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G.V. SUNEEL KUMAR* AND O. SARADA
Agricultural Research Station, Darsi, Prakasam District – 523 247, A.P., India
Experiments were conducted at Krishi Vigyan Kendra farm, Undi and its adopted villages viz. Matsyapuri, Adavikolanu, Mogallu, Kakaraparru and Guttulavaripalem, West Godavari district, Andhra Pradesh in the farmer‘s field during kharif and rabi seasons of 2008-09, 2009-10 and 2010-11 to assess the performance of Bio Intensive Pest Management (BIPM) module against major insect pests of rice (var. Swarna) in comparison to the farmers practice of recommended insecticidal control schedule (non-BIPM module). Analysis of three year results showed that BIPM treated plots recorded significantly lesser dead hearts (1.4 to 6.4 %), white ears (2.1 to 8.0 %) and leaf folder damage (2.6 to 8.2%) compared to the plots grown using farmers’ practices. Similarly significantly lower incidence of brown plant hopper (4.6 to 9.6 / 10 hills), white backed plant hopper (2.8 to 11.7 / 10 hills) and green leaf hopper (2.8 to 9.3 / 10 hills) was noticed in BIPM plots as compared to non-BIPM plots (10.2 to 21.1 BPH / 10 hills, 5.4 to 17.1 WBPH / 10 hills and 6.7 to 15.6 GLH / 10 hills). BIPM plots also recorded significantly higher numbers of predatory population of spiders, coccinellid beetles and mirid bugs. Grain yield in biocontrol field (5996 Kg ha-1) was significantly better as compared to 5626 Kg ha-1 in farmer‘s practice. The average net returns in biocontrol package were` 30312 ha-1 as compared to ` 22951 ha-1 in farmers’ practice with cost benefit ratio of 1: 2.04 and 1: 1.71, respectively. Therefore, the BIPM technology used was not only directly environment friendly but also more sustainable with a vide increase in biodiversity.
Bio intensive pest management, rice, major insect pests, predators
India has the largest area under rice in the world and ranks second among the rice producers, accounting for above 20 per cent of global rice exports. However, insect pests are responsible for considerable yield losses and about 128 species of insects have been reported to ravage the rice crop. Out of this, only 15 to 20 insects are regarded as economically obnoxious species (Kalode, 2005), the stem borer being the major one, which cause losses up to 90% if not managed timely. Rice is cultivated with selected high-yielding varieties in temporal and spatial continuum, with high inputs of chemical fertilizers and insecticides most often used indiscriminately resulting in several problems including that of residues. With a view to reduce the load of pesticides in environment and to improve socio economic status of farmers, Integrated Pest Management (IPM) practices have been formulated and have been successfully validated in rice in selected districts of the states such as Andhra Pradesh, Tamil Nadu, Kerala, Haryana, Madhya Pradesh and Utter Pradesh. Results have demonstrated that there had been a reduction of pesticide sprays (Razak, 1986). With further refinement
and utilization of Bio Intensive Pest Management (BIPM) techniques, viz. pheromone traps and bio-agents which are environment friendly, reduce pest pressure and can earn profitable incomes for the farmers certainly seems to be an effective alternative for managing the rice insect pests.
Biointensive IPM incorporates ecological and economic factors into agricultural system design and decision making and addresses public concerns about environmental quality and food safety. Its benefits include reduced chemical input costs, reduced on-farm and off-farm environmental impacts and more effective and sustainable pest management (Dufour, 2001). Pheromone and bioagents are species-specific, have no adverse effect on the non-targets and hence would be fully compatible with other management approaches to control rice insect pests (Katti et al., 2001; Garg et al., 2002; Kaur et al., 2003; Ignacimuthu, 2005; Mahal et al., 2006). Hence, the present study was undertaken to evaluate BIPM practices in rice in comparison to the recommended insecticidal control schedule against major insect pests of rice.
In order to validate rice BIPM module to suppress major insect pests at regional level, on farm testing of BIPM practices in rice was carried out with widely cultivated paddy variety Swarna (MTU 7029) during three consecutive kharif and rabi cropping seasons of 2008-09, 2009-10 and 2010-11 at Krishi Vigyan Kendra farm, Undi and its adopted villages viz. Matsyapuri, Adavikolanu, Mogallu, Kakaraparru and Guttulavaripalem of West Godavari district, Andhra Pradesh in the farmer‘s field covering an area of 6 ha each year. On farm trials (OFTs) were taken up each in one hectare block divided equally into two identical plots, one half receiving the BIPM technology and other half with farmers practice of recommended insecticidal control schedule. Paddy in each plot was grown separately under the supervision of single management schedule. Seedlings were raised in the nursery for both the plots at the rate of 25 kg seed for 5 cents seed bed during 29 and 49 standard meteorological weeks (SMW) respectively for kharif and rabi seasons. Main field experiment was conducted with 25-30 day old transplanted seedlings. Transplantation with 2 seedlings / hill was done during 33 and 52 SMW respectively for kharif and rabi seasons in pre-puddled field.
