Quattro-TK5 is a new, snow-endurant, early-heading cultivar developed for double-crop cultivation in locations with 80 days of snow cover. Areas with 100 days of snow cover are unsuitable for Quattro-TK5 cultivation. This study investigated the yield and map cultivation area of Quattro-TK5 in nine locations in Japan. This strain showed better snow endurance and headed three days earlier than Waseaoba, which previously had the best snow endurance among early-heading cultivars in Japan. In locations with prolonged snow cover, the dry matter yield of the first cut of Quattro-TK5 at the heading stage was superior to that of Waseaoba. In areas of short snow cover, the dry matter yield of the first cut of Quattro-TK5 at the heading stage was equal to that of Waseaoba.

Organic farming is a cultivation practice with a lower environmental burden than conventional farming. The low yield and the difficulty of weed control in organic farming can be resolved by developing new suitable cultivars. This study investigated the adaptability of Monster Rice 2 (MR2), a new rice line with extra-long culms and high fertilizer use efficiency, to the three aspects of organic farming: growth under green manure (GM) application, weed competitiveness, and deepwater avoidance by comparing it with a semidwarf cultivar, Takanari. In GM application, the above-ground biomass of MR2 at the heading stage was marginally higher than that of Takanari due to a higher net assimilation rate. Although MR2 did not have higher weed competitiveness, it had a better survival rate and growth than Takanari under 20 cm of water in the early growth stage, when most weeds are typically exterminated. These MR2 properties are partially attributable to SD1, an allele that promotes shoot elongation, based on the results that a near-isogenic line of SD1 showed slightly higher growth in GM application and significantly higher deepwater avoidance than Takanari. Our results suggest that long-culm rice has notable future utility and that MR2 could serve as a prototype breeding material in organic farming.

Although sub-Saharan African countries comprise a large amount of low-grade phosphate rock (PR), they do not consume this because of the high cost of P fertilizer processing. For less expensive P fertilizers, a suitable processing method must be selected for each low-grade PR. As phosphate solubility and suitable processing differ by PR, ten low-grade African PRs were collected from different countries and analyzed. Their phosphate solubilities correlated with their chemical and mineralogical compositions. Based on mineral composition-related results supported by TG-DTA and XRD analyses, we broadly classified the ten low-grade African PRs into five groups. These low-grade PRs consisted mainly of hydroxyapatite and were suitable for direct application to agricultural land as powdered PR. Low-grade PRs with low Fe and Al contents are suitable for partial acidulation and may be effective, whereas low-grade PRs with high Fe, Al, and heavy metal contents are suitable for high-temperature treatment. Regardless of the difference in origin, the phosphate solubility of low-grade African PRs is indicated by 2% citric acid solubility, assuming a dependence on the crystallite sizes of francolite and fluorapatite.

The rice stink bug, Niphe elongata (Dallas) (Hemiptera: Pentatomidae), is a re-emerging pest that has seriously infested rice over a wide area of western and central Japan since the 2000s. This study developed a novel method for rearing this insect using mixed grains of brown rice, wheat, and foxtail millet supplemented with solution of vitamin C. While the body size of emerged adults reared using this method was smaller than that of field-collected ones, 39.2% of individuals developed from first instar nymph to adult at 28°C under a 16:8 h L:D photoperiod, had an average developmental period of 25.4 days. We maintained a strain of the insect for eight generations over 14 months without the addition of field-collected individuals. The diet was easy to prepare throughout the year. This convenient technique for rearing N. elongata will promote field and laboratory studies of the biology of this pest.

In Japan, invasive alien raccoons (Procyon lotor) cause severe agricultural damage. To address this issue, it is essential to understand their distribution and ecology. Using environmental DNA (eDNA) is an efficient strategy for quickly detecting their presence and determining their distributions; however, species-specific eDNA detection methods are limited for terrestrial mammals. In this study, we developed a specific qPCR-based detection method for raccoons and tested its effectiveness through captive and field samples. Species-specific primers and probes were designed for the cytochrome c oxidase subunit I (COI) and cytochrome b (cytb) regions of mitochondrial DNA. Water samples were collected from cage water and from field ponds and rivers in a raccoon habitat. For a comparison of detection sensitivity, a metabarcoding analysis targeted to mammals was performed. In captivity, raccoon eDNA was detected in cage water that had been in contact with raccoons for a short time. In field surveys, eDNA was detected at a pond where footprints were found, as well as at other sites. Additionally, the developed qPCR assay detected raccoon eDNA at a higher frequency than the metabarcoding analysis. These results indicate that the newly developed raccoon-specific detection assay is a valuable tool for eDNA monitoring.

