Sugarcane (Saccharum spp.) is an important sugar and energy crop worldwide. As a core regulator of the salicylic acid (SA) signaling pathway, nonexpressor of pathogenesis-related genes 1 (NPR1) plays a significant role in the response of the plant to biotic and abiotic stresses. However, there is currently no report on the NPR1-like gene family in sugarcane. In this study, a total of 18 NPR1-like genes were identified in Saccharum spontaneum and classified into three clades (clade I, II, and III). The cis-elements predicted in the promotors revealed that the sugarcane NPR1-like genes may be involved in various phytohormones and stress responses. RNA sequencing and quantitative real-time PCR analysis demonstrated that NPR1-like genes were differentially expressed in sugarcane tissues and under Sporisorium scitamineum stress. In addition, a novel ShNPR1 gene from Saccharum spp. hybrid ROC22 was isolated by homologous cloning and validated to be a nuclear-localized clade II member. The ShNPR1 gene was constitutively expressed in all the sugarcane tissues, with the highest expression level in the leaf and the lowest in the bud. The expression level of ShNPR1 was decreased by the plant hormones salicylic acid (SA) and abscisic acid (ABA). Additionally, the transient expression showed that the ShNPR1 gene plays a positive role in Nicotiana benthamiana plants’ defense response to Ralstonia solanacearum and Fusarium solani var. coeruleum. This study provided comprehensive information for the NPR1-like family in sugarcane, which should be helpful for functional characterization of sugarcane NPR1-like genes in the future.

A two-year field study evaluated biodegradable plastic film (BPF; thicknesses: 0.006, 0.008, and 0.010 mm) versus polyethylene film (PE; 0.010 mm) and no-mulch control on sugarcane yield and weed suppression. Key results demonstrated that 0.010 mm BPF significantly enhanced sugarcane emergence (CV = 5.07% in ratoon), reduced weed biomass by 70%, and increased perennial yield by 3.83% (+5.6 t ha⁻¹), while PE film decreased yield by 3.80%. Regression analysis identified the effective stem number, plant height, and stem diameter as primary yield predictors (R² = 0.996). Logistic models revealed that film mulching duration >119 days was critical for achieving high yields (>122.2 t ha⁻¹) and sustained weed control (R² = 0.81). These findings establish 0.010 mm BPF as an optimal sustainable alternative to PE film for enhancing sugarcane productivity.

Ratooning is an important cultivation practice in sugarcane production around the world, with underground buds on the remaining stalk acting as the source for establishment of a subsequent ratoon crop. However, the optimal depth of cutting during harvest in terms of yield and root growth remains unknown. We carried out a two-year field study to determine the effects of three cutting depths (0, 5 and 10 cm below the surface) ratoon cane root and yield. Results showed that cutting to a depth of 5 cm increased the root fresh weight and root volume by 32-40% and 49-85%, respectively, compared to cutting depths of 0 and 10 cm. Remarkably, cutting to a depth of 5 cm also had a significant effect on the development of fine roots, which is closely linked to cane yield. The effect was particularly noticeable in terms of two root traits, root volume and the surface area of roots with a diameter of 1.0-2.0mm, and root length and the number of root tips in roots with a diameter of 0-0.5mm. As a result, a cutting depth of 5 cm below the surface increased cane yield by 35 and 25% compared to depths of 0 and 10 cm below the surface, respectively. Overall, these findings suggest that a cutting depth of 5 cm is optimal in terms of sugarcane yield, largely due to the enhanced effect on root traits, especially the development of fine roots. These findings will help optimize sugarcane ratoon management and improve the ratoon cycle.