Panicum maximum cv. Tanzânia: climate trends and regional pasture production in Brazil

Projected change in forage production under a range of climate scenarios is important for the evaluation of the impacts of global climate change on pasture‐based livestock production systems in Brazil. We evaluated the effects of regional climate trends on Panicum maximum cv. Tanzânia production, predicted by an agro‐meteorological model considering the sum of degree days and corrected by a water availability index. Data from Brazilian weather stations (1963–2009) were considered as the current climate (baseline), and future scenarios, based on contrasting scenarios in terms of increased temperature and atmospheric CO₂ concentrations (high and low increases), were determined for 2013–2040 (2025 scenario) and for 2043–2070 (2055 scenario). Predicted baseline scenarios indicated that there are regional and seasonal variations in P. maximum production related to variation in temperature and water availability during the year. Production was lower in the Northeast region and higher in the rainforest area. Total annual production under future climate scenarios was predicted to increase by up to 20% for most of the Brazilian area, mainly due to temperature increase, according to each climate model and scenario evaluated. The highest increase in forage production is expected to be in the South, Southeast and Central‐west areas of Brazil. In these regions, future climate scenarios will not lead to changes in the seasonal production, with larger increases in productivity during the summer. Climate risk is expected to decrease, as the probability of occurrence of low forage productions will be lower. Due to the predicted increase in temperature and decrease in rainfall in the Northeast area, P. maximum production is expected to decrease, mainly when considering scenarios based on the PRECIS model for the 2055 scenario.     

China’s potato industry and potential impacts on the global market

While China has been the world’s largest potato producer since 1993 and accounted for more than 80% of the increase in global potato production from 1990 to 2002, few studies have analyzed the remarkable growth in China’s potato industry and its potential impacts on the global market. This paper reviews the development and growth of China’s potato industry since 1961, especially since the economic reforms started in 1978, identifies major factors that have contributed to the dramatic growth in China’s potato production in the past two decades, examines the trends of China’s potato production and consumption, and discusses the potential impacts of China’s potato industry on the global market. Results suggest that China’s ongoing transitions in economic system and food-consumption patterns will contribute to further growth in its potato market and China’s potato output may reach 71 mmt in 2006 and 81 mmt in 2010. Furthermore, China as the world’s largest potato producer and a new member of the World Trade Organization (WTO) will play an increasing role in the global market of potatoes and potato products.     

Methodologies for simulating impacts of climate change on crop production

Ecophysiological models are widely used to forecast potential impacts of climate change on future agricultural productivity and to examine options for adaptation by local stakeholders and policy makers. However, protocols followed in such assessments vary to such an extent that they constrain cross-study syntheses and increase the potential for bias in projected impacts. We reviewed 221 peer-reviewed papers that used crop simulation models to examine diverse aspects of how climate change might affect agricultural systems. Six subject areas were examined: target crops and regions; the crop model(s) used and their characteristics; sources and application of data on [CO₂] and climate; impact parameters evaluated; assessment of variability or risk; and adaptation strategies. Wheat, maize, soybean and rice were considered in approximately 170 papers. The USA (55 papers) and Europe (64 papers) were the dominant regions studied. The most frequent approach used to simulate response to CO₂ involved adjusting daily radiation use efficiency (RUE) and transpiration, precluding consideration of the interacting effects of CO₂, stomatal conductance and canopy temperature, which are expected to exacerbate effects of global warming. The assumed baseline [CO₂] typically corresponded to conditions 10-30 years earlier than the date the paper was accepted, exaggerating the relative impacts of increased [CO₂]. Due in part to the diverse scenarios for increases in greenhouse gas emissions, assumed future [CO₂] also varied greatly, further complicating comparisons among studies. Papers considering adaptation predominantly examined changes in planting dates and cultivars; only 20 papers tested different tillage practices or crop rotations. Risk was quantified in over half the papers, mainly in relation to variability in yield or effects of water deficits, but the limited consideration of other factors affecting risk beside climate change per se suggests that impacts of climate change were overestimated relative to background variability. A coordinated crop, climate and soil data resource would allow researchers to focus on underlying science. More extensive model intercomparison, facilitated by modular software, should strengthen the biological realism of predictions and clarify the limits of our ability to forecast agricultural impacts of climate change on crop production and associated food security as well as to evaluate potential for adaptation.     

