Madras Agric. J. 92 (10-12) : 753 - 756 October-December - 2005

753

RESEARCH NOTES

IMPACT FROM ORGANIC MANURES AND INORGANIC FERTILIZERS ON THE INCIDENCE OF SUCKING PESTS OF COTTON UNDER RAINFFD CONDITION N. BALAKRISHNAN*, R.K. MURALI BASKARAN and N.R. MAHADEVAN Department of Entomology, Agricultural College & Research Institute Tamil Nadu Agricultural University, Madurai-625 104.

Cotton (Gossypium spp.), considered as 'King of fibre' and ‘white gold’, is one of the most important commercial crops which is grown in about 80 countries in the world occupying 33 million ha and sharing 44 per cent of the world production in Asia. In India cotton is cultivated over an area of 9 million ha with a production of 146 lakh bales and productivity of 276 kg/ha in 2000-'01 which is very low compared to some of the cotton growing countries and the world average of 590 kg/ha. In Tamil Nadu, cotton occupies a total area of 1.8 lakh ha in which 65 per cent area comes under rainfed condition with a production of 3.4 lakh bales and productivity of 324 kg lint/ha. Despite the recent setbacks, cotton continues to remain the backbone of the rural economy, particularly in the dry land areas. There are number of insect pests attacking cotton. Among the key pests, sucking pests viz., jassids (Amrasca devastans), whiteflies (Bemisia tabaci) aphids (Aphis gossypii) and thrips (Thrips tabaci) are very important since they damage the crop at earlier stage and cause severe yield loss. Organic manuring in pest management is getting its importance in recent past since it is eco-friendly and environmentally safe. Hence, the study was undertaken to evaluate the efficacy of organic manures and inorganic fertilizers on the incidence of sucking pests of cotton. The study was undertaken in a farmer's field at Sengappadai, Tirumangalam taluk of Madurai district during September 2001. The variety SVPR 2 was raised with a spacing of 45 x 30 cm and recommended agronomic practices were followed. Plot size of 8x5 m was adopted per replication and for each treatment three replications were maintained. In case of organic manure application it was carried out as basal dose and for inorganic fertilizers (40 : 20 : 0 kg NPK/ha), they were applied

as half dose of N and full dose of P as basal and remaining half dose of N at 45 DAS. Uniform plant protection measures were adopted from 105 DAS to manage bollworms (two sprays of endosulfan 0.07 %) in all the treatments including untreated check. The treatments are as follows: T1 : Farmyard manure (FYM) 12.5 t/ha T2 : Vermicompost 2t/ha T3 : NPK 40 : 20 : 0 kg/ha T4 : FYM 12.5 t / ha + NPK 20:10:0 kg/ha T5 : Vermicompost 2 t/ha + NPK 20 : 10 : 0 kg / ha T6 : FYM 12.5 t / ha + NPK 40 : 20 : 0 kg / ha T7 : Vermicompost 2 t / ha + NPK 40 : 20 : 0 kg / ha T8 : Untreated check Population of sucking pests viz., nymphs and adults of jassids (A. devastans), whiteflies (B. tabaci) aphids (A. gossypii) and thrips (T. tabaci) were recorded from ten randomly selected tagged plants in each replication. In each plant, three leaves (top, middle, bottom) were considered for observation (Singh et al, 1995). The observations were made during 15, 30, 45, 60, 75, 90 and 105 DAS and finally mean population was worked out. The yield data were also recorded. Statistical analysis of data from randomized block design was done using methods suggested by Panse and Sukhatme (1961). The data on population of sucking pests were transformed into square root values. The mean values of treatments were separated by Duncan's Multiple Range Test (DMRT) (Duncan, 1955). The use of organic manures in the pest management is considered as ecologically viable, economically feasible proposition, which avoids environmental pollution. In addition, organic

* Senior Research Fellow, Department of Entomology, Tamil Nadu Agricultural University, Coimbatore-641 003

