Magnitude of aphid infestation, root rot and rust disease of lentil

Lentil is the major cultivated pulse crop of Bangladesh. Even if there are available high-yielding modern varieties of this crop but because of the higher yield gap, its demand is largely met by import. Thus, to evaluate the pest-related factors of low yield seven modern lentil varieties viz. Binamasur-5, Binamasur-8, Binamasur-9, Binamasur-10, BARI Masur-5, BARI Masur-6, and BARI Masur-8 were assessed to enquire the extent of aphid infestation, foot rot and rust disease incidence, and severity on seed yield. The experiment was laid out in a Randomized complete block design during Rabi season at BINA Sub-station, Magura. Data on insects and disease were recorded at definite SMW (standard meteorological week) and DAS (days after sowing). Outcomes divulged that maximum aphid infestation (number of aphids/plant) was noted between 7th to 9th SMW; where BARI Masur-6 had significantly lowest infestation level on 7th and 8th SMW. Summative foot rot disease incidence (%) was most in Binamasur-8 and Binamasur-9, but least in BARI Masur-6 and Binamasur-5. For rust, the highest incidence (%) was recorded with Binamasur-8 and Binamasur-5; contrary the lowest was seen with BARI Masur-6 and BARI Masur-8. Severity index (DSI) of foot and root rot was abundant by Binamasur-8 (72.89%) and Binamasur-9 (71.56%); conversely, Binamasur-10 (52.11%) and BARI Masur-8 (50%) had scarce DSI. In the case of rust, BARI Masur-5 (74.00%) showed top DSI accompanied by Binamasur-8 (58.33%). The utmost seed yield of 8.25 g/plant was produced by Binamasur-10; in contrast, the least was yielded by Binamasur-8 (5.45 g/plant). Weather factors (temperature, relative humidity, rainfall) were positively related to the number of aphids per plant. However, seed yield was negatively affected by aphid population, foot rot, and rust disease incidence. Overall, Binamasur-10 corroborated having better resilience to biotic and abiotic factors for delivering desirable economic yield