石家庄地区春季早熟马铃薯高产高效栽培技术

石家庄地区是典型的二季作区,这里的耕地面积多为平原,相对自然条件较好,春季化冻较早,3月1日～6月20日气候凉爽昼夜温差大,非常适合早熟马铃薯的生产。而6月20日～9月1日温度高且昼夜温差小,不再适宜马铃薯的生长,因此这里种植马铃薯必须掌握关键种植技术才能高产高效。但是当地农民因为对早熟马铃薯关键技术缺乏了解,经常在种植技术上出现很多失误,造成高投入低产出现象时有发生,严重制约了马铃薯生产的发展。为此根据石家庄地区气候特点,通过多年实践从操作时间及关键技术上把播前准备、种薯处理、科学播种、田间管理、病虫害防治、收获储存六方面进行了总结,从而提出了适宜石家庄地区采用的高产高效栽培技术,使当地的马铃薯种植面积逐年增加,经济效益得到显著提高。     

Incidence and severity of powdery scab on potatoes in Pennsylvania

Studies were conducted in Potter Co., Pennsylvania to investigate the effect of powdery scab (Spongospora subterranea) on five potato cultivars (Norchip, Rosa, Kennebec, Katahdin, and Monona) at two planting dates. Soil temperature was within the range of 15–18 C and soil moisture was within 15–19% based on dry weight throughout the season. The effect of planting date was significant at each disease assessment, except for the severity on the fourth assessment. By the end of the season, incidence of scab was 66% or more for all cultivars. Rosa, Kennebec and Katahdin had a greater scab incidence over both planting dates and a greater severity at the first planting date than Monona and Norchip.     

Changing Phenology of Potato and of the Treatment for its Major Pest (Colorado Potato Beetle) – A Long-term Analysis

Potato Solanum tuberosum is one of the world’s four most important crops. Its cultivation is steadily increasing in response to the need to feed a growing world population. The yield of potato is influenced inter alia by both climate and pests. The main defoliator pest of potato is Colorado potato beetle Leptinotarsa decemlineata. Using data from a long-term experiment (1958–2013) in western Poland, we show that increasing temperature has affected the trophic relationship between potato and Colorado potato beetle. The planting, leafing, flowering and harvest dates for potato were advanced, after controlling for different cultivars, by 2.00 days, 3.04 days, 3.80 days and 3.42 days respectively for every 1 °C increase in temperature. In contrast, first treatment against Colorado potato beetle advanced by 4.66 days for every 1 °C increase in temperature, and, furthermore, the number of treatments against the beetle increased by 0.204 per 1 °C increase in temperature. This suggests that the beetle responds faster to increasing temperature than the plant does, but both parts of the system are probably greatly modified by farming practices.     

辽宁省玉米种植农业气候要素分析及精细化气候区划研究

根据农业气候条件的地区差异，研究辽宁省玉米种植气候区划的变化，规划辽宁省玉米种植和促进辽宁省玉米产业的可持续发展。研究结果表明，1961～2018年辽宁省农业气候资源在时间上呈现“降水减少、积温升高”的暖干化趋势。空间分布上呈现地域性差异，对辽宁省玉米气候区划因子进行指标划分，通过GIS得到近58年辽宁省玉米气候区划，分为最适宜区、适宜区和基本适宜区。从1961～1990年、1971～2000年、1981～2010年，基本适宜区和最适宜区呈现先增加再减小的趋势，适宜区呈现先减小再增加的趋势。     

Simulation study of past climate change effect on chickpea phenology at different sowing dates in Gorgan, Iran

