To improve the trafficability of farm use vehicle, the measurement of stress distribution under the driving devices is needed. Some kinds of method for finding the stress distribution, therefore, have been studied such as pressure cell transducer with strain gage on it. The motion and movement of soil under rigid wheel or rubber tire wheel have been observed in the perspex-sided soil bin test. Photoelasticity can be applicable to this kind of problem as far as the assumption that the soil is elastic can be useful.
In this paper, the author tried to see directly the stress distribution under rigid wheel by the application of photoelasticity experimental method.
The results ware discussed from the theoretical point and compared with the calculated results obtained by the finite element method.
New procedure to determine the unknowh values was introduced, in which the stress distribution under rigid wheel and various values were determined by obtaining the center of gravity of the closed area in the stress distribution curve. Various unknown values such as θ, e, R, F and a in Fig. 1(c) were obtained from the stress distibution of photoelastic material under rigid wheel by taking the isochromatic line diagram.
Those values obtained in this method were valid with the ones determined from the theoretical approach. New procedure in determining the various unknown factors such as θ, e, F and R etc. are valid even though the photoelasticity can only be applied to the problem of elasticity.
The author wishes, therefore, further investigation should be taken place by repeating more experiments to reconfirm this new procedure.

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The performance of the oil hydraulic control system on the rotary tillage was studied.
The control circuit is shown in Fig. 13.
To detect the tilling torque, the relation between torque and speed of the tractor engine are used and the engine speed is hydraulically transformed to the piston displacement of the detecting cylinder. This displacement is amplified by the link and acts on the hydraulic control valve. This valve is a manual operated type and is an approximate on-off type with dead band.
The oil from this valve flows into a operating cylinder and the tilling unit is moved upward or downward.
Some experiments is performed by using the tractor with this control system. At the tilling in hard soil, the control system operates but the tilling unit moves upward or downward widely.
This phenomenon is the limit cycle and it occurs in the unstable condition of control system.
The consideration and improvement of this system will be done in the next report.

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Heretofore attempts have been made to measure the tilled depth more accurately and automatically, but so far no practical method has been found. The tilling depth meter developed by the author is primarily for measuring tilled depth continuously and automatically, and has the following features:
1) The basis for variation in tilled depth is the ground surface which is the working collation.
2) For the actual ground surface such as roughness and slope, it always measures tilled or worked depth in the vertical direction.
3) Independent of dynamic variation and change of position due to other causes of the operating machine, it measures its change of the working parts relative to the ground surface.
4) Together with various power measurements of the working parts, the measurements synchronized to the same recording equipment may be carried continuously and automatically.
5) The tilled depth relative to the tilled width may be measured as a mean tilled depth.
6) Matching when make and size of the operating machine are different and matching for various ground hardness is possible by adjusting or inter-changing the ground measuring parts.
7) Since the tilled depth and measuring error are in a linear relation, it is possible to know tilled or worked depth at once during working operation.
It may be applied not merely to a description of tilled depth but of wheel sinkage and shape of ground surface, etc. It may be applied either to a real field or artificial one in laboratory. The tilling depth meter has been used in practice ever since the second report.

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The authors applied the weeder for walking tractor to wheat and obtained the next results.
(1) Losing of wheat is little and the effect of weeding is high when depth of covering of wheat is deep and its dispersion is little. The effect of the weeder was high when depth of the weeder was 2.5cm and depth of covering of wheat was 3cm on the test.
(2) Remaining ratio of weed was less than 5-10% when the weeder was used two times within 40 days after the seeding.
(3) The losing of wheat was discovered fairly in case of high soil moisture (above d. b. 38%) especially at 2-3 leaves of wheat and above 3cm on depth of the tines. The losing of wheat was also discovered highly in case of the same cases.
(4) The losing of wheat was not discovered when the weeder was used before and after germination of wheat.
(5) Using of weeder did not result in the decrease of crop of wheat.
(6) The soil moisture as far as 1cm under the surface of the field decreased to d. b. 20%, but the soil moisture of the deeper did not decrease.
(7) The authors considered that the weeder (depth of tines: 2.5cm, interval of locus of tines: 1.25cm) had adaptability for wheat except some examples.

