The experiment was conducted in the research field of Plant Pathology Division, Bangladesh Agricultural Research Institute (BARI), Joydebpur, Gazipur during 2019-2020. The experiment was carried out in randomized completely block design (RBD) with three replications. The treatments were applied to the plots randomly in each block. The plot size was 3.0 × 6.0 m2. Three management package with control were used as treatment. The management packages tested in the present experiment was as follows:
T1: Net in seedbed + one spray of Imidacloprid 0.1% at 5 days before transplanting + Sticky yellow trap in the plot + 3 sprays of Imidacloprid 0.1% at 15 days interval starting after observing the vector population (aphids) by the yellow trap.
T2: Same as T1 except spray with 0.2 % Bio-Neem instead of Imidacloprid 0.1%.
T3: Same as T1 except spray with 2% mineral oil (Paraffin oil).
T4: Untreated control
BARI-Marich-1 was used in this experiment. Seedlings were raised in the nursery bed. Five weeks old seedlings were transplanted in the field on 30th December 20019. Spacing was maintained 50 50 cm. Irrigation, drainage, weeding and other intercultural operations were done as and when required. The experimental plots were monitored regularly to observe CMV symptoms. Diseases incidence was calculated using the following formula.
Diseases incidence (%)
Severity of Cucumber mosaic virus (CMV) was determined according to Monma and Sakata (1997) based on a 0-4 scale as follows.
Severity Index
Symptom index 0= No Symptom, 1= Mild Mosaic, 2= Mosaic and leaf waving leaf 3= Mosaic and deformed leaf 4= mosaic, deformed leaf and stunted plants
Data on yield kg/plot were recorded. Fresh fruit yield of chilli ton ha-1 was calculated by converting the fresh fruit weight per plot yield into hectare and was expressed in ton. Data were analyzed statistically for analysis of variance (ANOVA) using Open Source R software and means were compared according to Duncan’s Multiple Range Test (Gomez and Gomez 1984). Data were transformed as and when necessary using the Arcsine transformation method.
Economic analysis:
Economic analysis was performed by partial budget technique as described by Rahman et al. (2011). Following formulae were used for economic analysis:
Variable Cost = Cost (Taka) that vary in different packages
Gross Return (TR) = Yield in terms of money (@ Taka 20/kg (Yield price)
Gross margin = Gross Return – Variable cost
Marginal benefit =
The marginal benefit-cost ratio (MBCR) was calculated