Comparison Of Two Methods For Evaluation Of Microwave Application Effects For Killing Weeds
Different methods other than herbicides are used for controlling weeds especially in organic farming. Among these methods microwave applications are very new method for killing the weeds. Just recently conducted researches proved that microwave energy can control the weeds effectively. It is well known fact that herbicides use for controlling weeds destroys the environment and increases the cost. New methods such like microwave applications are considered for controlling weed plants due to the growing concerns about herbicide resistance and chemical residues in the environment.
One of the main problems for microwave applications is that deciding the right method for evaluation of the results. For this reason, the objective of this study was to compare two methods, 0-5 scale and GR50, for evaluation of the data at the stage of determining if the weed is killed totally with microwave applications. This study was conducted at laboratory conditions and four weed varieties cocklebur (Xanthium strumarium), Johnson Grass (Sorghum halepense (L.)), Black Nightshade (Solanum nigrum), Bermuda Grass (Cynodon dactylon) were killed by microwave power at microwave laboratory prototype. Weeds with three different development stages: weeds with four leaves, eight leaves and weeds at seeding stage were exposed to minimum 0,8 kW and maximum 5,6 kW microwave power with two different forward speeds were 0,3 – 0,1 m s-1. The 0-5 scale methods and GR50 method which is commonly used for evaluation of the data in herbicide use are used for evaluation of the data. According to the results; in the first growing stage of the weeds similar results were found in both methods. There was found no statistical difference between two methods in the first stage of the weeds. But in the second and third stages of the weeds, when the weeds are over grown vegetatively, the differences were found for evaluation of the data with two methods. According to the observations, the weeds that were killed by microwave energy were indicated died weeds by 0-5 scale whereas GR50 method did not agree with the scale method. Evaluations form control and microwave applied weeds by GR50 method were found to be statistically not significant. This is because there was found no difference for dry weights of control and microwave applied weeds after applications with GR50 method.
Keywords- Microwave power, weed management