FLORISTIC DIVERSITY AND WEED COMMUNITIES OF MAIZE, POTATO AND MUNGNEAN CROPS OF KALASH VALLEY CHITRAL HINDUKUSH RANGE KHYBER PAKHTUNKHWA, PAKISTAN
The present study was conducted during 2016-2017 to record the weed flora of economically important crops, viz. maize, potato and mungbean in Kalash Valley, Chitral, Pakistan. All the three localities of Kalash Valley (Bumburet, Birir and Rumbor) were surveyed. For each crop three locations from each valley were selected and five 1x1 m2 quadrants were used at each location. For the first time phytosociological data regarding absolute density, relative density, frequency, relative frequency, importance value %, average importance value, Constancy classes and Importance value constancy index of various weeds of the area were recorded. The mean data across surveyed localities revealed that the flora is dominated by Digitaria sanguinalis with the highest relative density of 63.78% in maize, 58.78% in potato and 33.11% in mungbean, among all species. In all three crops studied, 23 weed species were competitive with the crops. Based on the Importance Value Constancy value index the most competitive weeds in all crops studied were Digitaria sanguinalis (L.) Scop. (123.3), Amaranthus viridis Linn. (107.9), Rumex dentatus L. (89.3), Solanum nigrum (79.7), Chenopodium album L. (75.8) and Setaria viridis (64.6). Digitaria sanguinalis (98.6), Solanum nigrum (70.7), Trifolium repens (56.4) and Amarathus viridis (49.2). On the basis of IVCI the communities established in Kalash Valley in the studied crops are Digitaria-Amaranthus-Rumex in maize, Digitaria-Solanum-Rumex in potato and Digitaria-Solanum-Setaria in mungbean. Regarding life form classification, 18 species (78.3%) were therophytes, four (17.4%) were geophytes and one species (4.3%) belonged to nanophanerophytes. Leaf size spectra evidenced the highest and equal number of species (seven ea.) in nanophylls and microphylls, either class comprised 30.7% of the species. Mesophylls four spp. (17.3%) followed by three spp. in macrophylls (13%). Aphyllous and leptophyllous groups were merely represented by one species ea. either sharing 4.3%. In order to harvest the optimum yields of these crops appropriate management of the highlighted weeds is recommended.