This simulation study was mainly aimed to find the probable difference between sowing dates for response of four chickpea cultivars to past climate change. Firstly, the model CYRUS was recoded in QBASIC programming. Then phenology of cultivars Jam, Hashem, Arman and Beauvanij, seeded at day of year 50, 70 and 90, was evaluated during years 1961 to 2003 in Gorgan, Iran. The changes in some climatic variables were also studied. Results revealed that the solar radiation has been decreased for month December. Although the value of maximum temperature appeared to be the same across years 1961 to 2003 for all months, that of minimum temperature tended to show increasing trend for May and August. The increase in number of days with temperature higher than 35 degrees C was considerable for April and October, but negligible for other months. The warming of night temperature was significant only for May and August. It found about 34 mm per 43 years decrease in monthly rainfall for March. The rate of increase in number of days with rainfall was 0.0737 day per year for December. Nearly similar situation was found for number of days with rainfall lower than and/or equal to 10 mm. The change in number of days with rainfall higher than 10 mm and lower and/or equal to 30 mm was in decreasing manner (March, October and December). The length of time from sowing to emergence appeared to be constant across past years. The advance in flowering (R1) was true only for cultivar Jam seeded at day of year 70. The length of period from R1 to pod initiation (R3) has been diminished for sowing at day of year 70 (Jam and Arman). Only cultivar Hashem seeded at day of year 90 tended to have decreasing trend for length of period between R3 and pod filling. It found one day (per 43 years) decreases from pod yellowing to maturity for cultivar Beauvanij seeded at day of year 70. Based on these findings and on the fact that future climate change is predicted using past changes, it seems that the adaptation strategies for future, including agronomy and/or breeding programs, may be not the same for different sowing dates of chickpea.     

黑龙江省马铃薯种植区划的研究

黑龙江省是我国主要的马铃薯产区,也是国家种薯和商品薯生产的重要基地之一。合理的种植区划与生产布局对发展我省的马铃薯生产,提高种薯和商品薯的质量是非常必要的。黑龙江省地域辽阔,各地所处地理位置、地势地貌、土壤与气候等适生条件的不同,以及社会经济条件综合因素的作用,都影响着马铃薯的分布和生产。依据马铃薯的生物学特性的要求和各地自然条件的分异规律以及社会经济条件等因素,把我省马铃薯的种植划分为北部最适宜区、南部适宜区、西部次适宜区和东部次适宜区。     

Global distribution of the potato crop

The global distribution of potato area is described using country-level statistics and a new geo-referenced database. There are two main peaks in global potato distribution by latitude. The major peak is between 45°N and 57°N and represents potato production zones in the temperate climates where potato is a summer crop. The other peak is between 23°N and 34°N, and mainly represents production zones in the subtropical lowlands, where potato is a winter crop. Between 1950 and 1998 potato production area increased at low latitudes and decreased at high latitudes, particularly around 53°N (this zone includes parts of Belarus, Germany, Poland, Russia, and Ukraine). The northern limit of potato production coincides with the boundaries of agriculture and the presence of human population. The peak between 23°N and 34°N coincides with the area of highest population density (per area of land and per area of arable land). About 25% of the global potato area is in the highlands (above 1000 m).     

Changing global risk of invading greenbug Schizaphis graminum under climate change

The geographical range, abundance, growth rate, survival and mortality of insects are largely influenced by abiotic factors such as temperature and humidity. When suitable, these factors can positively influence the abundance of insect pests. It is in this light that the influence of climate change, particularly global warming, has direct bearing to crop protection. In this study, we simulated the potential distribution of the greenbug or wheat aphid Schizaphis graminum (Rondani) (Aphididae), a major global pest of wheat, using the climate matching tool CLIMEX (CLIMatic indEX) in global warming scenarios. To predict the potential distribution of the insect on CLIMEX at time periods 2030, 2070 and 2100, we utilize two global climate models (GCMs) at two emission scenarios. The result of CLIMEX modelling shows that the favourable climatic areas for S. graminum are subtropical to temperate at the current time. With global warming, under different scenarios current suitable and highly suitable areas in the northern hemisphere are expected to expand to higher latitudes by 2030 towards 2100; while areas in the southern hemisphere, where the pest’s living areas already have high temperature ranges, the occurrence of the pest will contract by 2030 since temperatures will exceed its heat limits. This study assists in predicting the potential risk areas that may be threatened by this pest in the future, providing supportive information for agricultural management practices and aid in the preparation of strategic plans to avoid possible economic damage posed by future expansion of the pest population due to climate change.     

