Algae, Tree, Herbs, Bush, Shrub, Grasses, Vines, Fern, Moss, Spermatophyta, Bryophyta, Fern Ally, Flower, Photosynthesis, Eukaryote, Prokaryote, carbohydrate, vitamins, amino acids, botany, lipids, proteins, cell, cell wall, biotechnology, metabolities, enzymes, agriculture, horticulture, agronomy, bryology, plaleobotany, phytochemistry, enthnobotany, anatomy, ecology, plant breeding, ecology, genetics, chlorophyll, chloroplast, gymnosperms, sporophytes, spores, seed, pollination, pollen, agriculture, horticulture, taxanomy, fungi, molecular biology, biochemistry, bioinfomatics, microbiology, fertilizers, insecticides, pesticides, herbicides, plant growth regulators, medicinal plants, herbal medicines, chemistry, cytogenetics, bryology, ethnobotany, plant pathology, methodolgy, research institutes, scientific journals, companies, farmer, scientists, plant nutrition
Select Language:
 
 
 
 
Main Menu
Please click the main subject to get the list of sub-categories
 
Services offered
 
 
 
 
  Section: Principles of Horticulture » Weeds
 
 
Please share with your friends:  
 
 

Weed identification

 
     
 
Content
Weeds
  Damage
  Weed identification
  Weed biology
  Ephemeral weeds
  Annual weeds
  Perennial weeds
  Mosses and liverworts

As with any problem in horticulture, recognition and identification are essential before any reliable control measures can be attempted. The weed seedling causes little damage to a crop, but will quickly grow to be the damaging adult plant bearing seeds that will spread. The seedling stage is relatively easy to control, whether by physical or by chemical methods. Identification of this stage is therefore important and with a little practice the gardener or grower may learn to recognize the important weeds using such features as cotyledon and leaf shape, colour and hairiness of the cotyledons and first true leaves (see Figure 13.3).
Figure 13.3 Seedlings of common weeds. Notice the difference between cotyledons and true leaves. (Reproduced by permission of Blackwell Scientific Publications)
Figure 13.3 Seedlings of common weeds. Notice the difference between cotyledons and true leaves.
(Reproduced by permission of Blackwell Scientific Publications)


Within any crop or bedding display, a range of different weed species will be observed. Changes in the weed flora may occur because of environmental factors such as reduced pH, because of new crops that may encourage different weeds to develop, or because repeated use of one herbicide selectively encourages certain weeds, e.g. groundsel in lettuce crops or annual meadow grass in turf. Horticulturists must watch carefully for these changes so that their chemical control may be adjusted. The mature weeds may be identified using an illustrated flora book, which shows details of leaf and flower characters.

 
     
 
 
     



     
 
Copyrights 2012 © Biocyclopedia.com | Disclaimer