Assessment on major apple diseases and insect pests in Chench and Bonke Woredas of Gamo Gofa zone, Southern Ethiopia

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1 Scholarly Journal of Agricultural Science Vol. 4(7), pp July, 2014 Available online at ISSN Scholarly-Journals Full Length Research Paper Assessment on major apple diseases and insect pests in Chench and Bonke Woredas of Gamo Gofa zone, Southern Ethiopia Seifu Fetena 1* and Berhanu Lemma 2 1 Arba Minch University Department of Horticulture P.O.Box 21 Arba Minch, Ethiopia 2 Arba Minch University Department of Plant Science P.O.Box 21 Arba Minch, Ethiopia Accepted 14 July, 2014 Assessment on major apple diseases and insect pests was conducted in Chencha and Bonkeworedas of Gamo Gofa Zone in 2012/13 cropping season. The aim of the study was to determine occurrences and assess impacts of major diseases and insect-pests. Survey was done to assess the awareness level of the farmers about the apple insect pests and diseases. From the two woredas, five administrative kebles were purposively selected. A total of 90 respondents (73 male and 17 fem ale) were interviewed using semi-structured questionnaires. In addition group discussions were made with selected farmers of the study areas. Data was analyzed by using descriptive statistics by employing SPSS software version 15. Apple scab and powdery mildew (45.1%) as measured during the survey period was the serious disease. Insect pests such as apple aphids, scale insects and green plant bugs were also observed. Royal Gala variety being replaced by Crispin in Chencha due to its susceptibility to apple scab disease. About 35% of respondents revealed that farm tools and winds were the main spreading mechanisms of major apple diseases and insect pests. About 48.3 % of the respondents indicated that they are using different traditional apple disease and insect pest control methods. About 28.3% of the respondents were revealed that apple seedlings and apple mother trees lost due to major apple diseases and insect pests. About 28.3% of the respondents were revealed that less than 25 kg of apple fruit lost due to major apple diseases and insect pests. It can be concluded that the awareness of farmers about most of the diseases and insect pests were very low. Therefore, this study recommended that there is an urgent need from concerned offices to improve apple farming system in the study area. Key words: Assessment, Apple, Diseases, Insect pests, Respondent, Chencha and Bonke. INTRODUCTION The origin of cultivated apple is not definitely known. But, the center of origin is probably in the area containing Caucasus region (central Asia and the Himalayas). The origins of the domestic apple are uncertain, but it is usually believed to have derived from Maluspumila, a small-fruited species that occurs naturally in Eastern Europe and western Asia (John, 1986). Although Ethiopia is not in temperate climate zones; *Corresponding author s seifegb@gmail.com. temperate fruits are widely adapted and produced at highlands of the different regions. The crops were first brought to Chencha area in the Gamo hills by Missionaries (Kale -Hiwot Church) about 60 years ago. Since and gradually the crops are well adapted in the area produce good quality of fruits and introduced/promoted to some other different new areas of the region. In SNNPR, at the present time, the temperate fruits commercially grown at hilly areas of different zones, inparticular at Chencha, Ezzo -Bo roda, Kamba, Bonke(Gamo-Gofa zone), Angacha, Doyogena (KT zone), Gumer, Ijsa (Gurage zone), Misha, Lemo, Duna,

