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WEED RISK ANALYSIS AND ASSESSMENT OF WEED SEED CONSIGNMENT WITH IMPORTED GRAINS

MEKKY, M.S., E.E. HASSANEIN , A.N. M. NASSAR , M. R. MOSHTOHRY ,

A. S. KHOLOSY AND M.F.I. DAIE.

Weed Research Laboratory, Field Crops Institute, ARC, Giza, Egypt

Abstract

This is a pioneer work for weed risk analysis in Egypt, where  1334 samples of imported grains in the period from 1/3/2009 to 1/3/2010 were used to detect weed seed consignment in imported grain shipments as well as to estimate weed risk assessment of the main four weed species, namely wild oat (Avena spp.), rye grass (Lolium temulentum), field bindweed (Convolvulus arvensis) and ragweed (Ambrosia artemisiifolia), giant ragweed (Ambrosia trifida) as alien weed on agriculture in Egypt. Results indicated that 91.1% off samples contaminated with weed seeds less than the permissible level (> 24 seeds/kg of grains) and were accepted. Meanwhile, the rest of samples had more than this level (<25 – 996 seeds/kg) and were refused to be screened at the permissible level. Weed risk analysis scores for the above mentioned four species indicated that the probability of  their entry was 6.3, 6.3 and 5.6, establishment was 6.6,7.5 and 6.4 and the economic impact was 5.6, 4.9 and 4.3 for wild oat, rye grass and field bindweed respectively (the maximum score =9). For the genus of Ambrosia, it has three species, common ragweed (Ambrosia artemisiifolia), giant ragweed (Ambrosia trifida) and perennial ragweed (Ambrosia psilostachya) were frequently detected in imported wheat, maize and sorghum seeds and seen to possess the highest potential phytosanitary risk for Egypt. These weed species were not found in Egypt and achenes of these weeds were detected, they had the ability to germinate and to produce viable seeds under growth chamber and wire house conditions. The probability scores for the introduction of Ambrosia spp. in Egypt is 6.3 and is considered relatively high in the large quantities of imported grains where they can survive and transit easily after dropping into the soil to germinate causing field infestation and the probability of establishment was relatively high economic impact showed a degree because 6.0 causing an economical loss by, and the Ambrosia spp. because of these reasons imported plant materials, i.e. wheat, maize and sorghum should be completely free of Ambrosia spp. achenes by screening through quarantine work to prevent its entrance to the territory of Egypt. Meanwhile, the other weeds of wild oat, rye grass and field bindweed, which were recorded in Egypt should be under the permissible level of seed contamination (>25 seeds per kg) in the imported grains to be allowed to enter the territory of Egypt.