Description : . A non-competitive crop requiring weed free period of three or more months a). Maize b). Rice c). Soybean d). Onion
Last Answer : d). Onion
Description : A period in the ontogeny of crop at which maximum crop weed competition occurs is called a). Economic threshold b). Gain threshold c). Competitive threshold d). None
Last Answer : d). None
Description : The competitive crop requiring weed free period of about 3-4 weeks a). Soybean b). Carrot c). Garlic d). Onion
Last Answer : a). Soybean
Description : Critical period of crop weed competition in sugarcane is a). 30-40 days b). 30-120 days c). 10-40 days d). 15-30 days
Last Answer : b). 30-120 days
Description : The period at which maximum crop weed competition occurs is a). Critical period b). Dormancy c). Flaming d).Threshold
Last Answer : a). Critical period
Description : Wheat and bajra have critical period of crop-weed competition a).10-20 days b).15-30 days c). 30-45 days d). 20-40 days
Last Answer : c). 30-45 days
Description : Two or more species coexist in a place due to the reason a). Different nutritional requirement b). Different causes of mortality c). Different time demand for growth factors d). All
Last Answer : d). All
Description : Production practices that influence weed shift are a). Effectiveness of weed management program b). Speed of weed shift occurrence c). Interface areas d). All
Description : If weed population is 70/m2 and the crop 140/ m2, weed intensity would be a). 33.3% b). 66.6% c). 50% d). 73.4%
Last Answer : a). 33.3%
Description : A curvilinear relationship between weed density and crop yield was reported by a). Zimdahl 1980 b). Roberts and Bonds (1975) c). Cousens et al (1985) d). None of these
Last Answer : b). Roberts and Bonds (1975)
Description : The sigmoidal relationship between weed density and crop yield was proposed by a).Zimdahl 1980 b). Roberts and Bonds (1975) c). Cousens et al (1985) d). None of these
Last Answer : a).Zimdahl 1980
Description : The effective solution to manage weed shifts a). Herbicide combinations b). Herbicide rotations c). Crop rotations d). All
Description : November sown berseem crop induces the weed a). Chenopodium sp b). Anagallis sp c). Vicia sp d). All of these
Last Answer : d). All of these
Description : The official peer-reviewed Journal of the EWRS (European Weed Research Society) is a). Journal of Crop and Weed b). Weed Research c). Weed Science
Last Answer : b). Weed Research
Description : Integrated weed management practices that a). Enhance crop competitive ability b). Decrease weeds ability to reduce yield c). Practices that eliminate weeds from an area d). Both a and b e). Both a and c
Last Answer : d). Both a and b
Description : Environmental factors which increases the allelopathic effects are a).low soil fertility b). Warm wet condition c). Cold wet conditions d). a and b
Last Answer : d). a and b
Description : With poor weed management, a field could shift to a). Predominant weed species b). Species not effectively controlled c). Species not responded to control meas ures d). All the above
Last Answer : d). All the above
Description : Weed species which has nematicidal prop erty a). Crotolaria b). Parthenium c). Eichhornia sp d). All of these
Description : Number of weed species identified in the world a). 30 b). 300 c). 3000 d). 30000
Last Answer : d). 30000
Description : Weed species wgich can tolerate so larisation effect a). Phalaris minor b). Sorghum halepense c). Alopecurus myosuroides d). Lolium temulentum
Last Answer : b). Sorghum halepense
Description : A nitrogen fixing weed species in wheat a). Lathyrus aphaca b). Medicago denticulata c). Vicia sativa d). All
Description : Intra-specific competition is between a). Plants of the cultivated species and weed species b). Plants of the same weed species c). Plants of the different weed species d). None of the above
Last Answer : b). Plants of the same weed species
Description : The greatest factor affecting herbicide adsorption is a). pH b). Salt c). SOM d). Soil nutrient
Last Answer : c). SOM
Description : Growth of the weed is reduced due to root exudates of maize a). Chenopodium album b). Amaranthus retroflexus c). Both a and b d). None of these
Last Answer : c). Both a and b
Description : .Which weed is considered as biopesti cide and severely inhibit the growth of water hyacinth? a). Parthenium b). Echinochloa c). Cuscuta d). Lantana
