ABSTRACT
Various kinds of field crops growing on two commercial farms in the Whitehorse area of the southern Yukon Territory were surveyed for diseases in summer 2020 by staff of the Agriculture Branch of the Government of Yukon. They included barley, wheat, canola, beets, broccoli, cabbage, carrots, potatoes and turnips. Fields were visited one or more times during July and August. The incidence and severity of diseases were visually assessed on a crop-by-crop basis and samples were collected for laboratory analysis of the pathogens present, if any. Both infectious and non-infectious diseases were present on most crops. The infectious diseases were caused by various species of plant pathogenic bacteria and fungi that were common on these crops growing in other areas of Canada. INTRODUCTION AND METHODS: The 2020 field crop disease survey is believed to be the first organized study of its kind on agricultural crops in the Territory. In his book, "An Annotated Index of Plant Diseases in Canada . . . ", I.L. Conners lists over 300 records of plant diseases on trees, shrubs, herbs and grasses in the Yukon that were published by individuals who were surveying forests and native vegetation mainly for federal government departments, universities and other agencies (Conners 1967). The objectives of the 2020 survey were: (1) to determine the kinds and levels of diseases on selected Yukon crops, (2) to identify the major pathogen species attacking Yukon crops, and (3) to use the results to plan future surveillance activities aimed at helping producers to improve their current disease management programs. All of the fields included in the 2020 survey were situated on two commercial farms, which were designated as Farm #1 and #2, in the Whitehorse area in the southern Yukon (Fig. 1). The crops surveyed included cereals (barley and wheat), oilseeds (canola) and vegetables (beets, broccoli, cabbage, carrots, potatoes and turnips). Fields were visited one or more times in the mid- to late growing season (July/August) at a time when damage from diseases was most noticeable. Symptoms were visually assessed on a crop-by-crop basis by determining their incidence and severity. Incidence was represented by the percentage of plants, leaves, heads, kernels, etc., damaged in the target crop, while severity was estimated to be the proportion of the leaf, fruit, head, root/canopy area, etc., affected by a specific disease as follows: Proportion of the canopy affected based on a 0-4 rating scale, where: 0 = no disease symptoms, 1 = 1-10% of the crop canopy showing symptoms;2 = 11-25% showing symptoms, 3 = 26- 50% showing symptoms, and 4 = > 50% showing symptoms. Photographs of affected plants were taken and sent to plant pathologists across Western Canada for their opinions on causation. Where possible, representative samples of plants with disease symptoms were packaged and sent to the Alberta Plant Health Lab (APHL) in Edmonton, AB for diagnostic analyses. Background information, such as the general cultural practices and cropping history, was obtained from the producers wherever possible. GPS coordinates were obtained for each field to enable future mapping Cereals: Individual fields of barley (11 ha) and wheat (30 ha) located at Farm #1 were surveyed. The barley was a two-row forage cultivar 'CDC Maverick', while the wheat was an unspecified cultivar of Canada Prairie Spring (CPS) Wheat. Plant samples were taken along a W-shaped transect for a total of five sampling points for the barley field (< 20 ha) and ten sampling points for the wheat field (> 20 ha). The first visit, which occurred on July 30, involved visual inspection and destructive sampling wherein plants were collected and removed from the field for a detailed disease assessment at a lab space in Whitehorse. There, the roots were rinsed off and the plants were examined for disease symptoms. The second visit to these fields, which occurred on August 27, only involved visual examination of the standing crop. Oilseeds: A single 40 ha field of Polish canola (cv. 'Synergy') was examined o
ABSTRACT
This paper proposes to identify Agricultural futures’ roles (Safe haven, Hedge, and Diversifier) in the Thai stock market during 2000-2020 by applying a bivariate Cross-Quantilogram (CQ) approach. The CQ approach can examine the cross-quantile correlation between assets, while the traditional approaches (such as GARCH, DCC, and MSV) examine only mean-to-mean dependency structures. The CQ methodology can estimate the tail dependencies and directional predictability between financial assets more accurately than traditional methods since financial assets typically have a skewed and asymmetric distribution. The correlation between assets during the extreme market condition (tail dependencies) is important to classify a financial asset as a Safe-haven role. The agricultural commodities considered in this study are the most active asset categories in the markets (cereals, oilseeds, other soft commodities, and miscellaneous commodities). The results show that the agricultural assets are more explicitly correlated with the Thai stock market in crisis periods, such as a negative result in canola during COVID-19. Agricultural commodities, including wheat, oats, and canola, can play a strong safe-haven role in the Thai stock market, according to the lowest cross-quantiles (bearish market) data. According to the results of overall quantiles (normal situations), wheat, corn, canola, soybean, and sugar can all be used as hedges. The rolling windows for directional predictability, which show the time-varying CQ, confirm that these agricultural commodities can be served as Safe-havens throughout the study periods. Therefore, including these specific agricultural commodities (Safe-haven or Hedge) in a portfolio of Thai stocks will help lower risk and boost performance under normal and extreme downturn situations.
