Growing potato plants by the water culture technique

A water culture technique was developed for the study of the nutrient requirements of the potato plant. Tuber formation was avoided by pinching off the stolons as they developed and hence vegetative growth could be studied without the complication of abnormal tuber formation in the culture solution. The K deficiency symptoms obtained by this method were essentially the same as those observed for field grown plants.     

Luxury Absorption of Potassium by Potato Plants

Pot and field experiments were conducted to test whether excessive potassium (K) uptake by potato plants occurs under conditions with or without irrigation at different sites. The results from both pot and field experiments showed that potato biomass and tuber yield peaked at a certain level of external K, and did not increase further with additional K supply. However, K absorption by potato plants continued to increase within the range of K used. It was concluded that luxury absorption of K by potato plants occurred with high K availability in the media. This suggests that K fertilizer recommendation based on the index “K requirement per tuber production” may be unreliable, because the optimum crop need varies with production conditions.     

Yield, water use efficiency and nitrogen uptake in potato: influence of drought stress

Summary A lysimeter experiment was performed to study the optimal allocation of limited water supply in potatoes. Irrigation regimes equal to 40, 60 and 80% of maximum evapotranspiration (ET) were evenly applied over the crop cycle. Other treatments involved withholding 80 mm of irrigation, based on ET, beginning at each of three designated growth stages (tuber initiation, early and late tuber growth). An irrigated control treatment, restoring the entire ET, was included for comparison. Continuous drought stress reduced photosynthesis as irrigation volumes were reduced. Plant biomass and tuber yield decreased almost proportionally to water consumption, so that WUE was roughly constant. N uptake was highest in the control and in 80% ET treatment. Withholding water during tuberisation severely hindered plant physiological processes and penalized tuber yield. Reductions in photosynthesis, total biomass and yield were the greatest when drought was imposed during tuber initiation. The earliest stress resulted in the lowest WUE and N uptake. A new crop water stress index (SI) was proposed, which combines atmospheric demand for water and canopy temperature.     

Influence of irrigation regimes on growth and yield of potato cv. Spunta

Summary The effect of furrow and drip irrigation giving 0, 33, 66, 100 and 133% of the maximum evapotranspiration (ETM) was studied on leaf transpiration, stomatal resistance, tuber growth, yield and yield response of cv. Spunta. The research was carried out in Sicily in 1988 and 1989 on early potato crops grown during the winter/spring cycle. Increased water supply increased leaf transpiration, plant fresh weight, tuber growth rate, yield and earliness, and decreased stomatal resistance and tuber dry weight. A higher yield response was obtained at the lower water regimes (ETM of 33 and 66%). There were no significant differences between the two methods of irrigation.     

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.     

马铃薯试管苗低成本快繁方式研究

为适应脱毒种薯工厂化生产的要求 ,降低成本 ,对马铃薯脱毒试管苗快繁方式进行了研究 ,以不影响脱毒苗生长为前提 ,筛选出成本低、生长好的培养方法。研究结果表明 :①液体培养由于省去了价格昂贵的琼脂 ,培养成本降低了 80 0 3% ,并且试管苗的生长比固体培养要好 ;②在液体培养过程中 ,不加有机成分 ,培养成本降低 2 3 71% ,脱毒试管苗生长正常 ;③液体培养基的用量要少于固体培养基的用量 ,为固体培养基 1/ 2～ 1/ 3,一般以 10ml为宜     

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。     

亏缺灌溉对大豆根系生长和养分积累及产量的影响

采用盆栽方法以新大豆8号为试验材料,研究了4种土壤水分处理(下限分别为田间持水量的80%、70%、60%、50%)对春大豆根系生长、根系活力和单株产量的影响.结果表明:随着水分亏缺加重,根干重、根系吸收表面积、根伤流、根活力均呈现显著降低的变化趋势,表现为80%>70%>60%>50%;7月20日前后亏缺灌溉降低大豆根...     

Effects of transitory water stress on potato tuber stem-end reducing sugar and fry color

Potatoes grown for processing in irrigated regions of the Pacific North-west sometimes develop undesirably high concentrations of reducing sugars in tuber stem ends due to hot weather and water stress during tuber development. Such tubers usually produce french fries with dark stem ends or sugar ends. In order to better quantify the relationship between water stress and stem-end sugar levels for Russet Burbank, single episodes of transitory water stress were established by delaying irrigations until soil water potentials ranging from -32 to -107 kPa were reached during early tuber bulking. To determine when the increase in reducing sugars occurred, tubers were sampled before transitory stress, at maximum stress, after stress was relieved with sprinkler irrigation, and post harvest. Reducing sugar concentrations did not increase in tuber stem ends until two weeks or longer after the plant water stress was relieved. Increased reducing sugar concentrations were positively associated with decreased soil water potential (drier soil). Tubers were sliced and fried at harvest and six weeks post-harvest. Decreasing soil water potential (drier soil) was associated with progressively darker fry colors at harvest and post harvest. Significant darkening in the average stem-end fry color light reflectance of tubers at harvest as observed at -80 kPa in 1988 and -69 kPa in 1989. The effect of imposed water stress on tuber stem-end reducing sugar concentrations was most pronounced post harvest.     

