养分管理对马铃薯安全贮藏的影响

马铃薯贮藏造成的经济损失数额巨大,如何控制贮藏损失已成为马铃薯产业亟待解决的问题。为探明田间养分管理与马铃薯安全贮藏的关系,试验设置不同氮、磷、钾施肥梯度,研究其对马铃薯块茎养分含量的影响,以及不同处理块茎养分含量与马铃薯贮藏期干腐病的发病情况的关系。研究结果显示,在一定范围内,块茎氮、钾营养状况对马铃薯贮藏安全存在影响;从马铃薯贮藏安全的角度给出临界块茎氮含量应小于12.66 g/kg,临界块茎钾含量应大于20.43 g/kg。     

马铃薯氮素营养状况的SPAD仪诊断

以马铃薯品种克新1号为材料,研究了叶片SPAD值、叶片全氮含量、叶绿素含量以及块茎产量随供氮水平的变化规律及相互关系,旨在为使用叶绿素仪进行马铃薯无损伤氮素诊断和推荐施肥奠定基础。研究结果表明,从马铃薯苗期到块茎淀粉积累各个生育阶段叶片的SPAD测定值均与马铃薯叶片含氮量呈显著正相关关系。除苗期外,块茎形成期、块茎膨大期、淀粉积累期的马铃薯叶片含氮量和叶片SPAD值随土壤施氮量的变化均表现为线形加平台的模式。因此马铃薯块茎形成期后叶片的SPAD读数可揭示马铃薯的氮素营养状况。统计分析结果还表明,叶片SPAD值与块茎相对产量呈线形加平台的数量关系模式,据此确定了应用叶绿素仪SPAD-502进行马铃薯推荐施肥的SPAD临界值为块茎形成期47.3、块茎膨大期45.1、淀粉积累期40.2。     

旱作马铃薯块茎产量相关性状的通径分析

本试验以２０个马铃薯无性系为材料，进行块茎产量相关性状通径分析。结果表明，９个相关性状对块茎产量影响的顺序为：块茎数＞块茎大小＞根数＞根系拉力＞根鲜重＞冠层鲜重＞商品薯率＞出苗天数＞冠层覆盖度。提高块茎数和块茎大小是增加块茎产量的主要途径。选择根系发达的材料，是提高块茎产量的重要途径。商品薯率通过块茎大小，冠层覆盖度通过块茎数进行间接选择，亦可提高块茎产量。出苗天数的增加可导致块茎产量大幅度减少。     

不同马铃薯品种(系)块茎膨大规律研究

试验研究了CIP晚疫病水平抗性优良品系395049.62、西南山区大面积栽培品种Mira、目前推广品种鄂马铃薯3号在冠层覆盖率、块茎鲜重、商品薯率、经济系数等性状的变化差异。Mira在冠层覆盖率达到最大值后,只维持了较短时期即开始缓慢下降,鄂马铃薯3号表现出与Mira相似的趋势,但进入急剧下降的时间比Mira推迟7d左右。395049.62则相反,保持最大冠层覆盖率的时间可达1个月左右;Mira的块茎鲜重增长速率较鄂马铃薯3号和395049.62快,达到最大值的时间较鄂马铃薯3号和395049.62提早15 d,鄂马铃薯3号和395049.62基本相似,在后期的增长速率较快,说明两者的块茎主要是在后期膨大的,尤其是395049.62在成熟前一周左右增长速率明显加快;395049.62的商品薯率最高,鄂马铃薯3号次之,Mira最低;而经济系数则以鄂马铃薯3号最高,Mira次之,395049.62最低。     

旱作马铃薯块茎产量相关性状的通径分析

本试验以２０个马铃薯无性系为材料，进行块茎产量相关性状通径分析。结果表明，９个相关性状对块茎产量影响的顺序为：块茎数＞块茎大小＞根数＞根系拉力＞根鲜重＞冠层鲜重＞商品薯率＞出苗天数＞冠层覆盖度。提高块茎数和块茎大小是增加块茎产量的主要途径。选择根系发达的材料，是提高块茎产量的重要途径。商品薯率通过决茎大小，冠层覆盖度通过块茎数进行间接选择，亦可提高块茎产量。出苗天数的增加可导致块茎产量大幅度减少。     

六个马铃薯品种的干物质生产和氮肥利用

马铃薯(Solanum tuberosum L.)的品质和产量受土壤肥力的影响很大。氮肥用量过高会延迟块茎膨大并增加冠根比。一些资料表明氮可起调节作用,促进或延迟块茎形成及增加或减少块茎数。据报道,在整个生育期中,氮对形成并保持最佳株冠,以维持块茎继续膨大起了主要作用.     

