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NiTi98-xSixC2 (x = 0, 4, 8 wt%) coatings were prepared on Ti-6Al-4V substrate by laser cladding to improve the surface mechanical properties of NiTi coatings. The effects of Si content addition on the microstructure, phase composition, microhardness, and tribological properties of the coatings were systematically analyzed. The results show that NiTi98-xSixC2 (x = 0, 4, 8) coatings are mainly composed of NiTi, NiTi2, TiC, and Ti5Si3 phases. The rod-like phase of Ti5Si3 was found in NiTi90Si8C2 coating, while the rod-like phases were found broken. The fragmentation of the rod-like phase is related to the growth of the NiTi phase around it. At the same time, TEM results show that the NiTi (B2) phase and Ti2Si second phase are exited in the NiTi90Si8C2 coating. Ti2Si, which has not been decomposed into Ti5Si3, remains during the laser cladding process. In addition, the eutectic structure in NiTi90Si8C2 coating was observed in some regions. The average microhardness of the NiTi98-xSixC2 (x = 0, 4, 8) coating were at 534.08 HV0.5, 598.06 HV0.5, and 974.08 HV0.5, respectively. The wear resistance of NiTi98-xSixC2 (x = 0, 4, 8) coatings increased with the increased Si content. The NiTi90Si8C2 coating exhibits the highest microhardness (974.08 HV0.5) and wear resistance (friction coefficients, wear trace, widths loss weight, and wear rate are 0.320, ~1.25 mm, 12.2 mg, and 5.78 × 10−6 g/Nm, respectively). In NiTi90Si8C2 coating, Ti5Si3 phase plays a significant role in the second phase strengthening to improve its tribological properties. The above analysis confirms that NiTi90Si8C2 coating has optimal tribological properties.

A field experiment was conducted to investigate the effects of paclobutrazol on ear characteristics and grain yield by regulating root growth and root-bleeding sap of maize crop. Seed-soaking at rate of 0 (CK1), 200 (S1), 300 (S2), and 400 (S3) mg L−1, and seed-dressing at rate of 0 (CK2), 1.5 (D1), 2.5 (D2), and 3.5 (D3) g kg−1 were used. Our results showed that paclobutrazol improved the ear characteristics and grain yield, and were consistently higher than control during 2015–2016. The average grain yield of S1, S2 and S3 were 18.9%, 61.3%, and 45.9% higher, while for D1, D2 and D3 were 20.2%, 33.3%, and 45.2%, compared to CK, respectively. Moreover, paclobutrazol-treated maize had improved root-length density (RLD), root-surface area density (RSD) and root-weight density (RWD) at most of the soil profiles (0–70 cm for seed-soaking, 0–60 cm for seed-dressing) and was attributed to enhancing the grain yield. In addition, root-activity, root-bleeding sap, root dry weight, diameter and root/shoot ratio increased by paclobutrazol, with highest values achieved in S2 and D3 treatments, across the whole growth stages in 2015–2016. Our results suggested that paclobutrazol could efficiently be used to enhance root-physiological and morphological characteristics, resulting in higher grain yield.