Plant spacing - a non polluting tool for aphid (Hemiptera: Aphididae) management in canola, Brassica napus

Current study was initiated to generate the information on the effect of row-to-row distance of brassica crop, Brassica napus L., on aphids population. Three line spacing (20, 30 and 40 cm) with a constant nine cm plant to plant distance were evaluated on aphids infestation and its impact on seed yield. The collected and edited data on fixed parameters indicated that an inverse relation was found between increased line spacing and aphids population. It was evident that the mustard aphid, Lipaphis erysimi (Kaltenbach), population increased significantly as the inter row spacing decreased. Distance of 30 cm was quite respondent towards holding aphids number and grain yield, where optimum number of aphids (103.00 per plant) was recorded with maximum yield (980.00 Kg/Hectare). Maximum mean aphids number (163.5) was observed on the plants spaced at 20 cm apart rows with minimum seed yield (683.20 Kg). Minimum mean number of aphids (63.3) was recorded from the lines grown at the distance of 40 cm from each other with 783.20 Kg yield. The information accruing from this study showed that in areas where aphids problem is endemic, narrow rows spacing would tend to increase aphids population. Therefore, the row-to-row spacing not less than 30 cm with nine cm plant-to-plant distance is recommended in oleiferous brassica especially canola crop, as a component of integrated pest management tool to culturally control of aphids.