马铃薯无性一代植株性状相关及通径分析

本文对马铃薯30个杂交组合无性一代的14个性状与单株产量的相关关系作了估算,其中无效生育期、播后74天和92天冠层覆盖度、平均冠层覆盖度、最高冠层覆盖度、有效生育期、单株块茎数、单块重8个性状与单株产量的相关性达显著或极显著水平。进而对影响单株产量(y)的平均冠层覆盖度(x_1),有效生育期(x_2)、单株块茎数(x_3)、单个块茎重(x_4)进行通径分析。结果表明,该4个性状决定单株产量变异的94.61％,说明这4个性状是影响单株产量的决定因素。     

马铃薯无性一代植株性状相关及通径分析

本文对马铃薯３０个杂交组合无性一代的１４个性状与单株产量的相关关系作了估算，其中无效生育期，播后７４天和９２天冠层覆盖度，平均冠层覆盖度，最高冠层覆盖度，有效生育期，单株块茎数，单块重８个性状与单株产量的相关性达显著或极显著水平。进而对影响单株产量的平均冠层覆盖度，有效生育期，单株块茎数，单个块茎重进行通径分析。结果表明，该４个性状决定单株产量变异的９４．６１％，说明这４个性状是影响单株产量的决定     

马铃薯氮素的吸收、积累和分配规律

植株体内氮素浓度的高低反映了其生长势的强弱,马铃薯生育期间各器官氮素浓度的变化始终表现为叶片>地上茎>块茎,叶片中的氮素浓度高低反映了叶片光合活性的大小。马铃薯对氮的吸收与营养生长和块茎的增长密切相关,植株对氮的需求量受其生长状况所控制。而且,氮在植物体内很容易流动,块茎形成后,大量的氮素转移到块茎中,用于块茎的建成和营养贮存。马铃薯植株在淀粉积累开始后,各器官中氮素加快了向块茎的转移,使叶片和地上茎的衰老进一步加剧。因此,在马铃薯高产栽培实践中,须注重氮、磷、钾的适量与配合施用,使之既能满足块茎的形成与生长的需要,又可防止植株生长过旺或后期发生早衰。本试验表明,在因素中量(适量)组合下,每生产500kg块茎需要纯N2 65kg。     

氮肥施用时期对马铃薯氮素积累与分配的影响

以马铃薯克新13号脱毒种薯为材料,在相同氮肥用量下,设置不同生育时期施氮的田间小区试验,通过测定主要生育期植株各器官干物重和含氮量,研究施氮时期对马铃薯不同器官氮素积累、分配及块茎产量和质量的影响。结果表明,马铃薯在营养生长期的吸氮素量仅为全生育期的1/3,块茎形成中期达到马铃薯的吸氮高峰期,块茎增长后期至成熟期块茎中的氮素主要来自营养器官的二次分配。与N 150 kg/hm2全部做基肥相比,将1/3的氮在块茎增长初期追施可使商品薯产量提高25%(P<0.05),达到30.01 t/hm2。氮肥利用率达到44%(P<0.05)。适宜氮肥用量下,基肥和追肥的合理分配是获得马铃薯高产优质的重要条件,基肥氮不足,氮肥集中在苗后施用,则易导致植株贪青。试验在肥力中等的土壤种植马铃薯,150 kg/hm2氮素用量条件下,将2/3的氮作基肥施用,1/3的氮在块茎增长初期追施,较有利于养分在块茎中的分配,同时也能获得最高的块茎产量。     

Leaf Positions of Potato Suitable for Determination of Nitrogen Content with a SPAD Meter

