Bollworm complex, Bramhastra extracts, Dr. PDKV-Entomology formulation, Panchpatre extract, Garlic-Chilli extract.

Cotton is a most important fiber and cash crop in India. It plays an important role in the textile industries and economy of the nation, it contributes 1/3rd of total foreign exchange earning of India (Mayee and Rao 2002). But, continuous cultivation of hybrid cotton in large areas increases its vulnerability to bollworms viz., American bollworm, Helicoverpa armigera (Hubner), spotted bollworm, Earias vittella (Fabricius), pink bollworm, Pectinophora gossypiella (Saunders) attack in different growth stages of cotton. Insect pest management in cotton has traditionally been relied upon synthetic insecticides. The indiscriminate use of chemical pesticides is resulting in environment and land pollution (Gill and Garg 2014). The chemical pesticides kill non- target and beneficial insects, leading to outbreaks of secondary pests. Awareness about harmful effects of chemical pesticides has attracted many farmers towards organic farming. Use of more biodegradable pest control material with greater selectivity might help to reduce the adverse effects on the non-target organisms and other environmental risks (Wondafrash et al., 2012). The deleterious effects of crude plant extracts on insects are manifested in several ways including toxicity, feeding inhibition and growth inhibitors (Wheeler and Isman 2001). Various plants has been identified with insecticidal properties viz., Neem, Custard apple, garlic, Lanatana camara, datura, tobacco, Ipomoea carnea, chilli, Kanheri which are effective against Helicoverpa armigera, cotton leaf worm, Spodoptera littorallis, pink bollworm, Pectinophora gossypiella, Spodoptera littoralis, sap sucking insect pests (Upadhyay and Singh 2012; Paul and Chaudhary 2016; Rajput et al., 2017; Moustafa et al., 2018; Nassar et al., 2018; Pareek et al., 2018). Cow urine has the ability to inhibit the bollworm complex on cotton plants (Shalaby et al., 2018).  

Many organic farmers and Non-Governmental Organizations (NGOs) have developed number of innovative formulations which can be effectively used in control of various pests (Yadav, 2012). But, limitations such as lack of immediate effect of organic extract on insect pests, seasonal availability of plants used in organic extract, time consuming preparations of organic extracts, lack of knowledge about preparation of organic extracts and its use at individual level rather than in community or village level lower down the adaptation and use of organic extract by farmers. Hence, a study needs to be carried out to provide data on efficacy of organic extract against insect pests at field condition. Keeping in mind the above facts an investigation was undertaken to evaluate the efficacy of organic extracts against bollworm complex on cotton crop.

An experiment was conducted at Research farm, Department of Entomology, Dr. PDKV, Akola, during Kharif season in July-December, 2019. Experiment was laid in Randomized Block Design with seven organic extracts and one control treatment (water spray) which replicated thrice. Cotton variety AKH-9916 was sown on the plot size of 4.80 m × 4.20 m for each treatment with row to row spacing of 60 cm and plant to plant spacing of 60 cm. All the agronomic practices were followed as per the recommendations of Dr. PDKV, Akola in raising cotton crop. Five plants were selected randomly from each plot for recording observations. As soon as the level of bollworm infestation reached at 5 per cent green fruiting bodies damage, schedule of spraying was initiated. The pre-treatment observations were recorded 24 hours before spraying. The post-treatment observations were recorded on 3rd, 7th and 10th days after spraying. The subsequent spraying was given at 10 days interval.

Table 1: Details of treatment used against bollworms.

Total fruiting bodies (squares, flowers and bolls) and bollworms damaged fruiting bodies were counted from randomly selected five plants in each plot and per cent bollworm complex damage in green fruiting bodies was worked out. The damage caused by Earias sp. and H. armigera on squares, flowers and bolls were considered together for the estimation of total fruiting bodies damage due to bollworms by using following formula

% Bollworm damage in fruiting bodies = 

Incidence of pink bollworm was recorded at 110 and 125 days after crop emergence by plucking twenty matured green bolls from border rows from each plot. These bolls were dissected and observed for pink bollworm larvae and damage. At the time of dissecting bolls for larval count, the number of bolls damaged by pink bollworm was counted. Per cent green boll damage by pink bollworm was calculated by using following formula

% Green boll damage by pink bollworm = 

Yield of seed cotton in q/ha was calculated in order to compare the effect of different treatments. As per Gomez and Gomez (1984) the data obtained during the present course of investigation was converted to appropriate transformations and was subjected to statistical analysis to test the level of significance.

Pre-treatment count on fruiting bodies damage due to bollworms complex (Earias sp. and H. armigera) was recorded in range of 5.55 to 8.10 per cent. Cumulative data calculated after three sprays revealed that Dr. PDKV-Entomology formulation was more effective treatment with least bollworm complex damage in green fruiting bodies i.e. 4.09 per cent. However, this treatment was found at par with Brahmasthra extract (4.28%) and Panchpatre extract (4.69%). Broad-spectrum formulation (5.83%), Neem seed extract (5.86%), Garlic-Chilli extract (6.23%) and Cow urine (8.04%) appeared as next best treatments. The maximum percentage of bollworm damage was recorded in untreated control i.e. 10.13% damage (Table 2). 

