Comparative effects of bark and peat based composts on the occurrence of vine weevil larvae and the growth of containerized polyanthus

A series of experiments was conducted to investigate the effect of inclusion of bark in potting composts on the numbers of vine weevil larvae on polyanthus plants. In 1989 more larvae were recovered from plants grown in peat compost than those grown in bark but these results were reversed when the study was repeated in 1990. Numbers of larvae also increased with higher ratios of bark:peat in composts but declined as the size fraction of bark used increased. The degree to which bark was composted did not appear to materially affect the numbers of vine weevil recovered. A strong, positive, relationship between larval numbers and foliage dry weight was found. Similarly, larval numbers were bigger with greater root development in bark composts. The results are discussed and it is suggested that the use of bark may promote more vigorous growth in polyanthus and thus enable plants to support more larvae.     

Mixtures of crushed rock, forest soils, and sewage sludge used as soils for grassed green areas

In two container experiments, we evaluated mixtures of crushed rock, forest soil, and sewage sludge for use as growth media in green areas. We applied two types of crushed rock (0–2 mm fraction), two forest soils (sandy loam), and limed sewage sludge (pH 10), and studied the growth of ryegrass (Lolium multiflorum var. westervoldicum) during one growing season.Including ≥0.2 m³ m⁻³ sewage sludge in the soil mixtures initially inhibited growth, presumably due to toxic levels of ammonium-N. Up to 0.25 m³ m⁻³ sludge increased the total yield of ryegrass, but at a level as low as 0.1 m³ m⁻³, more nutrients were available than could be taken up by the crop. At present, up to 0.3 m³ m⁻³ sewage sludge is allowed in soil mixtures used in green areas in Norway, although that level should probably be lowered due to the risk of abnormal (enhanced or inhibited) plant growth, and leaching of nutrients. We recommend a maximum of 0.1 m³ m⁻³ when applying the kind of sludge used in our experiments.All mixtures containing acid forest soil gave better results than those comprising slightly alkaline forest soil. The best mixture for ryegrass was crushed rock and acid forest soil at a ratio of 1:2. Compared to pure acid forest soil ryegrass grew equally well or better on mixtures containing ≥0.50 m³ m⁻³ acid forest soil. The differences in growth between the various soil mixtures were due to texture and physical properties, and to dissimilarities in the effects of sewage sludge on mineralisation of nitrogen in the mixtures comprising acid and slightly alkaline forest soil.     

Influence of nickel-contaminated soils on fenugreek (Trigonella corniculata L.) growth and mineral composition

Leafy vegetables accumulate higher amount of heavy metals like nickel (Ni) due to their more leafy vegetative growth. Therefore, a screenhouse experiment was conducted using an alkaline sandy loam soil equilibrated with graded levels of Ni (0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 150, 200, 250 and 300 mg kg⁻¹ soil) to assess the Ni accumulation pattern and its influence on growth and micronutrient distribution in fenugreek plants. Green as well as the dry matter yields of fenugreek increased slightly up to 20 g Ni kg⁻¹ soil but decreased significantly with the application ≥40 mg Ni kg⁻¹ soil. Crops showed characteristic toxicity symptoms of interveinal chlorosis in pots receiving ≥40 mg Ni kg⁻¹ soil. While the total content of Ni in the plant tissues increased consistently with increasing rates of applied Ni, the roots accumulated much higher amount of this element compared to the shoot. The content of Fe in plants showed an increase whereas that of Cu and Zn experienced a decrease with the rise in the applied Ni.     

枝梢环剥对荔枝新梢生长和叶片矿质营养的影响

环剥处理中断韧皮部光合产物向下运输及抑制枝梢生长的效应已经明确,但对不同矿质营养运输的影响则有待进一步揭示。研究以妃子笑荔枝为试材,揭示了枝梢环剥处理对新梢生长和叶片矿质营养的影响。结果表明,枝梢环剥处理可强烈抑制枝梢上的新梢发生;环剥17 d后,叶片叶绿素指数明显下降;同时,环剥口上端的叶片不同的矿质营养发生不同的变化。其中对钾和镁影响微弱,而氮、磷、钙、铁、锰、铜、锌等矿质营养含量发生不同程度降低,其中微量元素铁、铜、锰的含量下降较为明显,这表明,中断韧皮部运输也会导致叶片摄取这些矿质元素的减少。     

