The influence of mist irrigation on the potato IV. Tuber quality factors

The influence of irrigation method on tuber quality factors was assessed during three seasons. Low volume “mist” irrigation (M), furrow irrigation (F), mist plus furrow (MF) and no irrigation (NI) were compared. Tubers from misted treatments (M and MF) tended to be lower in dry matter, had a high incidence of secondary growth and hollowheart, yielded darker chips, required more time to condition, were less mature, and contained more reducing sugars than those from NI treatments. Further the tubers from misted treatments tended to contain more P, Mg, Ca, Fe, Al, B and Mn, than those from NI plots at various times during the latter part of the season.     

The influence of mist irrigation on the potato: II. Growth and development

The influence of irrigation method on potato growth and development was assessed during three years. Low volume “mist” irrigation (M), furrow irrigation (F), mist plus furrow (MF) and no irrigation (NI) were compared. During a high and moderate stress season misting maintained the haulm later into the season and increased the proportion of small and medium size tubers. Further during the high stress season misted plots (M and MF) yielded more than NI plots.     

The influence of potassium fertilizer application on tuber yield and mineral element content of potato petioles during the growing season

Potassium was applied at rates equivalent to 0, 135, and 250 pounds per acre (0, 151, 180 kg K/ha) to study the effect of soil applied K on tuber yields and concentration of mineral elements in the petioles of potato plants during growth both measured at 14 day intervals. Petioles were analyzed for N, P, K, Ca, Fe, Mg, Zn, Cu, Al, Mn, and B. Seasonal trends in petiolar K content were highly correlated with tuber bulking regardless of rate of K application. Increasing K application rates generally increased petiolar levels of K and Zn (early in the season) and decreased the levels of N, Mg, Ca, Zn (late in the season), Al, Fe, Cu, and B in the petioles. Concentrations of P and Mn were unaffected by K applications. Seasonal trends in the mineral element content of petioles were not influenced by K. Results indicate that a prediction model for tuber yield based upon trends in the K content of petioles is valid under differing soil levels of K.     

不同品种椰子凋落叶的营养成分分析

测定6个不同品种椰子凋落叶中的营养成分。结果表明,6个品种椰子凋落叶的叶柄中C、N、P、K、Na、Ca、Mg、Mn、Zn营养元素之间差异显著,其中Fe和Cu含量差异不显著;小叶中,C、N、P、K、Na、Ca、Mg、Fe、Mn、Zn营养元素之间差异显著,其中Cu含量差异不显著。同时,小叶中的C、N、Fe、Mn、Zn含量高于叶柄,而叶柄中的P、K、Na、Ca、Mg含量高于小叶。     

主栽品种龙眼生物学性状及营养累积特点

在华南龙眼主产区挖取16~17 a成熟期中高产石硖、储良、福眼和松风本龙眼（Dimocarpus longan Lour.）各1株,调查树体生物学性状,探讨养分元素在树体的累积和分配。结果显示,4株龙眼地上部树体生物量平均为264.3 kg（鲜重）,果实、叶片和树干分别占地上部生物量的28.4%、12.3%和59.3%。在果实成熟期,叶片、树干、根系和果皮均以Ca含量最高,果肉以K含量最高,果核N含量最高。为生产50 kg果实,龙眼地上部需吸收N 668.6 g、P 102.0 g、K 461.6 g、Ca 1310.4 g、Mg 80.7 g、S 43.3 g、Si 63.8 g、Fe 20.1 g、Mn 5.8 g、Cu 349.9 mg、Zn 1245.9 mg、B 849.5 mg和Mo 8.7 mg。Ca是龙眼最重要的营养元素。收获50 kg龙眼果实,带走养分量为N 167.8 g、P 23.1 g、K 156.4 g、Ca 57.0 g、Mg 12.6 g、S 8.4 g、Si 0.7 g、Fe 0.7 g、Mn 0.4 g、Cu 110.5 mg、Zn 155.6 mg、B 125.3 mg和Mo 1.6 mg。为维持立地土壤养分肥力及龙眼植株正常生长,果实带走养分量应为翌年施肥量的下限。对生产中因营养问题引起的龙眼叶片缺素和果实生长异常现象进行讨论后,建议今后加强龙眼Ca、Mg、Si和B营养的研究。     

Nutritional characteristics of the leaves of native plants growing in adverse soils of humid tropical lowlands

