Dr. S. S. Punia
Principal Scientist (Weed Control)
CCS Haryana Agricultural University, Hisar
Orobanche ?
• Commonly known as broom rape, margoja, rukhri, sarson kamaama and khumbi.
• Dicotyledonous annual plant that reproduce only by seeds
• Strongly competing with other parts of the host plant forwater, mineral and assimilate absorption and unloading.
• Chlorophyll lacking root holo parasite totally dependent onhost roots.
• Seeds are usually dark brown, oval shaped, measure 0.35 x0.25 x 0.1 mm and weigh 3-6 µg
• In case of severe infestations, Orobanche can cause totalcollapse and death of crop plants
The Orobanche genus includes six species that are ofagricultural importance and cause devastating yield and qualitylosses to many agricultural crops around the globe
• O. aegyptiaca L . Haryana (Mustard, Tomato and Brinjal)
• O. cernua
• O. ramosa L.
• O. crenata Forsk.
• O. cumana
• O. minor
Haryana
Orobanche infestation in mustard in Rajasthan
5
Orobanche Infestation
Chiplima
Sporadic Infestation
Districts CropsCrop area
(acres)
Orobanche
infested area
(acres)
Erode Tobacco 4800 2125
Dindigul Tobacco 2650 1020
Coimbatore Tomato 42,500 1220
Chinnusamy, 2013
Orobanche infestation Tobacco and Tomato in Tamil Nadu
Orobanche spp. infestation in different districts of Gujarat state
Valsad
NavsariDang
Surat
Bharuch
Narmada
Vadodara
Anand
KhedaPanch-
Mahal Dahod
Sabarkantha
Am
davad
Patan
Mahesana
Banaskantha
Kutchh
Surendranagar
JamnagarRajkot
Porbandar
Junagadh
Amreli
Bhavnagar
LegendNegligibleMildMediumHeavy
Gandhinagar
Crops: Tobacco, Mustard, Tomato,
Brinjal, Potato and Chilli,
BIOLOGY: Orobanche
• Orobanche seeds germinate in the soil due to release of viz.Orobanchol and alectrol exuded by host roots 7-10 days.
• Only seeds within the rhizosphere (10 mm) of anappropriate host root will germinate.
• The parasite seedling radicle known as germ tube can growonly a few millimeters and contact a host root a few daysafter germination.
• Optimum temperature is 15-23ºC.
• GDD is the best parameter for predicting theinitiation of infestation and time of application ofherbicide.
• In general, broomrape attachment occurs at 800GDD and shoot emergence at 2000 GDD
LIFE CYCLE: Orobanche
PHENOPHASIC DEVELOPMENT: Orobanche
100-200 capsules/plant; 800-1000 seeds/capsule; 1.0-1.5 lakh seeds/plant
SEEDS: microscopic, dark brown, oval shaped, rough surfaced, 0.35x 0.25 x 0.1 mm in size, 3-6 µg in weight ,1-2 lakh/plant
SYMPTOMS: Wilting of plant
Mustard Tomato
OROBANCHE: DIFFICULT TO CONTROL?
• Seed production potential is tremendous (Av.1,00,000-1,50,000 per plant) .
• Underground location- inaccessible to conventionalcontrol measures.
• Late appearance of parasite shoots above the soil.
• Lack of photosynthetic system.
• Higher seed longevity: 10-13 years.
• Tiny small seeds easily dispersed due to animals,farm machinery, organic manures etc.
• Seed viability is not lost after passing animaldigestive tract.
PREVENTIVE MEASURESPhyto-sanitary measures for avoiding the dispersal of Orobancheseeds from infested locations are as :
• Prevent movement of infested soil by vehicles, farm machineryand planting material.
• Clean farm, machinery and equipment i.e., tractors, combines,containers, etc.
• Prevent spreading seeds by farm animals. Since Orobanche seedsmay pass animal digestive systems without losing viability, grazingon or feeding hay from broomrape infested fields is prohibited, aswell as using animal manure from unknown sources.
• Use only certified seed.• Prevent Orobanche seed dispersal by wind or water soil erosion.• Collect parasitic weeds prior to flowering.• Practice deep tillage (>20 cm) during hot summer months.
CULTURAL MEASURES: Limitations
• Late sowing – Significant yield reduction
• Crop rotation – wheat, barely, gram, lentil and longer viability
• Higher fertilizer requirement- 120 kg N/ha in three equal splits
• Flooding – undulating topography and light soil texture
• Deep Tillage- No inversion in light soils
• Soil solarization – Possible on small scale
• Trap crops/suicidal parasite germination – Not feasible, higherrate of seed production
• Catch crops – Not feasible and needs several repeated seasons,only small percentage of seeds is stimulated
• Host plant resistance/tolerance
• Hand weeding – regeneration and only to reduce seed bankfor next season
FUNGICIDES: No Control
• Psuedomonas inflorescence at 3.75 kg/ha at sowing
• Trichoderma viridae at 3.75 kg/ha at sowing
BIOLOGICAL CONTROL : Phytomyza orobanchia
Limitations: Mass rearing, release, formulation and delivery system
CHEMICAL CONTROL: Use of Kerosene and Soybean oil
Spray of soybean and kerosene oil was not atall effective at any concentration. Moreover, itis not feasible to spray soybean oil due to itshigh viscosity.