2 Fetena and Lemma 395 Soro (Hadiya zone), H/Selam (Sidama zone) and Bulle (Gedeozone)(Bayeh, 2007). In most cases apple fruit share common diseases with similar management practices. The most important diseases occur in commercially temperate fruits grown areas are apple scab, powdery mildew (PM), cankers, collar and white root rots, Leaf spots, Crown gall, and viruses. The postharvest diseases such as Penicillium, Monilinia, Glomerella, Alternaria, Phomopsis, Aspergillus spp. are reported to infect pome fruits in storage (Thind, 2001). Apple trees are prone to several pests and diseases depending on different local conditions. It is a melancholy fact that the apple is attacked by a wide range of pests and diseases which at worst can reduce the crop to zero, and damage or even kill the tree. The yearly per head income of some farmers in the ChenchaWoreda has risen up to 100, ,000 birr from pome sales only (BANRD Chencha, 2012). Thus, today, every grower of the apple fruits in all areas of the region focus/target in production of grafted seedlings. However, there is a paucity of information on its production limiting factors especially on diseases occurrence, distribution and severity in the areas. Therefore, in the current study, occurrences and impacts of major diseases and insect-pests of apple trees were studied in Chencha and Bonkeworedas of Gamo Gofa Zone. MATERIALS AND METHODS Description of the project locations The survey was conducted at Gamo Highlands, Southern Ethiopia in the two woredas named Chencha and Bonke because of apple become a very voluble crop of the area and highly cultivated over large hectares. They are located 37 and 54 km far from Arba Minch Town, respectively. The mean annual temperature and rainfall of the study areas are 22.5 and c and and mm/annum, respectively. The altitude ranges up to and m.a.s.l, respectively (GGZAARD, 2009). During the survey period in selected kebeles, it was observed that apple was the main occupation of the Chencha farmers and subsistent activity in Bonkeworeda. More than 100 varieties of temperate fruits found in the study area, but the dominant were about 40 and among these nine (seven old and two new) apple varieties were assessed in this study. Survey methods Survey was done to assess the awareness level of the farmers in Chencha and Bonkeworedas about the apple insect pests and diseases. Damaged parts of the plant was counted, recorded on data collection sheet and calculated during field observation. The questionnaires were prepared. A simple random sampling technique was used to conduct the study. Five kebles were purposively selected from two apple growing districts of Gamo Gofa Zone with classifying in type of specific variety three from Chencha and two from Bonke. Comprehensive lists of apple growers in the selected sites were prepared. Out of total 1207 apple growers from the selected woredas, samples of 90 farmers were selected by using the Table for determining the sample size (Fitzgibbon and Morris, 1987). A proportionate sampling procedure was adopted for the selection of farmer respondents from each kebele. Therefore, 45 from Chencha and 15 from Bonkeworeda were selected. The data were collected with the help of validated and pre-tested interview schedule through personal interviews by the research team in addition to questioners collected by the development agents. Group discussions were made with selected farmers of the study areas. Photo of damaged part of the study plant had taken and then comparison of the collected data done. Data Collection All number of apple tree in the selected apple farm was counted and recorded Diagonal and W-shape sampling technique laid out to select mother apple tree The presence and absence of the major insect- pests and diseases in selected apple farm recorded Percentage of infected apple trees counted and recorded The diseases and insect damage taken using the 0-5 rating scale and percentage respectively, where 0 = no symptoms (healthy), 1= slight, less than 5% of leaves affected, 2= moderate, 5-20% of leaves affected, some yellowing, little or no defoliation, 3= extensive, 20-50% of leaves affected, significant defoliation, 4= heavy, 50-80% of leaves affected, severe defoliationand 5 = extreme, % leaves affected, complete or nearcomplete defoliation. Damaged fruits was rated by 0-3 scale and average percentage respectively for each plant where 0 = no symptoms (healthy), 1= slight, less than 5% of fruits affected, 2= moderate, 5-20% of fruit affected, some yellowing, little or no defoliation, 3= extensive damage. Method of Data Analysis The collected data were coded and entered in SPSS software version 15. Descriptive statistics was computed and the output presented in the form of percentages using tables.