Acid sulfate, peat, sandy podzolic, and saline soils are widely distributed inthe lowlands of Thailand and Malaysia. The nutrient concentrations in theleaves of plants grown in these type of soils were studied with the aim ofdeveloping a nutritional strategy for adapting to such problem soils. In sagoand oil palms that were well-adapted to peat soil, the N, P, and Kconcentrations were the same in the mature leaves, while the Ca, Mg, Na,and Fe concentrations were higher in the mature leaves of the oil palm thanof the sago palm. Melastoma malabathricum and Melaleuca cajuputi plantsthat were well-adapted to low pH soils, peat, and acid sulfate soils were alsostudied. It was observed that a high amount of Al accumulated in the M.marabathricum leaves, while Al did not accumulate in M. cajuputi leaves.M. cajuputi plants accumulated large amounts of Na in their leaves or stemsregardless of the exchangeable Na concentration in the soil, while M.malabathricum that was growing in saline-affected soils excluded Na.Positive relationships between macronutrients were recognized between Pand N, between K and N, and between P and K. Al showed antagonisticrelationships with P, K, Ca, Mg, Fe, Zn, Cu, and Na. Na also showedantagonistic relationships with P, K, Zn, Mn, Cu, and Al. Fe showed weakantagonistic relationships with Zn, Mn, Cu, and Al.     

Influence of zinc concentration in nutrient solution on growth and elemental content of the “Katahdin” potato plant

Hoagland’s solutions containing nine levels of zinc ranging from 0 to 50 ppm were applied as a drench tri-weekly to potato plants (cultivar Katahdin) growing in perlite. Although no deficiency symptoms were observed during the 46-day growing period, varying degrees of toxicity were associated with solution concentrations of 25 ppm Zn and higher. The tissue concentration necessary to induce toxicity symptoms appeared to fall between 648 and 932 ppm Zn, with an indication that growth may be reduced at tissue concentrations less than 648 ppm. Solution concentrations in excess of 20 ppm Zn caused a significant reduction in dry weight of top, root and rhizome portions, and number of secondary rhizomes. Increasing Zn treatment concentrations influenced elemental tissue content as follows: Al, Ca, Mn, Mo and Zn increased, B increased only at 40 ppm Zn or above, N and K decreased and P, Mg and Fe contents were generally decreased by the addition of Zn. Cu content was unaffected.     

Potato yields as related to nitrate levels in petioles and soils

The effects of various rates and times of nitrogen application on the yield of potatoes were determined in field experiments in Michigan. Both irrigated and non-irrigated trials were conducted with Katahdin, Russet Burbank, or Sebago varieties. Petioles were sampled for nitrate determinations one or more times during the growing season on each experiment, and the nitrate level in the soil was also followed throughout the season on Kent sandy loam. Nitrate levels in plant petioles tended to be high when the plants were young (4 tto 6 weeks) and then decreased rapidly as the plants matured. At any sampling date, differences in nitrate content between treatments could be measured and a critical nitrate level established for that sampling date. However, nitrate in petioles decreased so rapidly during the season that no valid interpretation of these levels could be made unless the age of the plants was precisely known. In the soil, nitrate levels tended to be more stable, although they also tended to decrease as the season progressed. Neverthehless, soil nitrate level may be a more stable criterion of nitrogen needs during the growing season than the nitrate content of petioles. Critical nitrate levels in soil need to be more firmly established, and movement of nitrate into the subsoil under irrigation more completely characterized. Preliminary data suggest that supplemental nitrogen fertilizers should be applied if soil nitrate falls below 20 ppm N before the end of July (10 to 12 weeks after plant emergence).     

甘肃省红粘土营养诊断与玉米平衡施肥研究

温室盆栽与田间试验研究甘肃省临夏积石山红粘土营养状况。结果表明,盆栽红粘土缺N、P、K、S、Cu、Mn和Zn,未表现缺Mo;Fe和B元素充足。减N、P、K、S、Cu、Mn和Zn处理的作物相对产量分别为53.2%、39.5%、89.4%、84.4%、82.5%、83.5%和95.2%。土壤养分亏缺顺序为P>N>Cu>Mn>S>K>Zn;N、P和Zn肥为大田该红粘土主要限制因子,其次为S、Cu和K,土壤中不缺Mo,OPT中氮量适中。与OPT相比,减N、P、Zn和Cu玉米分别减产52.0%、21.2%、22.3%和17.3%,增加N用量产量降低8.4%。推荐施肥配方为N210kg/hm2、P2O5120kg/hm2、K2O60kg/hm2、S90kg/hm2、Cu3.75kg/hm2和Zn1.5kg/hm2。     

