CABI - Biocontrol News and Information 21(2) June 2000 News

Biocontrol News and Information

June 2001, Volume 22 No. 2

IPM Systems

This section covers integrated pest management (IPM) including biological control, and techniques that are compatible with the use of biological control or minimize negative impact on natural enemies.

IPM Steaming Ahead in Basmati Rice

The foothills of the Himalayas are blessed with fertile soil irrigated by the phosphorus-rich waters of the Ganges and the Indus, and it is here that the world-famous basmati rice is grown. The Government of India is currently embroiled in a fierce battle to protect the name from being patented by foreign interests. Meanwhile, the National Centre for IPM (NCIPM) is helping the farmers of Uttar Pradesh by developing an IPM module for this crop.

The word 'basmati' comes from a Sanskrit word meaning earth, and basmati rice is recognized by its distinctive aroma. The extra-long grained, soft textured, aromatic rice has been cultivated since time immemorial in the foothills of the Himalayas, and it is the rare agro-climatic conditions of this region that endow it with its unique characteristics, which are not amenable to replication. This makes basmati a premium product in the international market and, so the argument runs, the uniqueness needs to be preserved and protected. India's basmati rice exports are worth some Rs 12 billion [~US$ 250 million] annually.

Shikohpur village in Baghpat District was chosen as the location for a large (100 acre/40.5 ha) field validation trial in 1999, because a socioeconomic survey had revealed the village to be a site of excessive pesticide use in recent years. Some farmers had been making 10-12 applications per year in a vain attempt to combat insect pests (leaf folder, Cnaphalocrocis medinalis, yellow stem borer, Scirpophaga incertulas and gundh bug, Leptocorisa acuta) and diseases (sheath blight, Rhizoctonia solani and bacterial leaf blight, Xanthomonas oryzae pv. oryzae), yet their final yields fell substantially short of expectations. It was surmised that excessive chemical use had eliminated the beneficial natural fauna from the fields and this had contributed to an unusually high incidence of pests.

The IPM strategy comprised:

seed treatment with carbendazim for controlling seed-borne diseases
monitoring yellow stem borer by pheromone trapping
releasing Trichogramma japonicum against leaf folder and yellow stem borer
applying insecticide against these and other insect pests only as a last resort, if they reach pest status
monitoring sheath blight and other diseases and applying fungicides on a needs-only basis
balanced fertilizer and water management

In the event, only a few of these options were needed and weekly monitoring led to timely and directed intervention against what problems did arise. Two releases of T. japonicum made against leaf folder and stem borer, and a dusting of methyl parathion (10 kg/acre) to manage gundh bug on about 2 ha were the main insect pest treatments applied. Sheath blight became important in some fields and was managed by spraying these sites once with 0.1% carbendazim. Thus widespread pesticide application was avoided. In contrast, farmers applied insecticides (phorate), fungicide (carbendazim) and bactericide (streptocycline) three to four times in 12 ha of non-IPM control fields.

Monitoring of IPM and non-IPM plots indicated differences in pest populations and disease incidence. Infestations of leaf folder in IPM plots 50 days after transplanting (DAT) were just over half those in non-IPM plots (8.75% c.f. 15.0%), which indicates the efficacy of the parasitoid releases. A further release reduced incidence to less than 5% at 75 DAT, while it remained at 14.5% in the non-IPM plot. It was a similar story with sheath blight, the major disease in the area that season, which was at far lower levels in IPM plots throughout the season. Incidence topped 13% in the non-IPM plot by 55 DAT, but it was under half this in the IPM plot thanks to timely and targeted application of fungicide.

The mean yield from the 40-ha trial (5.7 t/ha) was 11.6% higher than the mean for the non-IPM plots. The economic gains were even more striking: the mean cost per hectare of plant protection for the IPM fields, at Rs 658, was only 28% of the cost in non-IPM fields. The cost benefit ratio for IPM was 1:7.51.

A website on basmati rice has been set up through collaboration between NCIPM and the National Informatics Centre.

