Variations in climate are widely recognized as central factors governing the competitive balance in mixedspecies plant communities. In agricultural systems, highly variable patterns of crop yield reduction as a function of weed density have been documented across sites and among years at the same site for several crop–weed combinations. This variation is typically attributed to contrasting envi...

Plot-scale field studies were conducted to evaluate the efficacy of steam for the control of cropland weeds in comparison with common herbicides. Weed densities, biomass, or emergence after treatment were measured. Steam (3,200 kg/ha, energy dosage equivalent to 890 kJ/m2, speed of 0.8 m/s) and glyphosate (560 g ai/ha) gave similar control (. 90%) of seedling common lambsquarters and seedling r...

abstract in order to investigate the effect of crop row spacing and cocklebur (xanthium strumarium) densities on yield and its components of two sesame cultivars, a field experiment was conducted in 2009-2010 growing season at research farm of university of agricultural sciences and natural resources of gorgan, iran. the experiment was established as factorial arrangement using a randomized com...

Effect of cover crops intercropped with pineapple (Ananas comosus) on Rotylenchulus reniformis population densities and activity of nematode-trapping fungi (NTF) were evaluated in two cycles of cover crop and pineapple. Sunn hemp (Crotalaria juncea), rapeseed (Brassica napus), African marigold (Tagetes erecta), or weeds were intercropped with pineapples. Beds planted with sunn hemp or rapeseed ...

The presence of volunteer potato Solanum tuberosum L., cutleaf nightshade, S. triflorum N., and hairy nightshade, S. physalifolium Rusby (Solanales: Solanaceae), throughout potato crop rotations can diminish the effectiveness of crop rotations designed to control disease and pest problems associated with growing potatoes. In greenhouse bioassays, larvae of the Colorado potato beetle, Leptinotar...

management of a companion crop is critical to successful establishment of perennial forages (Albrecht and Hall, Weed control during alfalfa (Medicago sativa L.) establishment is 1995). a primary concern of forage producers. Companion crops and clearWeed management is important for decreasing comseeding with an herbicide are commonly used methods for establishing alfalfa. This study evaluated an...

FOREWORD The impact of environmental weeds on the natural environment is an area that has been little studied in Australia. More often than not, impact is assumed rather than quantified. If the impact of environmental weeds on nature conservation values is not quantitatively assessed before a control program is begun, valuable resources can be wasted. For instance, how would it be possible to d...

an experiment was conducted in bandar kyashahr research field in 2002 to evaluate the effects of plant density and planting pattern on weed populations and yield of peanut (arachis hypogaea l.). the experiment was of a randomized complete block design with three replications. a factorial trial with two factors of planting pattern (square and rectangular arrangements) and plant density (3, 5.3, ...

in this research corn were planted in 3 densities (8, 12, 16 plant/m2) in two planting patterns (single and double-row) with seven summer weed species, including redroot pigweed, green foxtail, annual bluegrass, common lambsquarter, jimsonweed, black nightshade and johnsongrass were planted. temperature, quality and quantity of light reaching to soil surface were measured and the number of emer...

Lowland ecotype Cyperus rotundus L. has been reported to infest irrigated lowland ricefields in the Philippines. Its effects on growth and yield of rice under flooded conditions are unknown. Two experimental runs were conducted a screenhouse determine C. with transplanted wet direct-seeded at sowing densities 0, 22, 44, 66, 88 initial germinating tubers m–2, as well its rice. Except for height,...