Abstract

Hand-held SPAD meter can be used to evaluate the leaf nitrogen status of potato. For practical use, it is necessary to select a proper compound leaf, a proper leaflet within compound leaf and position of leaflet suitable for measurement. Therefore, field experiments were conducted in northern China in 2009 and 2010. The SPAD values, plant growth, N uptake of potato plants at tuber initiation and tuber bulking stages under different N supply levels, and final tuber yields were examined. The criteria for determining the most suitable leaf, leaflet and position within a leaflet are that the SPAD values show less variation at a given N supply level, and show a more sensitive response to different nitrogen levels. Our results showed that the coefficients of variance of SPAD values ranged from 8.7 to 25.9% with a leaf N concentration range of 2.1 to 3.8 gN 100 g-¹ at tuber initiation stage, and 7.2 to 21.6% with leaf N concentration range of 0.96 to 1.26gN 100 g-¹ at the tuber bulking stage. The SPAD values of the 4th compound leaf from apex were more stable and more sensitive to the nitrogen level than those of other leaves, suggesting that the 4th compound leaf is suitable for estimating the leaf N status using a SPAD meter. Within a compound leaf, the SPAD value of the top leaflet was more sensitivethan the other leaflets to nitrogen supply, whereas it was less stable, making it difficult to chose the leaflet for measurement. However, the top leaflet emerges and expands much earlier than the side leaflets, and should be better for SPAD value measurement. The SPAD measurements at the top point of the top leaflet of the 4th leaf demonstrated both less variation and higher sensitivity to nitrogen supply. Therefore, we conclude that the top point of the top leaflet of the 4th compound leaf is the best position for potato N status diagnosis using a SPAD meter.     

马铃薯根际器官的呼吸变化

采用改良的桶栽法和排除根系法两种方法测定马铃薯植株在苗期、块茎形成期和块茎膨大期三个阶段根际器官CO2和O2呼吸速率的变化。结果表明:一天之中,马铃薯根际器官的呼吸速率先升高,后降低;O2的呼吸速率和CO2的变化趋势相反;在整个生育期过程中块茎形成期的呼吸速率最大。两种测定方法的根际器官呼吸速率变化趋势一致。     

Potato Stolon and Tuber Growth Influenced by Nitrogen Form

Abstract

Potato tuber initiation and its growth are key processes determining tuber yield, which are closely related to stolon growth, and are influenced by many factors including N nutrition. We investigated the influences of different forms of nitrogen (N) on stolon and tuber growth in sand culture with a nitrification inhibitor during 2010 – 2011, and using two potato cultivars. Plants supplied with NO₃-N (N as nitrate, NO₃^-) produced more and thicker stolons than those supplied with NH₄-N (N as ammonium, NH₄⁺) at tuber initiation stage. In the plants fed NO₃-N, the stolon tips swelled or formed tubers earlier and produced more tubers than in those fed with NH₄-N. However, no significant difference was observed among N forms in terms of tuber yield at harvest, this may have been because of the shoot growth rate at tuber initiation stage was lower in the plants fed NO₃-N. During the tuber bulking stage, the difference in shoot DWs among N forms began to decrease, and the shoot DW of plants fed NO₃-N was even heavier than those fed NH₄-N in some cases. The influence of N form on potato plant growth may therefore vary with the potato growth stage.     

不同播种深度对马铃薯产量及其构成因素的影响

为探讨马铃薯播种时最佳深度,本试验以马铃薯品种‘会-2’为材料,研究了5个不同播种深度（10 cm,15 cm,20 cm,25 cm,30 cm）对马铃薯产量及其构成因素的影响。结果表明：不同播种深度对马铃薯出苗期、生育期、株高、大中薯块茎数及产量均有不同程度的影响;播种深度为20 cm时能极显著提高马铃薯产量。     

氮肥基追肥比例对马铃薯微型薯生产的影响

为探讨马铃薯微型薯合理的氮肥施肥方式,以‘早大白’马铃薯脱毒试管苗为材料,在温室内进行了氮肥不同基施和追施比例对马铃薯微型薯生产影响的试验。结果表明:在施氮肥量为纯氮105 kg/hm2条件下,单株结薯方面,基追比为5:2时,单株结薯最多,全部做基肥的处理,单株结薯最低;单粒重方面,基追比为2:1时,单粒重最大,全部追肥的处理最低。可见氮肥基施和追施配合有利于提高单株结薯率及平均单粒重。因此,微型薯生产重视氮肥基施同时配合追施比较符合移栽的试管苗对氮肥的吸收规律。     

