Integrated Major Pest Management Systems of Enset ( Ensete ventricosum (Welw.) Cheesman) in Ethiopia

: Enset is an important root crop widely used as a staple food for millions of people in Ethiopia. Despite it being dominantly produced in southern and south western parts of the county, diverse diseases and insect pests have been challenging the growth and productivity of the crop. Hence, this review was aimed to discuss the available management option to overcome this limiting factor. Since the integrated pest management (IPM) system has been widely practiced to control the major enset pests (disease and insect) in different production areas of Ethiopia. Enset is a root crop that is highly susceptible to different kinds of diseases and insect pest problems. Enset bacterial wilt (EBW) is a major devastating disease causing important economic losses and can lead up to killing the whole plant parts that are commonly observed around enset growing areas of the country. Enset root mealybug is also a major insect found on the upper half of the corm and root parts of enset which can retard the plant growth and causes to dry the outer parts of the leaf that might be leading finally to the whole plant death. However, most enset growers are practicing different controlling mechanisms against these major diseases and insect pests around production areas. Due to the chemical control method needs the cost of purchase and usage on root mealybug has usually not been effective, the producers are widely using IPM systems incorporating with their indigenous knowledge to prevent the major disease and insect introduction to the enset field and to control an already infected plant. Hence, the enset producers mainly use the IPM components like the host plant resistance, the cultural controlling system, the biological controlling system and the chemical controlling system as the last option to manage their enset farms in Ethiopia. These IPM components are not only optional pest controlling methods but necessitate its practice against the major pest problems due to environmentally friend, cost-effective and alternative options to various behaviors of pests. However, breeding for pest-resistant enset genotype and adoption of successful IPM controlling mechanisms to all enset growing areas need further work to alleviate the encountered challenges on the enset production areas in Ethiopia


INTRODUCTION
countries, its domestication and uses as a food and fiber Enset (Ensete ventricosum [Welw.]Cheesman) is a been cultivated as a food and fiber crop in Ethiopia for perennial herbaceous and monocarpic root crop with several years and over 80% of the production is long broad leaves and bulky pseudo stem that belongs to concentrated in the south and south western part of the the Musaceae family known to be originated in Ethiopia country [1].

