Floristic and Vegetation Study on the Main Weed Communities Associated with Wheat (Triticum aestivum L.) Crop

Abstract

The present study aims at studying the floristic features and community types of the main weed species associated with wheat crop in Menofia Province, Egypt. Sixty stands (each 10 × 10 m) were randomly selected in five wheat farms for monthly determining the cover of weed species along the growing season of wheat. Twenty nine species belonging to 28 genera and 17 families were recorded associated with wheat crop. The most dominant families were Poaceae, Brassicaceae and Fabaceae. Annual weeds were represented by 26 species, while perennials were 3 species. Therophytes were the dominant life form (26 species), while geophytes-helophytes, chamaephytes and hemicryptophytes were represented by on species (Cyperus rotundus, Solanum nigrum and Convolvulus arvensis, respectively). The application of TWINSPAN on the cover estimates of 29 associated species recorded in the 60 sampled stands in wheat, led to the recognition of 8 vegetation groups: A: Convolvulus arvensis, B:

Floristic diversity and vegetation analysis ofMalva parviflora L. Populations in Egypt

“…Where, these families constitute the bulk of the flora of the study area. This result is similar to those in Dakahlia-Damietta coastal region (Mashaly, 1987), the wastelands the Zagazig governorate (Abd El-Fattah et al, 1992), Kafr ElSheikh province (Shalaby, 1995), the Nile Delta region (Shehata and Galal, 2014) and in Al Kalubya, Mynufia and Buhayra (Khalafallah et al, 2016b). Of 141 species associated to M. parviflora, 88 were annuals and 55 species were perennials.…”

“…Zohary (1973) referred to the dominance of interregional species (bi-, tri-and pluri-regional) over mono-regional ones to the presence of inter-zonal habitats, such as anthropogenic or hydro-, halo-and psammophilous sites. The present result isn't in consistent with the results of Suliman et al (2016)and Khalafallah et al (2016a and2016b), where they found that mono-regional species were the dominant elements in maize and wheat crops in Middle Delta and Opuntia ficus indica orchards. On the other hand, Mashaly (1987) recorded 50% of the species in the Deltaic sector are Mediterranean, 32% are pluri-regionals, and 8% are Saharo-Sindian elements.…”

“…The high species richness may be related to this environmental micro-heterogeneity that promotes diversity (Palmer and Maurer, 1997). The variations in species richness, diversity and evenness among the different community types may be attributed to differences in soil characteristics, substrate discontinuities and the allelopathic effects of one or more invasive species depending on their relative dominance among other associated species (James et al, 2006;Galal and Shehata, 2015;Khalafallah et al, 2016a and2016b). Moreover, the difference in field management practices may also be a factor that explains differences in species richness (Stevenson et al, 1997;Sher and Al-Yemeni, 2011;.…”

“…Heneidy and Bidak (2001) and Shehata and Galal (2014) pointed out that the dominance of therophytes over the other life forms seems to be a response to the hot-dry climate, topographic variation and biotic influence. According to Galal (2001) and Khalafallah et al (2016a and2016b), therophytes are the main life forms and most of them are weed species characteristic to the cultivated lands, coinciding with Hassib (1951) on the Egyptian flora. The variations in species richness, diversity and evenness among the different habitat types may be attributed to differences in soil characteristics, substrate discontinuities and the allelopathic effects of one or more invasive species depending on their relative dominance among other associated species (James et al, 2006) in addition to habitat characteristics (Khalafallah et al, 2016a).…”