Severity and pestiferous effect of aphid on Mustard plants, and analysis of host plant physiomorphic traits

The abundance, infestation, and severity of aphid Lipaphis erysimi Kaltenbach (Hemiptera: Aphididae) were studied on Mustard Brassica napus Linnaeus variety BARI Sharisa 13, B. campestris Linnaeus varieties BARI Sharisa 14 and BARI Sharisa 15, and B. juncea Czem varieties BARI Sharisa 16 and BARI Sharisa 17. The study also investigated the relationship of the abundance of aphid with Mustard plant physiomorphic characteristics and the pestiferous effect of aphid on the Mustard varieties. The Mustard variety BARI Sharisa 13 revealed statistically the lowest abundance of aphid as well as its infestation and severity index. The growth stages of the studied Mustard varieties were found statistically different, and the variety BARI Sharisa 14 revealed the shortest duration for silique maturation. The abundances of aphid on the Mustard varieties exerted negative relationships with plant height, the number of branches, leaf and silique per plant, flower and silique per raceme, chlorophyll a, chlorophyll b, protein, and pH contents; however, proline content depicted positive relationship. The infestation of aphid significantly reduced the morphological traits, phytochemicals, oil content, and yield of the Mustard varieties. Proline content was increased in all the tested varieties of Mustard. The BARI Sharisa 13 followed by BARI Sharisa 16, resulted in the lowest reduction levels of the plant physiomorphic traits, yield, and oil content. These varieties can be promoted for cultivation in aphid prone areas and used to develop resistant cultivars against this pest through the breeding process.