A field experiment was conducted to determine the integrated effect of planting dates, insecticides, and their interaction on the reduction of yield and yield related components of haricot bean caused by haricot bean foliage beetle damage at Sirinka Agriculture Research Center, Ethiopia. Planting dates were normal planting (NP) and late planting (10 days after normal planting) (LP), while insecticides comprised Apron star seed dressing (A) and without insecticide (WI). The combined analysis revealed that late planting combined with Apron star seed dressing (LPA) resulted in the highest yield (1223.7 Kg/ha). On the other hand, normal planting date without insecticide application (NPWI) gave the lowest yield (209.6 kg/ha) and the maximum yield loss (209.6%). The cost-benefit analysis showed that use of LPA gave by far better high net profit over control. Thus, LPA are recommended for haricot bean foliage beetle management in northeastern Ethiopia.
Haricot bean (
Bean foliage beetles (
There are limited options available for bean leaf beetle management, and foliar insecticide applications and insecticidal seed treatments are the primary methods of bean leaf beetle management [
The field experiment was conducted at Sirinka in 2012 and 2013 main cropping seasons. Sirinka is located between 110 41′ 13′′ and 110 45′ 11′′ N latitude and 390 31′ 15′′ and 390 43′ 2′′ E longitude with an altitude of 1850 m.a.s.l and situated 508 km away from Addis Ababa, the capital of Ethiopia. The annual rainfall of the area is up to 980 mm (ten years average). The area has bimodal rainfall, the main cropping season (June-August), and short rainfall, which is locally known as “belg” (March and April). The common planting dates of the area extend from the end of June to mid-July. The average maximum and minimum temperatures of the area are 26 and 13°C, respectively. The dominant soil types of the trial site are Eutric Vertisols and Eutric Cambisol.
The experiment was laid out in a randomized complete block design (RCBD) with a factorial combination of treatments in three replications, where planting dates and insecticides were tested in factorial combination. Planting dates were normal planting and late planting (10 days after normal planting). The insecticides were Apron star seed dressing and without insecticide. Seeds were dressed with Apron star at a rate of 250 gm/100 kg seed and shaken in a plastic bag for uniform distribution.
Adults of foliage beetle are predominantly feeding on the youngest leaves of the bean plant. Accordingly, leaf damage was assessed from randomly selected plants of central rows of each plot. The degree of leaf area damage was estimated as the percentage of round holes fed by foliage beetle. Number of dead plants after two-month period was also recorded. Data on the number of pods per plant was from five randomly sampled plants per net plot at harvest and number of seeds per pod was recorded from ten randomly sampled pods per net plot at harvest. Grain yield (kg/ha) was determined by harvesting all plants from the net plot and converting it on per hectare basis at 10% moisture content. Relative yield loss was computed using the following formula [
The seed price (Birr ton−1) of haricot bean was obtained from the local market at Sirinka and total sale from one hectare was computed. The price of common bean seed was Birr 666.67/100 kg. The price of Apron star, which was used for seed treatment, was Birr 10/10 gm. Cost of labor at Sirinka was 15 Birr per man per days. Cost of dressing equipment for 90 kg seed per hectare was also calculated and taken as Birr 100.0 day−1. Based on the data obtained, the cost-benefit analysis was performed using a partial budget analysis. Partial budget analysis is a method of organizing data and information about the cost and benefit of various agricultural alternatives [
The following points were considered during cost benefit analysis using partial budget analysis. Costs for all agronomic practices were uniform in all treatments. Costs, return, and benefit were calculated on the basis of per hectare. Farmers in the area were assumed to obtain 0.9% of experimental (actual) yield.
Data on the number of pods per plant, seeds per pod, and seed yield were analyzed using SAS software [
The combined effect of Apron star seed dressing and planting dates on the reduction of yield and yield components caused by foliage beetle damage has been conducted at Sirinka Agricultural Research Center, Ethiopia, under field condition for two years during 2012 and 2013. The two-year combined result revealed that there was a highly significant effect on the number of plants with the damaged symptom, the number of dead plants, yield, and yield-related traits due to planting date, insecticide application, and their interaction.
The effect of planting date, Apron star seed dressing, and their interaction was significant (P<0.05) on the number of plants with damaged symptom and number of dead plants. The result showed that Apron star seed dressing during late planting showed a lower number of plants with foliage beetle damaged symptom and number of dead plants (Table
Effect of the combination of planting date and seed dressing on number of damaged symptoms and dead plants of haricot bean in 2012 and 2013 main cropping season.
Planting date | Seed dressing | NPDS | NDPL |
---|---|---|---|
Normal planting | Apron star | 43.7 ± 7.07 | 37.8 ± 4.83 |
No Apron star | 112 ± 10.92 | 65 ± 16.07 | |
Late planting | Apron star | 27.4 ± 3.90 | 8 ± 2.91 |
No Apron star | 36.9 ± 1.58 | 15.7 ± 3.39 | |
| |||
CV (%) | 8.53 | 77.15 | |
LSD (5%) | 5.59 | 48.19 |
Efficacy of integrated management of foliage beetle: (a) normal planting without Apron star seed dressing and (b) late planting with Apron star seed dressing.
The result of the present study showed that the interaction effect of planting time and insecticide application was significantly (P<0.05) higher in affecting the number of pods per plant (Table
Effect of the combination of planting date and insecticide application on yield and yield components of haricot bean in 2012 and 2013 main cropping season.
