The occurrence and intensity of mustard aphid Lipaphis erysimi (Kalt.) on dates of sowing in different varieties respect to yield parameter S.A. Dwivedi * and R.S. Singh Department of Entomology, Lovely Professional University, Phagwara - 144 411, Punjab, India ABSTRACTS Signifcantly lowest aphid intensity of 7.3 and 7.4 aphids/10 cm apical shoot on the seasonal total emergence to maturity (ST) was noticed on 15 th October sown crop during rabi 2013-14 and 2014-15, respectively, which provided signifcantly highest seed yield of 1800.1 and 1945.0 kg/ha in the respective year. Sowing of variety Rohini on 15 th October during both years proved to be best combination as received signifcantly lower mean aphid intensity, 58.6 and 60.4 aphids/10 cm apical shoot. This also gave signifcantly superior seed yield, 1670.7 and 1915.1 kg/ha seed yield during 1 st and 2 nd year. Key words : Mustard aphid, seasonal incidence, varieties, yield and date of sowing. INTRODUCTION Oilseed crops have occupied an important place in human nutrition as they remain the major sources of calories and proteins for a large proportion of the world population. Oilseeds are those seeds that contain considerably large amounts of oil. The most commonly known oilseeds (conventional oilseeds) are groundnut, soybean, palm kernel, cotton seed, olive, sunfower seed, rapeseed, sesame seed, linseed, saffower seed, etc (Ajala et al., 2014; Aremu et al., 2006). Mustard plant is a plant species in the genera Brassica and Sinapis in the family Brassicaceae. Mustard seed is used as a spice. Grinding and mixing the seeds with water, vinegar, or other liquids creates the yellow condiment known as prepared mustard. The seeds can also be pressed to make mustard oil, and the edible leaves can be eaten as mustard greens. India is an important rape seed mustard growing country in the world, occupying largest area and has second position in production after China accounting for about 12% of the world. The production under nine oil seed crop grown in India, rapeseed and mustard accounting for about 22.2% of the acreage and 22.6% of the production. The average rapeseed and mustard yield in India is about 1188 kg/ha compared to the combined oilseed crop average of 1153 kg/ha in 2013-14 (Anonymous, 2014). The name ‘mustard, is derived from the Latin word mustum, or (must of old wine mixed with crushed seed makes it one of the most important spice in the world (Hemingway, 1976). In India, rape seed mustard is an important source of edible oil followed by groundnut (Pandey et al., 1999). Mustard seeds have high energy content, having 28 - 32% oil with relatively high protein content (28 - 36%). Well refned mustard oil has a yellow to brown color and its smell and taste are enjoyable. Mustard oil has a special fatty acid composition: 20 - 28% oleic acid, 10 - 12% linolic, 9.0 - 9.5% linolenic acid and 30 - 40% erucic acid (Abul-Fadl et al., 2011). The protein quality and quantity of B. campestries obtained oil cake is high (Chowdhury et al., 2014). Mustard seeds contain 28-32% protein by weight, although these values can vary slightly between varieties, growing regions and crop years. The amino acid composition of mustard protein is well balanced; it is rich in essential amino acids and mustard contain relatively lower amount carbohydrate. It consists mainly glucose, sucrose and fructose crude fber, dry mustard seeds contained 20 - 23% carbohydrate. Mustards seed are rich source of many health benefting minerals such as calcium, manganese, copper, iron, selenium, and zinc (Sarwar et al., 2009). Mustard seeds act as a laxative, stimulant to gastric mucosa and increase intestinal secretion (Sarwar et al., 2009; Sarwar et al., 2004). These © J. ent. Res., 43 (4) : 491-498 (2019) DOI : 10.5958/0974-4576.2019.00086.0 *Corresponding author's E-mail: sunil.21186@lpu.co.in