Electrothermal control of weed beet and bolting sugar beet

Abstract

Small plot trials were carried out in years 2001-2003 with sugar beet. In the treatment without weed control, dry weight of sugar beet top and LAI of sugar beet were very low (approx. 50 g/m 2 and 0.5 m 2 /m 2 , respectively). Yield loss of sugar beet was 80-93%. Dominant weeds were Chenopodium album, Fumaria officinalis and Galium apari-ne. In the treatments where weeds were removed (by hand) until 4 leaf stage of sugar beet, dry weight of sugar beet top and LAI of sugar beet at first increased normally, but were markedly decreased from the half of the vegetation period. Yield loss of sugar beet was 54-28%. Dominant weed in this treatment was Amaranthus retroflexus. The development of sugar beet top dry weight and LAI of sugar beet was practically identical in the treatments where weeds were removed until 8-10 leaf stage of the crop and in those where weeds were removed during the whole vegetation period (500-900 g/m 2 , or 4-7 m 2 /m 2 , respectively). No yield loss of sugar beet was recorded. Dry weight of weeds did not exceed 30 g/m 2 and LAI 0.1 m 2 /m 2. A. retroflexus and Mercurialis annua were the most frequent weeds in this treatment.

Power on! Low‐energy electrophysical treatment is an effective new weed control approach

“…Electrical energy (electrophysical treatment of weed) is considered a sustainable means of control as it neither causes soil erosion nor leaves chemical residue or contamination in the soil or the plant 17 . Furthermore, the electrical current can be targeted exclusively to the weeds, thereby minimizing the impact on nontarget organisms 18 . Electrophysical weed treatment is performed via two main methods: nondirect spark discharge and continuous electric shock by direct contact with the plant 19 .…”

Flatness-Based Control of a Mechatronic Weed Killer Autonomous Robot

“…. ., zl) is called a flat output or a linearising output of the system (12). Notice that the second condition means, that the components of a flat output are variables of the system (12) or can be simply expressed in terms of the system variables.…”

“…., zl) is called a flat output or a linearising output of the system (12). Notice that the second condition means, that the components of a flat output are variables of the system (12) or can be simply expressed in terms of the system variables. The third condition implies that every variable of the system or every function of the variables of (12) can be calculated using the flat output and its derivatives, without the need for integration of any differential equation.…”

“…Sometimes, an admissible nominal trajectory can be called an (admissible) reference trajectory or even an (admissible) predicted trajectory if one wants to emphasis the predictive aspect of any flatness based control [15]. (17) In the same manner, any (admissible) nominal trajectory z: of the flat output gives rise to a nominal state trajectory xc of the state x which is defined, Vt C I, by (18) Equations (17) and (18) illustrate the parametrization of the trajectories t P-4 (e (t),xs(t)) of the differential system (12) in terms of the flat output. In the same way as z:, the function e: is called the reference input trajectory or even the predicted input trajectory of the input e while xz is called the reference or predicted state trajectory of the state x.…”

“…Since twenty years other methods are studied to protect environment by reducing chemical weed-killing in agriculture. Most of them are designed for a global processing and dedicated ones involve a complex system as for electrolysis that requires a robot arm and image processing [12]. The idea we develop here is that an agricultural robot can perform the necessary work with simple mechanical and sensor systems, using an advanced control method that takes into account the complete kinematic model.…”