Table 2:  Effect of organic extracts on bollworm complex damage in green fruiting bodies.

Mean data of two sprays of organic extract on pink bollworm damage in green bolls revealed that Neem seed extract and Dr. PDKV- Entomology formulation with least damage of 18.67 and 21.15 per cent respectively were most effective treatments. Maximum green boll damage by pink bollworm was recorded in the untreated control plot (47.17%). Overall damage was ranged between 18.67 to 47.17 per cent in the plots treated with different organic extracts (Table 3). 

At harvesting, minimum bollworm damage in open bolls was observed in plots treated with Dr. PDKV-Entomology formulation (25.17 per cent) which was found at par with Brahmasthra extract (28.33%) and Panchpatre extract (34.00%). Broad-spectrum formulation (40.67%), Neem seed extract (45.50%) and Garlic-Chilli extract (50.00%) found moderately effective in this respect. Cow urine was found comparatively less effective with 65.67 per cent open boll damage. Whereas, highest per cent open boll damage was recorded in untreated control i.e. 68.33 % (Table 4).

Table 3:  Effect of organic extracts on pink bollworm damage in green bolls.

Present findings are in confirmation with previous researchers such as Singh et al. (2014) who reported use of neem leaves extraction (5 lit of solution/ 200 lit of water) and asafoetida solution (100gm/ 150-200 lit of water) by farmers for the control soybean pests, Helicovepra spp, Melonoagromyza obtusa and Girdle beetle. Patel and Yadav (2017) revealed that the highest mortality of Spodoptera litura obtained in 5 per cent concentration of Parthenium hysterophorus leaf extract at 24 hrs (53.33%), 48 hrs (66.67%), 72 hrs (80%) and 96 hrs (80%) after application. They concluded that the P. hysterophorus leaf extract possesses antifeedant, larvicidal and growth inhibiting activity against Spodoptera spp. Rajput et al. (2017) observed maximum reduction in pink bollworm larval population (13.17%) in non-Bt cotton due to tobacco extract (@ 37.19 ml/ 2 lit of water), followed by neem extracts (8.76%) and datura extract (5.85%) (@ 37.19 ml/ 2 lit of water. Moustafa et al. (2018) reported 70.7 and 63.6 per cent reduction in bollworm larvae by cow’s urine-dung extract (1:1) and cow’s urine-dung extract: water (1:4) respectively. While in cow’s urine-dung extract with neem oil in 1:1:50 and 1:4:50 ratio reported reduction of 80 and 71 per cent larval population respectively. Cow`s urine-dung extract was found more effective on bollworm complex with ability to inhibit the bollworm complex on cotton from the beginning of flowering to the boll maturity. Yousef et al. (2018) evaluated 70 per cent hydroethanolic extracts of Nerium oleander (leaves, stems and flowers) against 1st instar larvae of pink bollworm and reported increased toxic effect of this extract with the increasing concentration. Joshi et al. (2020) showed feeding inhibition of bioformulations viz; Neemastra, Agniastra, Brahmastra, Dashparni ark and garlic + ginger + mint mixture at 1.5% to 24% concentrations against fourth, fifth and sixth instar larvae of Agrotis ipsilon. 

Table 4: Effect of organic extracts on open boll damage due to bollworm complex at harvesting.

According to data Dr. PDKV- Entomology formulation with highest seed cotton yield of 12.10 q/ha was most effective treatment. The next effective treatments were Brahmasthra extract and Panchpatre extract which recorded seed cotton yield of 9.50 and 8.30 q/ha, respectively. Whereas, plots treated with Broad-spectrum formulation and Neem seed extract recorded seed cotton yield of 7.80 and 7.10 q/ha, respectively and proved moderately effective. Garlic-Chilli extract and Cow urine treatment showed seed cotton yield of 6.20 and 5.50 q/ha, respectively and both treatments were found statistically at par with untreated control (5.20 q/ha) (Table 5). Data on incremental cost benefit ratio showed Brahmasthra extract more economically viable treatment with highest ICBR of 1:5.4. It was followed by Dr. PDKV-Entomology formulation (1:4.7) and Panchpatre extract (1:3.2). Cow urine was most uneconomical with ICBR of 1: -0.7 (Table 6).

Table 5: Effect of organic extracts on seed cotton yield.

Table 6: Incremental cost benefit ratio for organic extract.

Present study will be helpful in providing botanical pesticides as a safer option for bollworm complex control on cotton crop. These eco-friendly pesticides will eventually conserve natural enemies and will contribute as one of the important component of Integrated Pest Management in cotton crop. 

Pavan B. Somatkar, Sunil K. Bhalkare and Archana N. Borkar  (2024). Evaluation of Organic Extracts against Bollworm Complex of Cotton. Biological Forum – An International Journal, 16(4): 119-123.