Response of sweet potato clones to weevils and environments in Cameroon

Three sites differing in soil type, vegetation and weevil pressure, were used to evaluate the field performance of 18 improved sweet potato clones and two local cultivars, and their reaction to weevils (Cylas spp.) in Cameroon. Higher yields were obtained in the wet season than in the dry season. The highest yields were obtained in Nyombe in both wet and dry seasons; yields were halved in each of the other sites. Clones suffered more weevil damage in the dry season than in the wet season. Clones Tib 1, 1611, and 502 were very tolerant to weevils, whereas the high yielding clones 1112 and 1639 were very susceptible. Root yield was not correlated with root weevil damage, and yield potential and yield stability were found to be unrelated. Stability methods differed in identifying stable clones, and the rankings of clones varied with the trait measured. However, both Eberhart-Russell and Shukla stability methods rated clones 048, Tib 1, 1602, 1639, 002 and Njombe as stable for root yields. Also, there was no apparent relationship between weevil tolerance and cultivar adaptability. This study shows that the main sweet potato crop should be grown during the first cropping season when there is abundant moisture for slip sprouting and establishment, and when there is less soil cracking to expose roots to weevil infestation. The study suggests that although root yields are usually not adversely affected, weevil control measures should be seriously considered in commercial sweet potato production because the market value of the roots is much reduced by high weevil infestation. Lastly, it suggests that since fewer clones were found to carry high levels of tolerance to weevils, further research is necessary in breeding for weevil resistance.     

Effects of compost and defatted oilseed meals as sustainable organic fertilisers on cardoon (Cynara cardunculus L.) production in the Mediterranean basin

Cardoon (Cynara cardunculus L.) is considered as one of the most suitable energy crops for Southern Europe. The aim of this work was to outline the effects of organic fertilisers on the productivity and the global warming potential (GWP) on cardoon production. Six fertilisers (N 100 kg ha^?1, N 50 kg ha^?1, Compost 30 t ha^?1, Compost 15 t ha^?1 + N 25 kg ha^?1, 3 t ha^?1 of defatted oilseed meals of sunflower, 3 t ha^?1 of defatted oilseed meals of Brassica carinata), and unfertilised control, were evaluated on two cultivars (‘Gobbo di Nizza’ and ‘Altilis 41’) in a split-plot experiment. Defatted oilseed meal of sunflower recorded higher total dry weight (+10%), seed yield (+17%), nitrogen use efficiency (+14%) and better GWP (?66%) compared to the other organic fertilisers and performing as well as N 100 kg ha^?1. Altilis 41 cultivar showed the highest aboveground total dry weight (10 t ha^?1 y^?1), seed yield (1.7 t ha^?1 y^?1), stalk dry weight (7 t ha^?1 y^?1) and head dry weight (3 t ha^?1 y^?1). Our results highlighted that by combining suitable cultivar and fertilisation strategies, it could be possible to increase the production sustainability of C. cardunculus.     

北方地区菜用甘薯高效栽培技术

为进一步提升北方甘薯栽培种植效益，结合菜用甘薯的特点，因地制宜，从品种选择、种苗繁育、整地、定植、田间管理、病虫害防治、收获等环节，总结了适宜北方地区的菜用甘薯高效栽培技术，可实现露地种植连续采收3个月茎尖，667 m²效益在10 000元以上。     

影响甘薯食用品质因素分析

摘要：甘薯的食用口感主要分为质地和香甜程度两大方面，为明确甘薯食用品质的影响因子，对近10 年国内有关甘薯食用品质相关的研究成果进行了综述，探究营养成分及含量、贮藏环境、生物酶、栽培 技术等因素与甘薯食用品质之间的相关性，其中对淀粉含量、种类、颗粒、可溶性糖含量、烹饪温度等 要素进行了较为详细的阐述，以期为培育出符合市场需求的优质品种提供参考。     

甜椒抗疫病砧木筛选研究

以甜椒品种红苏珊为接穗,以辣椒品种布野丁、格拉夫特和富根卫士为砧木,研究了砧穗亲和性,嫁接对生长发育、疫病抗性和产量品质的影响。研究结果表明,3种砧木品种与接穗的亲和性均较强,成活率达97%以上;与自根苗对照相比,各嫁接苗株高显著降低,单株结果数显著增加;嫁接苗抗疫病效果显著,发病率最高仅为1.39%;3种嫁接苗分别比自根苗增产298.0%、262.9%和292.4%,3种砧木均可在实际生产中推广应用。     

