Biological Control. okf"kzd izfrosnu

Transcription

1 Biological Control Habitat management for conservation of natural enemies Promoting generalist predators in agriculture via habitat manipulation has gained much interest in biocontrol research during the recent past. This strategy helps in managing the insect pests and diseases by enhancing natural enemies without adversely affecting the main crops and also reduces the pesticide load. The present work on habitat management was aimed to assess the status of natural enemy populations already available in paddy and vegetable crops, to device habitat management strategies through intercropping/artificial contrivances for conservation of natural enemies and to study the impact of conservation/augmentation strategies on the pest and natural enemy populations. Rice Field trials were conducted during at Straw bundle (left) in paddy fields to enhance spider population; (right) the spider egg mass in bundle Atterna village (Sonipat Haryana) on habitat management through artificial structures and border cropping with other suitable crops. The experiments were conducted with Pusa Sugandh 4 (Pusa 1121) as the main crop with 5 treatments i.e. straw bundles+maize (T1), straw bundles + sunhemp (T2), straw bundles+sesbania (T3), only straw bundles (T4) and control (T5) without any additional structure or border crop. Each plot was of 0.5 acre in size. The straw bundles were prepared with wheat straw placed in plastic nets. Each bundle was about 3 feet in length and 10 inches in diameter. Both the ends of these bundles were tied with plastic rope. These bundles were placed in sorghum fields for charging with spiders and other natural enemies. After 15 days of charging, these bundles were fixed vertically with bamboo 20 bundles/ha in paddy field having 20 days transplanted seedlings in such a way that the lower portion of the bundle remained 6 inches above the water level. Pheromone 5 traps/ ha were also installed in all the experimental fields to monitor stem borer popoulation. One release of Trichogramma 000 adults/ha was carried out in 1 st week of September to mange stem borer. Control plot involved two insecticide sprays, one in August and the other in September. The observations on the infestation and population of natural enemies especially spiders were recorded from twenty hills selected randomly in each plot at 10 days interval. In all the treatments (T1 to T4) having straw bundles or straw bundles along with border crops, the population of leaf folder and yellow stem borer 39

2 Annual Report Table 31. Infestation of insect pests and population of natural enemies (other than spiders) in different treatments Parameters Insect pests (%) Natural enemies Stem borer Leaf folder Earwig/hill Dragonfly/m 2 Paddy+ Straw bundles+ Maize (T 1) Paddy+ Straw bundles+ Sun hemp (T 2) Paddy+ Straw bundles+ Sesbania (T 3) Paddy+ Straw bundles (T 4) Paddy (T 5) remained lower than the control (T5) (Table 31). The observation made on charging of the straw bundle for 15 days in sorghum fields indicated that each bundle contained spider adults, 8 10 spider egg masses, spiderlings and earwigs. The results on the population dynamics of spiders (Fig. 15) indicated that the adult spiders on paddy plants remained highest in the treatment having only straw bundle (T4) followed by straw bundles+sun hemp (T2), straw bundles+sesbania (T3) and straw bundles+maize (T1). Control (T5) indicated lowest population of spiders throughout the season. In September maximum spiders on the plant remained confined to lower part of the plant (upto 10 inches above the ground) as compared to middle (10 20 inches above the ground) and upper part (20 Fig. 16. Distribution of spiders on paddy plant in different treatments in September Fig. 17. Distribution of spiders on ground in different treatments Fig. 15. Population of spiders (per hill) on plant in different treatments 40 inches above the ground) (Fig. 16). On the ground, the population of spiders remained highest in the treatment having only straw bundle followed by straw bundles +Sesbania, straw bundles + maize, straw NCIPM

3 Fig. 18. Yield (q/ha) of paddy in different treatments bundles +sun hemp and lowest in control (Fig. 17). On the ground, most of the spiders belonged to two families i.e. Lycosidae (Wolf spiders) and Salticidae (Jumping spiders). The results of present study indicated that straw bundles along with border crops had played an important role in conservation of spiders in rice which has helped to contain the insect pests and reduce the pesticide load. Harvest of the crop indicated highest paddy yield in T 2 followed by T3, T4, T1 and lowest in T5 (Fig. 18). Brinjal Intercropping of brinjal and coriander Intercropping of brinjal and cowpea Field trial was conducted in farmers participatory mode on conservation of natural enemies in brinjal at Atterna with Golden Hybrid (Hybrid 321). Transplanting of 40 days old nursery was carried out on The experiment included four treatments i.e. Brinjal + Coriander (T 1), Brinjal + Coriander + Cowpea (T 2), Brinjal + Cowpea (T 3) (Fig. 7) and only brinjal (Control, T 4). Each plot was of 0.5 acre in size. The coriander was sown 1-day before brinjal as intercrop and cowpea was sown in 3 rows in the entire field after 30 days of transplanting of brinjal. All the treatments with habitat management tactics (T1 to T3) included the installation of pheromone traps for monitoring the population of shoot/fruit borer (Leucinodes orbonalis), 6 8 sprays of chemical insecticides for managing the borer, one spray of neem seed powder extract (5%) and one release of T. 000/ ha. The control (T4) included the installation of pheromone traps and 12 applications of chemical insecticides. Observations were recorded at 10 days interval on the infestation and population of natural enemies at regular interval on 20 plants/plot. Weekly observations were also recorded on shoot/fruit borer 41