754

N. BALAKRISHNAN, R.K. MURALI BASKARAN and N. R. MAHADEVAN

manures also supply macro and micro nutrients to the crop plants and improve the physical properties of the soil. Organic manures were reported to work like slow release fertilizers providing balanced nutrients to plants facilitating balanced growth, finally making them less prone to pest incidence (Gour, 1984; Bhawalkar and Bhawalkar, 1991). The present study on influence of organic manures on the incidence of sucking pests of cotton revealed that the mean population of sucking pests viz., leafhoppers, whiteflies, aphids and thrips was less in vermicompost 2 t/ha with NPK 20:10:0 kg/ha (half of recommended dose) (T 5) treated plots by recording 31.62, 16.33, 45.86 and 34.33 per ten plants, respectively, among the various treatments. This was followed by FYM 12.5 t/ha with NPK 20:10:0 kg/ha (T 4) by recording a mean population of 34.43 leafhoppers, 20.38 whiteflies, 50.43 aphids and 37.48 thrips per ten plants. Vermicompost 2 t/ha (T 2) and vermicompost 2 t/ha + NPK 40:20:0 kg/ha (T7) were the next best treatments compared to full dose of straight fertilizers (NPK 40:20:0 kg/ha) by registering 36.72 and 37.52 leafhoppers, 23.71 and 25.86 whiteflies, 54.33 and 57.24 aphids and 40.24 and 42.38 thrips per ten plants, respectively, in each treatment (Table 1). These findings are in agreement with the findings of Surekha and Arjuna Rao (2000) who reported on bhendi. Bhinde (1993) observed that vermicompost treated plants provide resistance to pest build up. Lyashenko et al. (1982) reported increased levels of leuco anthocyanins, catachins, flavanol, glycosides and phenol carboxylic acids in plants that received FYM. The higher polyphenol content in organic manure (FYM and vermicompost) treated plots have resulted possibly in low pest build up. This was supported by Rajasekara Rao (1997) who confirmed that the lower nitrogen in the leaves of organic manured treatments contributed to higher production of phenols and tannins in bringing induced / ecological resistance. The population of sucking pests was more in inorganic (straight) fertilizers (T 3 ) (48.57 leafhoppers, 35.24 whiteflies, 74.09 aphids and 52.24

thrips per ten plants) and untreated check plots (T8) (45.48 leafhoppers, 33.38 whiteflies, 70.76 aphids and 50.48 thrips) compared to vermicompost and FYM treated plots at all the stages of crop growth. These results are in confirmity with the findings of Balasubramanian and Iyengar (1950) on cotton, Singh et al. (1995) on mustard, Bhagyanakshatram (1995) and Surekha and Arjuna Rao (2000) on bhendi. The increased incidence of these sucking pests might be due to increased auxin content of plants under heavy nitrogenous manuring (Venugopal and Perumal, 1971). The inorganic fertilizers increase the plant growth and provide nutrients to the plants in larger amounts in shorter period, thereby the plants are endowed with luxuriant growth which offers adequate food to the insects leading to heavy insect population (Rajamohan et al., 1974). The increase in population in inorganic fertilizers applied plots over the untreated check plots may be due to more availability of nutrients from the former plots. Vermicompost 2 t/ha in combination with half dose of NPK (20:10:0 kg/ha) (T5) recorded highest seed cotton yield (845 kg/ha) followed by FYM 12.5 t/ha with half dose of NPK (20:10:0 kg/ha) (T4). These results are in consonance with the findings of Varma and Supare (1997) on chilli. Lowest yield (650 kg / ha) was obtained in NPK 40:20:0 kg/ha treated plots which had higher incidence of sucking pests among the treatments. The untreated check also recorded almost the same level of sucking pests incidence, compared to NPK 40:20:0 kg / ha (Table 1). However, untreated check recorded lower yield than the other treatments because of inadequacy of nutrients. The first author shows his high gratitude to Indian Council of Agricultural Research, New Delhi for the financial help rendered through Senior Research Fellowship. REFERENCES Balasubramanian, R. and Iyengar N.K. (1950). Influence of fertilisation on survival of Empoasca devastans on cotton. Ind. Cotton Green Rev., 4: 199-211.

IMPACT FROM ORGANIC MANURES AND INORGANIC FERTILIZERS ON THE INCIDENCE OF SUCKING PESTS OF COTTON UNDER RAINFFD CONDITION

Bhagyanakshatram, V. (1995). Influence of organic manures and botanicals on major pests of rice. M. Sc. (Ag.) Thesis, Andhra Pradesh Agricultural University, Hyderabad. Bhawalkar, V. and Bhawalkar, U. (1991). Vermiculture Biotechnology (Ed.) Bhawalkar, Earthworm Research Institute. Pune, M.S. pp. 41. Bhinde, M.R. (1993). Vermicompost. Paper presented at the short term training, organized by Prakruti at Yusuf Meharally Centre. Tara Dist, Raigud, 3 - 4 July, 1993.