Cottoning On

NCIPM has continued with participatory trials of its successful rainfed cotton IPM module [BNI 21(2), 32N-33N (June 2000) Indian cotton IPM is material success]. Now in their third year, these were conducted in Ashta village (Maharashtra). The IPM module was applied to 300 acres/120 ha of cotton and activities (supported by a Farmer Field School) included:

good field sanitation, soil fertilization and crop husbandry before sowing
trials to investigate best planting time
maize and cowpea border cover crops, and Setaria perches (to encourage birds that prey on Helicoverpa bollworm larvae) every tenth row
monitoring Helicoverpa with pheromone traps
Trichogramma chilonis release to coincide with bollworm egg laying
need-based 5% neem seed kernel extract (NSKE) spraying
need-based ecofriendly insecticide/fungicide application

Imidacloprid was not available for seed treatment to guard against sucking pests, and metasystox was applied 40 days after planting instead.

Although aphid numbers were initially higher in the IPM plot, and jassids up to mid-season, both their numbers declined below those in the non-IPM controls. The measures adopted to conserve beneficial species had a positive effect on coccinellids, with 7.5 times as many recorded in the IPM plots. Sprays of NSKE and Helicoverpa nucleopolyhedrovirus (HaNPV) were applied for Helicoverpa control. Monitoring of shed bolls and fruiting bodies indicated bollworm infestation levels of <2% throughout the season in IPM plots, up to four times lower than in non-IPM plots. Grey mildew appeared during the second lint picking, and carbendazim was applied.

In practical terms, this meant an average of two pesticide applications (0.19 kg/ha in total) in the IPM trial area in Ashtra, compared to eight (5.78 kg/ha) in the adjacent non-IPM village of Murli. The average seed cotton harvest in the Ashta IPM trial was 1350 kg/ha, more than twice that in Murli. The cost benefit ratios for the two villages were 1:2.08 and 1:1.34, respectively.

As NCIPM wind down the trials in Ashta, there are encouraging signs that the IPM message is being heard more widely and the technology is beginning to be adopted in many adjacent villages.

An IPM module for irrigated cotton is now being developed for Haryana in collaboration with Excel Industries Ltd.

Chickpea and Mustard

Chickpea IPM is in the second year of village trials. A Farmer Field School was used to mobilize field sanitation and land preparation of 50 acres/20 ha in October-November 1999. This laid the groundwork for timely planting of a wilt-resistant variety that had been seed-treated with Trichoderma. Coriander or linseed was planted as a cover crop. Pheromone traps and physical collection were used to monitor Helicoverpa pod borers. Birds that prey on pests were encouraged with bird perches and cooked rice spread on the field as an attractant. Sprays of HaNPV and other eco-friendly insecticides were made on a needs-only basis.

Seedling mortality (from Fusarium and Sclerotium infection) was a problem where sorghum had been the previous crop. But disease remained below 1% in IPM fields throughout the season; overall seedling mortality was below 5% and no intervention was made. Pod borer levels rose above economic threshold level twice and were controlled with one application each of HaNPV and NSKE. Monitoring showed that the population otherwise remained below the threshold. The situation in the non-IPM field was varied: pod borer was sometimes absent altogether, but then numbers rose and chemical sprays were applied, whereupon they fell again. Levels of Helicoverpa parasitism in IPM fields were higher than in non-IPM fields. These observations and the various treatments together translated into yields of 0.88 t/ha in the IPM field, compared to 0.50 in the non-IPM field.

A second year of on-station trials of mustard IPM were conducted at Bawal (Hisar), where the principal pest and disease constraints are mustard aphid and white rust, respectively. The effects of seed and soil treatment with Trichoderma viride, varying planting density and use of farmyard manure were assessed. Pest insects (aphid and sawfly) were not observed in IPM plots. Combined soil and seed treatment with Trichoderma gave most consistent protection from rust in three mustard varieties, but all treatments improved yield considerably (on average they were 23% higher than for an untreated control).

