Ear rot and stalk rot are among the most hazardous diseases of corn due to their toxicity to livestock. Fusarium spp., causing ear rot, were isolated from forage corn kernels in ten Japanese prefectures. Through morphological and molecular analysis of the translation elongation factor 1α (TEF) gene, 41 isolates were identified as F. verticillioides, 36 as F. proliferatum, 27 as F. fujikuroi, 3 as F. graminearum, 2 as F. concentricum, and 2 as F. miscanthi. F. verticillioides, F. proliferatum, and F. fujikuroi produced fumonisin (FUM); F. graminearum produced deoxynivalenol (DON); F. concentricum and F. miscanthi did not produce either mycotoxin. Piercing inoculations of female ears using cultured toothpicks containing these isolates revealed that F. proliferatum, F. fujikuroi, and F. concentricum were highly pathogenic, whereas F. miscanthi showed weak pathogenicity. FUM-producing species, such as F. verticillioides, F. proliferatum, and F. fujikuroi, are believed to be the major fungi causing ear rot in Japan. F. graminearum was isolated from corn with stalk rot symptoms and showed distinct pathogenicity.

Anaerobic soil disinfestation (ASD) with water-soluble organic materials such as molasses is used to control bacterial wilt of tomatoes caused by the Ralstonia solanacearum complex, but the disease often recurs in post-ASD cultivation. Changes in the soil population density of the pathogen caused by ASD with molasses and subsequent tomato cultivation were investigated in the lower (LL, 30–60 cm) and upper (UL, 0–30 cm) soil layers from three fields with different soil characteristics to understand the causes of the pathogen density suppression and bacterial wilt recurrence. In all fields, the population density decreased in both the LL and UL after ASD. The bacterial density increased in the LL of all fields after post-ASD cultivation, but there was no difference in UL. These results indicate that tomato cultivation can increase the pathogen’s survival rate after ASD treatment. Changes in the colonization of the pathogen in soil after ASD were investigated by laboratory tests. The colonization ability of the pathogen improved in both UL and LL soil after ASD but quickly returned to pre-ASD levels with air inflow. This may indicate that aeration can reduce the risk of pathogens surviving in soil after ASD.

Using data from 466 smallholder coffee farmers in Ethiopia, this paper examines the effect of a public agricultural market information system (AMIS) on production. Our findings confirm that providing market price information via an AMIS is positively related to coffee sales, the ratio of sales to production, and coffee revenue. In addition, our study considered market heterogeneity by comparing two zones with different market characteristics. The AMIS was positively associated with increasing coffee sales, the ratio of sales to production, and coffee revenue in only one zone with lower market participation. The sales and revenue of AMIS users in the other zone with higher market participation did not increase, although the selling price did. While public information provided through information and communication technology (ICT) is beneficial to underdeveloped markets, we suggest correcting other market imperfections, which is important to maximize the utility of AMISs, would be of greater utility.

Agrivoltaics—the integration of solar photovoltaic systems with agriculture—is a growing trend worldwide. Although studies have clarified the effects of photovoltaic panels above farmland on microclimate and crops, their impact on the organisms within farmland remains poorly documented. Assessing the influence of agrivoltaic installations on organisms within farmland is crucial, as biodiversity and beneficial arthropods that prey on pests can positively affect crop yields. This study assessed the effects of agrivoltaic structures on orb-weaving spiders, which are beneficial arthropods, in Chiba City, Chiba Prefecture, Japan. Over four investigations conducted from June to September 2023, we discovered that the vertical distribution of orb-weaving spiders was concentrated in the structural braces within the photovoltaic panel framework. In terms of horizontal distribution, spiders were most prevalent in areas adjacent to forests, where prey insects were relatively abundant. These findings suggest that agrivoltaic structures, which are typically absent on farmland, can serve as scaffolding for orb-weaving spiders and that the location of web construction within agricultural fields depends on prey availability.

This study analyzed production records from Hokkaido, Japan to develop a plan for farmers to improve milk quality. Over three years, 164 dairy herds were evaluated based on two milk quality indices: herd-level somatic cell count and chronic subclinical mastitis morbidity. Farms were ranked annually for each index, and the rankings were combined to determine an overall evaluation. After a comprehensive assessment, the herds were categorized into three groups: excellent (36 herds), good (90 herds), and poor (38 herds). A comparative analysis of nine production indices, including milk quality, was conducted between the excellent and poor groups. Our study revealed that poor herds exhibited significantly smaller herd sizes, higher culling rates at specific periods, higher mortality, and a greater proportion of dead cows among culled cows than excellent herds. The increased mortality in poor herds suggests lower animal welfare standards. Furthermore, the high rate of involuntary culling indicates suboptimal peripartum management. These findings underscore the strong link between poor milk quality and compromised animal welfare. The results suggest that improving animal welfare practices can lead to higher milk quality in dairy herds.