3 Scholarly J. Agric. Sci. 396 Table 1. Occurrence of diseases and insect pests on apple leaves. No Variety Leaves Chencha Bonke Powdery mildew (%) Apple Scab (%) Aphid and caterpillar (%) Powdery mildew (%) Apple Scab (%) Aphid and caterpillar (%) 1 BR Crispin Granny Smith Jonagoled Red Delicious Anna Royal Galla Table 2. Occurrence of diseases and insect pests on apple fruit in in the study areas according to own rating scale. No Variety Fruits Chencha Bonke Powdery mildew Apple Scab Aphid Powdery mildew Apple Scab Aphid 1 BR Crispin Granny Smith Jonagoled Red Delicious Anna Royal Galla RESULTS AND DISCUSSIONS Occurrences of insect pests and diseases in the study area during field visit/observation Observation data (T able 1) were collected on diseases and insect pest prevalence especially on grafted apple survival and rejuvenation for field transplanting, on leave and fruit of mother trees in Chencha and Bonke Woreda research Kebele s named Shaye, Zolo and Losha; Bonke Chosha, Yala and Zazie, respectively. Apple scab (46and 57 %) as measured during the survey period was the serious disease in the study area. This disease causes high losses in BR, Royal Galla, Crispin and Jonagold but lesser attach in Anna and Grany smith. Except rodents and aphid no more insect pests were recorded. Green apple aphid was recorded affecting tender leaf, apical bud and young leaves. Damaged sample plant was also taken from Chenchaworeda particularly from EzoTulla and then given to Gamo Gofa Zone plant health clinic for further identification. Based on the diagnosis result the white root rot disease was identified which cause death of around 35 mother tree and apple seedlings per three households. The disease symptoms were stunted growth, leaf fall and yellowing, branch dieback and finally died. According to our observation the farms in which this disease occurred had the problem of drainage which is favorable condition for the disease and we made immediate recommendation to replace the infected apple trees, use of drainage lines, deep cultivation and care for management practices to the respective farmers via Chenchaworeda Agriculture Office. Immediate recommendations to make fence surrounding grafted apple seedlings were given to Bonke agricultural bureau expertise and development agents to prevent from rodent damage of grafted apple. In addition to the above record, many rotten apple fruits were found in some farmer s field which dropped after disease, insect pests and bird attack. However, farmers don t collect the damaged apple fruits and not bury inside the soil or for any other purposes. From the above table 2 Royal Gala variety being replaced by Crispin in Chenchaworeda due to its susceptibility to apple scab disease. Even the yield is very low. BR apple variety was good in terms of total fruit but the quality is reduced by apple scab disease. If it is

4 Fetena and Lemma 397 Table 3: House hold condition of respondents. Gender Frequency Percentage Male Female managed well, BR apple variety can give good yield with good quality. During field observation many farmers grow apple varieties by mixing one another. This way of farming may facilitate the development or occurrence of diseases. All apple varieties are not resistant to insect pests and diseases so that if it is grown together insect pests and diseases may have a chance to spread from one variety to another. Also it was observed that many rotten apple fruits were found in some farmer s field which dropped after attack. However, farmers don t collected the damaged apple fruits and then bury inside the soil or for any other purposes. In addition to insect pests, birds were attacked some varieties based on their preference like Red delicious variety and Crispin due to high deliciousness it is prepared by birds so that there are huge losses. The management of diseases and insect pest on apple were different from farmers to farmers as observed during field visit. No any chemicals applied to control diseases and insect pest of apple in both woredas of the study areas. SOCIOECONOMIC IMPACTS OF APPLE DISEASES AND INSECT PESTS General demographic description Under this sub-title, some of the demographic detail of the respondents discussed. This mainly includes sex distributions and educational statuses of the respondents. It seems like as follows when putted in table form. The information about apple diseases and insect pests were collected by conducting interview and group discussion with randomly selected apple growing farmers including male and female participants between the age of 23 to 79 years. The above table (table 1) showed that the number of household by female and male. Among60 farmers selected from five kebeles 49 were male leaded households and the remaining 11 were female leaded household. In general, the percentages of male and female respondents were 81.7% and 18.3% of total sample unit respectively. According to above analysis, we understand that female play role in production in spite of traditional perception. The above table (table 2) showed that the educational status of the respondents. As it is shown above most of the respondents were able to read and write. When we put as general, about 86.7% are educated at certain level. Among these, about 63.3% of the respondents had educational status of primary and juniors level. The remaining 13.3% are neither read nor write. Basically education is important issue in