微量元素缺乏与过量对脱毒马铃薯苗生长的影响

采用不完全营养液法研究了微量元素的缺乏与过量对脱毒马铃薯苗生长的影响。采用营养液栽培时,脱毒马铃薯苗对微量元素吸收很少,但营养液中缺乏Fe和Mn会表现出明显的缺素症状,缺乏Cu、Zn、B、Mo无明显的表现;Cu、Mn、Zn、B、Mo等元素过量植株会出现明显的中毒症状,MS营养液中Mn元素需适当降低才能适应脱毒马铃薯苗的液体培养。     

应用诊断施肥综合法(DRIS)对槟榔叶片进行营养诊断

应用诊断施肥综合法(DRIS)对低产园和高产园槟榔进行了叶片营养诊断。结果表明,相对于高产园,低产园元素间关系较不平衡。槟榔叶片N、P、K、Ca、Mg以及Fe、Mn、Cu、Zn的适宜含量分别为(20.53±0.67)、(1.90±0.01)、(13.30±0.46)、(7.14±0.57)、(3.68±0.41)g/kg及(109.50±4.16)、(112.50±9.02)、(6.07±0.64)、(31.23±0.15)mg/kg。低产园N、P、K、Ca、Mg、Fe、Mn、Cu、Zn元素DRIS诊断指数分别为-44.58、-1.60、-17.16、0.09、-31.94、52.78、31.03、23.12、-11.74,需求强度较大的元素为N、Mg、K,其次是Zn、P。     

四棱豆绿肥营养元素含量及品质评价

对17份四棱豆绿肥N、P、K、Ca、Mg、S、Fe、B、Mn、Cu、Zn、Mo、Cd、Cr、Hg、Pb、As营养元素含量进行分析评价。结果表明,四棱豆是含N、P、K高的优质绿肥,且中微量元素含量丰富,重金属含量低。根据综合评价,17份四棱豆均属于二级或三级有机肥。     

Cotton leaf nutrient concentrations in response to waterlogging under field conditions

Cotton is known to be poorly adapted to waterlogged conditions. When grown on soils with inherently low drainage rates, combined with the use of furrow irrigation and with summer dominant rainfall patterns, there is a significant risk of intermittent waterlogging. Good surface drainage is the most effective management option but when land-forming is poor or when substantial rain occurs soon after an irrigation application, significant yield loss can occur. Two field experiments were conducted in which cotton was subjected to waterlogging by extending the duration of furrow irrigation events. In order to assess the impact of waterlogging on plant nutrition, mineral nutrient concentrations in the youngest fully expanded leaves were measured repeatedly during the imposition of waterlogging, during recovery and through to the end of the growing season. Almost all nutrient concentrations were reduced by waterlogging but the extent and timing of recovery varied. A single early waterlogging event had a much greater impact (especially on N, P and K) than a single event late in development. Recovery from waterlogging appears to have been impaired during the period of rapid boll growth. During this period also, normal irrigation events caused transient reductions in some nutrients if the crop had been previously waterlogged. As with other studies on waterlogging, there was evidence that sodium concentration in leaves increased. While P and K concentrations were negatively associated with leaf sodium, there was no evidence that this relationship was altered by waterlogging.Management of nutrition after waterlogging has previously focused on the correction of leaf N and Fe concentrations. The wide range of nutrients that was affected in our experiments suggests that the value of correcting nutrients other than N needs to be explored. In addition, the results suggest that there is also a need to promote growth after waterlogging, rather than only correcting the nutrient concentration, to provide a larger reserve of key nutrients to meet reproductive demand.     

施用大、中、微量元素对大豆品质及其它性状的影响

试验以3种大量元素(N、P、K)、3种中量元素(Ca、Mg、S)及6种微量元素(B、Mo、Zn、Fe、Na、Cl)及其组舍对高蛋白大豆品种东农42和高脂肪大豆品种东农163的蛋白质和脂肪含量进行了研究。结果表明，施S可增加高蛋白大豆品种蛋白质含量1．34个百分点，增加高脂肪品种的蛋白质含量1．44个百分点；施Zn可增加高蛋白大豆品种蛋白质含量1．07个百分点，B、Mo、Zn同时施用可增加高脂肪品种大豆的蛋白质含量2．19个百分点。Na、C1、Fe的施用似乎对大豆蛋白质含量均具有正向作用。以Na元素的作用最大，二个供试品种分别增加2．08和1．85个百分点；Fe分别增加1．11和1．43个百分点；Cl分别增加1．26和1．65个百分点。N、P、K对大豆脂肪含量具有显著影响，在高脂肪品种中，K单独处理在1％的水平上显著高于对照，增加脂肪含量1．57个百分点，P—K配合施用增加1．2个百分点，N—K配合施用增加1．52个百分点，N—P配合施用增加1．11个百分点。适量的施用Ca、Mo具有增加大豆中脂肪含量的趋势。肥料的施用具有降低株高，增加收获重、荚数、粒数的作用。特别是N—K配合施用对大豆的株高、收获重及产量的影响效果显著。     