ABSTRACT
Rapeseed (Brassica napus L.) is an important oilseed crop grown worldwide with a planting area of 6.57 million ha in China, which accounts for about 20% of the world’s total rapeseed planting area. However, in recent years, the planting area in China has decreased by approximately 12.2% due to the low yield and economic benefits. Thus, to ensure oil security, it is necessary to develop high-efficiency cultivation for rapeseed production. Crop growth models are powerful tools to analyze and optimize the yield composition of crops under certain environmental and management conditions. In this study, the CROPGRO-Canola model was first calibrated and evaluated using the rapeseed planting data of four growing seasons in Wuhan with nine nitrogen fertilizer levels (from 120 to 360 kg ha−1) and five planting densities (from 15 to 75 plants m−2). The results indicated that the CROPGRO-Canola model simulated rapeseed growth well under different nitrogen rates and planting densities in China, with a simulation error of 0–3 days for the anthesis and maturity dates and a normalized root mean square error lower than 7.48% for the yield. Furthermore, we optimized the management of rapeseed by calculating the marginal net return under 10 nitrogen rates (from 0 to 360 kg ha−1 at an increasing rate of 40 kg ha−1) and 6 planting densities (from 15 to 90 plant m−2 at an increasing rate of 15 plant m−2) from 1989 to 2019. The results indicated that the long-term optimal nitrogen rate was 120–160 kg N ha−1, and the optimal planting density was 45–75 plants m−2 under normal fertilizer prices. The optimal nitrogen rate decreased with increasing fertilizer price within a reasonable range. In conclusion, long-term rapeseed management can be optimized based on rapeseed and nitrogen cost using long-term weather records and local soil information.
ABSTRACT
To effectively cope with the shock of COVID-19 and its subsequent impact, and to promote stable and healthy development of rape industry, this paper systematically analyzed the impact of COVID-19 on China's rape industry. It includes perspectives of farmer's life, rape production and rapeseed processing enterprises, based on micro survey data provided by the National Rapeseed Industrial Technology System. The results showed that in terms of farmers' life, only 0.98% of the respondents were in a shortage of edible vegetable oil and 76.06% of them reflected no impact or a little impact on total household income. However, rural tourism decreased by 10.24 percentage points, and honey collecting behavior of bee farmers decreased by 4.6 points. On field production, 85.47% of the respondents reported "no change" and "small reduction" in field management workload, 90.38% reflected "no impact" and "a littlel impact" on rapeseed production employment, 79.06% considered "overall stability" in the price of agricultural materials, and 98.48% believed that it had a little impact on final output. However, the pest reporting rate increased by 4.99 points than last season. On rapeseed processing, it varied from region to region on the rapeseed processing enterprises' resumption rate, starting-up rate, specific difficulties faced by enterprises and government policies. Based on these results, future strategies should be taken to ensure improving development of rape industry. The strategies should include perfect construction of China's oil reserve system, more attention to diversification of imports, more innovation and technology promotion, optimization on marketing system and construction of information platform, and a"package"subsidy plan for the industry.