Advances in Variable Rate Technology Application in Potato in The Netherlands

Precision agriculture is a farming management concept based on observing, measuring and responding to inter- and intra-field variability in crops. In this paper, we focus on responding to intra-field variability in potato crops and analyse variable rate applications (VRAs). We made an overview of potential VRAs in potato crop management in The Netherlands. We identified 13 potential VRAs in potato, ranging from soil tillage to planting to crop care to selective harvest. We ranked them on availability of ‘proof of concept’ and on-farm test results. For five VRAs, we found test results allowing to make a cost-benefit assessment. These five VRAs were as follows: planting, soil herbicide weed control, N side dress, late blight control and haulm killing. They use one of two types of spatial data: soil maps or biomass index maps. Data on costs and savings of the VRAs showed that the investments in VRAs will pay off under practical conditions in The Netherlands. Savings on pesticide use and N-fertilizer use with the VRAs were on average about 25%, which benefits the environment too. We foresee a slow but gradual adoption of VRAs in potato production. More VRAs will become available given ongoing R&D. The perspectives of VRAs in potatoes are discussed.     

Changes in daily rainfall characteristics in major rice producing provinces in Laos

In order to find the changes in rainfall characteristics and to examine the flood damage to lowland rice, a statistical analysis was carried out on the 40-year daily rainfall record at four rainfall stations (Thangon, Paksane, Seno, and Pakse) in Laos. The rainfall record was divided into two periods of 20 years each. The results of this analysis revealed the trends in changes regarding the frequency and the timing of the heavy daily rainfall events at the four stations. In Paksane in particular, heavy daily rainfall events tended to occur in the latter half of the rainy season.     

Factors in the Reduction in Grain Number in Winter Wheat by Early-Sowing in Yamaguchi

Abstract

Grain number per spike of wheat is lower in early sowing than in the conventional standard cultivation in Yamaguchi, Prefecture, Japan. Components of the grain number per spike in five cultivars were analyzed with respect to temperature during the spike development period throughout three growing seasons 2001/2002, 2002/2003 and 2003/2004 to find the cause of the problem of early sowing cultivation. The plants sown in early-October and late-November were called the early sown group and the standard group, respectively, in the following. Three of the five cultivars, Hokushin, Akitakko and Nanbukomugi, showed a strong winter habit, which requires very cold temperatures for spike differentiation. The other two cultivars, Iwainodaichi and Airakomugi, had a moderate winter habit. Grain number per spike and grain yield were decreased by early-sowing (compare with the standard group) in almost all cultivars throughout the three growing seasons. The three cultivars which had a strong winter habit had fewer spikelets per spike in the early-sown group than in the standard group. The other two cultivars which had a moderate winter habit had fewer grains per spikelet in the early-sown group. The higher the temperature during the spikelet formation phase, which is from flag leaf initiation to terminal spikelet initiation, the higher the number of spikelets per spike in the standard group. The spikelet number per spike in the early-sown group increased with the increase in productive tillers under fertile conditions. Such conditions also increased the grain number per spike.     

Sugar and dry matter changes in potatoes overwintered in soil in Greece

Summary Potatoes were left in the soil from December, when the vines died, until February (cvs Claustar and Sebago) or April (cv. Spunta) in a location of central Greece with light, well drained soils and a mild climate. Tubers were analysed every two months for dry matter and sugar content and usually the dry matter content did not change significantly from December to February or April. The reducing sugars increased from December to February in tubers of all cultivars and significantly decreased in cv. Spunta from February to April.     