The interactive effects of phosphorus, potassium, lime and molybdenum on the growth and morphology of white clover (Trifolium repens L.) at establishment

The effects of simultaneously varying P, K, lime and Mo supplies on the growth and shoot morphology of white clover ( Trifolium repens ) at establishment were investigated in a factorially designed glasshouse experiment. Phosphorus and lime applications had almost identical, additive, effects on dry-matter (DM) production, and it was clear that the benefit of both treatments lay in the resultant improvements in plant available P. The adverse effects of P deficiency on young plants resulted, immediately, in a large decrease in stolon branch numbers, but only when the deficiency became acute did similar declines in the dimensions of leaves and petioles occur. It was suggested that this preferential maintenance of leaf and petiole expansion processes under moderate P deficiency, by enabling white clover to retain favourable upper canopy positions, could be an ecological adaptation to maximize its chances of survival in mixed grass–clover swards. Unlike P, K had little effect on clover growth or shoot morphology. However, there was some evidence that plants suffering from acute K deficiency preferentially partitioned resources to organs associated with exploratory growth, i.e. to stolons, at the expense of the plant's photosynthetic capability. Molybdenum application had no effect on DM production or shoot morphology, but did improve the N status of shoots, presumably by enhancing N₂ fixation. It was concluded that the survival of white clover in swards at establishment is critically dependent on P supply, and that one of the main benefits of liming is the resultant improvement in P availability.     

The influence of mist irrigation on the potato I. Micro-environment and leaf water relations

The influence of low gallonage “mist” irrigation on the following parameters were measured: leaf, air and soil temperature; and soil moisture, relative turgor and stomatal aperature. Misted canopies had lower leaf, air and soil temperature and higher soil moisture than the non-irrigated plants. Stomata of misted plants did not close as rapidly as those of non-irrigated plants.     

酸橘砧和枳砧沙糖橘果园土壤、叶片、果实养分比较与相关性分析

为了解广东省清远市沙糖橘园土壤养分丰缺状况,分析结果树不同砧穗组合叶片、果实养分丰缺状况,为沙糖橘营养科学管理、果园合理施肥及产业提质增效提供科学依据。采集清远市27个10~15年生枳砧和酸橘砧沙糖橘果园的土壤、叶片及果实,分析土壤、叶片及果实矿质养分含量,分析土壤、叶片及果实养分含量间的相关性。结果表明,清远沙糖橘果园土壤pH整体偏酸性,土壤有机质较丰富,有机质含量适量及以上果园占比70.4%。速效N含量缺乏果园为51.8%,81.5%的果园土壤速效P超量,有效K超量的占比48.1%,多数果园土壤有效Mn、有效Zn、有效Mo含量较适宜,但有效Ca、有效Mg、有效B缺乏占比分别达到81.5%、88.9%、77.8%。枳砧、酸橘砧沙糖橘叶片矿质养分丰缺程度存在差异,枳砧沙糖橘叶片N、B、Ca含量较少缺乏,而酸橘砧沙糖橘叶片3种元素含量存在严重缺乏的现象,2种砧木沙糖橘叶片中Cu、Mg均相对缺乏,Mo含量均严重缺乏。枳砧和酸橘砧沙糖橘果实矿质养分的大量元素中N、K含量高于P,中量元素Mg含量低于Ca含量,微量元素中Fe含量最高。枳砧沙糖橘果实单果重、果形指数、可食率、可滴定酸、可溶性固形物、Vc含量等指标均低于酸橘砧。2种砧木的沙糖橘果园土壤矿质养分与叶片矿质养分间,枳砧Mg、Fe分别呈极显著、显著正相关,酸橘砧B、Fe均呈显著负相关,枳砧沙糖橘叶片与果实中Mo含量显著正相关,酸橘砧沙糖橘叶片、果实、土壤三者间Mo含量均为极显著正相关。清远市沙糖橘果园管理应注重改良土壤酸碱度,施用适当配比的N、P、K肥,深施有机肥的同时适量添加或叶面喷施Zn、Mg、B、Ca、Mo,合理控制含Mn农药的使用次数。     