[1]. It is widely distributed in eastern and southern africa
The root of enset, which is rich in carbohydrates, is but cultivated only in southern and southwestern parts of the main edible portion as its fruit is not.It is an important Ethiopia as a staple food for about 15 million peoples in multi-purpose and drought-tolerant crop, used for food mixed subsistence farming systems [2].Although the wild (kocho, bulla and amicho), fodder, fiber and traditional species of enset are distributed throughout most of medicine [4].The food obtained from the crop is rich in central, eastern and southern Africa, as well as asian starch, a good source of calcium and iron and has overall crop is restricted only to Ethiopia [3].Thus, enset has nutritive values similar to potatoes [5].In terms of edible of plant parts at high land, mid land and low land areas.dry weight and energy, enset gives a higher yield than The natural epidemic of this disease was first reported other crops cultivated in Ethiopia [4].Due to these, enset from the banana cultivar Ducasse hybrid in the Kafa was appointed as "the tree against hunger" and is a province of the south western part of Ethiopia [10].It was straight forward way to facilitate people to achieve food widely spread to different parts of the country, which and livelihood security in parts of Africa [3].Also, enset could be through infected farm tools, infected planting has a positive contribution to the local environments by materials, repeatedly transplanting the damaged root and improving the nutrient balance and increasing the fraction corms, animal feeding of the infected plant and possibly of organic matter in the soil [6,7].In general, enset can be insects vector feeding on the foliage and male considered as part of farming systems with high inflorescence [11].Once the plant has been affected by biodiversity, which is the environmentally sustainable and this disease, it starts to show different and initial drought-tolerant crop that contributes to the mitigation symptoms like bacterial ooze in the leaf petioles and of climate changes [7].
leaf sheaths and progressive wilting of the leaves [12].Even though the number of improved enset varieties These critical effects lead to a gradual decline in the were released by the regional research institute, the production and productivity of the crop.The different Southern Agricultural Research Institute (SARI), at research studies showed that the infection rate of the Areka Research Center in Ethiopia, the production and disease in different parts of the country was higher.productivities of the crop have been challenged by Hence, the survey reported from borena mid-altitude on different limiting factors (biotic and abiotic).Most of the bacterial wilt incidence in both 2014 and 2015 years by released varieties are non-resistant and widely susceptible Desalegn and Addis, [13] indicated that about 38% and to different diseases and insect pests.Those varieties are 56% of enset farms were infected by this disease with a mostly affected by bacterial wilt diseases which currently mean incidence of 29.46% and 12.89%, respectively.becoming a great challenge in enset growing areas of the Also, the survey further showed that an average of country [7].In addition, inevitable insect pests are also 21.17% of enset stands was lost due to this disease becoming a great challenge for enset producers in the (Fig. 1 and 2).In addition, the assessed survey was noted growing areas by limiting crop production and that the extent of damage of enset is equal to the productivity.Integrated pest management (IPM) is the incidence percentages due to the plant certainly dying comprehensive and coordinated use of host plant after infected by the diseases.resistant, cultural, biological and chemical tactics to Furthermore, the study of Wolde et al. [14] was reduce a pest population below an acceptable threshold assessed the distribution and incidence of enset bacterial [8].Therefore, this review was mainly aimed to discuss the wilt disease in relation to the plant age, altitudinal range potential disease and insect pests found in enset growing and clonal variation in major three enset growing zones areas and their available integrated pest management (Gurage, Hadiya and Sidama) of South Nation systems in enset growing parts of Ethiopia.
Major Enset Diseases in Ethiopia: Regardless of enset is enset growing agro-ecologies of Ethiopia to the varying used as a staple food by more than 20 million Ethiopian extent based on plant growth stage, production cycle and peoples, its sustainability has been threatened by age of the plant at an altitudinal range of 2000-2500 m.a.s.l.different abiotic and biotic factors.Among the root crops They further elaborated that the disease incidence and produced in the country, enset is highly affected by biotic prevalence were also varied based on the growth cycle factors like diverse types of diseases, insect pests, and plant age in different enset growing areas of the nematodes and termites [2].The most devastating disease country (Fig. 3).According to the assessment report affecting the production and productivity of enset is the indicated that the highest mean disease prevalence bacterial wilt (Xanthomonas campestrispv.musacearum) (31.48 %) and disease incidence (37.50%) were observed disease.The bacterial wilt (Xanthomonas campestris pv. at the fourth production cycle of the crop at the age of musacearum) is originated in Ethiopia [9].It was first 4-5 years old than at its early and late ages.identified and reported by Yirgou and Brad bury [10] In general, currently, the enset bacterial wilt disease in Ethiopia and now a days it has been distributed to the is a devastating and the most challenging pest of enset entire region of enset growing areas of the country and growing areas of the country which can kill the whole found on wild enset, which affects all the growth stages plant parts leading up to crop loss.
They pointed out that the EBW disease is found in all  Major Enset Insect Pest in Ethiopia: Even though the diverse biotic stresses are affecting enset production and productivities in the production areas of the country, enset root mealybug (Cataenococcus ensete [Williams and Matile-Ferrero, (Homoptera: Pseudococcidae)]) is the most important and major insect pest of enset growing areas in Ethiopia [15].This root mealybug is a generic term for several Pseudococcidae feeding on underground plant parts.It has an elongate-val body, which is covered with wax secretions on the The Integrated Pest Management (IPM) system is an dorsal and lateral side body parts (Fig. 4).The wax effective and environmentally sensitive approach to secretion gives an appearance of cottony and spine-like managing pests, which mainly relies on the combination projections.While these waxy secretions are not part of of c ommon-sense practices [23].Thus, there was no the mealybugs' body, they are lost with each molt.clear-cut option has been reported to control enset wilt This insect pest was first reported in wonago, Ethiopia in disease in the enset growing region of the country.1988 [16].It was known to attack Enset in Gedeo, Sidama, But the growers in different enset production areas are Gurage, Kembata Tembaro, Hadyia, Kafa and Bench practicing different IPM components either alone or zones, Amaro and Yem special districts of enset growing together apart from using the chemical treatment as the areas of the country [17].According to the study of last option.These management options can control the Addis et al. [17] was noted, the insect pest can attack the EBW disease either by preventing its occurrences or crop at any growth stage, with infestations being most managing an already occurred disease under the severe on two to four years old plants as shown in economic threshold level in a sustainable manner.(Fig. 5).Addis, [18] was also further investigated the density and distribution of enset root mealybugs on Using Host Plant Resistance: Developingthe bacterial the enset and he was reported that most of the insect wilt disease-resistant enset varieties or using tolerant has been found on the upper parts of the corm and clones could be one of the best approaches to manage the the root parts within 20cm radius of soil as shown in enset bacterial wilt (EBW) disease.This approach is the (Table 1 and Fig. 6) bellow.
best way to control the enset bacterial wilt disease, According to the findings, the infestation of insect cheaper to the farmers and is safer for the environment pests retards the normal growth of plants by causing [24].Hence, Ethiopia was considered as the center of losses of plant vigor, drying of lateral leaves but not origin and source of enset diversity which is widely green central shoot and finally leading up to plant death, distributed around the southern and southwestern parts especially where the moisture stress is high.However, the of the country.It has been estimated that over 200 finding on the extent of economic loss of the crop by different enset clones were described by their vernacular mealybug attacks is little to found [14].

