In maize soybean intercropping-system maize plants significantly increase the shade density at soybean canopy, and few people studied the threshold level of shade for sustainable production of soybean in this system. This experiment was started to determine the effect of four different shade treatments T75 (75%); T50 (50%); T25 (25%); T0 (0%, control) on morphology, physiology and yield of soybean plants. Relative to T75, treatments T25 and T0 significantly increased the stem diameter and stem breaking strength while plant height was decreased. The chlorophyll a, chlorophyll b, and chlorophyll a + b, photosynthetic and chlorophyll fluorescence characteristics were improved as shade decreased, and maximum values were observed in T25 and T0. Similarly, enzymatic activity of Rubisco was accelerated from T75 to T0. However, genes related to sucrose synthesis (SS and SPS) were down-regulated by increasing shade (T75). Importantly, non-significant differences were measured for seed-yield between T25 and T0, and the plants of soybean under T25 produced 88% of T0 yield. Overall, these results implied that agronomist should develop an appropriate intercropping planting pattern where the maximum shade density ranges from 20 to 30 % to obtain higher seed yield of soybean crop under intercropping-system.

Ray traits affect secondary xylem development and wood properties. Pinus massonia and Cunninghamia lanceolata, commercially important timber species, were chosen to study the differences in wood ray traits of juvenile versus mature wood. Seven ray traits, i.e., percentage of rays, ray spacing, ray number, uniseriate ray height, fusiform ray height, ray parenchyma cell length and ray tracheid length, as well as eight wood axial tissue traits, were investigated quantitatively. Intraspecific variations in ray traits and axial tissue traits between juvenile wood and mature wood were displayed in violin plots. The results showed that anatomical differences between juvenile wood and mature wood were significant for both ray traits and axial tissue traits. Juvenile wood generally possessed the larger percentage of rays, higher ray spacing and ray number, smaller ray height and shorter ray cells than mature wood. A positive correlation was present between the ray parenchyma cell length and ray tracheid length. Negative correlations of the ray number and ray spacing with uniseriate ray height were found. Additionally, the axial tracheid cell wall thickness all had Pearson’s correlations with ray spacing, ray number and ray parenchyma cell length.

Various factors and propagation trends of stress waves in cross sections of wood need study to improve accuracy in the quality evaluation of wood and decay detection in standing trees. In this study, a Fakopp Microsecond Timer was used to measure the stress wave transmission time of Euphrates poplar (Populus euphratica Oliv.). Velocity was calculated to find the trend and make wavefront maps of stress waves. Results indicated that stress waves travel fastest in the radial direction and that velocity decreased as the angle between the two sensors increased. Velocity also increased as the number of annual rings increased. At the same time, the velocity in normal wood was higher than it was in tension wood, and it gradually increased in normal wood as the radial distance increased from pith to bark. Different influences on the stress wave propagation in wood were found when holes were made in the center of a cross section. Velocity showed little change with the increase in hole diameter when the angle between impacting and receiving sensors was 90°. At 180°, velocity was affected by hole diameter and rapidly decreased. Successful simulated wavefront maps of stress waves in cross sections of sound, hole, crack, and decay wood using two-dimensional contours were made. Three-dimensional maps were also reconstructed using Kriging interpolation and showed high similarity between cross sections.