Efficacy of rice-BIPM module advocated by the All India Coordinated Research Project on Biological Control, A.R.I. Campus, Rajendranagar, Hyderabad to suppress major insect pests was taken as working-standard after befitting modifications and it was compared with the module of farmer’s conventional practices. So, there were two treatment schedules (i) BIPM schedule and (ii) non-BIPM schedule i.e conventionally cultivated farmers’ practice (FP) of recommended insecticidal control schedule. Treatment particulars for both the management practices are delineated below:
Observations on pest incidence and population of natural enemies were recorded from both BIPM and non BIPM plots. Dead Heart (DH) and White Ears (WE) caused by stem borer during vegetative and panicle emergence stage; leaf scraping caused by leaf folder was assessed from 50 hills diagonally selected from each plot and is converted as percentage damage (Table 1). Further 10 hills were selected randomly from each plot and from that the numerical abundance of brown plant hopper, white backed plant hopper and green leaf hopper population was noted and the average was worked out. Population of spiders, coccinellid beetles and mirid bugs were recorded from 1 m2 area and the average was worked out.
Finally economics of both the treatment schedules under consideration was worked out depending on the final grain yield, existing market price of the produce and detail cost of field management (Table 2). The values of cost benefit ratio thus obtained are tabulated. Data on pest incidence, natural enemies and grain yield in BIPM and non-BIPM plots were analyzed statistically following student ‘t‘ test and relative superiority of the module was determined.
Considering of DH (%) non-significant difference between the BIPM and non-BIPM plots was noted during kharif, 2008 and kharif, 2009 (Table 1). But for the subsequent years the differences were significant for both DH (%) and WH (%). The extent of damage was 1.4 to 6.4 % for DH and 2.1 to 8.0 % for WH in BIPM plots. While the corresponding values were 2.8 to 13.7% for DH and 3.1 to 22.3% for WH in non-BIPM plots. Data on rice leaf folder damage (%) exemplified that the BIPM plots during the experimental years exhibited significantly low (2.6 to 8.2%) damage over the non-BIPM plots (4.3 to 13.6%). Similarly, significantly lower incidence of brown plant hopper (4.6 to 9.6 / 10 hills), white backed plant hopper (2.8 to 11.7 / 10 hills) and green leaf hopper (2.8 to 9.3 / 10 hills) was noticed in BIPM plots as compared to non-BIPM plots (10.2 to 21.1 BPH / 10 hills, 5.4 to 17.1 WBPH / 10 hills and 6.7 to 15.6 GLH / 10 hills). Present findings on lower pest population in BIPM plots are in conformity with those of Anitha and Parimala (2014).
Numerical abundance of spider and coccinellid beetle population in BIPM plots was 1.8 to 8.2 and 1.7 to 3.9 individuals sq.m-1, respectively. The corresponding value in non-BIPM field was 0.6 to 1.6 for spider and 0.6 to 1.3 for beetle population. BIPM module influenced the abundance of both spider and beetle number significantly in all the experiment years in comparison to non-BIPM plots. The important predatory spiders recorded were Oxyopes javanus, Clubiona, Tetragnattha sp. and Lycosa pseudoannulata. In case of coccinellids beetles, Micraspis sp. was more predominant up to panicle initiation stage of the crop. BIPM plots also recorded significantly higher numbers of mirid bugs (15.2 to 39.2 / 10 hills) over non-BIPM plots (3.5 to 14.7 / 10 hills). Thus the location specific BIPM package resulted in increased biodiversity as this is safer to natural enemies of rice pests thus
enhancing chances of natural control. Lower population of predators in non-BIPM module was due to the toxic effect of the insecticides. The present work highlights the importance of following eco-friendly pest management practices to safeguard the diversity of natural enemies in the rice crop ecosystem.
Significant impact of BIPM module over non-BIPM module was also reflected on grain yield (Table 2). The BIPM plots recorded higher grain yield (4750 to 6469 kg ha-1) as compared to non-BIPM plots (4375 to 6084 kg ha-1) during all cropping seasons. The mean value of grain production was 5996 kg ha-1 for BIPM and 5626 kg ha-1 non-BIPM field. BIPM plots showed an overall increase of 6.6 per cent grain yield over non-BIPM plots. Suneel Kumar et al. (2007) and Anitha and Parimala (2014) also reported that maximum grain yield was obtained from plots cultivated with BIPM practices compared to other package of IPM or farmers practice. BIPM plots were economically superior to non-BIPM plots. Average net returns under BIPM plots (` 30312 ha-1) was relatively higher than non-BIPM plots (` 22951 ha-1). Further the mean input expenditure in BIPM plots (` 28969 ha-1) was comparatively lower than non-BIPM plots (` 32511 ha-1). Ultimately the Cost Benefit Ratio (CBR) in BIPM plot (1:2.04) was superior than the non-BIPM plots (1:1.71). Ramandeep Kaur et al. (2007) also reported that adoption of BIPM technology in Basmati rice gave higher CBR.
It can be concluded that BIPM package proved effective over farmers practice on large scale for the management of important key pests of rice. Thus cultivation of rice by BIPM module is found to be economically prudent to suppress key insect pest incidence and accordingly to boost up the production besides maintaining ecological balance.