apple production and management strategies. Awareness about insect/pests and diseases so far (before) The respondents were asked about the awareness of insect/pests and diseases and their responses are displayed in Table 3 which reveal that a large majority (33.4, 23.4 and 18.3%) of the respondents was aware of apple insect/pests like aphid, apple maggot and borer respectively whereas caterpillar and plant bugs were known to 16.6 and 8.3% of the respondents respectively. However, powdery mildew and apple scab were the diseases which were known to a large majority (60.3 and 21.4%) of the respondents. Ripe rot and root rot were known less extent by the respondents. If the harvest is free from insect/pests and diseases, the produce not only appeals to the eye but also fetches high price in the market. However, because of the severe incidence of pests and diseases in the developing countries, many fruits cannot be cultivated on commercial scale (Hashmi, 1994). This indicates that apple growing farmers have better awareness about diseases that attack apple trees. Contrary to this, some respondents were not having ideas about the disease types that attack their apple trees. Occurrence and satisfaction level in controlling insect/pests and diseases as recorded in the study area Occurrence and satisfaction level in controlling of major apple diseases and insect pests surveyed in 2013 at both woreda s presented in Table 4. The survey result indicates that apple plants are subjected to major diseases and insect pests. Though some respondents reported the satisfaction level is medium in both woreda. Data recorded in Table 4 showed that occurrences and satisfaction level by farmers to control major diseases and insect pests is medium and low respectively. According to the survey results of Fikre and Messele (2007) temperate fruits are subjected to various diseases

5 Scholarly J. Agric. Sci. 398 Table 4. Educational status of the respondents. Education level Frequency Percentage Primary and Junior High school Illiterate Diploma Table 5. Respondents level of awareness about insect/pests and diseases of apple Awareness Farmers response about Frequency Percentage Farmers response about Frequency Percentage Disease types Insect pest types Powdery Mildews Aphid Apple scab Apple maggots Ripe rot Borer(Birds) Fern Caterpillar Root rot Plant bugs Table 6. Occurrence and satisfaction level to control of major apple diseases and insect pests. A. Occurrence Frequency Percentage B. Satisfaction level to control Frequency Percentage Medium 80.1 Low Low 13.3 Medium High 3.3 No idea No idea 3.3 High and insect pests. It was found that apple scab, powdery mildews and leaf curl were the most frequently and predominantly occurred at all locations surveyed in SNNPR. Insect pests such as apple aphids, scale insects and green plant bugs were also observed to damage the plants. During field observation many farmers grow apple varieties by mixing one another. This way of farming may facilitate the development or occurrence of diseases. All apple varieties are not resistant to insect pests and diseases so that if it is grown together insect pests and diseases may have a chance to spread from one variety to another. According to table 7, out of the total respondents 35% revealed that farm tools and winds were the main spreading mechanisms of major apple diseases and insect pests to their orchard and from their apple farm to the neighbor farms in the study areas but majority (55%) of the respondents have no idea about the spreading mechanisms of insect pests and diseases. Plant parts infected by diseases and insect pests as farmer s response As indicated in the table 8, about 48.3% of the interviewed apple growers revealed that fruits, leaves and roots were plant parts affected by diseases in the study area. From the total respondents 28.3% mentioned that fruits, stems and leaf part of the apple plant were damaged by diseases. Similarly about 35% of the interviewed apple growers revealed that fruits, leaves and roots were plant parts affected by different insect pests in the study area. From the total respondents 25% mentioned that fruits, stems and seedling part of the apple plant were damaged by insect pests. Many apple insect pests and diseases pass their life on dropped fruit, overcrowded branches and dead leaves. From apple growers interviewed 28.3% mentioned that sanitation as disease and insect pest control practices. As presented in table 10 out of the total respondents,

6 Fetena and Lemma 399 Table 7. Spread mechanisms of major apple diseases and insect pests. Spreading agents Frequency Percentage No idea Farm tools & wind Birds Birds & wind Source: own survey result (2012/13). Table 8: Plant part infected by disease and insect pests. A. Plant parts damaged by disease Frequency Percentage B. Plant parts damaged by insect pests Frequency Percentage Fruit, leaf & root Fruit, leave & roots Fruit, stem & leaf Fruit, stem & seedling Seedling, leaf & fruit Leaf & fruit Root Fruit No idea Flower Leaf No idea Table 9. Control mechanisms taken so far by the farmers. Control mechanism Frequency Percentage Indigenous (botanical) control Farm hygiene (sanitation) No idea Chemical control 0 0 about 48.3 % respondents revealed that they are using different traditional apple disease and insect pest control methods in the study area. To control apple diseases and insect pests from their farm, apple growers have tried