镉对苹果生长发育和矿质元素含量的影响

为了探究镉(Cd)对苹果植株生长发育和各组织矿质元素含量的影响,以2年生烟富3/T337和王林/T337为试材,测定了25mg/kg镉处理下叶片光合参数、解剖结构和各组织矿质元素含量。结果表明,镉胁迫对2个品种叶片光合参数具有明显的抑制作用,‘烟富3’和‘王林’叶片净光合速率分别降低62.46%和46.04%。镉处理下叶片厚度、栅栏组织和海绵组织厚度均显著低于对照,但‘烟富3’叶片上表皮厚度增加。镉能够抑制苹果叶片氮和钾含量,促进磷的吸收。镉处理对苹果植株不同组织钙、硼、铜、铁和锌含量的影响存在差异,根系钙、硼和锌含量均显著低于对照,铜含量显著高于对照。叶片铜、铁和锌含量均显著低于对照,‘烟富3’叶片钙含量显著高于对照,而‘王林’叶片钙含量低于对照。综上所述,镉能够抑制苹果植株生长发育,降低植株根系氮、钾、钙、硼、锌含量,以及叶片铜、铁、锌含量。     

Effects of copper deficiency and liming on the yield,quality and copper status of tomatoes,lettuce and cucumbers grown in peat

Tomatoes, lettuce and cucumbers, grown in beds of peat, received 3 levels of copper sulphate (0, 0.5 and 5 g/m²) in factorial combination with 2 rates of liming (average pH values 6.5 and 6.9). Omission of copper resulted in copper deficiency and decreased the yield of tomatoes, lettuce and cucumbers by 11% (P < 0.01), 53% (P < 0.001) and 48% (P < 0.001), respectively. In addition, this deficiency increased the proportion of unmarketable lettuce six-fold (P < 0.001) and that of poorly developed cucumbers by 67% (P < 0.05), but had no effect on the proportion of unevenly ripened tomatoes. Heavy liming (pH 6.9) reduced the yield of lettuce (14%; P < 0.01), but had no effect on quality throughout the trial. Although lettuce and cucumber leaves from the intermediate copper treatment contained only 2 μg/g Cu, the yield and quality of the produce were only slightly, and not significantly, inferior to those obtained at an adequate level of copper (> 7 μg/g).     

枯草芽孢杆菌对苦瓜生长、产量和矿质元素吸收的影响

为了给枯草芽孢杆菌在苦瓜上的应用提供科学依据,研究了根施不同浓度枯草芽孢杆菌对苦瓜生长、光合特性、产量和养分吸收的影响。以‘桂农科六号’苦瓜为供试材料,采用模糊综合评判方法,综合评判根施枯草芽孢杆菌8×10~5、4×10~5、2×10~5CFU·mL~(-1)对苦瓜的株高,茎粗,叶片数,叶片SPAD值,叶片全氮、全磷、全钾含量,瓜长,瓜横茎,瓜肉厚和小区产量的影响。结果发现,根施8×105CFU·mL~(-1)枯草芽孢杆菌后,茎粗和叶片数分别比对照增加7.14%和2.54%,叶片全钾含量比对照增加了4.00%,瓜长、瓜横茎、瓜肉厚及小区产量与对照相比分别增加了0.65%、2.02%、3.67%和2.96%。根据隶属函数的计算结果,各处理的强弱顺序为8×105CFU·mL-1> 4×105CFU·mL-1>空白处理> 2×105CFU·mL~(-1)。     

Vermicompost as a substitute for peat in potting media: Effects on germination,biomass allocation,yields and fruit quality of three tomato varieties

Commercial potting media often contain substantial amounts of peat that was mined from endangered bog and fen ecosystems. The main objectives of this study were to assess (1) whether the amendment of 0, 20, 40, 60, 80 and 100% (v/v) of vermicompost (VC) to a fertilized commercial peat potting substrate has effects on the emergence, growth and biomass allocation of tomato seedlings (Lycopersicon esculentum Mill.) under greenhouse conditions, (2) whether possible impacts on seedlings can affect tomato yields and fruit quality even when transplanted into equally fertilized field soil, and (3) whether effects are consistent among different tomato varieties. Amended VC was produced in a windrow system of food and cotton waste mainly by earthworms Eisenia fetida Sav. Vermicompost amendments significantly influenced, specifically for each tomato variety, emergence and elongation of seedlings. Biomass allocation (root:shoot ratio) was affected by VC amendments for two varieties in seedling stage and one field-grown tomato variety. Marketable and total yields of field tomatoes were not affected by VC amendments used for seedling husbandry. However, morphological (circumference, dry matter content, peel firmness) and chemical fruit parameters (contents of C, N, P, K, Ca, Mg, l-ascorbic acid, glucose, fructose) were significantly affected by VC amendments in seedling substrates; these effects again were specific for each tomato variety. Overall, vermicompost could be an environmentally friendly substitute for peat in potting media with similar or beneficial effects on seedling performance and fruit quality. However, at least for tomatoes, variety-specific responses should be considered when giving recommendations on the optimum proportion of vermicompost amendment to horticultural potting substrate.     