Developments in Potato Storage in Great Britain

Potato storage in Great Britain is focused on delivery of high quality crops for premium markets. For the fresh sector, crops from storage need to have clean skins free from blemish. Control of black dot, silver scurf and skin spot is, therefore, paramount to secure the best returns. Cold storage is used as a primary means of suppressing disease development and sprout growth. Recent work on black dot has also illustrated the importance of the time the crop spends in the ground (measured as crop duration from 50% emergence to harvest) in relation to the level of disease at harvest, with rapid reduction in storage temperature providing best control of the disease once in store. Storage for processing is carried out at higher temperature with the use of CIPC for sprout suppression. Optimisation of the application process has been a primary objective to maintain frying quality and ensure compliance with new legislation on residue levels. The addition of a catalytic converter to a CIPC fogger minimised any detrimental effect of the fogging process on fry colour. The use of CIPC, where the application of fog has been assisted by slow speed ventilation, has proved to be very successful in trials carried out over 3 years in bulk stores. This has resulted in more uniform sprout control across the store and the need for less CIPC per season. Computerised control systems offer close regulation of storage temperature which reduces the likelihood of condensation that can otherwise compromise crop quality. AssiStore?—a new risk-driven decision support system developed at Sutton Bridge for store managers—is now being evaluated in commercial storage. Whilst development of enhanced management and control remains a key element of storage improvement strategies, it must be remembered that the important aspect of any control system is to ensure the interface with the operator is sound to ensure that any system is meaningful and easy to use. PCR diagnostics also offer great potential for identifying likely storage risks at harvest more accurately; a new test for skin spot has just been successfully developed. As storage becomes more sophisticated, costs inevitably increase. These have been recouped in recent years through improved quality delivered from store. But now there is a need to apply new, more sustainable approaches in order to lower inputs and reduce losses. Developments include the use of inverter drives to match ventilation (and hence energy needs) to demand, and humidification which offers scope for lowering weight loss and providing adiabatic cooling. Reduced reliance on chemicals is also needed and, whilst the adoption of ethylene for fresh market storage has been a significant step forward in recent years, it remains likely that the plant breeders will offer the most sustainable and cost-efficient route to effective storage in the longer term.     

玉米抗旱性指标研究进展

干旱作为玉米生长发育最主要的非生物逆境因子,已成为限制玉米产量形成的关键生态因素,也是我国玉米产量产生波动的重要原因,对粮食生产安全构成严重威胁。玉米抗旱性是水分胁迫条件下表现出的一种复杂综合特性,其适应干旱的形态结构是长期进化的结果,其生理指标变化也是一系列适应性改变后的综合表现。当今水资源短缺日益成为突出问题,且对玉米造成干旱的外部因素较多。本文从鉴定方法、形态指标、生理生化等方面阐述玉米抗旱机制与鉴定方法,综述玉米抗旱性最新研究进展。发展抗旱性玉米研究,为创制选育新的耐旱种质提供支撑,最终提升玉米抵御干旱胁迫的能力,这对于保障玉米可持续生产、解决粮食安全具有重要意义。     

小麦族内的核质互作研究进展

本文从核质基因型互作、细胞质与染色体互作、细胞质与染色体（片段）互作和细胞质基因与细胞核基因互作４个层次综述了小麦族内核质互作研究的最新进展及其小麦遗传育种学的拓展,提出了小麦族内核质互作研究的重点领域－核质杂种的遗传变异、新型核质杂种的创制和杂种优势利用,并展望了这一领域的研究前景。     

象征意义仿生在我国景观设计中的应用

在景观设计中，景观不仅需要具备形式的美感，还要有一定的深层内涵。通过象征手法传达景观意义，赋予景观某种意义成为景观设计的重要发展形式，富有意义的景观艺术为人类精神世界的提升和人类文明的发展起到了举足轻重的作用。本文分析了我国象征意义的理论基础，认为它得益于我国古代的哲学思想体系，从自然的启示和社会文明的启示两方面举例说明事物的象征意义仿生设计，为景观设计运用象征意义仿生提供理论及实践依据。     

木薯生理生化及其分子遗传学研究进展

木薯是我国南方重要经济作物之一,在种植栽培、加工工艺等方面已有诸多的研究报道,但其生理生化及其分子遗传学研究相对滞后。本文综述了近年来木薯生理生化及其分子遗传学领域国内外的研究进展,并就其研究方向等提出一些看法和观点,旨在为木薯生产科研提供理论参考。     

兜兰离体快繁技术研究进展

由于生境破坏和人工过度采挖及繁殖的障碍,兜兰已是世界上最濒危的植物物种之一,所有野生种均被列入《濒危野生动植物种国际贸易公约》附录I而被禁止交易。突破其种苗繁殖技术瓶颈有利于兜兰种质资源的保护和可持续利用。本文对兜兰属植物无菌播种、共生萌发和组织培养技术等离体快繁技术的进展进行综述,并提出了目前存在的问题和解决方法,以期为兜兰属植物离体繁殖技术的深入研究和优质种苗的规模化生产提供参考。     