Ethiopia
diverse enset clones from the production potential areas Integrated Enset Bacterial Wilt Disease (Xanthomonas for further studies in the future that might include campestris Pv.Musacearum) Management Systems in Ethiopia: Bacterial wilt (Xanthomonas campestris pv.musacearum) is the most economically important disease putting the sustainability of enset farming systems in jeopardy compared with all other constraints of crop production.Due to 80% of enset farms being reportedly infected by bacterial wilt disease, currently, the enset production and productivity are declining from time to time in the enset growing parts of Ethiopia [22].This inevitable enset production problem has been directly or indirectly affecting the livelihood of more than 20 million enset growers in the country.This vividly observed problem needs strong attention and commitments to manage and conserve the available cultivars before the complete loss of the crop will occur.Hence, the EBW disease hasn't a single management system to control the crop by this major pest.However, different research findings have been reported as the application of IPM systems can sustainably reduce the effect of EBW disease below an acceptable economic threshold level.institutes, higher learning institutes and different levels of screening for resistant genotypes against EBW disease.The study of Handoro and Said [25] report indicated the startup of screening different enset clones for their resistance to enset wilt disease at Areka Research Center of SARI and some of the genotypes from the collected clones were showed promising resistance against EBW disease.Hunduma et al. [26] also reported similar findings on screening enset clones at Ambo Agricultural Research Center of Ethiopian Institute of Agricultural Research (EIAR).They were found a promising resistant genotype against EBW disease.Thus, the presence of the richest enset biodiversity in different parts of the country, the host and pathogen characterization, enset clone selection and breeding for wilt resistance can be suggested as a long-term management system to control the widespread of the enset bacterial wilt disease in the future [22].