Use of kerosene oil on Orobanche panicles
Use of two drops of soybean oil/panicle
PROTECTED SPRAY: Glyphosate and Paraquat in Mustard
• Protected spray of glyphosate at 0.5, 0.75, 1.0 and2.0 % (product basis) or paraquat at 0.3, 0.5 and0.75% applied after emergence of Orobancheaegyptiaca during first week of February caused onlylocalized burning of Orobanche panicles.
• Of no use except to prevent seed formation.
• More over not feasible to spray at this stage.
CHEMICAL WEED CONTROL
• Very few herbicides are selective to host crops
• Limited in their movement
Three type of herbicides can be used:
• Soil fumigants
• Residual soil applied herbicides
• Post emergence applied herbicides
SOIL FUMIGANTS
• Methyl bromide: Moist soil conditions are needed. Erraticresponses due to evaporation and difficulty in fumigatingmedium to clay heavy soils.
• Methylisothiocynate compounds: Metham sodium appliedby injection or via chemigation or irrigation systems in soil.Effective in deep layers but poor on surface soils due toevaporation losses.
*Can be dangerous to environment
RESEARCH DONE SO FAR………
• Different sources of nutrient supply in mustard i.e.SSP, Urea, CAN, poultry manure, vermi compost,castor cake and FYM – NOT EFFECTIVE
• No genotype of mustard and tomato found tolerantagainst Orobanche spp.
• Neem cake alone or in combination with metalxylproved ineffective in tomato, mustard and brinjal.
• Plant hole application of neem cake 200 kg/ha at 30DAT in tobacco provided effective control ofOrobanche under Tamil Nadu conditions.
No efficacy against Orobanche and even poor control of annual weeds due to lesssurface moisture
PRE-EMERGENCE SPRAY: Pendimethalin
Chemical weed control in mustard
SEED TREATMENT: Soil applied herbicides
• Delayed Orobanche emergence up to 90-110 DAS.
• No availability of chlorsulfuron and triasulfuron in the market.
• 10-15% reduction in mustard germination.
• No feasibility of adoption by farmers due to low dose.
ChlorsulfuronTriasulfuron
Sulfosulfuronat 0.1—1 ppm
Glyphosate: Application & Translocation
Glyphosate
• Glyphosate applied at 25 g/ha at30 DAS and 50 g /ha at 55-60 DAS
• Addition of (NH)4SO4 at 1.0%enhances the efficacy ofglyphosate
• Avoid moisture stress at time ofspray
• Dose and time of applicationshould be strictly followed.
• Repetitive/higher dose may leadto adverse effect on mustardcrop.
Use of Glyphosate
Glyphosate untreatedGlyphosate treated
LEAF CHLOROSIS due to 50 g/ha application of glyphosate
Recoverable within 7-10 days
Two sprays of ethoxysulfuron/sulfosulfuron at 25 & 50 g/haat 30 and 60 DAT, respectively provides 85-90 % control ofOrobanche.
No any adverse effect on crop
Yield advantage of 46-58 % as compared to untreated check.
October planted tomato needs two sprays of eithersulfosulfuron or ethoxysulfuron (25 & 50 g/ha) at 30 and 60days after transplanting where
Tomato transplanted in second fortnight of November needtwo sprays of sulfosulfuron and ethoxysulfuron at 50 g/ha at60 and 90 DAT.
Chemical weed control in tomato
Pre-emergence use of 25 g/haethoxysulfuron followed by postemergence application at same rateat 45 DAT although effective incontrolling Orobanche but causesstunted growth unrecoverable up to90 DAT resulting in poor yield .
No herbicide residues were observedin tomato fruits and soil at harvest.
No residual carry over effect of theseherbicides on succeeding sorghumplanted two months after harvest oftomato.
Tomato hybrids: Himsona, US 2853,Sampuran, Himshikhar, Namdhari,Rakshak, Satyam are not sensitive toany herbicides.
Chemical weed control in tomato
Glyphosate toxicity in tomato
Ethoxysulfuron(PRE) toxicity
Diagnosis of Orobanche infested tomato plants
32
• Neem cake + pendimethalin/metribuzin fb soil drenching of metalaxyl MZ 0.2 % at 20 DAT – NOT EFFECTIVE
• Metribuzin at 3 DAP - highly toxic to brinjal resulting in complete mortality.
• Excellent control of Orobanche with POST or PRE plus POST treatments of sulfosulfuron and ethoxysulfuron but highly phytotoxic to brinjal.
• Broom rape spikes which emerged in ethoxysulfuron andsulfosulfuron treatments were very weak and smallsized.
