Influence of Morphological Parameters on the Incidence of Abacarus
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Journal of Entomology and Zoology Studies 2021; 9(1): 285-290 E-ISSN: 2320-7078 P-ISSN: 2349-6800 Influence of morphological parameters on the www.entomoljournal.com JEZS 2021; 9(1): 285-290 incidence of Abacarus sacchari and Aceria © 2021 JEZS Received: 25-11-2020 sacchari on sugarcane varieties Accepted: 28-12-2020 Mohan Kumar KS Department of Agricultural Mohan Kumar KS, Sugeetha G, Vijayalaxmi Kamaraddi, Mahadev J, Entomology, College of Pankaja NS, Nagaraj TE and Patel VN Agriculture, V. C. Farm, Mandya, Karnataka, India Abstract Sugeetha G A study was conducted to know the incidence of eriophyiid mite pests, Abacarus sacchari and Aceria Department of Agricultural saccari were influenced by morphological parameters of sugarcane crop at ZARS, V. C. Farm, Mandya. Entomology, College of In the present investigation, distance at the base of the vein, leaf length, leaf area and plant height had Agriculture, V. C. Farm, positive correlation and influenced more incidence of sugarcane rust mite, Abacarus sacchari population. Mandya, Karnataka, India The parameters such as distance from one vein to another, width of the leaf, leaf inclination and trichome density did not support the growth of mite population and had negative correlation. In case of sugarcane Vijayalaxmi Kamaraddi blister mite, Aceria saccari, thickness of leaf sheath, girth of the shoot, moisture content in the leaf Department of Food Science and sheath and easily detachable leaf sheath were found to have significant positive correlation whereas leaf Technology, Extension sheath length, width, fresh weight were found to have non-significant relation. From the present Education unit, Naganahalli, investigation, it can be concluded that no single morphological factor is responsible in mite population Mysuru, Karnataka, India fluctuation but all the factors work in compliment with each other. Mahadev J Keywords: Morphological parameters, aceria sacchari, abacarus sacchari, sugarcane varieties Department of forestry and Environmental Science, College of Agriculture, V. C. Farm, Introduction Mandya, Karnataka, India Sugarcane is an important commercial crop of Indian agriculture and is grown extensively throughout the world. Anthropogenic climate change supports moderate crop growth and yield Pankaja NS but favors the pest abundance. The insect pests attack sugarcane crop from planting to harvest Department of Plant Pathology, and they include borers, sucking pests, defoliators, subterranean pests. Apart from these, College of Agriculture, V. C. sugarcane crop is also attacked by a number of phytophagous mites (Beard et al., 2003 [2]; Farm, Mandya, Karnataka, Leslie, 2004 [7]) belonging to the families Tetranychidae, Tarsonemidae and Eriophyiidae and India [11] are considered as minor pests (Ozman – Sullivan et al., 2006 ). About 30 species of [3] Nagaraj TE phytophagous mites have been reported attacking sugarcane (Bolland et al., 1998 ; Fitz AICRP (Millets) Head, GKVK, Gibbon et al., 1998 [4]). Among these, eriophyoid mites are more diverse, highly adaptable and Bangalore, Karnataka, India have close association with the host plants (Petanovic and Vidovic, 2009 [12]). These mites are considered as smallest arthropods in the world and play key role in ecosystem (Sabelis and Patel VN Bruin, 1996[13]). Totally, nine species of Eriophyoidea mites have been reported on sugarcane, Sugarcane Entomologist, AICRP namely Abacarus delhiensis, Abacarus queenslandiensis, Abacarus doctus, Abacarus (Sugarcane), ZARS, V. C. Farm, Mandya, Karnataka, India sacchari, Aceria sacchari, Aceria merwei, Cathetacarus spontaneae, Catarhinus sacchari and [11] [10] Diptacus sacchari (Ozman-Sullivan et al., 2006 ; Navia et al., 2011 ). Among these, sugarcane blister mite Aceria sacchari and sugarcane rust mite Abacarus sacchari are known to cause considerable damage to the sugarcane crop. The application of insecticides to manage these eriophyiid mites is not feasible in the sugarcane field as it is cumbersome. As the mite infestation starts from 3rd month onwards and the plant height reaches to certain extent, it hinders the movement of a person engaged in plant protection operation creating unhealthy situation and non-uniformity in the deposition of insecticides. Therefore, developing a resistant sugarcane variety is a suitable option to reduce the mite incidence and at the same time it is eco-friendly which fulfills the ultimate goal of integrated pest management. Hence, a study was undertaken to assess the morphological parameters associated with the different varieties of sugarcane against eriophyiid mites and that enables us to identify a promising variety with a Corresponding Author: modified morphological parameter that helps in reducing the mite incidence and infestation. Mohan Kumar KS Department of Agricultural Entomology, College of Material and methods Agriculture, V. C. Farm, The morphological components of nine sugarcane varieties were studied against the