4 Annual Report moth catches in pheromone traps at weekly interval. The infestation of shoot and fruit borer ranged from 5 15% in treatment T1 to T3 as compared to 40 50% in T 4 (farmers field) in September. In October and November months, the infestation of the borer increased to 70 80% in all the treatments (T1 to T4). The infestation again declined to low level in December. In the treatment T1 to T3, the adult spiders on plants ranged from adults/plant as compared to negligible population in T4 in September. The spiders on the ground ranged from 0.2 to 2.0/m 2 which were mainly from Lycosidae (Wolf spiders) and Salticidae (Jumping spiders) families. The spiders on the plant were dominated by crab spiders. Spider population in October was reduced to traces in all the treatments due to hoeing and weeding operation and frequent pesticide sprays. Population of coccinellids and other natural enemies remained highest in T 2 followed by T1 and T3. The control (T4) recorded very low population of natural enemies. The common natural enemies recorded were Chrysoperla carnea, Coccinella septumpunctata, Chilomenes sexmaculatus, syrphid fly and praying mentis. In general, decline in the population of natural enemies was recorded in all the treatments in November and was almost negligible in December and January. Pragmatic approach for the promotion of biological control of insect pests in IPM Production and maintenance of host insects and natural enemies Production and maintenance of host insect (Corcyra cephalonica) and natural enemies parasitoids (Trichogramma chilonis, T. japonicum, Trichogrammatoidea bactrae and Chelonus blackburni) and predator (Chrysoperla carnea) were done and also made available to various research Table 32. Production of biological control agents for release in various IPM trials during Crop Biocontrol agent No.of cards* produced Field releases Paddy T. japonicum 70 Brinjal T. chilonis 98 Cauliflower and Trichogrammatoidea cabbage bactrae 87 Each card contains about wasps institutes and entrepreneurs. These cultures were maintained for developing mass production technology of the biological control agents (Table 32). Natural enemies on brinjal plant in brinjal+cowpea+ coriander treatment (A-Crab spider; B-Coccinella septumpunctata; C- eggs of Chrysoperla carnea) 42 Exhibition & extension of technologies Practical trainings on mass production of natural enemies and host insects was imparted to the participants of the training on IPM in Basmasti rice. Visitors were given guidance and insight in to the role of biological control in IPM. Exhibition of live specimen of beneficial organisms and pictorial display of pests and their natural enemies were arranged and NCIPM

5 explained to the visitors in the Exhibition held at National Science Centre, New Delhi in GFAR Conference which was held from November 8 11, Development of innovative methods and techniques for the mass multiplication of natural enemies of insect pests directly under field conditions One of the major constraints in the mass production of natural enemies is the non-availability of low cost and efficient mechanical devices particularly under field conditions. In the absence of such devices and techniques, lot of manual labour is required for the mass production and maintenance of natural enemies. Manual handling of the cultures of natural enemies of insect pests is health hazardous process. Further, the availability of these biocontrol agents is a serious constraint in promotion of IPM. Therefore, this new project was initiated to design, develop and standardize the low cost methods and techniques for the mass multiplication of natural enemies of insect pests directly under field conditions. The field kit for the multiplication of insect larval parasitoid i.e., Bracon spp., was designed, and patented. This field kit provides a readily available food source and an alternative oviposition site to the parasitoid, allowing parasitoid numbers to increase in abundance in the crop fields or store godowns. To validate the field kits, a village named Bhora Khurd (Distt. Gurgaon, Haryana), a sesame growing area was selected. Sesame plants were found infested with the larvae of leaf webber/capsule borer (Antigastra catalaunalis), which is a major constraint in raising the productivity of sesame crop in this area. Therefore, cages containing food for mass multiplication of Corcyra larvae were installed in sesame field to reinforce the parasitization of A. catalaunalis by Bracon hebetor under natural condition to keep a check on pest population. To validate the field kits for the multiplication of insect natural enemies during rabi season another village named Kosi Kalan, Distt. Mathura, U.P. was selected. The field cage made of nylon cloth having wire mesh in the top portion was installed in the field. The mustard twigs infested with mustard aphids were plucked by hand from the fields and put in the cage and the aphid colonies were allowed to multiply so that the parasitoid Diaretiella rapae of Lipaphis erysimi may also multiply on the aphids and escape from the wire mesh installed on the top portion of the cage and spread in the mustard fields. The field kits for the multiplication of insect natural enemies will be refined further and will be validated in the next seasons. Commercialization of bioagent mass production technologies in intensive cotton districts (Technology Mission on Cotton MM 3.3 project) A biocontrol laboratory was established at Shri Ram Solvent Extraction Pvt. Ltd., Jaspur (Uttranchal) in 2005 for mass production of Trichoderma spp. MoU was signed as per the ICAR guidelines, supported with a follow up in 2006 and initiated production of Pseudomonas sp. was initiated. The establishment could produce >25 tons of Trichoderma in 2006 however, they had a problem of storing the end product. A system was developed by which the antagonist could be stored in active ingredient form for at least three months. In the final commercial product of Trichoderma, the CFU count was maintained at / g product, which is 50 times higher than the Indian standards. Utilization of Trichoderma was initiated in cotton, protected cultivation of gerbera, tea gardens, mango orchards, sugarcane crop etc. Protocol for production of Trichoderma using sorghum grain was further standardized with CFU count at /gm. 43