大豆和豇豆抗旱性的比较

本文用盆栽的大豆和豇豆经自然干旱比较研究了二者抗旱性的方式。试验证明大豆属低水势耐旱型,豇豆属于高水势耐旱型。豇豆以其敏感的叶片蒸腾调节机制保持体内的高水势状态,在干旱下RWC和φw变化很小。大豆则以渗透调节为主,使植株在中度水分胁迫下保持一定的生长速率,严重干旱使其生长停止或死亡。结果表明,豇豆具有比大豆更强的抗旱能力。     

AM真菌对石漠化地区桑树的促生及养分调控作用

为确定丛枝菌根（arbuscular mycorrhizal,AM）真菌对石漠化地区植物及土壤养分化学计量特征的影响,本研究以石漠化地区经济树种桑树为研究对象,通过模拟石漠化地区季节性干旱,研究水分供应发生变化时,AM真菌对桑树幼苗和土壤中养分调控作用。为模拟石漠化地区季节性干旱,试验设置正常供水和自然干旱2个时期,每个时期均设未接种对照（-M）、接种摩西斗管囊霉（Fm）和接种根内根孢囊霉（Ri）3个处理。桑树收获后,测定植物、土壤中的C、N、P、K含量。结果表明：在正常供水、自然干旱2个时期,接菌处理对桑树幼苗的促生效果显著,干旱胁迫发生之后,Ri菌种与桑树的亲和性、促生效果均强于Fm菌种。接菌处理对桑树幼苗N、P营养改善作用尤为明显,无论水分供应条件如何,接菌处理都显著增加桑苗各部分N、P含量。对比土壤养分含量发现,接菌处理增加了土壤有效P含量,降低了土壤中C含量,正常供水条件下,接种Fm、Ri分别使得土壤C含量下降了7.00%和8.55%。对比土壤养分计量比发现,正常供水条件下,接菌处理显著提高了土壤中的碳磷比（C/P）和氮磷比（N/P）;干旱胁迫条件下,接菌处理显著增加氮磷比（N/P）。综上所述,石漠地区发生季节性干旱时,AM真菌可以影响桑树对C、N、P养分吸收和分配,依据水分供应的变化和对养分资源需求的不同,调控土壤、植物体中C、N、P配比。     

刚果12号桉叶片水抽提物对4种植物幼苗生长的影响

采用盆栽法研究了刚果12号桉叶片水抽提物在水分胁迫（水渍与干旱）和养分缺乏与丰足的环境条件下对4种植物生长的影响。结果表明，植物种类与盆栽基质的肥力是影响植物幼苗生长的关键因素，而桉叶水抽提物与土壤水分对植物幼苗的生长虽有影响，但与前二相比作用较小。因此，在退化的桉树人工林地重建林下植被，首先应选择耐瘠薄、耐旱性强和对化感作用不敏感的植物，如柱花草等豆科植物，既能自身固氮，又能通过循环增加土壤养分，当然应该注意豆科与禾本科搭配。结果还表明，在逆境条件下，桉树的化感作用会增强，并与其它因素互相作用，抑制林下植被生长。     

黑土区水肥耦合对大豆产量的影响

通过盆栽试验条件,设置不同灌水和施钾处理,研究水钾耦合对大豆产量的影响,试验结果分析表明:水分对大豆产量影响大于钾肥的影响.大豆产量很大程度上依赖于水分供应的多少,在水分充足时增施钾肥可以提高大豆产量和株高,水分的增产十分显著,水分对产量影响增产最大为25.6%,但水分过高对大豆生产有毒害作用.随着水分和施肥量的增加,产量增加,在相对含水量为60%和肥料F3(N:0.04 g/kg、P2O5:0.02 g/kg、K2O 0.30 g/kg)情况下,产量最高(17.7 g/株),比无钾肥干旱增产33.7%.     

株行距和施肥量对木薯产量及生长的影响

采用裂区试验设计方法,研究株行距和施肥量对华南5号木薯产量和生长的影响.结果表明:在本试验株行距和施肥量条件下,施肥量对木薯产量和生长的影响比株行距大.密植(0.6～0.8 m)有利于提高淀粉产量、鲜薯产量和鲜薯淀粉含量,以0.8m株行距最佳,而疏植(1.2～1.4m)有利于提高单株薯数、单株鲜薯重、单株鲜茎叶重、收获指数和茎径.施肥有利于提高淀粉产量、鲜薯产量、单株鲜薯重、单株鲜茎叶重、茎径、株高和单株薯数,但降低鲜薯淀粉含量和收获指数.丰产栽培技术要兼顾单位面积株数、单株鲜薯重和鲜薯淀粉含量.建议在土壤肥力差和少施肥时,用0.6 m株行距;土壤肥力中等且较高施肥时.采用0.8 m株行距;土壤肥力中上且优越水肥管理,采用1.0 m株行距.     