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As the basic research for the study of the separating mechanism of the digger, a few experiments were performed with the separating device built as a trial.
The following results were obtained.
1) Quantity of the soil in the harvesting box increased in accompany with the increase of the finger speed and the decrease of the angle of inclination.
2) The size of clods in the harvesting box showed a tendency to increase with decrease of the finger speed.
3) The efficiency of regain of the tulip bulbs in the harvesting box was independent of the flow quantity of the soil, but was significantly influenced by the finger speed and the angle of inclination.
4) Torque of the finger shaft decreased with the increase of angle of inclination, and was influenced considerably by the peripheral speed of the finger, showing a minimum value at 1.1-1.3m/s.

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The author performed the simulation of harvesting and transporting by using the model device which is able to change the size, the number and the position of the model cucumber. The results were as follows:
(1) Designating the one kind of model cucumbers from among the four kind of model cucumbers that were hanged on the model planting device, the author had a person pick the designated model cucumbers. The length of the four kind of model cucumbers were varied, but the diameter were constant. The one kind of model cucumbers were hundred in number.
The longest and the shortest model cucumbers was picked very easy.
The accuracy of picking increased with increase of the time of picking, however there was a limit in the accuracy of picking.
There was the above tendency in the case of picking of model cucumbers that the diameter was varied too (the length was constant).
(2) Varying the number of the designated model cucumbers, the author had a person pick the desinated model cucumbers. In this case, the picker was designated.
In both case that the length of the model cucumbers was varied and the diameter was varied, the accuracy of picking decreased when the number of the designated model cucumber was a few.
The relation between the time of picking and the accuracy of picking was almost the same as the case of (1).
(3) Designating three kind model cucumbers which the size resemble real thing, the author had a person pick the designated model cucumbers.
The accuracy of picking was good and there was few difference between those values of the accuracy of picking.
Varying the number of the designated model cucumber, the accuracy of picking was increased with increase of the time of picking when the number of the designated model cucumber was a few.
(4) The time of picking per unit number of the model cucumber picked was increased with decrease of the number of the designated model cucumber, because the time of seeking increase when the number of the designated model cucumber was a few.
There was no difference in walking distance of picker between applying the cart and customary working with hand-basket when the number of the designated model cucumber was a few.

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In perceding report, it was suggested that weed control system is able to be formulated as a stochastic multi stage decision problem by introducing prediction value to the system state variable.
Following the results of above formulation, computer models were built up and simulation was carried out for the purpose of examining characteristics and roles of informations about agricultural production systems.
The results obtained are as follows;
1. Taking rc a ratio of yield prices to current prices, investment efficiency is larger than 1.0 when γc ranges from 0.1 to 1.0, but smaller than 1.0 when γc is larger than 1.0.
2. In the case that prediction probability of the systems and yield prices are constant, amount of information available to decision makers has a maximum restriction.
3. A degree of use of information, which is available to decision makers in the process of agricultural production, is affected by yield prices C. In the case of this paper, the degree is nearly satulated and the rate of increase is small when C is larger than 1.0. Consequently, if yield prices raise up, it is not only difficult to obtain good results by acting on maximum expectation criterion but also is losing, without improvement of system prediction accuracy.
4. Values of information depreciate as stages go by and the rate is proportional to yield prices.

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From the results of time study of works uisng power tiller for tilling and puddling, the effect of the location and feature of field on the working efficiency is considered as follows;
(1) Natural features were divided into three main parts: plain, foot, mount. On three parts, each total time of tilling work per a day is equally 650.4min., but the time of main work (to till a field) and annexed work (to move from field to field) is different between three parts.
(2) The each rate of main work for total time is 60.5% (plain), 59.7% (foot), 45.5% (mount), It is observed that tilling work is more efficient on plain than on foot or mount.
(3) From such a result, it is considered to be given a coefficient of field and a coefficient of natural features. It is sure that they are useful for makiug a plan of work using machines.

