Bioassay and chemical control of wheat seed gall nematode Anguina tritici

Abstract EN

Bioassay results indicated that the fungicides Vitavax, Dividentand Dithane and herbicide Granstar caused mortality to second stage juveniles (J2) of A.tritici.

Higher mortality (89.12%) appeared after a week of immersion of J2 in Dithane at concentration 8 ppm while less mortality (16.63%) was with Vitavax at concentration 2ppm.Regression analysis and correlation coefficient showed positive relation between concentrations of pesticides and J2 mortality.

From toxicity lines, LC50 and relative toxicity Dithane was more toxic to nematode juveniles while Vitavax was less.

Chemical control of A.tritici by mixing of wheat seeds (Sham 6 cv.) with fungicides revealed that less infection percentage (35.68%) and number of galls (3) were recorded with Dithane in the third planting date ( 15 Jan.2011) compared to the control treatment.

In general fungicides slightly improved the growth and yield criteria of wheat plants and an obvious improvement in leaf area (19.92 cm²), harvest index (27.43) in the first (15 Nov.2010) and second planting dates ( 15 Dec.2010 ) respectively with Vitavax, weight of seeds (0.44gm) in the first planting date with Dithane and number of seed/spike (18.75) in third planting date with Dividant.

Depending on the number of galls, the third planting date may be the most suitable planting date.

Herbicide Granstar® caused a nonsignificant reduction in the infection criteria compared with non sprayed treatment while it caused significant increasing some growth and yield criteria including harvest index, weight of seed/spike, spike length, straw weight and number of seeds/spike