基于灰色关联度分析的甘薯品种评价

为筛选出适应性强、高产、优质的甘薯良种,利用灰色关联度分析方法对17个甘薯品种进行评价。试验结果表明,甘薯品种云薯J-4、云薯104、云薯122、京杂4号及云薯119的产量高、淀粉含量高,综合性状好;云薯116、云薯50、台湾薯综合性状较差。     

Effects of Irrigation Frequency on Yield and Quality Parameters in Apple c.v. ‘Gala,Galaxy’

This study was conducted in 2007 and 2008 in order to determine the effects of irrigation frequency on the yield and quality parameters of dwarf trees of the apple cultivar ‘Gala, Galaxy’ in the first and second year of cultivation. Irrigation water was applied at 3?, 5?, 7?, and 10-day intervals as much as the amount of water consumed from the field capacity. Statistical analysis revealed that the effects of irrigation frequency on yield were significant. Since the trees used in the experiment showed mainly vegetative growth, the effects of irrigation frequency on the fruit quality characteristics varied. Irrigation water amount was applied as 355.7–446.5 mm and 359.2–538.9 mm to the experimental treatments in 2007 and 2008, respectively. The evapotranspiration measured was in the range 400.7–491.5 mm in 2007 but in the range 440.2–600.5 mm in 2008, while the yields in the same years ranged from 1.54 to 2.84 t ha^?1 and from 2.61 to 6.06 t ha^?1. Water use efficiency varied between 2.40 and 4.80 t ha^?1mm^?1 in the first year of the experiment but between 3.45 and 7.08 t ha^?1mm^?1 in the second year. The I₂ treatment, in which the highest yield and water use efficiency were recorded in both years of the experiment under the experimental conditions, was determined as the irrigation scheduling.     

甘薯新品种引进及大田对比试验

为筛选出适合在米东区种植的甘薯品种,以当地主栽品种普薯32为对照,对从国内甘薯研究单位引进的30个甘薯新品种进行了大田对比试验,通过对生物学性状、产量及品质等方面的综合分析,筛选出在当地具有推广应用价值的心香、岩薯7-3、徐薯55-2等18个新品种,表现出薯形好,口感佳,商品薯率和产量较高的优势,建议作为进一步优选的储...     

Effects of aspect and altitude on carbon cycling processes in a temperate mountain forest catchment

Context

Varying altitudes and aspects within small distances are typically found in mountainous areas. Such a complex topography complicates the accurate quantification of forest C dynamics at larger scales.

Objectives

We determined the effects of altitude and aspect on forest C cycling in a typical, mountainous catchment in the Northern Limestone Alps.

Methods

Forest C pools and fluxes were measured along two altitudinal gradients (650–900 m a.s.l.) at south-west (SW) and north-east (NE) facing slopes. Net ecosystem production (NEP) was estimated using a biometric approach combining field measurements of aboveground biomass and soil CO₂ efflux (SR) with allometric functions, root:shoot ratios and empirical SR modeling.

Results

NEP was higher at the SW facing slope (6.60?±?3.01 t C ha^?1  year^?1), when compared to the NE facing slope (4.36?±?2.61 t C ha^?1 year^?1). SR was higher at the SW facing slope too, balancing out any difference in NEP between aspects (NE: 1.30?±?3.23 t C ha^?1 year^?1, SW: 1.65?±?3.34 t C ha^?1 year^?1). Soil organic C stocks significantly decreased with altitude. Forest NPP and NEP did not show clear altitudinal trends within the catchment.

Conclusions

Under current climate conditions, altitude and aspect adversely affect C sequestering and releasing processes, resulting in a relatively uniform forest NEP in the catchment. Hence, including detailed climatic and soil conditions, which are driven by altitude and aspect, will unlikely improve forest NEP estimates at the scale of the studied catchment. In a future climate, however, shifts in temperature and precipitation may disproportionally affect forest C cycling at the southward slopes through increased water limitation.

     

食用型甘薯新品系比较试验

为选育出符合市场需求的食用型甘薯新品种,对通过甘薯集团杂交法筛选得到的3个甘薯新品系进行比较试验。结果表明:3个甘薯新品系熟食品质均为优,其中内17-71(紫薯),产量与南薯88相近,口感柔和细腻,符合现代人们对于薯形大小、口感的要求,适宜于进一步扩大种植试验;内16-22(紫薯),产量与南薯88相比偏低,口感偏硬,但薯肉颜色较内17-71更紫,需留种观察;内13-17(红薯),产量高,以大中薯为主,但含水量偏高不耐存储,不符合市场对甘薯大小的要求,宜淘汰。     