This paper examines optimal paddy-upland rotation systems, considering the trade-offs between economic, environmental, and food security indicators (crop revenues, nitrogen fertilizer inputs, and food calories, respectively). A regional optimization model targeted at a rich rice-producing region in Hokkaido, Japan was built for the analysis. It incorporates economic and food security objective functions to be maximized and an environmental objective function to be minimized under land-use constraints. A multi-objective genetic algorithm was applied to solve the multi-objective optimization problem at the regional level. Using k-means clustering, Pareto-optimal solutions were classified into three types of clusters: economic and food security, balanced, and environmental. The total crop revenue, total nitrogen fertilizer input, and total food calories were 11.5%, 4.8%, and 42.0% higher, respectively, for the economic and food security cluster than those for the environmental cluster. Considering the low nitrogen contamination in groundwater in the targeted region, the four-year paddy-upland rotation systems based on dry direct-seeded rice, spring wheat, soybeans, and direct-seeded sugar beets, which represent the highest adoption rate (83.9%) in the economic and food security cluster, should be promoted regionally to prioritize maximization of crop revenues and food calories. These findings are useful for local policymakers.

Animal movement plays a critical role in the transmission of infectious diseases. The movement of infected cattle is suggested to contribute to the spread of chronic diseases such as bovine brucellosis and tuberculosis. When infected cattle are detected in disease-free countries, follow-up tests are conducted on all cattle with a history of cohabitation with the detected cattle to detect additional cases. Because follow-up tests require considerable human and testing resources, this study simulated the inter-regional movement of dairy and beef cows to identify regions where testing will be required after disease detection. The inter-regional movement probability was estimated from a complete set of cattle movement records in Japan, reflecting the characteristics of Japanese cattle movements between seven categories (Hokkaido, Tohoku, Kanto, Chubu, Kinki, Chugoku/Shikoku, and Kyushu/Okinawa). The results suggest that the possibility of conducting follow-up tests was higher in Hokkaido for dairy cows. In contrast, this possibility was higher for beef cows in Hokkaido and Kyushu/Okinawa, regardless of the region where the infected cows were detected. These findings are beneficial for allocating human and material resources to high-risk regions and developing more efficient disease control programs.

This study reviews the effects of low-protein diets supplemented with essential amino acids (LPS diets) on egg production performance, nitrogen excretion, and environmental gas emissions from layer-manure composting for laying hens across the entire laying period, focusing mainly on our previous studies. Compared to hens fed control diets (Cont diets), hens fed LPS diets showed no significant differences in egg-laying rates or egg weights across the laying period. Furthermore, LPS diets decreased the nitrogen intake and nitrogen excretion of laying hens as well as the emissions of greenhouse gases and ammonia from layer-manure composting compared to Cont diets throughout the laying period. Integrating the results of the studies and calculating the effects across the entire laying period based on the experimental conditions in the studies (White Leghorn hens and manure composting without forced aeration), we found that feeding LPS diets with a 2% lower crude protein content to laying hens decreased nitrogen influx to Japan and nitrogen load in Japan associated with egg production by 11.7% and 19.7%, respectively, and emissions of greenhouse gases and ammonia from layer manure composting by 23.8% and 29.2%, respectively, compared to feeding Cont diets. Therefore, feeding LPS diets to laying hens throughout the laying period was suggested to reduce the nitrogen load and environmental gas emissions from manure composting without affecting egg production performance.

Hanaemaki and Sansanmaru are rice cultivars suitable for direct seeding cultivation in Hokkaido, because they show high levels of lodging resistance and grain yield. The grain amylose contents of Hanaemaki and Sansanmaru are approximately 10% and 16%, respectively, which are lower than those of other cultivars for direct seeding cultivation. Because of their lower levels of amylose content, these cultivars showed higher eating quality of cooked rice in the sensory test compared to other cultivars. Thus, the low amylose content trait may be important for improving the eating quality of rice cultivars used in direct seeding cultivation in Hokkaido, as is the case with cultivars in transplanting cultivation.

Some species of apple snail, genus Pomacea, as represented by P. canaliculata (Lamarck 1822), are serious invasive freshwater snails worldwide. These snails have threatened rice production in East Asia since their introduction in the 1980s. After the development and spread of countermeasures such as molluscicide application, crop rotation, rotary tillage, and the use of natural enemies, the level of injury caused to rice by the snails eventually settled. However, after about 2010, snail infestations became serious again, due to increments in population density in invaded areas and range expansion of populations to new areas because of recent climate change: warmer winters have resulted in the expansion of the snail’s overwintering areas and better survival in winter; and higher temperatures in the rice transplanting season (spring to early summer) have activated the snails in rice paddies. The recently developed method of detecting apple snail invasions early from environmental DNA is effective in preventing the snails from localizing in new habitats. To mitigate rice damage, new control concepts, such as trapping snails using long-lasting attractants and applying molluscicides efficiently using climate data and drones, together with conventional countermeasures, should be of practical use.