Effect of seedpiece spacing and nitrogen fertilization on tuber yield, yield components, and nitrogen use efficiency parameters of two potato cultivars

The effect of seedpiece spacing on the efficiency of nitrogen (N) use by the potato crop is generally unknown. The objective of this experiment was to determine the effect of seedpiece spacing on tuber yield, yield components and N use efficiency parameters of two potato cultivars. Potato cultivars Atlantic and Shepody were grown at two rates of N fertilization (0 or 100 kg N ha^?1) and three seedpiece spacings (20, 30, or 40 cm) in 2000 to 2002. Wider seedpiece spacing increased mean tuber weight and the number of tubers per stem, but decreased total tuber yield. The higher tuber yield at the narrow seedpiece spacing was attributed to higher biomass production in combination with lower tuber specific gravity. Seedpiece spacing had no consistent effect on plant N accumulation, and therefore no consistent effect on N uptake efficiency (plant N accumulation /N supply from the soil plus fertilizer). However, a small increase in soil NO₃-N concentration in the hill at topkill at wider seedpiece spacing suggested plant N accumulation was slightly reduced at wider seedpiece spacing, but at a level that could not be detected from a plant-based measure of N accumulation. The reduced dry matter accumulation, but similar plant N accumulation, resulted in lower N use efficiency (plant dry matter accumulation / N supply) at wider seedpiece spacing. Wider seedpiece spacing also resulted in generally lower values of N utilization efficiency (plant dry matter accumulation / plant N accumulation) for the 40-cm compared with the 20- and 30-cm seedpiece spacings. Effects of seedpiece spacing on N use efficiency parameters were generally consistent across cultivars and fertilizer N rates. Wider seedpiece spacing did reduce the efficiency of N use by the potato crop; however, the magnitude of the effect was small under the conditions of this study.     

马铃薯稻草覆盖免耕栽培与传统栽培比较研究

为探索马铃薯稻草免耕栽培增产机理,我们开展了马铃薯稻草覆盖免耕栽培与传统栽培比较研究。结果表明,与传统栽培相比,稻草覆盖免耕栽培马铃薯薯皮光滑,块茎大小整齐,出苗率高,株高和叶片数较多,中、后期植株生长速度明显加快。分枝数多、单株块茎重和大薯率高是马铃薯稻草覆盖免耕栽培增产的主要原因。     

马铃薯磷素的吸收、积累和分配规律

磷元素在马铃薯植株体内的流动性较大,磷营养水平与块茎膨大密切相关,块茎是磷素的最终贮存库。在块茎增长初期,叶片、地上茎和块茎中的磷素浓度均为一生中的最高值,此时是马铃薯对磷需求最多的时期,块茎形成后,则大量的磷(P2O5)向块茎转移。马铃薯对磷素(P2O5)吸收速率较低。在整个生育期内吸收速率呈单峰曲线变化,峰值出现在块茎增长期。     

Water usage by potato plants at different stages of growth

Three groups of single-halm potato plants were tested for water usage at different stages of growth under growth chamber, greenhouse and field conditions by conducting 24-hour uptake studies at weekly intervals. Although the water usage was higher and more variable in the greenhouse and field than in the growth chamber because of varying environmental conditions during the 24-hour test periods, similar patterns were obtained. From emergence, the potato plant appeared to have four growth stages based on morphological development and water use. The young plant stage from emergence to tuber initiation is characterized by rapid growth, high transpiration rate per unit of plant material (essentially foliage), transpiration significantly correlated with the amount of foliage and a higher percentage of moisture being retained in the plant. The second stage is essentially a short transition stage of tuber initiation where top growth continues, transpiration levels off and a lower percentage of moisture is retained in the plant. The third stage is the tuber bulking stage where transpiration and water use remain relatively static because of non-expanding top growth and a lower percentage of moisture being retained in the plant during the bulking process. The final stage of senescence and tuber ripening is characterized by a marked reduction in water use primarily because of lower transpiration and loss of functioning foliage.