郧县甘薯生产现状及可持续发展对策

在对郧县甘薯生产发展经验,现状分析的基础上,阐述了甘薯产业发展的有利条件和区域优势,提出郧县要实现甘薯产业的可持续发展,应健全甘薯良繁体系,加快新品种推广,同时应以市场为导向,拉长产业链条,并加强甘薯制品食用安全方面的监管。     

Energy Input-Output Analysis in Organic Mulberry (<Emphasis Type="Italic">Morus spp.</Emphasis>) Production in Turkey: a Case Study Adiyaman-Tut Region

The goal of this study is to do the energy input-output analysis of organic mulberry. This study was conducted at the organic mulberry producing facilities during the 2015–2016 production seasons in Adiyaman-Tut region of Turkey. The agricultural input energies and output energies used in organic mulberry production were computed to determine the energy input-output analysis. According to the research findings, the energy inputs in organic mulberry production were computed respectively as 3948?MJ ha^?1 (59.01%) drip and sprinkler irrigation energy, 1092.42?MJ ha^?1 (16.33%) gravity irrigation energy, 449.33?MJ ha^?1 (6.72%) diesel fuel energy, 416.52?MJ ha^?1 (6.23%) farmyard manure energy, 335.14?MJ ha^?1 (5.01%) human labour energy, 253.52?MJ ha^?1 (3.79%) machinery energy, 93.12?MJ ha^?1 (1.39%) transportation energy, 75.78 MJ ha^?1 (1.13%) animal labour energy and 26.62?MJ ha^?1 (0.40%) organic fertilizer energy. Total input energy was computed as 6690.46?MJ ha^?1. Production output organic mulberry yield were calculated as 37,627.84?MJ ha^?1. The energy output/input ratio, specific energy, energy productivity and net energy computations were computed respectively as 5.62, 1.51?MJ kg^?1, 0.66?kg MJ^?1 and 30,937.37?MJ ha^?1. The consumed total energy input in organic mulberry production could be classified as 88.20% direct, 11.80% indirect, 88.10% renewable and 11.90% non-renewable.     

Adventitious shoot formation from sections of sweet potato grown in vitro

Sweet potato (Ipomoea batatas Lam.) root sections were obtained from the cultivars ‘Centennial’, ‘Redmar’ and ‘Jewel’ with a No. 6 cork borer. These sections were cut into 2–3-mm discs and explanted on to modified Murashige and Skoog (MS) medium consisting of MS high mineral salts, myo-inositol (100 mg l^?1), Staba vitamins, 6-benzyl-aminopurine (2.0 mg l^?1), naphthaleneacetic acid (0.1 mg l^?1), sucrose (30 g l^?1) and agar (10 g l^?1). Root discs from internal regions of the tuberous roots gave rise to calli and meristematic bud-like centers (MBLC's). A small percentage of ‘Centennial’ MBLC's burst open to reveal plantlets which grew and rooted well on the medium. Some of the ‘Jewel’ MBLC's contained only roots, while those of ‘Redmar’ did not differentiate. MBLC-formation occurred most often on discs taken from fresh (unstored) roots of ‘Centennial’. Petiole sections taken from in vitro-cultured plants of all 3 cultivars developed plants quite readily on the medium. Shoots of all 3 cultivars grew rapidly, to yield whole rooted plants which could easily be moved to soil and grown in the greenhouse and field.     

郧县菜用甘薯新品种清洁栽培比较试验

对4个菜用甘薯品种进行清洁栽培比较试验。试验结果表明,对茎尖采摘批次、茎尖产量、市场认可度、食用口感、清洁栽培效益进行分析和综合评价,两个菜用甘薯品种BC04,BC03可作为郧县城区乃至十堰地区新兴蔬菜进行适度规模种植,以丰富市民“菜篮子”,满足市民对蔬菜食品安全和保健功能的要求。     

Genetic variation and its relationship to root weight in the sweet potato as revealed by RAPD analysis

The aim of this work was to evaluate the genetic variations of the sweet potato by a random amplified polymorphic DNA (RAPD) assay with emphasis on correlations with morphological traits. Cuttings of superior and inferior lines derived from tissue culture-regenerated plants and asexually propagated plants of the Tainung 57 (TN57) and Tainung 66 (TN66) sweet potato were planted in the field. Three important agronomic traits, top weight, root weight, and root numbers, were measured 3 months after planting. The RAPD-PCR (polymerase chain reaction) technique was used for detecting genomic variations within and between varieties. Of the 160 primers tested in this study, 38 revealed clear and repeatable RAPD polymorphisms. Among the 38 primers, 8 showed consistent amplified band patterns among the plants with variations within and between varieties, while the others indicated polymorphisms within or between varieties. RAPD markers demonstrated a clear association with root weight. However, the presence and absence of these genetic markers did not correspond well with either the top weight or root number. Genetic instability revealed in the selection stress of superior and inferior plants was found to be independent of variety. In addition, both asexual propagated and tissue culture-induced somaclonal variations were observed in this study. Our results show that RAPD is a useful tool for detecting somaclonal variations from varietal and intra-varietal sweet potato for monitoring of DNA changes in somaclonal variants. The identification of regions which are associated with the character of root weight by RAPD markers enables us to use these markers as selection tools to improve root weight in sweet potato.     

