RESISTANCE SOURCE(S) AMONG MUSTARD VARIETIES / GENOTYPES AGAINST APHID

Abstract

The study on the resistance source(s) among eight mustard varieties/genotypes against mustard aphid, J.ipap/ii.c ervsimi (Kalt.) was conducted at the experimental field of Sher-e-l3angla Agricultural University, Dhaka during winter season from November. 2007 to Felruary 2008. The experiment was laid out in randomized complete block design with three replications. The abundance of aphid populations, infestation level. yield and yield attributes among eight mustard varieties were studied to ideiuify the resistance source(s). Out of eight mustard varieties. Tori-7 (545.00) was found as the most preferred host for aphid followed by SAU Sarisha-I, (53 .00) where as .Agrani (214.00 aphids-plant') perfoniied as least preferred host. None of these varieties were lbijnd to be resistant in terms of percent plant infestation by aphids and only one variety Agrani (49.43%) was graded as moderately resistant, four varieties BA.Rl Sarisha-6 (53.57%), Safol (56.03%). SS 75(61.271/;,) and BINA Sarisha-6 (65.70%) were graded as moderately susceptible, and the varieties Tori-7 (78.17%), SAU Sarisha-1 (76.20%) and I3ARI Sarisha-9 (70.07%) were graded as susceptible. The highly aphid susceptible variety Tori-7 produced higher percentage of deformed pod (13.48%), and the Icast performer in all aspects of yield attributes and yield (373.4 kg/ha), but caused maximum yield loss (71.5%). Conversely, the least susceptible variety Agrani produced lower percentage of deformed pod (7.15%), and performed as the best in all aspects of yield attributes and yield (615.5 kg/ha), caused minimum yield loss (46.2%). Considering the national demand of the edible oil and resistance to aphid pest, the mustard variety Agrani should be the preferred variety to cultivate.