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Design of the instrumentation car and its vibration analysis were mainly reported in this paper.
1) The dimensions of the instrumentation car have been determined through strength-rigidity calculations. 16 rubber wheels were used so that the transmitted vibrations to the instrumentation car could be reduced to the minimum.
2) Assuming 1 or 2 degrees of freedom for the vibration system of the two test cars which are spring-hitched each other and forced by frictions, the vibration analysis was performed. A spring hitch which reduced the vibration to the minimum was desiged through this analysis. The analytical solutions agreed well with the test results in the low frequency range of under 30Hz.
3) An emergency brake which was actuated by a coil spring in a hydraulic cylinder proved to be effective. A stopper device for emergency was designed for low speed range of under 2.5m/sec.

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This experiment was conducted to examine the effects of hull on the drying characteristics of rough rice. The experimental apparatus used was the same as the one reported in previous papers (ref. 1, 2).
Results obtained were shown in Figs. 1 through 3.
1) The drying curves of one grain of hulled rice showed either the constant drying period or the falling period from the beginning and were influenced by both the temperature and the relative humidity of the air.
2) The drying rate of one grain of hulled rice was larger than the drying rate of one grain of unhulled rice and reached the equilibrium moisture content in shorter drying time.
3) The cracking of hulled rice occured from air temperatures of 40 C up (Table 1).
4) Therefore it seemed that the hull worked as resistance to the drying of rough rice wrapped by husk and also as protective material against cracking of brown rice which was contained in rough rice.

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When analyzing the grain drying performance, it is most difficult to measure grain moisture content continuously, which becomes a bottle-neck in automating the grain drying operation. The authors proposed an appropriate method to estimate the grain drying process, computing the state of inlet and exhaust air.
By means of this method we can follow the drying process continuously without disturbing the drying operation so that the method could be considered to be applicable to automatic control of grain drying.
Using this method the authors analyzed the intermittent (tempering) drier performance and the following tendencies are recognized from nine rice drying experiments.
1) Humidity ratio increment (Δx) curves which also represent the drying rate, have the tendency shown in Fig. 10. At the beginning of the 1st pass the drying rate increases, while at the middle remains constant and at the end of the 1st pass the drying rate decreases.
In the 2nd pass the curve does not continue from the 1st pass but begin at higher value. The 3rd pass curve has the same tendency as the 2nd but lower in value.
2) The typical enthalpy difference (Δ_i) curves are shown in Fig. 11. At the beginning of each drying pass Δ_i shows the positive value, especially highest value in the 2nd pass. This phenomena is explainable that the rice is dried getting the enthalpy also from the rice itself. After that Δ_i decreases and shows the negative value at the minimum, which is considered to be caused from the enthalpy consumption for heating the rice.

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This paper is concerned with aerodynamic properties at suspension velocity of forage stem particles of various length, diameter and moisture.
Some general characteristics of the behavior of these various paticles in a supporting airstream were also investigated. The orientation of stem particles in the supporting airstraem is determined by the length-to-diameter ratio.
The short pieces of stem (2-3.3 in the ratio of length-to-diameter) tend to orient toward the vertical, while the long pieces (5-10 in the ratio of length-to-diameter) tend to assume a horizontal attitude.
Stem samples were observed to spin in the supporting airstream. Observation indicated that the short pieces of stem rotate round a vertical axis and the long pieces tend to a inclined or horizontal axis.
The suspension velocity of stem particles is influenced by the behavior in the airstream. The practical suspension velocity of short pieces become relatively higher than that of long pieces.