磁化咸水灌溉对葡萄生长和土壤矿质养分的影响

【目的】以2 a(年)生'夏黑'葡萄(Vitis vinifera×V. labrusca'Summer Black')为试材,分析了磁化咸水灌溉后土壤根系形态特征和不同形态养分含量,以揭示磁化咸水灌溉对葡萄幼苗生长和土壤矿质养分特征的影响。【方法】分别采用0、3.0和6.0 g·L~(~(-1))三种不同质量浓度的咸水灌溉葡萄幼苗,磁化处理是接入磁化器装置处理灌溉水。通过野外调查和室内试验相结合的方法,对咸水和磁化咸水灌溉后葡萄幼苗生物学特性、叶片和土壤不同形态氮磷钾以及土壤微量元素含量进行分析。【结果】磁化处理对新梢生长量、叶面积、叶片数、根系总长度、表面积、平均直径、体积、土壤全氮、有效磷含量有极显著影响(p0.01),对速效钾含量有显著影响(p0.05);NaCl处理对葡萄地上部分生长指标、根系形态指标、叶片Fe、Mn、Zn、土壤硝态氮、无机氮、全磷、有效磷、速效钾、Mn和Zn含量有极显著影响(p0.01);两处理交互作用对叶片Zn、土壤铵态氮、有效磷、速效钾含量有极显著影响(p0.01),对叶片Fe、Mn、土壤中无机氮和Cu含量有显著影响(p0.05);M_0与NM_0相比,叶面积和叶片的Zn分别提高19.42%和57.18%,差异显著(p0.05);M3与NM3相比,新梢生长量、叶面积、叶片数、根系总长度、表面积、平均直径、体积均显著提高(p0.05),叶片Zn、土壤全氮、铵态氮、无机氮、有效磷和速效钾含量分别显著降低19.41%、44.37%、27.79%、29.72%、28.53%和10.40%(p0.05);M6与NM6相比,新梢生长量、叶面积和根系总长度、叶片Fe和Mn含量分别提高25.56%、26.16%、33.75%、5.87%和15.57%,土壤Cu的含量降低10.72%,差异显著(p0.05)。【结论】磁化咸水灌溉能促进矿质养分的积累和有效态养分的释放,促进植物对有效态养分的吸收利用,促进盐分环境中植物的生长发育以及改善土壤-植物间的养分循环,为微咸水或咸水资源的开发及应用提供理论依据。     

树盘覆黑膜对梨树生长及矿质营养含量的影响

对梨树树盘覆黑膜后树体营养生长和果实生长指标、叶片及果实矿质营养含量的测定。结果表明,树盘覆黑膜梨树叶片相对含水量、叶绿素相对含量和果实可溶性固形物含量显著提高;影响叶片和果实中矿质营养含量。为梨树树盘覆黑膜能促进生长和提高果实品质提供理论依据。     

Effects of watering on the yield,quality and composition of tomatoes grown in bags of peat

Two crops of tomatoes, grown in bags of peat, were supplied with 60,80,100 and 120% of the water requirement estimated from solar radiation integrals for 12 weeks after planting. Restricting water to 60% and 80% of the requirement controlled vegetative vigour but reduced final yield by about 20% and 4% respectively. These decreases were mainly because of a reduction in fruit size rather than number. Overwatering had little effect on yield but caused Mn deficiency. As restricted watering reduced the water content of the fruit, so.the dry matter, sugar, acid and potassium concentrations in the fresh material increased; this was particularly marked in plots receiving only 60% of the water requirement. The response to the treatments disappeared 4-5 weeks after they were discontinued. Retention of six extra leaves in one crop had no effect on yield. The data suggest that watering should be restricted to 80% or less of the estimated requirement in order to achieve a significant improvement in the flavour components of the fruit.     