to use some indigenous control methods that are presented in table 10 below. They mentioned that cow milk after mixing with chopped white onion to control some apple diseases like powdery mildew after spraying on surface of the apple trees. Respondents mentioned that this trial was not effective to manage apple diseases and insect pests. Therefore, in addition to the above practices it is important to remove all dropped fruits around the apple trees to control the occurrence of diseases and insect pests from the area. Tolerance level of varieties grown in study area to major apple diseases and insect pests Apple scab and powdery mildew (45.1%) as measured during the survey period was the serious disease in the study area. This disease causes high losses in BR, Royal Galla, Crispin and Anna but lesser attach in Jonagold and Granny smith. Except rodents and aphid no more insect pests were recorded. Green apple aphid was recorded affecting tender leaf, apical bud and young leaves. Gala apple variety bears many fruits but there were huge losses of fruit which attacked by scab disease. Farmers also confirmed that this variety was highly susceptible to disease. They asked what should be harvested from this variety by indicating that children have a right to collect the fruit for free. The farmers already neglected the variety but not removed from the farm yet. There is no any information given concerning resistance of varieties for insect pests. Impact of major diseases and insect pests on apple production As of table 11 above, about 28.3% of the respondents were revealed that apple seedlings and apple mother trees lost due to major apple diseases and insect pests. During the apple orchard observations for disease and insect pest attack, some apple plant dead due to diseases and insect pests at different growth stage. Majority of respondents (43.3%) interviewed about apple tree lost due to issues at have no ideas about the

7 Scholarly J. Agric. Sci. 400 Table 10. Resistant varieties grown in the study areas for diseases as depicted by respondents Name of varieties Diseases Apple scab and powdery mildew Frequency Percentage Red delicious Golden delicious Granny smith Jonagored Anna Crispin BR Table 11. Number of apples dead due to major diseases and insect pests. Number of apple trees & seedlings dead Frequency Percentage No idea Less than Greater than Table 12. Yield losses due to major diseases and insect pests on apple trees. Yield loss in kg Frequency Percentage Less than No idea condition of their apple plant. As of table 12 above, about 28.3% of the respondents were revealed that less than 25 kg of apple fruit lost due to major apple diseases and insect pests. During the apple orchard observations for disease and insect pest attack, some apple fruit dropped, eaten by birds and rotten due to diseases and insect pests at different maturity stage was observed in different farmer s orchards in the study areas. Similar to the current findings, Fikre Handoro and Messele Gemu (2007) reported about causes of diseases and insect pests which reduce the yield and quality differently on temperate fruits in the study areas. Further investigations have to be undertaken how and when to harvest apple fruits particularly to control some post-harvest diseases that attack apple fruit. Group discussions with model farmers and key informants In addition to the questionnaire, the research team had made a group discussion with model farmers and key informants. During the discussion almost all informants argue that the present status of insect-pests and diseases of apple shown devastating from time to time, especially in summer and winter season where the plant escape from dormancy and get high vegetative growth. Meanwhile, in the discussion, farmers and the key informants added the number of apple tree disappeared due to the effect of the major diseases and insect pests (5-14 years old BR and 7 years Granny smith) and apple production (200kg to 50kg BR decline in yield per tree and 40kg to 10kg Granny decline in yield per tree).

8 Fetena and Lemma 401 Beside to the listed problems above, lack of applying management practices (weeding, pruning, training, fertilization, watering and separate plantation of seedling and orchard) by the farmers have a significant role on the occurrence of apple disease and insects in the area. Though farmers and key informants have been taught the mechanisms (use of chopped garlic and tobacco mixed with hot milk spray) of preventing major diseases and insect pests of apple by Kalehiwot Church and Bureau of Agriculture, the outcome was not effective. Discussion carried out with key informants in both woredas revealed also that green apple aphid (Eriosomalanigerum Hausman) and blossom thrips (Taeniothripsrhopalantennalis Shamsher Singh) were the major insect-pests and scab ( Venturiainaequalis), powdery mildew ( Podosphareaieucotricha) and collar rot (Phytophthoracactorum), were the major diseases notified at different kebeles limiting apple production. Apple varieties that can resist/tolerate major diseases and insect pests are Jonagored, Golden Delicious and Red Delicious while BR, RoyalGalla and Crispin are susceptible to major diseases and insect pests according to farmer s response. The woredas have not showed any intervention concerning the sustainable prevention of major diseases and insect pests. There can be little doubt that lacks of supply of special farm