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The fundamental characteristics of wafering of Guinea-grass hay were experimented by use of a roller-die apparatus with groove, and following results were obtained.
1. The performance of pushing hay into die hole (in this roller-die method) was generally not so good as piston type, but it was improved by close falling of the roller into the die groove, and the degree of hay crush was reduced.
2. The vertical force V was about 3-5 times of horizontal force H on the roller shaft, each maximum value of two compornents were about 1.47 and 1.44 times of each mean value, respectively.
3. When the experimental conditions were impertinent, the die hole was plugged or hay was discharged in pieces from die bottom.
4. Generally, the vertical force V was reduced with the increase of hay temperature. When the moisture content of hay was same, the V value of water added hay which was sprayed after dried down to 14% m. c. was smaller than that of hay dried from high moisture, The V indicated, generally, the maximum value at moisture content of 20-25%, and slightly increased with the increase of compression speed that is travel speed of the roller.
5. The wet density ρ_w, the dry density ρ_d, the tensile strength T_s and the falling shock durability W_r of wafer were increased with the increase of hay temperature.
The maximum value of magnification of dry density of wafer to that of hay was about 62 at 80°C and 25% m. c. of hay.
6. In case of same moisture content of hay, the ρ, T_s and W_r values of water added hay wafer were fairly smaller than those of dried hay wafer when the moisture content was 20% and the temperature was 80°C.
7. On the dried hay at 80°C, the order of ρ, T_s and W_r values of wafer due to the hay moisture contents were as follows;
20-25%>30%>14%,
those values indicated the maximum at moisture content of 20-25%. On the water added hay at 120°C, the order of ρ and T_s values were as follows;
14%>20%>25%≥30%,
that is both characteristics were increased with the decrease of moisture content, but the order of W_r value was
20%>25%>30%>14%.
8. At the normal temperature (15-22°C), the contraction of width or thickness with taper and the extension of die length were not particularly effective on grass hay.
9. The correlation between the components of force and durability (include densities, tensile strength) was not recognized.
10. Some similarity among the densities, tensile strength and falling shock durability was recognized, but strong correlation between the densities and other two was not especially recognized. A considerable similarity between the tensile strength and falling shock durability was fund, but it was considered that the falling shock durability was most desirable as the standard of durability indication of wafer.
11. On this roller-die method, in case of dried hay, the practical wafer was obtained by heating the die up to the temperature of 80°C in the region of 20-30% m. c..
In case of the hay dried down to 14% m. c. and the hay which was added water up to 20-25% m. c., they had to be heated up to about 120°C to obtain the practical wafer.

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In order to study the basic data for the automatic control of degreening method, the authors investigated the effects of ethylene concentration and fruit temperature on both the rate of respiration and the change of peel color.
The results obtained are as follows.
1. Foundamental experiment using a desiccator:
(1) When Citrus Unshiu, having a general characteristic of decreasing in respiration rate after picking, was exposured to the air included with a slight content of ethylene, the respiration rate increased in 2 to 3 hours and reached in its high peak in about 30 hours.
(2) The respiration rate of the fruit increased with the content of ethylene up to 100ppm, and almost maintained the same rate at the higher concentration.
(3) The fruit exposured to the atomosphere of some ethylene concentration was wilted in the peel and lost the gloss. Especially, the calyx was perished into the concentration of 1000ppm.
(4) The relation between the ethylene concentration and the amount of respiration-heat produced by the fruit for 30 hours was investigated to give the criteria of adequate air circulation, cooling capacity and stacking method of the load.
(5) The respiration rate of the fruit increased with the rise of fruit temperature and the relation between the two was expressed as follows.
Q=5.94×10^0.0401T
Q: respiration rate (CO₂mg/kg·h)
T: fruit temperature (°C)
2. Degreening test by the pilot plant
(1) Fruits treated with ethylene in a pilot plant was inclined to be vanished their green color and accompanied with the emergence of oil cell to the surface of the peel. This tendency was remarkable in the case of the fruits with the color degree of 7 (7/10 yellow).
(2) Weight loss of the fruits of ethylene-treated, in spite of the increase in respiration rate, is less than that of the control up to the lapse of 4 days.
This is because the fruits were being held in the atomosphere having higher humidity than about 90% RH.
(3) Brix and specific weight of the juice showed little differene between the control and the treated.
On the other hand, the content of citric acid of the treated diminished more or less than that of the control.

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