Last Answer : c). Cuscuta
Description : Competitive crops such as corn or soybean require weed-free period of a). 2 months b). 3-4 weeks c). 3 months d). None of the above
Last Answer : b). 3-4 weeks
Description : Noncompetitive crops such as onion or garlic require a weed-free period of a). 3 months or more b). One month c).10 days d). None of the above
Last Answer : a). 3 months or more
Description : A herbicide applied to the soil before planting a crop is called a a). pre-emergence b). Post-emergence c). Pre-plant d). None
Last Answer : c). Pre-plant
Description : The ecological phenomenon of plant-plant interference a). Competition b). Allelopathy c). Both d). None
Last Answer : c). Both
Description : .Phenolic acid as root exudates of which crop has detrimental effects on wild mustard? a). Wheat b). Oats c). Chickpea d). a & b
Last Answer : d). a & b
Description : An eradication method of weed control a). Killing underground parts of weeds by tillage b). Using soil sterilants c). Repeated foliar application on perennial weeds d). All of these
Description : Most dominant factor influencing weed composition in a field is a). Soil moisture b). Soil type c). Soil texture d). Soil temperature
Last Answer : a). Soil moisture
Description : A dominant weed of puddle paddy soil a). Echinochloa b). Caesulina c). Eclipta sp d). All of these
Description : The practice that directly hit soil weed seed bank in minimizing future weed infestation a). Microwave irradiation b). Soil solarization c). Stale seed bed d). All e). None
Description : . A shortest time span in the life cycle of a crop when weeding results in highest eco nomic returns a). Economic threshold b). Critical period c). Competitive threshold d). None of these
Last Answer : b). Critical period
Description : Persistence herbicides pose hazard in soil when a). High persistence herbicides are used b). Crop failure necessitate re-planting c). Susceptible crop follows a short crop d). All
Description : Important quality of bioagents a). Attack only host plant b). Free from predators/parasites and quick adoption to new environment c). Able to kill reproductive parts of weed d). All of these
Description : Which of the following is a monocot weed but broad-leaved plant? a). Eichhornia crasipus b). Commelina banghalensis c). Cynnotis axillaris d). All of these
Description : In which weed seeds mature after uproot ing the plant? a). Stellaria media (Chick weed) b). Portulaca oleracea c). Both a and b d). None of these
Description : A weed producing > 1 lakh seeds/plant a). Amaranthus sp b). Portulaca sp c). Both a and b d). Cascutta sp
Description : Weed Biology and Management Q.313. Weed Science of America is publish ing which of the Journals a). Weed Science b). Weed Technology c). Invasive Plant Science and Manage ment d). All the above
Description : .Which crop is an indicator plant for the bio assay of Triazines and Aliphatics? a). Sugarbeet b). Sorghum c). Cotton d). Mustard
Last Answer : a). Sugarbeet
Description : If Echinochloa falls in frequency class ‘E’, the weed community is said to be a). Contiguous b). Heterogenous c). Homogenous d). Random
Last Answer : c). Homogenous
Description : If the count of Echinochloa in weedy check is 70 and that in a treatment 25/m2, weed control efficiency will be a). 54.3% b). 64.3% c). 73.4% d). 79.6%
Last Answer : b). 64.3%
Description : If the yield from weed free is 3500 kg and that from weedy 1500 kg/ha, weed index would be a). 57.1% b). 133.3% c). 45.0% d). 25.6%
Last Answer : a). 57.1%
Description : . A ceremonial weed a). Cynodon dactylon b). Datura stramonium c). Tagetus sp d). All of these
Description : A ceremonial weed a). Asparagus racemosus (Shatawari) b). Cynodon dactylon (Dhoob ghaas) c). Nelumbo nucifera (Lotus flower) d). All of these
Description : A ceremonial weed a). Asparagus racemosus (Shatawari) b). Cynodon dactylon (Dhoob ghaas) c). Both a and b d). Digitaria sanguinalis
Description : To manage grassy weed flora in barley which of the herbicides is to be applied a). Pendimethalin b). Isoproturon c). a and b d). Metsulfuron
Last Answer : c). a and b
Description : To manage mixed weed flora in barley which of the herbicides is to be applied a).2,4-D b). Isoproturon c). a and b as tank mix d). None of these
Last Answer : c). a and b as tank mix