• Ethoxysulfuron 25 g/ha, PRE was more phytotoxic than POST and brinjal exhibited 50-60% growth reduction under pre treatments resulting in cracked and wrinkled fruits.
• Developmental delay in brinjal with ethoxysulfuron and sulfosulfuron applied PRE or 30 DAS.
• Maximum fruit yield (32.0 t/ha) was recorded from use of sulfosulfuron 25 g/ha at 60 and 90 DAS, respectively which was which was 22.1 % higher than untreated check and significantly higher than all herbicide treatments.
Orobanche management in brinjal
WP 3.2.1 (a) Orobanche management in brinjal
0
10
20
30
40
50
60
70
80
90
NC fb pendifb metalxyl
Ethoxy 25g/ha (PRE)
and 50 g/haat 45 DAT
Ethoxy 25g/ha at 60 &
90 DAT
Sulfo 50g/ha at 60
and 90 DAT
Sulfo 25g/ha at 60
and 90 DAT
Weedycheck
0
82 85 85 85
0
24.220.6
25.728.8
32
24.9
0
50
30
38
10
0
Orobanche panicles/m2 visual control(%)Fruit yield (t/ha) crop phytotoxcity( %)
Ethoxysulfuron 25 g/ha, PRE was more phytotoxic than POST
and brinjal exhibited 50-60% growth reduction under pre
treatments resulting in cracked and wrinkled fruits.
Tamil Nadu
Plant hole application of neem cake at 200 kg/ha on 30 DAT.
DCA of imazethapyr 30 g/ha at 55 DAT.
Neem cake 200 kg/ha at sowing fb soil drenching of metalaxyl0.2 % at 20 DAP.
Karnataka
Growing of trap crops (sun hemp/green gram) in the early spring and incorporate in-situ 45 DAS
Apply imazaquin at 30 DAT at 0.01 kg/ha or one hand weeding within 45 DAT
Apply glyphosate 0.5 kg/ha at 60 DAT and remove theremaining spikes with hand.
Chemical weed control in tobacco
Sequential application of glyphosate (20 + 40 and 20 + 40 +60 DAPE) at 60-80 g/ha.
Injuries in the form of leaf yellowing, plant stunting andcompact plants occurred at 10 days after first spray butdisappeared by 75 DAPE with significant on plant height at60 DAPE.
Higher dose of 100 g/ha although effective but causedeformed and small tubers.
Timing of application varies among potato varieties andgrowing seasons.
(Haidar and Shdeed 2015), Lebanon
Chemical weed control in potato
Three repeated application of rimsulfuron at 12.5 or 25 g/hasprayed at two weeks after crop emergence and reapplied at twoweeks intervals controlled Orobanche and found safe for potatoesas well as tuber quality.
Rimsulfuron is registered for use in commercial crop of potato.
Split application of three doses of 5 g/ha each imazapic applied at10, 20 and 30 DAPE through foliar or chemigated through sprinklerirrigation caused suppression in Orobanche aegyptica.
Although crop vigor, potato yield were good but tuber quality wasseverally damaged in light textured soils.
Triasulfuron is very toxic to potato at 7.5 to 15 g/ha resulting incurly leaves and inhibited crop growth
(Goldwasser et. al. 2003), Israel
Chemical weed control in potato
Use of post emergence spray of glyphosate by farmers
Preparation of glyphosate dose for OFT
FIELD DAY: Orobanche Management
CONCLUSIONS
• Several methods for managing broomrapes include hand weeding, deep ploughing,crop rotation, alteration in seeding windows and fertilizer N scheduling, theapplication of organic manures, chemical seed treatment,; however, they areinconsistent and have limited effectiveness.
• Each of these methods has its merits and provides its own or in combination withothers a solution to certain situations, but the general problem remains somewhatunresolved.
• No single technique provides complete control of Orobanche, and resorting to someof them is unavoidable.
• Physical methods are very useful to prevent the Orobanche but are tedious, time-consuming and costly and prevent only seed setting not yield losses.
• Chemical, agronomic control methods and host resistance appear to be the mostappropriate measures when available and affordable.
• Integration of cultural, preventive and biological and chemical methods is requiredeven though it is very costly to deplete weed seed bank and to avoid furtherdispersal. However, these integrated programmes are practiced only on a small scalein a few countries because of cost and technical problems. Therefore, it is reasonableto hypothesize that GMO approaches will be adopted for parasitic weed control in thenear future.
Future Thrusts……….
• Surveillance system for regular monitoring should be sound.
• Training of research specialists, extension workers andfarmers on biology and ecology of Orobanche and controlmeasures.
• Continued research programme towards cost effective,technically sound and environmentally viable interventions.
• Genetically engineered herbicide resistant crops.
• Development and dissemination of improved technologiesthrough use of appropriate aids such as technical leaflets,manuals, broachers in regional language.
• Holistic, systematic and farmers’ participatory approach.
• Practical demonstrations at farmers’ fields.
SYMBOL OF TRUST
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