Search Results (2)

This study investigates growth responses, heavy metal (Cd, As) uptake, translocation, and mineral nutrient regulation in leafy vegetables with varying heavy metal tolerance, addressing the threat posed by combined Cd and As pollution. Three high-tolerance, four moderate-tolerance, and one sensitive leafy vegetable were grown in Cd+As-contaminated hydroponics. Post-harvest yields and concentrations of Cd, As, and trace elements were assessed. Results showed that (1) compared with single heavy metal treatments, the combination of Cd and As significantly increased the translocation factor of Cd in black bean sprouts and white radish sprouts by up to 83.83% and 503.2%; (2) changes in mineral nutrient concentrations in leafy vegetables were similar between single and combined heavy metal stresses, but the regulatory patterns varied among different leafy vegetable species; (3) under Cd/As exposure, high-tolerance leafy vegetables (e.g., pak choi) had strong heavy metal accumulation abilities, and heavy metal stress positively regulated mineral elements in their roots; In contrast, sensitive leafy vegetables (e.g., pea sprouts) often exhibited suppressed mineral element content in their roots, which was a result of their strategy to reduce heavy metal uptake. These results offer key insights into resistance mechanisms against combined heavy metal pollution in leafy vegetables, supporting phytoremediation efforts and safe production. Full article

In view of the low level of mechanized harvesting of white radish in China and other developing countries and the current situation of “no machine can be used” due to the expensive imported machines, a self-propelled white radish combine harvester was designed based on the material, growth characteristics, and agronomic pattern of white radish. This combines harvester can realize the functions of white radish tassel gathering, deep soil loosening, clamping and conveying, tassel cutting, and collecting. In this research, the overall design of the harvester is described, and the structural and working parameters and kinematic requirements of the tassel gathering device, clamping and conveying device, tassel cutting device, and vibrating deep loosening device are determined by mechanical and kinematic analysis. Innovatively, a range of values for the tassel gathering speed ratio of 1.7–4.2 is proposed for the operation of the tassel gathering device suitable for white radish harvesting. The prototype was bench tested with the loss rate, damaged rate, and impurity rate as performance evaluation indexes. The results show that under the pitch of 240 mm between the taper angle of the tassel-raising device, a speed of 80 rpm for the tassel gathering device gathering claw belt rotation, a speed of 120 rpm for the clamping and conveying pulley rotation, a vibration frequency of 2 Hz and an amplitude of 15 mm for the vibrating deep loosening device, and a forward speed of 0.5 m/s (tassel gathering speed ratio: 1.7). The loss rate was 2.75%, the damage rate was 4.99%, and the impurity rate was 1.64%. During the operation, the innovatively designed white radish leaf gathering device can better fulfill the function of tassel gathering, and the systems worked well together, meeting the requirements of mechanized combined harvesting of white radish, but the adaptability to complex working conditions in the field needs to be further strengthened. This research can provide a reference for the design and optimization of mechanized white radish harvesting equipment. Full article