不同生育期干旱对花生衰老特性及产量的影响

在防雨棚池栽和盆栽条件下,通过人工控水研究了不同生育期干旱对花生衰老特性和产量的影响。研究表明,不同生育期干旱均导致花生叶片叶绿素含量、净光合速率、SOD、POD、CAT活性和花生根系活力的降低,致叶片MDA含量提高,其中花针期和结荚期干旱对花生衰老特性影响最大。干旱处理均导致荚果产量、生物产量降低,花针期和结荚期干旱对花生产量形成影响最大。     

Influence of irrigation and nitrogen management on potato yield and quality

The effects of irrigation, water and nitrogen management on yield and quality of the Russet Burbank cultivar are discussed relevant to developmental stages of growth. Recent research on the interactions of irrigation and nitrogen management on total and U.S. No. 1 yields and specific gravity are presented. Total and U.S. No. 1 yields decline with increasing soil moisture stress. Yield of U.S. No. 1 potatoes is particularly sensitive to short periods of irrigation deficit during tuber initiation. Total yield appears most sensitive to short periods of irrigation deficit during tuber bulking. Allocation of longer term irrigation deficits during years of limited water supply should be either a) avoided during mid-season tuber bulking, or b) uniformly distributed over the entire tuber bulking growth period. Yield increases with higher total available soil nitrogen under deficit irrigation, but the yield response diminishes as the amount of total seasonal water decreases. The influence of irrigation and nitrogen availability is also discussed for specific gravity and tuber maturity. Seasonal (split) nitrogen management is proposed as a method to improve yield, quality and nitrogen fertilizer use efficiency of indeterminant cultivars.     

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。     

马铃薯需钾特性及钾肥效应

试验结果表明，钾对马铃薯营养生长有明显促进作用。团棵期施钾处理株高较对照平均增加３．２ｃｍ，鲜重增加１１．６ｇ；盛花期分别增加２．４ｃｍ和４９．１ｇ。植株含钾量随着植株生物量的增大而减小，前期植株中钾的含量３．８５％～４．６２％，后期钾的含量为１．６３％～４．１９％。植株吸钾量则随着生物量的增大而增加，前期０．６～０．８ｇ／盆，后期４．１２～５．８６ｇ／盆。施钾处理较对照平均增产６．８％，不施钾土壤速效钾和缓效钾均有下降，分别降低２７．７和５３．０ｍｇ／ｋｇ。     

Yield-evapotranspiration relationships and seasonal crop coefficients for frequently irrigated potatoes

‘Russet Burbank’ potatoes (Solarium tuberosum L.) were subjected to various levels of water application during the growing season. Water applied, rainfall, and soil water changes were measured at weekly intervals. Tuber yield and quality increased as water consumption increased from 300 mm to 650 mm. Evapotranspiration (ET) increased rapidly from plant emergence until early tuber bulking and declined gradually as plants matured. Comparing ET with pan evaporation provided coefficients (K) which changed in response to crop growth stages. K increased from 0.3 at emergence to over 0.8 during maximum leaf area and declined with crop maturity. The relationship between K and crop growth stage can be used with confidence in scheduling irrigation of potatoes in north central Oregon.     

Soil water stress and the growth and yield of potato plants grown from microtubers and conventional seed tubers

Tuber yields of potato plants grown from microtubers in fields are more variable than yields from conventional seed tubers (CT). One reason could be their higher susceptibility to water stress. This study clarified the effect of soil water stress from 1 month after emergence on the growth and yield of plants grown from conventional seed tubers and microtubers in fields. Microtubers (0.5–3 g) and conventional seed tubers (50 g) were grown in Hokkaido, Japan, over three field seasons. One month after emergence, poly-shelters were placed over the plots to prevent rainfall, and either irrigated (wet plot) or non-irrigated (dry plot) treatments were formed. At mid-flowering (about 50 days after emergence) leaf area index (LAI) in microtuber plants was decreased relatively more due to soil water stress than LAI in conventional seed tuber plants. However, at maximum shoot growth (about 80 days after emergence) both microtuber and conventional seed tuber plants had a similar relative decrease in LAI due to soil water stress. At mid-flowering and maximum shoot growth microtuber and conventional seed tuber plants had reduced stomatal conductance due to soil water stress, but the reduction in stomatal conductance was greater in conventional seed tuber plants than in microtuber plants. Microtuber and conventional seed tuber plants had similar root development at maximum shoot growth. Tuber production from mid-flowering until plant maturity was similarly affected by soil water stress in microtuber and conventional seed tuber plants. At harvest, plants affected by soil water stress had about 87% of the tuber dry weight of irrigated plants. We conclude, that the greater variation on tuber yield of microtuber plants cannot be attributed to soil water stress from 1 month after emergence.