Current status of the TPS technology in the world

Summary The availability of improved True Potato Seed (TPS) varieties for short and long photoperiod conditions has recently increased the interest in the TPS technology. A summarized overview is presented of the TPS technology for potato tuber production, TPS breeding and production. TPS competes successfully with clonal cultivars in Egypt and India. In other developing countries higher yields and better adaptation are needed to make the TPS technology economically attractive; the case of TPS in Indonesia is used to illustrate this. In industrialised countries, well-performing seed tuber programmes, productivity and legislative restrictions are difficult to beat by TPS. However, the use of TPS can be economically attractive where disease pressure is high. It is concluded that TPS has a place within potato systems where agroecological conditions for seed tuber systems and steady supply of good quality tubers from a formal seed programme are most constrained. Further genetic improvement will increase the areas where TPS provides better and cheaper planting material.     

Climate Change and Potato Production in Contrasting South African Agro-Ecosystems 2. Assessing Risks and Opportunities of Adaptation Strategies

This study aims to assess the risks and opportunities posed by climate change to potato growers in South Africa and to evaluate adaptation measures in the form of changes in planting time growers could adopt to optimise land and water use efficiencies in potato, using a climate model of past, present-day and future climate over southern Africa and the LINTUL crop growth model. This was done for distinct agro-ecosystems in South Africa: the southern Mediterranean area where potato still is grown year round with a doubling of the number of hot days between 1960 and 2050, the Eastern Free State with summer crops only and Limpopo with currently autumn, winter and spring crops where the number of hot days increases sevenfold and in future the crop will mainly be grown in winter. A benefit here will be a drastic reduction of frost days from 0.9 days per winter to 0. Potato crops in the agro-ecosystems will benefit considerably from increased CO₂ levels such as increased tuber yield and reduced water use by the crop, if planting is shifted to appropriate times of the year. When the crop is grown in hot periods, however, these benefits are counteracted by an increased incidence of heat stress and increased evapotranspiration, leading in some instances to considerably lower yields and water use efficiencies. Therefore year-round total production at the Sandveld stabilizes at around 140 Mg?ha^?1 (yield reduction in summer and yield increase in winter), increases by about 30% in the Free State and stays at about 95 t?ha^?1 at Limpopo where yield increase due to CO₂ is annulled by a shorter growing season. When the crop is grown in a cool period, there is an additional benefit of a reduced incidence of cold stress and a more rapid canopy development in the early stages of crop growth. In all three areas, potato growers are likely to respond to climate change by advancing planting. In Limpopo, a major benefit of climate change is a reduction in the risk of frost damage in winter. The relevance of these findings for potato grown in agro-ecosystems elsewhere in the world is discussed.     

未来气候变化情景下中国橡胶主产区内植被净初级生产力预估

气候变化影响生态系统的最重要表现之一是引起植被净初级生产力（NPP）的变化。全球气候变暖对中国天然橡胶树种植区内植被NPP的影响值得深入研究。根据1981—2010全国气候数据和RCP4.5情景的气候预估数据,基于气候植被NPP模型,对1981—2010、2041—2060、2061—2080年中国天然橡胶种植区内NPP变化进行分析。结果表明：（1）随着气候变暖,天然橡胶种植区内NPP呈现整体先增加后略减小趋势,其中1981—2010年研究区内植被年平均NPP为12.89 tC/hm ²;2041—2060年研究区内植被年平均NPP为15.07 tC/hm ²;2061—2080年研究区内植被年平均NPP为15.01 tC/hm ²;（2）从空间分布上看,不同时期的NPP的高值区主要集中分布在海南岛的东部沿海,广东的信宜、电白,广西的东兴,云南的景洪、勐腊等地;低值区主要分布在云南的临沧、屏边以北,海南岛的西部沿海,广东的徐闻等地。相关结果可为相关部门制定天然橡胶适应未来气候变化的决策提供依据。     