Planting date | Seed dressing | Number of pods per plant1 | Number of seeds per pod1 | Seed yield (Kg/ha) 1 |
---|---|---|---|---|
Normal planting | Apron star | 8.13± 2.33 | 4.48 ± 0.77 | 669.3± 60.36 |
No Apron star | 5.02± 1.38 | 2.83 ± 0.27 | 209.6± 53.85 | |
Late planting | Apron star | 12.0± 1.06 | 5.61 ± 0.39 | 1223.7± 100.52 |
No Apron star | 9.0± 1.19 | 5.01± 0.45 | 802.4± 73.05 | |
| ||||
CV (%) | 23.85 | 15.03 | 27.27 | |
LSD (5%) | 2.74 | 1.14 | 130.48 |
Analysis of the two-year data showed that there is an interaction effect between planting date and insecticide application in affecting the number of seeds per pod. The highest number of seeds per pod was recorded during late planting date combined with Apron star seed dressing (5.61) (Table
The result of the two-year experiments data showed that there was a significant (P<0.05) interaction effect between planting date and insecticide application. The highest seed yield (1223.7 Kg/ha) was recorded from normal planting plus Apron star seed dressing (1223.7 Kg/ha). The lowest seed yield was obtained from normal planting without insecticide application (Table
Yield losses caused by haricot bean foliage beetle on haricot bean under different treatments during 2012 and 2013 main cropping season.
Planting date | Seed dressing | Relative yield loss (%) |
---|---|---|
Normal planting | Apron star | (669.3) 82.8 |
No Apron star | (209.6) 483.8 | |
Late planting | Apron star | (1223.7) 0.0 |
No Apron star | (802.4) 52.5 |
The present study showed that late planting combined with Apron star seed dressing significantly reduced the effect of foliage beetle thereby increasing seed yield (Table
The present study revealed the effect of seed treatment in reducing yield loss caused by foliage damage. The result of this study was supported by the report of Lam
The result of cost-benefit analysis over the two-year data (Table
Result of partial budget analysis for the integrated management of haricot bean foliage beetle during 2012 and 2013 main cropping season.
Treatment | Cost-benefit data | ||||||||
---|---|---|---|---|---|---|---|---|---|
No | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | |
Adj. yield (t ha-1) (yield x 0.9) | Price (Birr t-1) | Sale revenue (1x2) | Total input cost (Birr ha-1) | Marginal cost (Birr ha-1) | Net profit (3-4) (Birr ha-1) | Marginal benefit (Birr ha-1) | Marginal rate of return (7/5) (%) | ||
LPA | 1.27 | 6333.4 | 8020.0 | 932.6 | 402.0 | 7087.5 | 6261.3 | 1557.5 | |
NPA | 0.64 | 6333.4 | 4071.0 | 932.6 | 402.0 | 3138.4 | 2312.2 | 575.2 | |
LPWI | 0.83 | 6333.4 | 5256.2 | 530.6 | 0.0 | 4725.6 | 3899.5 | 734.9 | |
NPWI | 0.21 | 6333.4 | 1356.8 | 530.6 | 0.0 | 826.2 | 0.0 | 0.0 |
LPA = late planting with Apron star seed dressing; NPA = normal planting with Apron star seed dressing; LPWI = late planting without Apron star, and NPWI = normal planting without Apron star.
The higher marginal rate of return was obtained from late planting combined with Apron star seeds dressing (1557.5%). The highest cost-benefit ratio was obtained from late planting without insecticide application (1:9) followed by late planting combined with Apron star seed dressing (1:7.6). For every one birr investment of variable cost, there was a gain of 9 and 7.6 Birr from late planting without insecticide application and late planting with Apron star dressing, respectively. The sensitivity analysis showed that, for either increase or decrease of chemical cost as well as seed price, use of Apron star seed dressing with late planting showed the highest net benefit (Table
Sensitivity analysis for the management of haricot bean foliage beetle during 2012 and 2013 main cropping season.
Treatments | Cost increase price decrease | Cost increase | Cost constant price decrease |
---|---|---|---|
LPA | 6226.3 | 7032.1 | 6319.6 |
NPA | 2668.8 | 3079.3 | 2762.0 |
LPWI | 4171.7 | 4700.1 | 4224.8 |
NPWI | 609.6 | 742.2 | 662.6 |
LPA = late planting with Apron star seed dressing; NPA = normal planting with Apron star seed dressing; LPWI = late planting without Apron star, and NPWI = normal planting without Apron star.
The present study showed that the highest number of pods per plant, seeds per pod, and seed yield was obtained from the use of Apron star seed dressing combined with late planting. This treatment was very much effective in reducing the yield loss caused by foliage beetle. Cost-benefit analysis also showed that use of Apron star combined with late planting is economically feasible management option. Thus, combined use of apron star and late planting is highly recommended for the management of foliage beetle in northeastern Ethiopia.
The data used to support the findings of this study are included within the article.
The first author is a lecturer in the University of Gondar, Ethiopia and now he’s doing PhD in South Korea.
The authors declare that they have no conflicts of interest.
The research was financed by Amhara Region Agricultural Research Institute (ARARI) and partly by University Industry Cooperation Foundation of Kangwon National University.