Phosphorus and micronutrient sources for potato

Potatoes(Solarium tuberosum L.) were grown on two sites of St. Johns’ fine sandy soil (sandy, siliceous hyperthermic Typic Haplaquod) during 1980 and 1981, to evaluate the effects of four P sources and four micronutrient sources on crop production. Mehlich-I (0.05 M HC1 + 0.025 M H₂S0₄) extractable Cu (0.1 to 0.2 ppm), Mn (1.0 to 1.4 ppm), and P (8 to 15 ppm) were considered low. In both seasons, tuber yields were increased with an application of P. Yields were significantly lower with diammonium phosphate (DAP) than with liquid poly-P, liquid ortho-P or triple superphosphate (TSP) P sources. In both seasons, application of Cu, Fe, Mn, Zn, B and Mo did not increase yield over treatment without micronutrients added. Plant-leaf and shoot-tissue P concentrations were increased by the application of P and were higher with DAP than with the other P sources. Micronutrient applications decreased leaf and shoot P concentrations and increased Zn concentrations in one of the two years. Applications of P increased the soil Mehlich-I extractable P and Zn and micronutrient applications increased Cu, Zn, and Mn. Increases in extractable P and Zn were greater with DAP and TSP than with liquid poly-P and ortho-P. Soil Cu increases were greater with frit and sulfate than with chelates and oxide micronutrient sources, Zn was lower with chelates than with the other three sources, and Mn concentrations were highest with sulfate, lowest with frit, and intermediate with chelate and sulfate micronutrient sources.     

Mineral characteristics of leaves of plants from different phylogeny grown in various soil types in the temperate region

The objective of this research was to analyze selected minerals in leavesof plants, belonging to 166 species growing in alluvial, low pH, brownforest and serpentine soils. Mineral characteristics of the soils involved werealso determined.For the macronutrients, in trees grown in alluvial soil, N, P, Ca, and Mgconcentrations of leaves were higher in recently evolved plants than inplants with a longer period of evolution; K concentration remained constantregardless of evolution. In grasses grown in alluvial soil, it was difficult todetect the general tendency of mineral concentration. N, P, and Kconcentrations in alluvial soil were closely related to those in low pH andserpentine soils. Ca concentration in alluvial soil was lower than that in lowpH and serpentine soils. Mg concentration in alluvial soils was higher thanthat in low pH soils, while lower than that in serpentine soil. Therefore, N,P, and K accumulated according to the plant characteristics for theseelements, while Ca and Mg accumulation was strongly affected by the soilproperties.For the micronutrients, in trees, Fe and Mn remained constant regardlessof evolution; Zn concentration was lower in recently-evolved plants than inplants with a longer period of evolution. In grasses, Fe, Mn, and Znconcentrations in Caryophyllids were high. Except for Caryophyllids, Fe andCu concentrations remained constant, Mn concentration decreased withevolution, Zn concentration was higher in recently-evolved plants than inplants with a longer period of evolution.     

Zone-subsoiling effects on potato yield and grade

Soil compaction and erosion are problems in many Pacific Northwestern potato fields. We wanted to determine if zone-subsoiling would reduce these problems and improve potato yields and or grade without adversely impacting other production practices. Studies were conducted in Southern Idaho at six locations over two years on different soils and with different irrigation methods to assess the effects of zone-subsoiling immediately after planting on tuber yield and grade. Reservoir-tillage comparisons were made at three locations where sprinkler water application rates were higher than soil infiltration rates. Russet Burbank was represented by eight location-years and Russet Norkotah by two. Zone-subsoiling consistently improved tuber grade or increased tuber size. The biggest improvement was under furrow irrigation. Zone-subsoiling also tended to increase total yield in eight of ten location-years. Reservoir-tillage improved yield and grade, but zone-subsoiling did not without reservoir-tillage when water application rates were high. At no location did zone-subsoiling significantly decrease tuber grade or yield. Zone-subsoiling had no appreciable effects on hill configuration or seed-piece dislocation. Surface cracking and “water piping” occurred under furrow irrigation but were not significant problems. Results were similar for both cultivars. Additional studies will be needed to successfully incorporate zone-subsoiling into commercial production practices