Potato viruses in China

Potato (Solanum tuberosum L.) is globally the fourth largest staple crop after rice, wheat and maize. China is the largest potato producer worldwide, accounting for 26.3% and 22.2% of the global total area and yield, respectively. Viral diseases have been a limiting factor for sustainable production of potato in China. This article provides update and comprehensive information on the most important viruses, their effect on yield and their control in China. Meristem culture is currently the most widely used technique for production of virus-free potato plants and these plants are used as nuclear stock for the production of certified seed tubers. Although a significant increase in tuber yield has been achieved using certified seed potatoes, lack of application of a national seed potato production scheme has hindered progress. Conventional breeding using virus-resistant cultivars introduced from other countries as parents has already led to the production of Chinese cultivars. Use of virus-resistant wild Solanum species and genetic transformation techniques will provide new virus-resistant varieties in the future to further enhance control of potato viruses in China.     

全生育期增温对冬小麦物侯期、产量和水分利用效率的影响

为明确太行山山前平原地区冬小麦生长发育、产量形成及水分利用对气候变暖的响应,以冬小麦品种藁优5218为材料,于2017-2018和2018-2019连续两个冬小麦生长季在旱棚内采用开放式增温系统(free air temperature increase,FATI)模拟气候变暖趋势,分析了FATI的增温效果及全生育期增温对冬小麦物候期、茎秆发育、产量及水分利用效率的影响。结果表明,与自然条件(CK)相比,增温后冬小麦穗分化进程加快,整个生育期缩短4~6 d,主要表现为越冬—拔节期的生育进程缩短,而灌浆期的持续时间延长;增温导致冬小麦茎秆基部变细薄,降低节间横截面维管束数目及木质化程度,增加倒伏风险;增温降低了冬小麦产量和水分利用效率(WUE),两个生长季分别减产10.4%和5.3%,WUE分别下降16.1%和12.7%。因此,气候变暖不利于该区域小麦产量和WUE的提高,可通过栽培管理措施或品种改良来使冬小麦生产系统适应增温趋势,实现稳产提效。     

Utilization of potatoes for life support in space. V. Evaluation of cultivars in response to continuous light and high temperature

Twenty-four potato (Solanum tuberosum L.) cultivars from different regions of the world were evaluated in terms of their responses to continuous light (24 h photoperiod) and to high temperature (30 C) in two separate experiments under controlled environments. In each experiment, a first evaluation of the cultivars was made at day 35 after transplanting, at which time 12 cultivars exhibiting best growth and tuber initiation were selected. A final evaluation of the 12 cultivars was made after an additional 21 days of growth, at which time plant height, total dry weight, tuber dry weight, and tuber number were determined. In the continuous light evaluation, the 12 selected cultivars were Alaska 114, Atlantic, Bintje, Denali, Desiree, Haig, New York 81, Ottar, Rutt, Snogg, Snowchip, and Troll. In the high temperature evaluation, the 12 selected cultivars were Alpha, Atlantic, Bake King, Denali, Desiree, Haig, Kennebec, Norland, Russet Burbank, Rutt, Superior, and Troll. Among the cultivars selected under continuous irradiation, Desiree, Ottar, Haig, Rutt, Denali and Alaska showed the best potential for high productivity whereas New York 81 and Bintje showed the least production capability. Among the cultivars selected under high temperature, Rutt, Haig, Troll and Bake King had best performance whereas Atlantic, Alpha, Kennebec and Russet Burbank exhibited the least production potential. Thus, Haig and Rutt were the two cultivars that performed well under continuous irradiation and high temperature conditions, and could have maximum potential for adaptation to varying stress environments. These two cultivars may have the best potential for use in future space farming in which continuous light and/or high temperature conditions may exist. However, cultivar responses under combined conditions of continuous light and high temperature remains for further validation.     