tools (knife, scissor, saw, watering cans etc) affect the ways to control diseases and insect pests indirectly. In other cases, use of cultural approaches that could include: removal of rush/debris, crop rotation, tillage, cover crops, plant/row spacing, timing of harvest and water management, trap crops, avoiding planting in areas with historically high levels of pests, and pest-free seeds placed a high role to minimize pest levels. CONCLUSION AND RECOMMENDATION The study area, Chencha and Bonkeworedas are the most potential apple producing woredas found in Gamo Gofa Zone of Southern Nation Nationalities and People Regional State. The study showed that diseases and insect pests on apple fruit has decreased the market value of the fruit. The main aim of this study was to determine occurrence of major diseases and insect-pests of apple in the study area and to assess impacts of major diseases and insect pests of apple based on community s perception. A total of 90 respondents (73 male and 17 female) included from three kebeles of Chenchaworeda and two kebeles from Bonkeworeda were interviewed using semi-structured questionnaires. In addition qualitative data were collected using group discussion among selected apple growers and development agents who were working in the selected kebeles. The analysis of data was done using descriptive statistics by employing SPSS software version 15. Apple varieties grown in the study area are BR, Crispin, Granny Smith, Jonagoled, Red Delicious, Anna and Royal Gala. Apple diseases and insect pests recorded in the areas include Apple scab, Powdery mildew, Root rot, green apple aphid, birds, green plant bugs, and some caterpillars damaging on seedlings. Apple scab and powdery mildew (45.1%) was the major diseases. Insect pests such as green apple aphids, scale insects and green plant bugs were also observed damaging on leaves of the plant. Royal Gala variety being replaced by Crispin in Chencha due to its susceptibility to apple scab disease. About 35% of respondents revealed that farm tools and winds were the main spreading mechanisms of major apple diseases and insect pests. About 48.3 % of the respondents indicated that they are using cultural apple disease and insect pest control methods. About 28.3% of the respondents were revealed that apple seedlings and apple mother trees lost due to major apple diseases and insect pests. About 28.3% of the respondents were revealed that less than 25 kg of apple fruit lost due to major apple diseases and insect pests.it can be concluded that the awareness of farmers about most of the diseases and insect pests were very low. Similarly occurrences status and satisfaction level by farmers to control major diseases and insect pests is medium and low respectively.agronomic practices of apple production to control diseases and insect pests are not satisfactory in the study area. Some of the missing agronomic practices that have paramount significant to control apple diseases and insect pests are pruning, soil cultivation, spacing between plants, using chemicals, using resistant varieties, etc. Therefore, this study recommended that there is an urgent need to improve apple farming system in Chencha and Bonkeworedas by establishing demonstration site and then farmers will learn and scale up the improved agronomic practices to their farm are expected from Arba Minch University to overcome particularly the constraints of major diseases and insect pests of apple plants in the study area. Most of the farmers in the study area were practiced poor apple farming system. Hence, in order to manage insect pests and diseases of apple, some functional action plan has to be designed and field day progammes at each apple growing woredas should be organized by the concerned offices. An integrated pest management approach should be introduced in the study area in place of depending on any single apple disease and insect pest control measures. ACKNOWLEDGEMENT The authors are thankful to Arba Minch University Research Directorate Office for funding the project and continuous follow-up. Authors are also grateful to the

9 Scholarly J. Agric. Sci. 402 rural people of Chencha and Bonkeworedas for sharing their experience/knowledge of insect pests and diseases of apple plant. Appreciation also goes to the bureau of Agriculture for their kind assistance during the field observations, discussions and interview. REFERENCES GGZAARDO (Gamo Gofa Zone Agriculture and Rural Development Office). (2009). Annual Report, Arba Minch Ethiopia. Hashmi, A.A. (1994). Insect pest and diseases management. In: O. Mayers, G.M. Khattak, H.R. Mian, M.Ayaz, E. Bashir, and R. Bental (Eds.). Horticulture.National Book Foundation, Islamabad, Pakistan. pp: John, W. (1986). Tropical fruits, New York, united states. Thind, T. ( 2001). Diseases o f fruits and vegetables and their management.kal.pub.lud. p BANRD ( Bureau of Agriculture and natural Resource Department Chencha). (2012). Annual Report, Chencha Ethiopia. Bayeh, M. (2007). Overview of temperate fruits research and production in Ethiopia, Addis Ababa, Ethiopia. Berrie, A.and Cross, J. (2005). Development of an integrated pest and disease management system for apples to produce fruit free from pesticide residues. Fikre, H. and Melesse, T. (2007).A survey of temperate fruit diseases in SNNPR, Ethiopia. Fitzgibbon, C.T. and Morris, L.L. (1987). How to Design a Program Evaluation. Newbury Park, CA: Sage.