马铃薯亲本材料试管苗的耐盐性筛选

用含0%、0.2%、0.4%、0.6%、0.8%5种NaCI浓度的修改MS培养基胁迫马铃薯品种资源脱毒试管苗的方法,鉴定和筛选了35份不同熟期马铃薯亲本材料的耐盐性,筛选结果:耐盐级别为4(即0.2%盐浓度下仍然存活)的亲本材料11份,耐盐级别为3(即0.4%盐浓度下仍然存活)的亲本材料3份,耐盐级别为2(即0.6%盐浓度下仍然存活)的亲本材料2份,耐盐级别为1(即0.8%盐浓度下仍然存活)的亲本材料3份。     

Variability in the antinutritional constituents in greengram Vigna radiata

Five greengram varieties, viz. Mg 161, M₃, Co₂, Pusa 8793 and Pusa baisakhi, were analyzed for phytic acid, tannic acid and trypsin activity. Significant varietal variation in tannin (310 to 400 mg percent), phytic acid (201.33 to 265.33 mg percent) and trypsin inhibitor activity (55.74 to 97.70 TIU/mg) were observed.     

广东花生抗青枯病育种研究进展

广东70％～80％的花生种植在轮作周期较短的瘦瘠旱坡地上,青枯病危害较重,严重威胁花生生产。在调查品种与发病关系中,发现花生抗青枯病力在类型间和品种间有明显差异,因此,应以品种抗病性鉴定和选育作为研究的主攻方向。利用国内外花生品种资源鉴定筛选出抗原材料并通过各种育种途径,选育出高产抗青枯病的花生品种投入生产,减轻青枯病危害,提高花生单产和总产。     

水稻耐热性研究进展

随着工业化的加快和温室效应的加剧,短期异常高温发生频繁,高温已成为作物生长的主要灾害因子之一.综述了高温对水稻生长发育、产量、品质、生理生化特性的影响和水稻耐热性遗传与育种及克服高温危害措施的研究进展,对进一步开展水稻耐热性研究提出了一些建议.     

Chrysin Reduced Acrylamide-Induced Neurotoxicity in Both in vitro and in vivo Assessments

Background: Acrylamide (ACR) is a well-known industrial toxic chemical that produces neurotoxicity, which is characterized by progressive central and peripheral neuronal degeneration. Chrysin is a natural, biologically active flavonoid compound, which is commonly found in many plants. The antioxidant and neuroprotective properties of chrysin have been demonstrated. Methods: In this study, the possible effect of chrysin on ACR-induced toxicity was evaluated in both in vitro and in vivo experiments. PC12 cells were used as a suitable in vitro model. Cells were exposed to chrysin (0.5-5 µM) for 12 and 24 h, and then ACR in IC₅₀ concentration was added to the cells. Finally, cell viability was determined using (4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium assay. For in vivo assay, Wistar rats were treated with ACR (50 mg/kg i.p. for 11 days) alone or in combination with chrysin (12.5, 25, and 50 mg/kg). At the end of treatment, behavioral index was evaluated. Results: ACR decreased cell viability and pre-treatment with chrysin (0.5-5 µM) significantly decreased ACR-induced cytotoxicity in the time- and dose-dependent manner. In Wistar rats, exposure to ACR significantly induced severe gait abnormalities, but treatment with chrysin (50 mg/kg) reduced ACR-induced neurotoxicity in animals. Conclusion: In the current study, chrysin exhibited neuroprotective effect on PC12 cells as an in vitro model and also on Wistar rats. Iran. Key Words: Acrylamide, Chrysin, Neurotoxicity, Antioxidant     

菠萝不同月份采收果实品质变化规律研究

以我国菠萝主栽品种‘巴厘’为试材,分析不同月份采收的菠萝果实Vc、可滴定酸、可溶性糖和可溶性固形物的变化,结果表明：不同月份成熟的菠萝果实Vc含量有差异,1～12月呈先降低后升高的趋势,11～4月较高,5～9月较低;可滴定酸含量与Vc含量变化趋势一致,11～3月较高,4～9月较低;不同月份成熟菠萝果实可溶性糖含量变化无明显规律,1、5、6、7、12月较高,其他月份较低;可溶性固形物含量表现出与Vc、可滴定酸含量变化相反的趋势,5～7月较高,其次为9、11,2、3月,可溶性固形物含量最低;各月份果实糖酸比情     