Forewarned is Forearmed

The Centre, together with a number of collaborators, has been making considerable progress in developing forecasting systems for India's most devastating pests. For example, field data on Helicoverpa catches and meteorological information were used to develop a model of weekly pest populations. Testing at the University of Agricultural Sciences Campus, Raichur (Karnataka) showed that the fit of the model with actual catches from 1987 to 1994 was strikingly accurate. Similarly rewarding results were obtained with a forecasting systems for potato aphids (Myzus persicae), which accurately reflected observed populations at sites in West Bengal and Gujarat. Modelling work on groundnut pests (aphids, jassids and thrips) is underway.

Distribution maps are being prepared for pests and diseases of major crops, to pinpoint problem 'hot spots' in the country so appropriate action can be targeted more effectively. So far, 66 maps have been prepared for 11 cotton pests (six insects and five diseases) for 1992-97. From these, 'hot spot' maps have been produced which show geographical areas that have been moderately to severely affected by pests and diseases during recent years.

More about these projects and other activities of NCIPM (including assessing threats from exotic pests and diseases; monitoring and surveillance of nematodes in the rice-wheat cropping system; biocontrol agent rearing; computer software including electronic keys for plant parasitic nematodes and the Pest Management Information System for cotton; and other technology transfer activities) are described in the report cited below.

Source: NCIPM (2000) Annual report 1999-2000. National Centre for Integrated Pest Management,
Indian Council for Agricultural Research,
Lal Bahadur Shastri Building,
Pusa Campus, New Delhi - 110 012,
India, 88 pp.

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SP-IPM: Through the Eye of the Storm

Since the Systemwide Program on Integrated Pest Management (SP-IPM) was launched in 1995 it has weathered fair and foul conditions. It has emerged from the storms a little battered but seaworthy. In particular, its flagship whitefly project has come through with flying colours and has made substantial advances in line with the aims and ideals of the programme. Other initiatives, while functionally becalmed through lack of funds, have been making quiet but significant progress that has put them in a strong position to move forward when the financial climate eases. Undeterred by previous setbacks, in 2000, the SP-IPM launched the Pilot Sites Initiative, aimed at creating a matrix of IPM trial sites each managed by a consortium of stakeholders. Beginning with sites spread through Africa, national and international research organizations, extension services and NGOs are teaming up to help farmers develop and test 'best bet' IPM options that offer most promise of providing solutions to crop health problems.

SP-IPM was set up by the CGIAR (Consultative Group for International Agricultural Research) in response to its own recognition that it was falling short in its goal to provide solutions for tropical agricultural problems: farmer uptake of the IPM technologies developed by the international agricultural research centres (IARCs) was all-too-often poor. The CGIAR recognized that it had placed perhaps too much reliance on host plant resistance as the only worthwhile strategy for crop protection, and to have acquiesced at, or actively encouraged, the use of chemical pesticides as a stop-gap where resistance was hard to achieve. It recognized missed opportunities for joining forces across disciplines and developing truly integrated crop management strategies. It recognized that poor communication between IARCs meant that interactions were not always as fruitful as they could be. The CGIAR saw that fundamentally different approaches and new methods of working were needed if its goals were to be fulfilled - and hence SP-IPM was born.

SP-IPM signalled a sea change in the way in which IARCs pursue the CGIAR Mission: "through research and related activities...contribute to sustainable improvements in the productivity of agriculture, forestry and fisheries in developing countries in ways that enhance nutrition and well-being, especially of low-income people". In this regard, IARCs affirm that IPM is their preferred plant and animal health strategy and that, through research and training/learning methods, they will promote IPM adoption by farmers. Their shared objectives are to:

develop mechanisms and linkages to strengthen partnerships for IPM development
establish more holistic IPM approaches to increase the ability of farmers to make informed IPM decisions based on an understanding of ecological and economic principles of production
promote more effective communication between farmers, extensionists and researchers to ensure that research efforts are clearly focused on farmers' needs, and encourage the integration of traditional and `science-based' knowledge
become effective public advocates of IPM

The work of SP-IPM is guided by the Inter-Center Working Group on IPM, which meets annually and reviews progress and emerging challenges in the achievement of the objectives. The latest of these meetings was held in Nairobi, Kenya in March 2001. The agreed programme is impleme