6 Annual Report A total of 240 tricho-cards were produced and distributed among cotton growing farmers of Sirsa (Haryana) and Sriganganagar (Rajasthan) during Guidance was provided to the following Entrepreneurs/Govt. Organizations/NGOs for production of biological control agents since the inception of the project which concluded in March 2007: 1. Deptt. of Botany, Patna Univ. (M.Sc. Student) 2. Tarai Biotech Pvt. Ltd, US Nagar, Uttarakhand 3. Deptt. of Plant Protection, Allahabad Agri. Institute 4. Biocontrol Laboratory, SVBPUAT, Meerut 5. Maharashtra Manufacturers Association for Biocontrol agents, Nashik 6. Sri Ram Solvent Extractions Pvt. Ltd., US Nagar, Uttrakhand 7. Dhariwal Biotech Ltd., Sahibabad, Ghaziabad, Uttar Pradesh 8. JR Biocontrol Laboratories, Arni, Distt Yavatmal 9. CIPMC, Lucknow 10. Vidarbha-Marathwada Biocontrol Association, Nagpur Utilization and promotion of microbials in the management of key insect pests and diseases of crops Screening of volatiles and antagonistic/parasitic ability of 30 isolates belonging to 6 species of Trichoderma against three pathoges (Sclerotium rolfsii wide spectrum, Fusarium oxysporum f sp. vasinfectum cotton and F. ciceri chickpea) was completed. Volatiles from isolates 1, 14, 18, 19, 20 and 26 were effective against the growth of S. rolfsii, Specificity in Pseudomonas flurescens against S. rolfsii RAPD profiles of 25 Trichoderma isolates/spp using primers OPA 13 & OPA NCIPM

7 whereas in the dual culture technique isolates 1, 10, 13, 17, 18, 20, 21, 22, 23, 24, 25, 26 and 30 were effective with some isolates parasitizing the sclerotia produced. Against F. oxysporum f. sp. vasinfectum culture numbers 7, 10, 13, 26, 28 and 29 were effective in dual culture technique. Isolates 1, 10, 13, 18, 20, 21, 22, 23, 25 and 26 were effective against F. ciceri. An interesting phenomenon was observed as F. ciceri was found to develop a strong inhibition zone against several Trichoderma isolates (isolates 2, 3, 4, 5, 6, 7, 8, 9, 11, 12, 15, 16, 19, 28 and 29), thus indicating a need for validation of the commercial products in the lab before their field use. Trichoderma cultures effective against all the three pathogens were: 10, 13 and 26; those effective against two pathogens, namely, S. rolfsii and F. ciceri were 18, 20, 21, 22, 23 and 25. Specificity of three Pseudomonas fluorescens isolates against S. rolfsii and Phytophthora nicotianae was found out. It was noted that Jaspur isolate of NCIPM P. fluorescens was strongly inhibitory to S. rolfsii, whereas the GBPUA&T isolate was not. The Jaspur isolate of P. fluorescens was however, ineffective against P. nicotianae compared to the Delhi isolate. This study provided important conclusion that we can not use the antagonist as blanket recommendation against different pathogens since we can not expect their positive performance. Molecular characterization of 5 Trichoderma isolates showing variable antagonistic abilities against the three pathogens was done using RAPDs and marked differences were observed. Further characterization considering antagonistic abilities of some of the isolates across the three plant pathogens as indicated above, has been taken up. 45