Table 1 shows respondent characteristics. On average, the household size was 7 persons. A majority of the respondents (48%) had attained secondary level of education, 42% primary level, and 5% had no formal education which is below the national literacy level average of 53%. A majority of farmers (86%) who participated in the FAW campaign had experienced FAW on their farms during the November 2018–April 2019 cropping season, compared to 88% of the non-campaign participants.
On average, male farmers had more land for all activities compared to female farmers (7 acres compared to 5). Radio campaign participants (who are we refer as radio listeners) had more land for all activities (6.6 acres) compared to non-listeners (5.7 acres). Both household head and spouse worked most of the time on their farms. This was confirmed by the study where most of the household heads (92%) work on the farm full time and 6% part-time while 95% of the spouses of the household head worked full time on the farm while 4% work part-time. The average age of the household head was 51 years for the female heads and 53 years for the male heads.
Farmer participation in radio campaign on FAW
Farmer reach with radio messages was estimated based on radio coverage and signal strength, total potential adult population, total potential rural population, as well as proportion of maize growers. This approach has been used before for example Farm Radio International (Hudson et al. 2017, Wanyama et al. 2015), to map audience coverage and reach. In our analysis, we include a factor of proportion of respondents in the broadcast areas who listened to at least one radio episode on FAW during the campaign season, to estimate actual reach. Figure 2 shows mapping of radio reach in Zambia based on signal strength and population within the radio coverage that were used for computation of reach figures for the radio campaign. Where tower data were not available, for example Radio Yangeni and Sky FM, the broadcasters were asked to provide an estimate of their listenership based on their experience and research. The adult population in Zambia is 52% according the national bureau of statistics, and from our survey, 49% of the respondents listened to at least one episode of the FAW campaign during the 2018/19 cropping season. Table 2, shows the estimation of reach based on the statistics estimates, a total of 1.4 m people were reached with fall armyworm messages via radio. While it is not possible to disaggregate public service message and radio viewership/listenership by gender and age, it is estimated that about 40% of the population reached were women and that 48% were under 35 years of age. The estimate does not include secondary reach e.g. information sharing within the family, farmer groups or social clubs, which is common in rural setting. Figure 3, shows a comparing of the FM radio mostly listened to and where the FAW message was received from, by the listener categories, where ZNBC Radio 1, is the most listened followed by ZNBC Radio 2 but this differed by province where Icengelo is listened more in Copperbelt.
Probit regression model was used to assess factors affecting farmer participation in radio campaign. The dependent variable took the form of 1, if farmer listened to at least one radio episode on fall armyworm and 0, otherwise. Table 3 shows results of the logit model. Data showed that gender of respondent and land under maize cultivation had positive and significant effects on farmer participation in the radio campaign. Gender of respondent was significant (P > 0.05) in influencing farmers decision to take part in the of radio campaign. Relative to the base province, Luampula had a positive and significant influence to the radio listening at 5% level. This may be attributable to the number of FM radio stations covering the province. On the other hand, compared to the base age of above 60 years, the age between 36 and 60 and those 35 years and below, had a positive and a significant influence on farmers participation in FAW radio campaign at 5% level of significance, (Table 3). Education levels relative to the base level had no influence on participation on the radio campaign by farmers except the primary education that was shown to positively influence participation at 10% level of significance. It therefore implies that, gender has a positive influence on radio listening in Zambia and while developing and intervention on this nature, gender ought to be considered.
Farmer knowledge of fall armyworm
Table 4 shows results of the knowledge questions—identification, monitoring and management. Overall, farmers responded correctly to most of the FAW knowledge questions, but farmers who listened to radio had higher knowledge scores generally compared to those that did not. On FAW awareness, data showed a significant difference (P < 0.05) between radio listeners and non-listeners. More radio listeners (86%) than non-listeners (80%) agreed that FAW can cause 100% damage and loss on maize and that the signs of FAW damage include small pinholes. Conversely, more non-listeners (45%) than listeners (36%) agreed that FAW is spread through infested seeds respectively significant at 10% level. There was however no significant difference between the proportions of listeners and non-listeners that said FAW only attacks maize.
The results show a significant difference in knowledge on FAW management, between the two groups (p < 0.01), with 88% of the listeners and 76% of non-listeners agreeing that early planting at the onset of rains can help reduce FAW incidence. Further, 68% of listeners and 43% of the non-listeners agreed that crop rotation can help reduce FAW infestation. However, there was no significant difference between the two groups on the statements that FAW can be managed through hand picking and crushing on small scale, where 58% of both groups agreed. When it came to monitoring, the two groups differed significantly (p < 0.001) on the statement that it is important to visit the maize farm 2–3 weeks after planting and to continue monitoring every 3 days, with 92% and 75% of the listeners and non-listeners agreeing, respectively. There was however no significant difference between the two groups on the statement that monitoring FAW is done by walking along edges of maize fields, with 42% of the listeners and 43% of the non-listeners agreeing.
Fall armyworm management practices used by farmers
Campaign messages on management practices included both prevention and direct control. Prevention approaches are aimed at reducing the chances of the pest attacking the field, while control relates to practices to reduce impacts of the pest once already in the field. Results show that both groups of farmers employed different FAW prevention and control practices with radio listeners more likely to adopt management practices than non-radio listeners, particularly preventive measures such as frequent monitoring, intercropping and rotating crops in their fields. Whilst the use of pesticides by radio listeners was higher (Fig. 4). There was no significant difference between radio listeners and non-radio listeners in using biological methods for controlling FAW. This may mean that there is a knowledge gap in Zambia in regard to the use of biological methods in managing FAW infestations. This is an opportunity for both government and development partners to intervene and avail these technologies which are friendlier to human health, environment and are sustainable. Both male and female farmers showed awareness of FAW and implementation of management practices as promoted by the radio campaign albeit with some differences. More male farmers than female were more likely to apply pesticides, while women were more likely to use agronomic and cultural practices than men for the control of FAW. Other studies have also noted differences in practices employed by male and female farmers for FAW management (Kansiime et al. 2019; Tambo et al. 2020), which is largely attributed to differentials in access to resources, inputs and decision making.
Regression results of factors affecting farmer knowledge and management of FAW are shown in Table 5. The results show that participation in the radio campaign by listening to the radio was positively associated with outcomes on FAW identification, monitoring and management. The result is consistent with previous studies e.g. (Adamides and Stylianou 2018; Tambo et al. 2019), who found that radio contributed significantly to farmers’ agricultural knowledge. Hudson et al. (2017) show that the percentage of radio listeners implementing at least one agricultural practice was 2.7 to 2.9 times the percentage of non-listeners in Uganda and Tanzania respectively. This shows that the radio campaign had positive effects in increasing awareness and facilitating farmers’ decisions to take up promoted FAW practices.
Household size was positively associated with FAW identification and management, while age of farmer (36 and 60 years) was positively associated with proper FAW identification in comparison to younger or older farmers. This implies that farmers aged between 36 and 60 years were more likely to monitor their maize farms for FAW compared to other age categories. Geographically, farmers in Eastern and Luapula provinces had lower knowledge bases on FAW compared to Southern province. While gender of respondent showed no significant effect on FAW knowledge bases, management practices tended to differ between men and women. Gender of respondent showed no significant influence on FAW awareness, monitoring and management highlight the potential of this approach to enhancing women's participation and access to information.