Tobamoviruses that infect cucurbits are significant pathogens in crops of the Cucurbitaceae family, spreading through seed-borne, mechanical, and soil-transmission methods. The cucumber green mottle mosaic virus (CGMMV) and the kyuri green mottle mosaic virus (KGMMV) have been prevalent in Japan since the 1960s. In contrast, the zucchini green mottle mosaic virus (ZGMMV) has only been reported in South Korea and China. To understand the potential impact of ZGMMV on cucurbit production in Japan, we compared the systemic symptoms and virus quantities in infected plants across four cucurbit crops: cucumber, melon, watermelon, and zucchini. Each of these crops was inoculated with each virus. All the viruses caused systemic infections. However, KGMMV generally induced the most severe leaf symptoms and showed the highest accumulation of the coat protein followed by ZGMMV and CGMMV in terms of symptom severity and protein accumulation. These findings, although derived from a small-scale, short-term experiment, could be instrumental in assessing the risk these tobamoviruses pose to cucurbit production.

We investigated the impact of crop and soil conditions at the time of harvesting on the fuel efficiency of head-feeding combine harvesters and developed a correction method for quantitatively calculating fuel efficiency under comparable conditions. The fuel consumption during travel and driving increased with the softness of the soil, showing a strong correlation with the index of hardness indicated by the Yamanaka model soil penetrometer. We also confirmed that the fuel consumption during travel and driving increased with the mass of rough rice in the grain tank. As a result of a multiple regression analysis using a stepwise regression for hourly fuel consumption under various conditions, the fuel consumption during reaping, conveying, threshing, sorting, and cutting can be calculated from the flow rate of dried crop (kg s^–1), number of unhusked rice grains per gram (g^–1), and moisture content of unhusked rice (%). We used the multiple regression equation developed in this study to propose a method for extending it to other combines. Furthermore, to easily calculate the fuel efficiency of head-feeding combine harvesters in a 3,000 m² area, we developed an algorithm that accounts for each fuel consumption component in determining fuel efficiency, considering the mechanical elements of head-feeding combine harvesters and crop conditions, and confirmed its validity.

Buffalo meat is a nutritious alternative to beef, offering the advantages of lower fat and cholesterol levels. This study compared the fat characteristics of five crossbred water buffalo and five crossbred cattle. The ten growing animals averaged 22 months of age and were fed a diet of 50% Napier grass and 50% commercial concentrate, administered in two equal portions at 7:00 and 16:00 hours. During a 16-week fattening period, the total plasma cholesterol concentrations in water buffalo were significantly lower (P < 0.05) than in cattle. Additionally, the ether extract and cholesterol content in muscle tissue were significantly lower in water buffalo (P < 0.05). However, there were no significant differences between the species in relative leptin mRNA levels in fat tissue (P > 0.05) or adipocyte diameter (P > 0.05). In terms of fatty acid composition, monounsaturated fatty acid levels were similar (P > 0.05), but water buffalo exhibited higher levels of polyunsaturated fatty acids than cattle (P < 0.05). Overall, buffalo meat presents lower fat, cholesterol content, and higher essential fatty acids than beef, making it a potentially healthier choice for health-conscious consumers.

To suppress the environmental problems caused by livestock manure, we attempted to reduce the amount of nitrogen excreted in urine and feces by feeding low-crude protein (CP) diets to Japanese Black steers. The dietary CP contents were 12%-13% on a dry-matter basis in the control diet (CON, n = 4, initial body weight [BW] 268 kg) and 11% in the low-CP diet with amino acids (LCPAA, n = 4, initial BW 276 kg). The LCPAA diets were supplemented with rumen-protected lysine and rumen-protected methionine during the early and middle fattening stages. The nitrogen excretion in urine was significantly lower in the LCPAA-fed than CON-fed steers at the early (P < 0.01) and middle (P < 0.05) fattening stages. In both cases, the plasma urea nitrogen concentrations were mostly lower in LCPAA- than CON-fed steers. The BW gain during the early fattening stage tended to be lower in LCPAA- than CON-fed steers (P < 0.10), but the dietary CP content affected neither the carcass weight nor the lean weight. The dietary CP content had no adverse effect on carcass traits. These results indicate that in Japanese Black steers, the 11% CP diet throughout the fattening period suppressed BW gain during the early period but reduced nitrogen excretion.

A multi-excitation fluorometer, the Multi-Exciter (MEX), is designed to identify phytoplankton composition based on the fluorescence provided by nine different excitation wavelengths. The phytoplankton community structure was monitored using MEX off the coast of eastern Hokkaido, Japan, from 2019 to 2021, encompassing the period of an outbreak of the harmful dinoflagellate Karenia spp. (Karenia selliformis, K. mikimotoi, and K. longicanalis) in autumn 2021. MEX could distinguish the vertical structure of spring diatom blooms but not that of dinoflagellate blooms in October 2021. This is possibly because MEX identified peridinin-type dinoflagellates, whereas Karenia spp. lacked peridinin. The Karenia index was defined based on the similarities in fluorescence properties (36 combinations of the ratio of fluorescence values obtained using MEX) of representative Karenia bloom water, aiming to overcome this misidentification. High Karenia indices were observed at depths of 1 m-20 m in October 2021. This implied that Karenia spp. were distributed at depths of < 20 m during their blooms, and MEX detected Karenia blooms with their vertical structure. No Karenia spp. were observed using microscopy in May 2021; however, high Karenia indices were observed in the subsurface. Hence, the fluorometric approach is a simple and rapid method for identifying distinguishing events in the phytoplankton community when combined with sporadic microscopic observations.