Using Cultural Control Method:
The cultural controlling method of the IPM system mainly refers to the practices of indigenous knowledge of the growers to control the EBW disease from their enset farming areas.Thus, the use of cultural practices of disease control systems can materials against Bacterial Wilt (Xanthomonas campestris disrupt the disease cycle, create unfavorable PV Musacearum) disease, they found the results based environmental conditions for the pathogen, reduce the on the invetro test which a combination of botanical plant pathogen population in the field and improve crop growth extracts of Etecha + Kabericho as well as, a single and vigor [27].Hence, the enset growers from the botanical extract of Etecha and a combination of Solle + southern and southwestern parts of Ethiopia have Hidafite + Tembosuse were showed a better antibacterial been practicing several cultural indigenous knowledges effect against Xanthomonas campestris pv. to control the EBW disease introduction into their musacearumisolates, next to standard check (penicillin).healthier enset farming areas.Some of the common Currently, an investigation on the effectiveness of the indigenous cultural control the growers' practicing are chemical and botanical control method is in progress in planting the healthier enset suckers, avoiding contact of different areas and a promising result will be expected.healthier plants from the infected ones, avoiding use and sharing of common farm tools with other growers, Integrated Enset Root Mealybug (Cataenococcus ensete) restriction of domestic animal movements in the enset farming areas by making fences and uprooting and burying already infected plants and cleaning the left-overs from their farm areas and keeping the farm hygiene.After uprooting and burying the infected enset plants, farmers fallow their land at least for six months until the pathogen will be eliminated from the soil by exposing the pathogen to the sun radiation [28].Also, when EBW causes severe damage to their enset plant, some of the growers undertake a variety of traditional practices like smoking bones, tires, burning porcupine bodies, doing local spiritual beliefs such as prayer ceremony ('Dua on khat chewing') and slaughtering a black goat under the plant [14].However, most of the growers haven't similar awareness on the routes of EBW disease transmissions and uses of all available cultural controlling practices to protect the disease from their farming areas.Thus, the best way of practicing cultural methods against EBW disease control is creating awareness to the growers about the potential effects of the disease and its prevalence and advising them strictly to practices the locally available cultural control options on their enset farming areas.
Using Chemical Control Method: Chemical applications are often used to control pathogens and can be an important component of the overall disease management plan [27].However, the chemical controlling methods are the last recommendation option in the IPM system.Even if various efforts were made by scholars at different times, there were scientific reports that hardly showed the effectiveness of a single chemical control method against the enset bacterial wilt diseases in the country.However, a study on different botanical extract controlling trial was conducted and showed significant results in the country.According to the study of Kasa et al. [29] reported on the trial by using different botanical plant extracts and other

Management Systems in Ethiopia:
The root mealybug (Cataenococcus ensete) is the major insect pest of the enset (Ensete ventricosum) growing area of southern Ethiopia.The adults and nymphs of insects are over lapping generations, which feed on corms and roots of enset and are difficult to control once it has been established [15].Thus, it is very difficult to control enset root mealybugs with a single management method once it has been infested the root of enset due to their cryptic habit, waxy body cover and formation of dense colonies of multiple and overlapping generations [19].However, finding the alternate solution against the insect pest is very crucial to control an insect sustainably by 'Integrated Pest Management (IPM)'.The first resort to enset root mealybug control is the use/production of clean enset planting material.This insect is greatly intense only atan altitude between 1400-2200 m.a.s.l (Fig. 7).Therefore, as the planting materials moved from one place to another areaof these altitude ranges, care should be given due to their invasiveness at these suitable altitudinal ranges.Because of great difficulties to control insect pests by a single mechanism, different IPM components have been used to control the problem aroused by insect pests in different enset growing areas of the country.

Use of Host Plant Resistance:
Growing mealybug-free enset is very important for the enset producers.Planting the insect-free sucker can restrict the mealybug introduction to the new production areas.On the other hand, the uses ofhost plant resistance area very important method to reduce the mealybug effects.The study of Kefelegn et al. [20] was reported as the growers indigenously use a locally well-known resistant genotype of enset called 'genetica' which was one of the dominant enset clones against the root mealybug in the area (Table 2).In addition, some of the enset growers prefer the availabilities of different cultural controlling methods against enset root mealybug in different enset growing Millettia ferruginoea in the root zone of infested enset areas of the country.Hence, some of the activities are in the field was found to be effective against the enset culturally practiced by enset growers to control enset root mealy bugs.Also, dipping of the young enset root mealy bag that includes the addition of farmyard seedlings into the solution to the root zone of manure and ash to the field, disinfection of enset plant infested plants can be used for the management of the by using hot water treatments, keeping the farm insect pest.hygiene by repeatedly plowing and removing of Generally, promoting the cultural indigenous insect weeds and grasses in the fields (makes the insect starve) controlling practices integrating with other IPM (Fig. 8), fallowing of the lands, cleaning of the components are very essential to control enset root seedlings (planting materials) before planting, increasing mealybug to the enset production areas the soil moisture, uprooting an infested plants and burning in the hole, site selection and removal of host REFERENCES plants are the main activities that have been widely practiced to prevent insect infestation.For these 1.

