Mechanics Characteristics of Tray Nursery of Tobacco Seedlings

In order to design a mechanized seedlings pickup machine, ‘Gexin 1’ tobacco seedlings, which was in nurture transplanting period, were taken from the greenhouses of Shandong Agricultural University as test material. Some mechanical properties of the seedlings such as plucking force, tension and compression intensities of the seedlings stem, bending intensity, and shearing intensity were carried out with a universal test machine. The results showed that the plucking force of tobacco seedlings was (2.09±1.28)N when the nutrient substrate moisture content was of (52.70±6.50)%;the stem tension intensity was of (1.96±0.68)MPa when the moisture content of the tobacco seedlings stem was of (85.15±2.21)%;the stem radial compression intensity and the axial compression intensity of the stem at the bottom and the central part were of (0.096±0.043), (1.20±0.34), (1.28 ±0.28)MPa, respectively;the charpy elastic modulus and the cantilever elastic modulus were of (0.0042±0.0018), (0.0130 ±0.0062) MPa;the shear intensity was of (1.64±0.39) MPa. The results provide a theoretical basis for the design of mechanized seedlings pickup machine.