Weeding is an important agricultural unit operation. Delay and negligence in weeding operation affect the crop yield up to 30 to 60 per cent. Weeders are used for all the intercultural operations performed in the field among which power weeders are mostly used nowadays and are also one of the most important intercultural machines for small or marginal agricultural field/crop famers. It is also more economical machine as compared to other manual or mechanical weeders. The present study deals with the design modification of existing power weeder and making it suitable for dry field condition. This research work was carried out in Department of Farm Machinery and Power Engineering, IGKV, Raipur (C.G.). The existing power weeder works well in wet land conditions but by modifying some parts of weeder and adding few parameters such as â€œCâ€ type Blade, Removable extension shaft and transport wheel it performs well in dry field conditions and even it also works more effectively when compared with wet land conditions. Overall, the machine was found satisfactorily and was best suited to opt in both conditions of land i.e. dry and wet.

https://www.phytojournal.com/archives/2018/vol7issue1/PartQ/7-1-133-199.pdf

Modification of power operated single row rice weeder for dry field condition

nique is presented for the volume estimation of very irregular small biomaterials (wheat and rice-paddy grains). Two common cylindrical small biomaterials, the Alvand variety of wheat grain and the Neda variety of paddy grain were considered for examination. The captured images were exported to be processed by an image processing software (ImageJ) and the edge-extracted image was used in SolidWorks for the 3D reconstruction of the model. The revolved images in the SolidWork were used to estimate the volume of the examined grains. The estimated volume was then compared with the conventional mathematical expression and also with the real volume measurement using the fluid displacement method. Volume estimation using machine vision and image processing techniques has a considerably lower mean error (9.5%) in comparison to the mathematical error (14.7%). The average value of cylindricity for Alvand wheat was found to be equal to 82.34% at a moisture content of 11.83%. The new cylindricity factor had a significantly smaller standard deviation in comparison to the standard deviation of the sphericity factor for the examined cylindrical crops (61.5% for the wheat grains and 59.6% for the paddy grains). The new cylindricity factor can be used for the heat and mass transfer modelling of cylindrical crops. K e y w o r d s: machine vision, physical properties, volume, image processing, ImageJ, sphericity INTRODUCTION Huge postharvest losses occur in the handling and processing of high-quality food products and biomaterials due to the non-optimized design of certain equipment (Narendra et al., 2010). Cereals are one of the most prominent nutrition materials in Iranian food consumption. More than 50 percent of the nutrition material for each Iranian is provided by different kinds of breads (Mirasi et al., 2014). Therefore, a knowledge of the physical properties of the cereals is necessary for manufacturing optimized devices for handling, cleaning, conveying, storing and milling (Unal, 2009; Kalantari, 2016; Kalantari and Eshtavad, 2013). An understanding of the aeroand hydrodynamic properties of agricultural products is required for the movement of biomaterials by water or air and the separation of foreign materials from them. The density, shape and drag coefficient are the physical properties required to calculate the terminal velocity of an object in a fluid. In air transport or pneumatic separation, the air velocity is greater than the terminal velocity of the object. Moreover, for small biomaterials such as grains to descend slowly, the air velocity must be slightly lower than the terminal velocity. © 2022 Institute of Agrophysics, Polish Academy of Sciences D. KALANTARI et al. 28 Therefore, the shape of the biological material, i.e., spherical or cylindrical, has a very important role to play in grain flow through the discharge gates of silos and grain drills, as well as determining the air flow around the grains during movement which in turn allows for the determination of the drag coefficient (Chen et al., 2020; Kalantari, 2016; Dziki and Laskowski, 2005). For most cereals, the bulk porosity is between 35 and 55%; therefore the porous nature of the grain mass provides the possibility that in the blowing and drying process, almost all of the grains are in contact with air (Navarro and Noyes, 2002). Another important physical property of agricultural crops and materials is volume, which is an important parameter in the mass transfer and heat transfer of these biomaterials. Several mathematical expressions have been proposed for computing and estimating the volume of irregular materials (e.g., Kheiralipour et al., 2008; Unal 2009; El Fawal et al., 2009). As an example, the temperature rise of a biomaterial, e.g., a cereal grain in a microwave field is equal to Eq. (1) (Jafari et al., 2018):

Development of a machine vision system for the determination of some of the physical properties of very irregular small biomaterials

A manual type operated weeder was designed and developed at the workshop of the Department of Farm Machinery and Power at BCKV, Nadia district, West Bengal, India. This Study was conducted to know the design features of manually operated weeders for paddy weeding. The weeder was made of locally available materials to reduce the cost of weeding. The weeder was tested at the experimental field of the Department of Farm Machinery and Power to evaluate its functional and economical parameters. The travel speed of this type weeder is 1.3 km/h. The weeding efficiency of weeder was found 65.6% to 74.2%. The average field capacity of the weeder was observed as 0.013 ha/h. 
The field efficiency of this type weeder was found as 81.2%. The plant damage of this weeder was found as 2.96%. Operating cost of this type weeder is Rs. 3557.3/ha. Therefore, designed of this type weeder is the best in terms of cost of operation and it is more economical compared to other weeding operation.

Design and Fabrication of Manually Operated Paddy Weeder

Automatic hydraulic adjustable rotavator is obstacle sensing unit and will take action on it as it will move entire structure to the either side. Rotavator is a specialized mechanical tool used for tillage of soil by series of blade. Now a day, utilization of rotavator has been increased in agricultural application because of simple structure and efficiency. However the use of rotary tiller is strongly restricted to shallow type tillage purpose because of high forces coming on blade, life span of blade is less and which result in higher maintenance cost. When rotavator is pulled through a field, the resulting soil texture will be a function of soil condition and geometry of blade. We will use hydraulic actuator  for the shifting moment of frame as we have inbuilt hydraulic pump in tractor.

Automatically Hydraulic Adjustable Rotavator

One of the widely used tillage implements in gardens and paddy fields is rotary tiller, which can prepare the seed bed in a single step. However a special consideration in using rotary tillers is the unevenness of the bottom of the furrows due to the consecutive intersection of two adjacent trochoids, i.e., blade trajectories, yielding roiling and displacement of a seed inside the furrow in precision planters. Precision planting is possible when furrow unevenness is reduced to a minimum and meanwhile planting depth remains constant. This is especially important when the distance between two neighbor seeds in a row is low. This paper studies analytically the effect of design parameters of the rotary tiller on the quality of the furrows. The obtained results indicate that height of unevenness of the furrows decreases with increasing the number of blades on each flange, increasing the rotor speed and decreasing the forward velocity.

Effect of Design Parameters of Rotary Tillers on Unevenness of the Bottom of the Furrows

An analytical and experimental study is performed in this paper for evaluation of discharge rate of grain flow from different discharge gate of a grain seeder. Three different apertures (circular, rectangular and square shape with the same area) have been considered in this study. Based on the experimental and theoretical results obtained in this study, it is shown that the discharge rate of the circular aperture is the maximum. In contrast, the squared aperture has a minimum discharge rate. It is also found that with increasing the grain height in the tank, the discharge rate does not change significantly. Regarding the non-uniform and oscillating discharge from a squared aperture, it is not recommended to use for discharging grain materials from a reservoir, grain drills or silos and storage tanks.

Davood Kalantari

Papers

Effect of Design Parameters of Rotary Tillers on Unevenness of the Bottom of the Furrows

Grain Flow from Different Discharge Gates in a Grain Seeder