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Abstract
The Egyptian cultivation has been biginning since thousands of years in the Nile Delta and its Valley. The growth of weeds in crops, vegetables and orchards attracted the attention of farmers. They developed various practices in getting ride of them. Despite the use of clean seeds, ploughing, burning, hoeing, hand weeding and crop rotation, weeds persisted because of the inability to cope with maximum production and massive recycling potentiality of weeds (Sen et al., 1980). Mechanical, chemical or biological weed control is unthinkable without through knowledge of weed species, their distribution and ecological behavior (Kosinova`, 1975).
Detailed studies of weed vegetation associated with cultivated crops provide necessary information of understanding the nature of weeds. Recent studies in Egypt and elsewhere is concentrated on this problem. This issue is important to Egypt as a country of cultivation, and there are several recent studies that concentrate on the study of weed vegetation ecology, e.g. El Hadidi et al. (1999); Sheded et al. (2000); El Halawany (2000); El Halawany et al. (2002); Turki (2000); Turki and Sheded (2002); Daie and El-Khanagry (2004).
The area selected for the present study is a part of the east Nile Delta region (Ismailia governorate). It comprises well-established farmlands associated with Ismailia Canal and its extensions and the newly reclaimed lands east of the Suez Canal.
The study area includes a great variety of weed species associated with cultivated crops and orchards, hence this area is considered as a meeting point of several phytogeographical regions. Studies on variations in the composition and structure of weed vegetation with the changes in the microenvironment are still limited in this area. Therefore, this area was chosen to elucidate the variations in composition, structure and biological characters of weed species associated with cultivated crops in relation to environmental factors. The main important local factors are light, soil characters and agronomic practices. Information on such factors can serve as a guide in planning for weed management of this area.
The Egyptian crops are grown in a seasonal sequence and traditionally are classified according to its position in the yearly agricultural rotation into summer, winter and year- round crops.
Weeds are mostly annuals of either summer or winter affinity. Some summer and winter weeds are biologically active throughout the - year, beside the non-seasonal perennial weeds. The present work attempts to quantify as many environmental parameters as possible to determine some subtle weed vegetation-environment relationships. Furthermore, it attempts as well to classify and ordinate weed vegetation of that area. This work is considered as an extension of a previous study carried out by the author in a small district in the same governorate (Abd El- Hamid, 1996).