ABSTRACT
Weeds are defied as “the plants growing out of places, where they are not desired and their disadvantages are more than their advantages”. Many weeds compete strongly with pomegranate trees depending on the climate and geographical region. They compete with pomegranates for nutrient, water and sun light (generally for newly planted trees). For this reason, weed control is very important for economic production of pomegranates. However, on the other hand, weeds are also hosts for natural enemies and other biological elements of the earth. According to E. J. Salisbury (1961): “everyone (except evils) have some admirable qualities: a thief can be a compassionate father and husband in his home; similarly a very harmful weed can be a pleasant flower in another place”. Therefore, the aim of weed management should be to maintain the population below economic threshold rather than eradicating all. Before weed management, it is highly important to remember following features of weeds:
• Weeds (and buds) require a waiting period for internal maturity and external environmental conditions for being ready to germinate. This waiting period is called as dormancy. Most of the cultivated crops do not have dormancy and this characteristic makes weeds a troublesome problem for farmers. Some weed seeds (i.e., Wild mustard; Sinapis arvensis) can wait 35 years in soil to germinate. Therefore, controlling of weeds before seed production is highly important.