The Effect of High Temperature during Storage on the Vigour of Potato Mother Tubers

The aim of this work was to assess the impact of high temperature during storage and of de-sprouting before planting on the vigour of potato mother tubers of 24 potato cultivars. The study was conducted in the years 2006–2007 in the Jadwisin Branch of the Plant Breeding and Acclimatization Institute, Poland. Vigour was assessed by a field method and evaluated on a nine-point scale. It was found that mother tubers of five cultivars had maintained their growth vigour despite the high temperature in the period from autumn until the time of planting. There was no correlation between the length and mass of the emerging sprouts, plant height, mass of the above-ground part of plants, the LAI index, and the vigour of potato mother tubers. This characteristic was also not dependent on the length of the growing season of the individual cultivars.     

Seed Potato Performance after Storage in Light at Elevated Temperatures

In regions with short growth seasons, it is of great importance to use potato (Solanum tuberosum L.) seed tubers with a high growth vigour and a short growth cycle. Such qualities may be obtained by treatments advancing the physiological age of the seed tubers. In this study, we have exposed tubers from four cultivars to various combinations of temperature and light conditions (green-sprouting) for 3–7 months in controlled climate. Subsequent sprout quality, seed tuber health and performance were studied in laboratory, greenhouse and field trials. Satisfactory short, sturdy and leafy sprouts were produced even after 7 months storage at 15 °C under light exposure. An assay of black scurf (Rhizoctonia solani) on the tuber skin showed that light exposure significantly reduced the occurrence compared with dark-stored tubers, while the average effect of storage temperatures was insignificant. In general, green-sprouting advanced emergence and plant growth by 1–2 weeks, and showed early tuber initiation and growth, compared to untreated material. Yields, 107 days after planting in the field trial, did not deviate significantly from untreated tubers. However, plant development at harvest was in accordance with general responses to physiological ageing of potato seed tubers, i.e. still tall and immature plants from untreated tubers, and short and mature plants from aged tubers. Results demonstrated the possibility of successful long-term storage of potato seed tubers in light at elevated temperatures and a potential for earlier harvests and higher early yields from such treatments.     

Differential Growth Response and Minituber Production of Three Potato Cultivars Under Aeroponics and Greenhouse Bed Culture

We have evaluated and compared different methods and cultivars for the production of quality prebasic seed in potato. Two cultivation systems, aeroponics and greenhouse beds with a peat moss substrate, and three potato cultivars with different vegetative cycle, Agria, Monalisa and Zorba, were assayed. Plants in the aeroponic system showed increased growth and their vegetative cycle extended between 12 and 36 % compared to the plants cultivated in greenhouse beds. Flowering and tuberization dates, Absolute Growth Rates (AGR) during the period of 60 days after planting (DAP) and height presented a wide variation between cultivars. Zorba showed earlier flowering and tuberization, lower AGR and reached a minor height at 60 DAP. Instead the late season cultivar Agria showed later flowering and tuberization, presented higher AGR and reached an increased height at 60 DAP. The total tuber yield per plant was between 34 and 87 % higher in the aeroponic system, with a marked difference for the earlier cultivars Zorba and Monalisa. Tuber numbers increased between 60 and 80 %. Minituber production in aeroponics showed a better size distribution, with a reduction in the percentage of tubers smaller than 12 mm of between 33 and 86 %. In this soil-less culture system average tuber weight increased in Zorba and Monalisa over 60 % but was lower for Agria. Further studies are needed to optimize aeroponics system, which can be considered a high yield potato multiplication system, particularly for early or mid season potato cultivars that may produce best quality minitubers.