Fig. 1 :Fig. 5 :
Fig. 5: Frequency of enset root mealybug infestation observed across different age categories on Enset on farmers field at Dilla Zuria, Gedeb and Wonago areas Source: Addis et al. [21] Fig. 7: Effect of altitudinal ranges on enset root mealybug infestation Table 2: Rating of frequently cultivated enset varieties by farmers concerning plant productivity, quick maturation, tolerance of root mealybug in Gedeb, Wonago and Dilla Zuria districts et al. [20] Source: Azerefegne et al. [19] Fig. 8: Effect of food deprivation on the survival of the different stages of Cataenococcus ensete in the soil the suckers come from high land areas where the Uses of Cultural Practices: The cultural controlling prevalence of enset mealybug is low [20].Hence, attention practices used to manage enset root mealybug are very on the collection of different enset genotypes for common indifferent enset growing areas.The study of screening the resistant clone against enset root mealybug Addis et al. [21] and Kefelegn et al. [20] were reported has been started to alleviate the losses of the plant.

Table 1 :
Distribution of Cataenococcus ensete population on corm and roots of enset plants (n=10) [17]tal 86.7 18.1 20.43 Means followed by the same letter within a column are not significantly different according tothe x test at a 5% probability level.2Source:Addis et al.[17]

Uses of Chemical Control:
Taye, B., F. Asrat and B. Regassa, 1967.The practices, most of the farmers use the presence of Cultivation of The Genus Enset in Ethiopia.Soil and ants for inspection purposes because the ant is the vector Crop Science Society of Florida, 27: 133-141. of mealybug and indicatomealy bug availability in the 2. Zipper, 2005.Diversity Over Time and Space in areas.Enset Land races (Ensete ventricosum) in Ethiopia.Tesfaye, A. and P.C. Struik, 2001.Enset enset root mealybugs.Thus, they recommended as the (Ensete ventricosum (Welw.)Cheesman) Kocho fungal isolates have the potential to kill the insect and can Yield Under Different Crop Establishment Methods be integrated for the management of enset root mealybugs as Compared to Yields of Other Carbohydrate-Rich with other methods.Food Crops.Netherlands Journal of Agricultural Using chemical insecticide 5. Mohammed, B., M. Gabel and L.M. Karlsson, 2013. is very difficult to control enset root mealybug due to Nutritive Values of Drought-Tolerant Food and their cryptic, waxy coat and lifestyle of forming dense Fodder Crop Enset.African Journal of Agricultural colonies of multiple and overlapping generations [30].Research, 8: 2326-2333.However, different findings have been reported as 6.Elias, E., S. Morse and D.G.R. Belshaw, 1998.some effective chemicals can be controlled by mealy Nitrogen and Phosphorus Balance of Kindo Koisha infestation despite its purchasing costs.According to Farms in Southern Ethiopia.Agriculture, Ecosystems the study of Azerefegne et al. [19] were reported the and Environment, 71: 93-113.selection of effective insecticide against root mealybug 7. Tesfaye, 2008.The Enset (Ensete ventricosum) in southern Ethiopia, the significant results had got Gardens of Sidama: Composition, Structure and which can control the root mealybug and they have Dynamics of a Traditional Poly-Variety System.been recommended a single application of Diazinion or Genetic Resources and Crop Evolution, Chlorpyrios for the insect pest control.The effect of 55: 1347-1358.some botanical extracts against root mealybug was 8. Riyaz, S.M. and K. Kathiravan, 2019.Integrated also reported by Tadesse et al. [31].The finding noted Pest Management Approaches.Gemini Viruses, that drenching the seed water suspension of 10% pp: 219-235.Doi.org/10.1007/978-3-030-18248-9_12.