The storage period of paddy is a critical factor affecting rice quality, and it is still unclear how fresh rice noodles, primarily made from paddy, respond to changes in the storage period. To elucidate the relationship between the paddy storage period and the quality of fresh rice noodles, this study used fourteen rice varieties as materials and set up three paddy storage periods (six months, nine months, and twelve months). It explored the quality variation patterns of fresh rice noodles processed from these paddies and analyzed the relationship between the two in conjunction with rice quality. The results indicated that fresh rice noodles produced from paddies stored for nine months exhibited superior quality compared to the other two storage periods. Grey relational analysis and correlation analysis confirmed that this was primarily attributed to changes in the gel consistency of the paddy. When the paddy was stored for nine months and the rice gel consistency was approximately 32 mm, the quality of the fresh rice noodles produced was optimal, serving as an important basis for selecting raw materials for fresh rice noodles.

To sustain agricultural productivity and safeguard global food security, and confront the escalating challenges posed by climate change and water scarcity, it is essential to enhance the growth and productivity of rice under water stress. This study investigated the effects of lanthanum chloride on the chlorophyll fluorescence characteristics and grain yield of rice under different irrigation modes. The rice cultivar H You 518 was selected and sprayed 20, 100, or 200 mg·L⁻¹ lanthanum chloride at the booting and heading stages under deficit irrigation (where no rewatering was applied after the initiation of stress, allowing the water layer to evaporate naturally under high temperatures) or conventional irrigation (with daily rewatering to maintain a consistent water level). The results showed that the application of low concentrations lanthanum chloride promoted the chlorophyll content, whereas high concentrations decreased the chlorophyll content, under deficit irrigation, the effect of lanthanum chloride on the green fluorescence parameters of rice leaves at the booting stage was greater than that at the heading stage, and the booting stage was more sensitive to water deficit. The application of 100 mg·L⁻¹ lanthanum chloride reduced the initial fluorescence (F0) and the non-photochemical quenching coefficient (qN); promoted the activity of leaf photosynthetic system II (PSII); and maximized the photochemical quantum yield (Fv/Fm), photochemical quenching coefficient (qP), and PSII relative electron transfer efficiency (ETR). Under deficit irrigation, this treatment significantly enhanced grain yield by increasing the thousand-grain weight, spikelet filling rate, and number of grains per panicle. These results suggest that spraying 100 mg·L⁻¹ lanthanum chloride at the booting stage under deficit irrigation can effectively increase the chlorophyll content, thereby increasing the light energy conversion efficiency of the PS II reaction center, ultimately resulting in increased spikelet filling rate and grain yields.

In early rice cultivation, the age of seedlings plays a crucial role in ensuring the annual safety production of double-cropping rice. When sowing staging and transplanting are performed simultaneously, it is still necessary to gather more data about the effects of seedling age on the growth period and grain yield of early rice machines transplanted. Two years ago, field experiments were conducted on machine-transplanted rice seedlings in the early season to compare the growth duration, crop growth characteristics, and yield attributes between the 18-day-old seedlings (SA18) and 32-day-old seedlings (SA32) of two rice cultivars. As a result of the study, it was found that SA18 reduced the total crop duration by between 11 and 12 days but delayed the maturity date by 2–3 days compared to SA32. SA18 had 14.5% fewer panicles per m² and 3.6% less harvest index but 7.5% more spikelets per panicle higher than SA32. The grain yield of SA18 was 3.4% less than that of SA32, but there was no significant difference between the two seedling ages. The machine-transplanted seedlings for early rice production are more efficient in reducing seedling management time without affecting harvesting time and yields. The authors provide a new cultivation management scheme for farmers who are interested in planting double-cropping rice at the same time.

Mechanical transplanting often causes root damage to rice seedlings, but its yield impacts in double-cropping systems remain unclear. A two-year field experiment was conducted in early- and late-season rice under three root damage treatments: no damage (CK), mild root damage (T1, seedling roots pruned to 2 cm), and severe root damage (T2, seedling roots pruned to 1 cm). Results showed that T2 reduced early-season rice yield by 8% but had no significant effect on late-season rice, while T1 did not affect yield in either season. In early-season rice, the yield loss was associated with reduced pre-heading biomass (BM_Pre) and total biomass (both 13% lower than CK), primarily due to decreases of 5–32% in SPAD, leaf area index, specific leaf weight, pre-heading crop growth rate, and leaf area duration, with no post-heading compensation. In contrast, late-season rice sustained yield despite a 9% reduction in BM_Pre (attributed to similar leaf trait reductions of 4–26%) by enhancing post-heading biomass (16% increase), driven by a 17% increase in post-heading crop growth rate and an 11% decrease in the rate of leaf area decline. Partial least squares path modeling confirmed that biomass dynamics, rather than yield components, constituted the primary pathway linking root damage to yield. These results demonstrate that the impact of root damage is season-dependent, highlighting the need for root protection in early-season rice and the exploitation of compensatory capacity in late-season rice to optimize mechanical transplanting practices.