Development of a Hopper-Type Planting Device for a Walk-Behind Hand-Tractor-Powered Vegetable Transplanter

Abstract

Purpose: In order to ensure that vegetable seedlings (with a soil block around their roots) are planted in an upright orientation after metering in a vegetable transplanter, they need to be dropped freely from a certain height. The walkbehind hand-tractor-powered machines do not have sufficient space to drop the seedlings from that height. In the present work, a hopper-type planting device was developed for the walk-behind hand-tractor-powered vegetable transplanter to ensure that the soil block seedlings are planted in an upright orientation. Methods: Various dimensionless terms were developed based on the dimensional analysis approach, and their effect on the planting of soil block seedlings in an upright orientation (planting efficiency) was studied. The optimum design dimensions of the hopper-type planting device were identified by the Taguchi method of optimization. Results: The ratio of the height of free fall to the sliding distance of the seedling on the surface of the hopper had the highest influence on planting efficiency. The planting efficiency was highest for plants with a height 15 ± 2 cm. The plant handling Froude number, in interaction with the design of the hopper-type planting device, also significantly affected the planting efficiency. Of the hopper design factors, the length of the slide of the seedlings on the surface of the hopper was most important, and induced sufficient velocity and rotation to cause the seedling to fall in an upright orientation. An evaluation of the performance of the planting device under actual field conditions revealed that the planting efficiency of the developed planting device was more than 97.5%. Conclusions: As the seedlings were fed to the metering device manually, an increase in planting rate increased missed plantings. The planting device can be adopted for any vegetable transplanter in which the seedlings are allowed to drop freely from the metering device.

Working Speed Analysis of the Gear-Driven Dibbling Mechanism of a 2.6 kW Walking-Type Automatic Pepper Transplanter

“…The ridge-to-ridge distance is 1500 mm, and the row-to-row distance in the same ridge is 400 mm, where the planting interval generally remains at 150 mm [35]. Seedlings are grown in a tray; after 45 days, they are transplanted into the mulched ridge [36]. Seedlings grown in a tray are generally of one or two types: plug or paper-pot seedlings.…”

“…Seedlings grown in a tray are generally of one or two types: plug or paper-pot seedlings. Whether cylindrical paper-pot seedlings (40 mm diameter and 40 mm height) are more sustainable compared to plug seedlings for a transplanting depth similar to pot height has been investigated [36,37]. Table 1 shows the variable notations, definitions, and measurement units used in the analysis.…”

“…Pepper seedlings that were 45 days old were suggested to be best suited for mechanical transplanting operations [36,37,41].…”

Kinematic Analysis of a Clamp-Type Picking Device for an Automatic Pepper Transplanter

“…For mechanical transplanting operations, seedlings are generally grown in paper pots in a plastic tray before transplanting them into the soil [31]. The 45-day-old paper pot seedlings (Ø 40 × 40 mm) are relatively convenient for mechanical transplantation in terms of sustainability and growth [32].…”

Kinematic Analysis of a Gear-Driven Rotary Planting Mechanism for a Six-Row Self-Propelled Onion Transplanter

“…Mechanized transplanting approaches for seedlings and plants have become popular in recent years since they allow minimizing production costs. Moreover, the use of semiautomatic transplanters allows more homogenous distribution of seedlings [6], which is typically inconsistent in manual transplanting due to human error [7]. However, laborers are still needed to regulate a transplanter's movement and to feed seedlings into its transplanting mechanism [2].…”