Abstract
The authors built a sumulation model of optimum design of volunteer wheat plants (VWP) Control system including a germination model of VWP in the winter wheat-summer crop-barley rotations.
This allowed the authors to examine thoroughly the relation between the VWP control system and net income in winter wheat-summer crop-barley rotations by simulation. The following items regarding the VWP control system were investigated.
(a) No measures taken to control VWP (system N).
(b) Hand picking of VWP just before the barley harvesting (system H).
(c) Tillage system of plow-tilling in summer followed by rotary-tilling in autumn (system P).
(d) Tillage system of rotary-tilling after 3 weeks of wheat harvest followed by tilling in late in November (system L).
(e) Calcium cyanamid treatment of the soil after wheat harvest (system C).
(f) Operation of rough rice separators to remove contamination (system S).
The results obtained are as follows;
(1) Winter wheat-soybean-barley rotation
The highest net farm income was produced by system P, followed by system S, C, H, L and N in that order.
(2) Winter wheat-buckwheat-barley rotation
The highest net farm income was produced by system C, followed by system P, S, L, H and N in that order.
As a result of the field experiments and simulation, it is considered that the new control system of VWP has a great significance in winter wheat-summer crop barley rotations.
