type of component crops in the tef based intercrops, as well as their seed rates. As opposed to Jemma and Wonchit River valleys, tef was dominant in area coverage than sorghum as the shift to tef appeared when sorghum was hit by sorghum chaffer in Shewarobit lowlands. Otherwise, sorghum is preferable to tef for it is higher yielding. Magna tef and brown or brown-white mix seeded sesame are dominant local cultivars. The timing and frequency of plowing and weeding varied according to the rainfall onset and distribution that together affect the sowing dates according to soil type and depth. Monocropping of sorghum for 3 - 5 and tef for 2 - 3 sequences is the common practice even though farmers realize the yield penalties. Because of the great potential of multiple cropping systems for increasing crop productivity as experienced by many countries in Asia (Reddy, 1996), there is an urgent need for the rapid generation and dissemination of appropriate and socio-economically viable tef based cropping systems in the sub agro-ecologies of the hot to warm moist valleys of North Shewa. Priority research areas are genotype evaluation for intercropping, optimizing population density, intercropping effect on oil yield and quality, nutrient requirement and use efficiency, rotation, tillage requirement and weed control options, response to different moisture regimes, the contribution of intercropping in improving resource utilization, disease and pest control aspects. ACKNOWLEDGEMENT Debre Birhan Agricultural Research Center is acknowledged for providing fund and logistic support for this study.

REFERENCES Anonymous (1998). Agroecological zones of Ethiopia. Natural Resources Management and Regulatory Department, Ministry of Agriculture, Addis Ababa, Ethiopia. Byerlee D, Collinson M (1980). Planning technologies appropriate to farmers: Concepts and procedures. CIMMYT, Mexico. Fageria NK, Baligar VC, Jones CA (1997). Growth and mineral nutrition of field crops, (2nd ed.). Marcel Dekker, Inc. New York. Geleta M, Asfaw Z, Bekele E, Teshome A (2002). Edible oil crops and their integration with the major cereals in North Shewa and South Welo, Central Highlands of Ethiopia: an ethnobotanical perspective. Hereditas, 137: 29-40. Keneni G, Woyessa B (1992). Sesame breeding in Ethiopia. In: Oilseeds research and development in Ethiopia: Proceedings of the

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first national oilseeds workshop, 3-5 December 1991, Addis Ababa, Ethiopia. Institute of Agricultural Research, Addis Ababa. pp. 57-65. Ketema S (1997). Tef (Eragrostis tef Zucc.) Trotter. Promoting the conservation and use of underutilized and neglected crops. 12. Institute of Plant Genetics and Crop Plant Research, Gatersleben/International Plant Genetic Resources Institute, Rome, Italy. pp. 36-46. Lynam JK, Sanders JH, Mason SC (1986). Economics and risk in multiple cropping. In: C. A. Francis (ed.), Multiple cropping systems. Mackmillan Publishing Company, New York. pp. 250-266. Putnam DH, Allan DL (1992). Mechanisms for over yielding in a sunflower/mustard intercrop. Agronomy J., 84: 188-190. Reddy MS (1996). Increasing crop productivity through crop management and multiple cropping systems. In: Sinebo W, Tadele Z, Nigussie Alemayehu N (eds) Increasing food production through crop management: Proceedings of the first and inaugural conference of Agronomy and Crop Physiology Society of Ethiopia (ACPSE), 3031 May 1995, Addis Ababa, Ethiopia. ACPSE, Addis Ababa. pp. 3-9.

Taylor TA (1986). Sesame agronomy in southeast Tanzania: II Intercropping with sorghum. Exp. Agric., 22: 253-261. Yadeta K, Ayele G, Negatu W (2001). Farming systems research on tef: Smallholders' production practices. In: Tefera H, Belay G, Sorrells M (eds) Narrowing the rift: Tef research and development. Proceedings of the international workshop on tef genetics and improvement, Debre Zeit, Ethiopia, 16-19 October 2000. Ethiopian Agricultural Research Organization, Addis Ababa. pp. 9-23.

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