Mandya, Karnataka, India phytophagous mites at the Zonal Agricultural Research Station, V.C farm, Mandya. ~ 285 ~ Journal of Entomology and Zoology Studies http://www.entomoljournal.com Studies were conducted to identify the differences in was calculated by using the formula suggested by morphology among the nine sugarcane varieties. To study the Vivekanandan et al. (1972) [16]. incidence of sugarcane rust mite Abacarus sacchari, five plants were randomly selected from each variety. In each plant, three randomly selected leaves were taken for the observations on leaf characters. The observations on the parameters like height of the plant, number of leaves, interveinal distance, length of the leaf, breadth of leaf, leaf Where, LA = Leaf area (cm2 per leaf) area, trichome density, leaf moisture per cent, thickness of the WD = Oven dry weight of 50 discs (g) leaf, leaf inclination were recorded. To study the incidence of A = Area of 50 discs (cm2) sugarcane blister mite, Aceria sacchari parameters like WA = Oven dry weight of all the leaves with discs (g) thickness of leaf sheath, length of the leaf sheath, moisture per cent of the leaf sheath, fresh weight of the sheath, girth of the Leaf moisture shoot, width of the leaf sheath and leaf sheath detachability of Leaf moisture was calculated based of fresh weight and dry the plants were recorded. The data was subjected to ANOVA weight of sheath. and was correlated with the incidence of mite to calculate ‘r’ value. Morphological parameters studied on different sugarcane varieties Number of fully opened green leaves on a plant was recorded Leaf Sheath moisture from each of the five plants and average was worked out. For Leaf sheath moisture was calculated based of fresh weight measuring the length of leaves, three green leaves were taken and dry weight of sheath. from five randomly selected plants and length was measured from the place of joint of leaf sheath with leaf (ligule) to the tip of the leaf and finally average was worked out. The breadth of the leaf was measured at the three places i.e., at tip, from the middle and at the base of leaf and finally average was worked out. Leaf angle was taken from five plants in Sheath length each plot with help of protractor and average was worked out. Length of the leaf sheath was measured with centimetre scale. The thickness of leaf sheath and leaf was measured by disc method. The girth of the shoot was measured from five Sheath width randomly selected plants. The average girth of the five plants Width of the leaf sheath was measured with centimetre scale taken from each genotype was then calculated and presented at top, middle and bottom portion of the sheath and mean as girth of the plant. The height of the plant was recorded sheath width was calculated. from five randomly selected plants and the average was taken. The trichome density was estimated by following the method Interveinal distance suggested by Maite et al. (1980) [8]. Interveinal distance was measured from top, middle and bottom portion of the leaf with the help of micrometre. Two Leaf area types of distances were measured first one was distance at the Leaf area was measured by disc method and was expressed in base of the veins i.e., from the base of one vein to base cm2. Fifty discs of known size were taken through a cork adjacent vein, second one was distance from the top of one borer from randomly selected leaves. Both discs and vein to top on adjacent vein. remaining leaf blades were oven dried at 65º C and leaf area Fig 1: Distance from one vein to another vain Data on the above-mentioned characters of the plant viz., the presented in the Table 2. The distance at the base of the veins height, girth, number of green leaves and length and breadth was maximum (63.00 µm) in the varieties VCF 0517 and Co of leaves etc., were analysed statistically. 86032 with the population of 5.80 and 1.16 mites/2 cm2 leaf area, respectively. Minimum distance (44.24 µm) was found Results and Discussion in the variety, CoVC 99463 with the population of 0.35 Morphological characters influencing the preference and mites/2 cm2 leaf area and 0.37 eggs/2 cm2 leaf area (Table 1). incidence of sugarcane rust mite, Abacarus sacchari A non-significant positive correlation (r= 0.56) was found The effect of different morphological parameters on the mite between distance at the base of the veins and A. Sacchari population of A. sacchari was observed and has been population indicating that larger the distance at the base of the presented in Table 1. A simple correlation between mite veins supported more number of rust mite population.(Table population and the leaf morphology was worked out and 2). ~ 286 ~ Journal of Entomology and Zoology Studies http://www.entomoljournal.com The distance from one vein to another vein was maximum in the variety, CoM 0265 with the population of 0.37 mites/2 (176.48 µm) in the variety, Co 0323 with the population of cm2 leaf area. Among the varieties number of leaves per plant 0.13 mites/2 cm2 leaf area and minimum (126.22 µm) was shows non-significant difference (Table 1).