Protection of hill crops
Zonate leaf spot of maize caused by Gleocercspora sorghi was recorded for the first time in Uttarakhand in 2008.
Blast and brown leaf spot in rice, Turcicum leaf blight and Banded leaf and sheath blight in maize, blast in finger millet, yellow and brown rusts in wheat are the important diseases in cereals.
Frogeye leaf spot of soybean, tikka disease of groundnut, Alternaria leaf spot of toria are the major diseases of oilseeds.
Among pulse crops, wilt and root rot in lentil, wilt in pigeon pea, root rot in rajmash and anthracnose in horse gram appear in moderate intensities.
Purple blotch in onion and garlic, early blight, bacterial wilt, buckeye rot in tomato, powdery mildew and wilt in pea, root rot and black rot in cauliflower, angular leaf spot and rust in French bean, bacterial wilt, powdery mildew and anthracnose in capsicum are important diseases of vegetables.
- White grub, a polyphagous pest, which devastates a number of rainfed kharif crops, is the most menacing insect of the region and nearly 75 species of this insect have been recorded in Uttarakhand.
- In addition, stem borer and leaf folder in rice and small millets, hairy caterpillar and sucking bug in soybean, leaf miner in garden pea, pod borer in pea and gram, fruit borer in tomato, blister beetle in beans and pigeon pea, aphids in crucifers are other major pests.
Crop Loss Assessment
Losses caused by major diseases and insects to important crops vary from slight to severe depending on the crop/variety and prevailing climatic conditions. Major pests, like blast and stem borer caused up to 65% and 52% losses, respectively in rice, stripe disease up to 72% in barley, white rot up to 58% in pea, buck eye rot up to 80% in tomato, anthracnose and frog eye leaf spot (combined) up to 30% in soybean and white grub up to 80% in rainfed rice.
Studies revealed that the temperature of 20-280C combined with RH > 80% is best suited for the development of Exserohilum turcicum in maize (Turcicum leaf blight) whereas minimum temperature of 15-200C along with higher number of days with RH >90% are contributory factors for the development of blast disease in rice. July to September provide the most congenial environment for the development of these diseases.
The resistant genotypes were identified in various station, national and international nurseries in different crops. Artificial epiphytotics for blast in rice, turcicum blight in maize, rusts, loose smut and hill bunt in wheat are created to screen genotypes and advanced breeding lines thoroughly. Over the years, these evaluations have helped in identification of suitable high yielding genotypes with resistance/tolerance to major diseases and resulted in release of the varieties.
Genetic Stocks Registered
VL 798 (Reg. No. INGR 03007, IC 296431) Wheat - an immune stock to hill bunt disease, VL 639 (Reg. No. INGR 03011, IC 296480) Wheat - a resistant stock to loose smut have been registered with NBPGR. VSR 8 (Reg. No. INGR06002, IC546941) Rice - a source of blast resistance have been registered with NBPGR, New Delhi.
Eco-friendly management of diseases
- Indigenous Trichoderma harzianum isolates either singly or in combinations, delivered as seed treatment, soil drenching and with fortified FYM, resulted in significant reduction in root rots of French bean and lentil, damping-off of cauliflower and white rot in pea.
- Three isolates of Trichoderma harzianum have been identified as effective sclerotial parasites. These isolates significantly reduced seedling rot and white rot of pea.
- Soil solarization along with incorporation of organic manures (FYM or poultry manure) prior to mulching, and seed treatment with Trichoderma isolates reduced damping-off in tomato.
- Bio-fumigation with brassicaceous plants such as broccoli and toria were found effective in reducing root rot of cauliflower.
- Soil and foliage application of composts and compost extracts prepared from poultry manure and Urtica sp. provided high suppression of Rhizoctonia root rot and angular leaf spot diseases of French bean.
- Organic amendments with Ageratum, Parthenium and Urtica parviflora were found effective and resulted in significant reduction in the root rot incidence of cauliflower.
- Effective management of diseases using plant part extracts such as Oxalis latifolia and Cannabis sativa extracts for hill bunt of wheat and walnut extract for stripe disease of barley was observed.
Management of Insects
- Melia azedarach (Batain) seed kernel extract 10% was found to be effective against sucking bugs of French bean and soybean. Batain powder is used for the management of cutworms in chilies. Chemical insecticide, flubendiamide is found effective against pink borer, Sesamia inferens in rice. Deltamethrin is effective against blister beetles in pigeon pea and indoxacarb against Spodoptera litura in chili and tomato.
- Diaretiella rapae is found to parasitize cabbage aphids, Brevicoryne brassicae to an extent of 8.4 to 12.6% in the field. Campoletis chlorideae is the major parasitoid of borer, Helicoverpa armigera in field conditions.
- VL White grub Beetle Trap-1, an efficient and eco-friendly light based insect trap is found very effective in attracting and trapping Scarabaeid beetles. Beetles were trapped from second fortnight of May to September with a peak period of July. Anomala dimidiata is the predominant species followed by Holotrichia longipennis and H. seticollis.
- A bacterium, Bacillus cereus strain WGPSB2 and Brevibacterium frigoritolerans HSB 15 are found effective against white grubs and thus mass multiplied, formulated in talc and used in white grub management. It is recommended to mix the talc based bacterial formulation in farmyard manure and subsequently in the fields.
- Female pheromone of whitegrub, Holotrichia seticollis is isolated, identified and being used for the effective management of the pest.
VL whitegrub beetle trap Microscopic view of Bacillus cereus
- Apiary with Apis cerana and A. mellifera hives are established and used for planned honey bee pollination especially in cross pollinated crops.
- About 20 species of non-Apis bee pollinators are identified and documented from the region.
- Conservation of pollinators by managing their habitat is being practiced