Adaptation and yield of pigeonpea in different environments in Tanzania

Pigeonpea is grown in wide range of cropping systems and environments, both in East Africa and internationally. An important feature of adaptation to these diverse systems and environments is the timing of flowering and maturity. Most traditional cultivars grown in Tanzania are medium to late flowering types (>150 days), although extra-early flowering cultivars are now available. The aim of the present investigation was to measure biomass (BY) and seed (SY) yield of a set of phenologically diverse cultivars to determine their adaptation to contrasting environments in Tanzania. Ten cultivars, from extra-early (60 days) to late (>180 days) flowering, were planted at six locations varying in mean temperature, photoperiod and rainfall. Days to flowering (DTF) and maturity, and above-ground BY and SY at maturity, were measured. A stress index (ETr:ETm ratio, 100 = no stress) was computed for each site. Rainfall and the stress index at the different sites varied from 322 to 1297 mm and 57 to 89, respectively. Among cultivars, DTF varied from 55 to 320 days, the stress index from 3 to 98, BY from 700 to 25,000 kg ha⁻¹, and SY from 0 to 4000 kg ha⁻¹. The highest yielding environment was at Selian, where mean temperatures were favourable (19 °C) and no stress occurred. At all sites there was an optimum DTF, which for SY varied from <100 to 150 days. The best adapted cultivars were ICP 7035, ICPL 90094, Kat 50 and QP37, which were all medium flowering (c. 150 day) types. Extra-early cultivars such as ICPL 86005 also showed considerable potential, especially in short-season environments.     

Changes in developmental duration of direct-seeded rice in a well-drained paddy field in response to late planting

We investigated changes in the developmental duration of rice cultivars with a wide range of maturities in response to late planting. Elucidating the relationship between cropping season and the progress of growth stages is important for establishing direct-seeded cultivation and creating growth models. Late planting of the intermediate to late maturing cultivars Akidawara and Hoshijirushi decreased the time from emergence to panicle formation and decreased the cumulative effective temperature (CET) and cumulative effective soil temperature (CEST). In the very early maturing cultivars Ichibanboshi and Fusakogane, the changes in number of days, CET, and CEST from emergence to panicle formation with late planting were small. From emergence to heading and maturity, the number of days, CET, and CEST of many cultivars tended to increase until mid-May and then decreased. The changes in the number of days, CET, and CEST caused by late planting were greater for the intermediate to late maturing cultivars than for the very early maturing cultivars. The differences between cultivars were greatest with early May sowing, and then decreased with later planting. Short-day condition revealed significant differences in the duration of vegetative growth and CET among cultivars, but long-day condition erased these differences. These results demonstrate that the photosensitivity and thermosensitivity of cultivars are especially important in crop planning and for creating growth models of direct-seeded rice.     

Changes in chlorpropham residues in stored potatoes

Chlorpropham (CIPC)³ concentrations were measured in peel samples of tubers taken from large commercial potato storages and from test bins after aerosol application. Tuber samples were taken at different levels within the pile and at numerous sites near the surface. The minimum concentration of CIPC in the peel layer for complete inhibition of sprouting was estimated to be 20 ppm. Immediately after commercial application of CIPC, 99% of the sample sites had concentrations high enough to completely inhibit sprouting, and residues in the peel were generally highest in samples obtained from the surface and from the bottom of the pile. CIPC concentrations decreased during the storage season in nearly all sites tested. Storages differed in the rate at which CIPC was lost. Mean peel residues fell below the level necessary for sprout inhibition in some storages but not in others. The rate of CIPC loss increased at the same time that air movement to maintain the desired temperature increased. With the 20 ppm threshold level as a guide, it is possible to monitor commercial storages for sprout-inhibition status. Retreatment before peel residues drop below 20 ppm can extend sprout inhibition in storage.     

人参遗传多样性研究进展

本文综述了人参在表型和DNA水平的遗传多样性的研究进展。其表型多样性主要体现在形态特征;DNA多态性是研究最多的,RFLP、RAPD和AFLP等分子标记已广泛用于人参的遗传多样性研究中,并根据国内的研究现状,提出了保护人参多样性和采用新方法研究人参基因的建议。