河南省春播马铃薯品种引种比较试验

对引进的9个马铃薯品种进行品种比较试验,以期筛选出高产、优质、抗逆性强,且适合河南郑州地区推广应用的马铃薯新品种。试验结果表明,2000-11-8、F34和中蔬05079-66这3个品种综合性状表现较好,平均每667 m2产量分别为2024.62、1891.51、1779.37 kg,分别比对照增产14.57%、7.04%和0.70%,较适合河南郑州地区春季露地示范推广种植。     

Virus-free sweet potato storage roots derived from meristem-tips and leaf-cuttings

The two common sweet potato viruses found in Taiwan, sweet potato virus-A and sweet potato virus-N, were eliminated from 14 sweet potato clones by culturing 0.2-0.4-mm long meristem-tips. Leaves from 2-month-old meristem-cultured plantlets were virus-indexed by enzyme-linked immunosorbent assay (ELISA). More than 80% of the plantlets were virus-free. Rapid multiplication of virus-free plantlets was carried out by using single-node cuttings in vitro. Small storage roots were then obtained by further culturing leaf-cuttings procured from the established, virus-free plants. Using this method, virus-free storage roots were obtained within 9 months of initial meristem-tip excision and culture. It is estimated that about 90 small, virus-free storage roots can be obtained from each established plantlet within 6 months.     

Phenology and Yield Efficiency of Early,Mid-, and Late-Maturing Cultivars of Peach in Irrigated Orchards under Mediterranean Climate

Productivity of peach cultivars with different ripening seasons was studied under the growers’ conventional conditions of Tunisia. Experiments were performed in northern Tunisia (36° 41? N, 10° 15? E). Performances of Flordastar, Royal Glory, and Carnival as respectively early, mid-season, and late ripening cultivars were evaluated under the grower’s conventional irrigation programs. Fruit growth, yield, water supply, and water productivity were determined through four years. For the three cultivars, Flordastar, Royal Glory, and Carnival, fruit maturity was achieved at 650, 1100, and 2200 GDD, respectively. Average yields were 17.4, 29.8, and 41.1 t ha^–1 and mean values of water productivity were 1.9, 3.1, and 3.6 kg fresh yield m^–3 for early, mid-season, and late cultivars, respectively. Results of agronomic performances evaluation at the farm scale provided a reference on the behavior of early, mid-season, and late cultivars of peach in irrigated orchards in semi-arid conditions.     

Variation in nitrogen deposition and available soil nitrogen in a forest–grassland ecotone in Canada

Regional variation in nitrogen (N) deposition increases plant productivity and decreases species diversity, but landscape- or local -scale influences on N deposition are less well-known. Using ion-exchange resin, we measured variation of N deposition and soil N availability within Elk Island National Park in the ecotone between grassland and boreal forest in western Canada. The park receives regionally high amounts of atmospheric N deposition (22 kg ha⁻¹ yr⁻¹). N deposition was on average higher ton clay-rich luvisols than on brunisols, and areas burned 1–15 years previously received more atmospheric N than unburned sites. We suggest that the effects of previous fires and soil type on deposition rate act through differences in canopy structure. The magnitude of these effects varied with the presence of ungulate grazers (bison, moose, elk) and vegetation type (forest, shrubland, grassland). Available soil N (ammonium and nitrate) was higher in burned than unburned sites in the absence of grazing, suggesting an effect of deposition. On grazed sites, differences between fire treatments were small, presumably because the removal of biomass by grazers reduced the effect of fire. Aspen invades native grassland in this region, and our results suggest that fire without grazing might reinforce the expansion of forest into grassland facilitated by N deposition.     

黑马铃薯在吉林省农科院经植所引种试验报告

在吉林省农业科学院经济植物研究所,通过3年黑马铃薯引种比较试验,从丰产性、稳产性、适应性和商品性等方面进行分析。结果表明:黑美人杂-5品系的产量较高,属高产稳产型品系,比对照黑土豆增产26.79%,且薯型好,食味佳,抗病性强,适合本地区及相同生态类型地区示范种植。