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Canola (Brassica napus L.) is one of the economically important crops of Pakistan and mustard aphid, Lipaphis erysimi Kalt. (Hemiptera: Aphididae), is a serious threat to this crop. This experiment was conducted with an aim to screen out selected canola cultivars for their tolerance against L. erysimi infestation under glasshouse conditions. Experiment was carried out using completely randomized design with ten replications for each treatment during growing seasons of 2018 and 2019. Data were documented based on the tolerance indices (TI) and proportional plant dry weight change (DWT) to identify tolerance of canola crop. Results revealed that commercial cultivar 'Zahoor' comparatively performed well despite higher number of aphids found on itas compared its other counterparts "Abaseen, Omega and KS-75" and hence, was identified as tolerant to mustard aphid. This cultivar also exhibited strong vigor against mustard aphid and minimal symptoms of damages were observed. The yield losses based on DWT and TI in susceptible cultivar "Abaseen" was 40.79%, whereas it was 23.56% in Zahoor which confirmed the reduced percent yield losses in the later genotype. This study identified "Zahoor" as the most tolerant cultivar to mustard aphid followed by KS-75 and Omega hence, other susceptible cultivars should be replaced by Zahoor to attain higher and sustainable yield production in canola. [ABSTRACT FROM AUTHOR]

Potato (Solanum tuberosum L.) is an important vegetable food crop in Pakistan. Myzus persicae is an insect pest of potato, feeding on phloem tissues of leaves of potato plant and significantly reduces the yield of potato. Antixenosis experiments were performed to assess the resistance potential of eight different potato cultivars against M. persicae under glasshouse conditions for three different durations of time (12, 24 and 48 hours) during spring and autumn potato growing seasons of 2016. Both the experiments were conducted using a completely randomized design. Each experiment having eight treatments and each treatment was replicated 10 times. The replicated pots containing each of the eight potato cultivars were infested with 100 and 200 adult of M. persicae. Significant antixenosis effects among the tested potato cultivars were observed while the different durations of M. persicae infestation on potato cultivars also displayed significant antixenosis effects against M. persicae during the spring and autumn experiments in 2016. During both experiments, Sarpo Mira displayed the lowest number of adults per plant on release of 100 and 200 adults per plant. Sarpo Mira showed M. persicae infestation of 3.3 and 2.4 per plant per pot on release of 100 adults per plant during spring and autumn seasons, respectively while an infestation of 5.3 per plant 4.7 per plant on Sarpo Mira was observed on release of 200 adults of M. persicae during spring and autumn seasons, respectively. FD-70 had the highest number of M. persicae (13.7 per plant) in the pots released with 100 M. persicae during spring season while Asterix showed the highest number of M. persicae (13.8 per plant) in pots infested with 200 M. persicae during autumn season. Sarpo Mira also appeared to be the most resistant potato cultivar against M. persicae at 12, 24 and 48 hours post infestation of M. persicae. Overall, this study revealed the resistant potential of potato cultivar Sarpo Mira against M. persicae. [ABSTRACT FROM AUTHOR]