Two field experiments were conducted during the successive seasons of 2012/2013 and 2013/2014 at Sakha Agricultural Research Station to study the effect of SOME herbicides on wheat, NPK uptake, associated weeds and determine its residues in soil, leaves and grains of wheat plant. The results indicated that using the herbicides Granstar at 8.0 g/fed for control broad-leaved weeds, Traxos at 0.5 L/fed for control grassy weeds and Panther at 0.6 L/fed and (Granstar/Traxos) for control annual weeds as applied post-emergence as well as hand weeding twice, gave excellent weed control.
Hand weeding treatment, Panther and (Granstar/Traxos) obviously increased plant height, spike length, weight of grains/spike, number of grains/spike, straw yield (ton/fed) and grain yield (ardab/fed) of wheat as compared with the control treatment. All herbicidal treatments as well as hand weeding treatment increased protein, phosphorus and potassium percentages and their uptake (kg/fed) in wheat grains over control treatment.
The times for 50% loss of initial Granstar in soil were 50.79 and 48.33 days. The loss of initial concentration in the leaves were (0.29 and 0.74 ppm) in the 1st and 2nd seasons, respectively. The Granstar residue become undetected in grains of the two growing seasons after 159 days from application. At the end of experiments about 97.73 and 97.32% of initial traxos in the soil in both seasons were lost. After 90 days, only 0.22 and 0.26 ppm of Traxos were reached to the grains. At the end of experiment (145 days), there were no residues in the grains of the two growing seasons. The times for 50% loss of initial Panther in soil were 56.78 and 53.67 days and the loss of initial concentrations reached 97.32 and 98.84%. At the end of the experiment (152 days) there were no Panther residues in wheat grains in the two growing seasons.
These results indicated that under heavy infestation with annual weed, it is possible to apply herbicides i.e. Panther and (Granstar/Traxos) treatments for annual weeds control, Granstar for broad-leaved weeds control and Traxos for grassy weeds control. These findings revealed obviously that such weed control measure can minimize weed/wheat competition and consequently gave the highest reduction in weeds and increase wheat yield, without any effect on wheat plants or on soil.