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on sunflower in relation to manuring and spacing. Madras Agric. J., 61: 488 - 489. Rajasekara Rao (1997). Influence of organic and inorganic sources of host plant nutrition on the incidence of major pests of groundnut (Arachis hypogaea). Ph.D. Thesis submitted to Andhra Pradesh Agricultural University, Hyderabad.

Duncan, D.B. (1955). Multiple range and multiple F tests. Biometrics, 11: 1-42.

Singh, J., Mahal, M.S., Singh, R., Brar, D.S., Dhaliwal, Z.S. and Singh, B. (1995). Apian for sampling cotton jassid and whitefly populations on hirsutum cotton. J. Res. Punjab Agric. Univ., 32(1): 46-50.

Gour, A.C. (1984). Response of rice to organic matterThe Indian experience in organic matter and rice. IRRI, Los Banos, Laguna, Philippines, pp. 503 - 504.

Sure kha, J. and Arjuna Rao, P. (2000). Influence of vermicompost and FYM on the pest Ny complex of bhendi. The Andhra Agric. J., 47 (3 & 4): 228 - 231.

Lyashenko, N.I. Solody, U.K.G.D. Godovany, A.A. Verzhbitskii, V.I. and Moskal Chuk, N.I. (1982). Biochemical contents in FYM treated plants. Rastenil, 14: 373 - 377.

Varma NRG and Supare N R (1997). Effect of vermicompost in combination with FYM and chemical fertilizers against sucking pests of chilli. The Andhra Agric. J., 44(3&4): 186-187.

Panse, V.G. and Sukhatme, P.V. (1961). Statistical methods for Agricultural workers. ICAR Publication, New Delhi, India, 328 p. Rajamohan, N., Ramakrishnan, C. Krishnaraj, J. and Subramanian T R (1974). The incidence of jassid Amrasca biguttula biguttula (Ishida)

Venugopai, M.S. and Perumal, R.S. (1971). Influence of nitrogen and method of 'application on the population of Aphis gossypii and the mite Tetranychus telarius L. on brinjal. Andhra Agric. J., 18: 211 - 212.

756 Table 1.

N. BALAKRISHNAN, R.K. MURALI BASKARAN and N. R. MAHADEVAN

Influence of organic manures and inorganic fertilizers on the population of sucking pests and seed cotton yield Mean population (Nos. /10 plants) A. devastans B. tabaci A. gossypii T. tabaci

Seed cotton yield (kg/ha)

T1 : FYM 12.5 t/ha

40.24 (5.88)de

28.90 (4.95)de

61.86 (7.34)de

45.14 (6.23)de

715d

T2 : Vermicompost 2 t / ha

36.72 (5.56)bc

23.71 (4.43)bc

54.33 (6.84)bc

40.24 (5.83)bc

770bc

T3 : NPK 40:20:0 kg/ha

48.57 (6.57)f

35.24 (5.57)f

74.09 (8.11)f

52.24 (6.82)g

650c

T4 : FYM 12.5 t/ha + NPK 20:10:0 kg/ha

34.43 (5.04)b

20.38 50.43 37.48 (4.03)b (6.51)b

784b (5.56)b

784b

31.62 (5.01)a

16.33 (3.54)a

45.86 (5.16)a

34.33 (5.23)e

845a

T6 : FYM 12.5 t/ ha + NPK 40:20:0 kg/ha

41.81 (6.01)e

30.24 (5.08)e

64.48 (7.52)e

47.33 (6.44)ef

698de

T7 : Vermicompost 2 t / ha + NPK 40:20:0 kg /ha

37.52 (5.64)cd

25.86 (4.62)cd

57.24 (7.04)cd

42.38 (6.01)cd

755cd

T8 : Untreated check

45.48 (6.34)f

33.38 (5.41)f

70.76 (7.92)f

50.48 (6.71)f

574f

Treatment

T5 : Vermicompost 2t/ha + NPK 20:10:0 kg/ha

Figures in parentheses are square root transformed values Means in a column followed by same small letter(s) are not significantly different (P = 0.05) by DMRT