Effects of high salinity and the exogenous application of an osmolyte on growth,photosynthesis, and mineral composition in two ornamental shrubs

A greenhouse experiment was carried out to determine the growth, photosynthetic activity, and mineral composition in two ornamental shrubs [Viburnum lucidum L. (arrow-wood) and Callistemon citrinus (Curtis) Stapf. (red bottlebrush)] that had been treated or not treated with 2.5 mM glycine betaine (GB) or 5.0 mM proline (Pro). Plants were supplied with a non-salinised or salinised nutrient solution containing 200 mM NaCl. Salinity caused reductions in plant growth parameters, shoot biomass production, and net CO₂ assimilation in both species. Neither Pro nor GB were able to mitigate the adverse effects of salinity in bottlebrush, whereas GB reduced the deleterious effects of salt stress on arrow-wood, indicating a differential species-specific response to these osmolytes. The application of GB to salt-stressed arrow-wood increased apical and lateral shoot lengths, the number of leaves per plant, and shoot dry biomass by 222%, 113%, 238%, and 49%, respectively, compared to untreated or Pro-treated plants. The improved performance of salt-stressed arrow-wood plants whose roots were treated with 2.5 mM GB was attributed to partial suppression of Na uptake, higher chlorophyll concentrations, and the better nutritional status (higher K) of shoots.     

Effects of irrigation with treated wastewater on olive tree growth,yield and leaf mineral elements at short term

In arid regions, such as Tunisia, the reuse of treated wastewater (TWW) in agriculture can be a sustainable solution for water scarcity. A two-year field experiment was conducted in order to investigate the short-term effects of TWW on olive growth, yield and concentration of total nitrogen (N_t), potassium (K), phosphorous (P), and heavy metals (i.e. Zn, Mn, Pb and Cd) in olive leaves. Olive trees were subjected to the following irrigation treatments: (i) trees irrigated with well water (WW) and (ii) trees irrigated with treated wastewater (TWW). For both treatments, the TWW and WW were applied at a rate of 4.5 m³ day⁻¹ tree⁻¹ (5000 m³ ha⁻¹ year⁻¹). After two years, non-significant injuries caused by salts and/or heavy metals were observed on shoot growth of trees irrigated with TWW. The application of TWW significantly increased concentration of N_t, P and K in the leaves, whereas heavy metals (Zn and Mn) showed a significant increase only after the second year of irrigation.     

The effect of salinity and porosity of sewage sludge compost on the growth of vegetable seedlings

Salinity and porosity of composted sewage sludge (CSS) were studied to evaluate their effect on vegetable seedlings, specifically on vegetable seedling performance and toxicity threshold of soluble salts. For the evaluation, CSS was mixed with different proportions of leached CSS to control the salinity. Soluble salt content of 1.45% or higher in growth media inhibited the growth of cucumber, tomato, and pepper seedlings, while that of 1.1% was relatively safe. Different porosities of CSS media were prepared by mixing CSS (<10 mm) with ground CSS (<1 mm) in different proportions (CSS and ground CSS were leached beforehand to prevent salt stress). The vegetable seedlings grew well in CSS media without showing symptoms of growth inhibition if the total porosity ranged from 66% to 81% and the water holding porosity ranged from 48% to 59%. However, the best seedling performances were achieved with the coarser media with high total porosities. The study indicated that when salt content was appropriate, CSS can be used alone as a vegetable seedling growth medium without the need for grinding or blending with other materials.     

Effect of night humidity on the vegetative growth and the mineral composition of tomato and strawberry plants

Conditions of low night humidity (50–55%) and high night humidity (90–95%) were imposed on tomato plants (Lycopersicon esculentum Mill. cv. Young-Kwang) for 30 days, and on strawberry plants (Fragaria grandiflora Ehrh. cv. Bogyo) for 40 days. Shoot dry weight and leaf area in tomato plants increased with high night humidity whereas the strawberry plants did not show any such increases. The concentrations of five major nutrients (N, P, K, Ca and Mg) were reduced in tomato plants under high night humidity, with the calcium content in younger leaves being the most severely affected. For the strawberry plants, however, high night humidity tended to increase the concentrations of major nutrients, including calcium in the younger leaves. Possible reasons for the differences in response of these two species to night humidity are discussed.     

受冻'富士'苹果花期应用植物生长调节剂和矿质营养试验

‘富士’苹果花期遭遇晚霜冻危害后,花粉活力、花粉萌发率降低,花粉管生长延缓,胚囊寿命和柱头接受花粉的时间缩短,影响花朵的授粉受精过程,导致坐果率下降,严重影响果品的产量和质量,甚至造成绝产绝收。为探索提高霜冻后‘富士’苹果花朵坐果率的有效途径．2008年我们对受霜冻危害的‘富士’苹果花朵采用矿质营养和植物生长调节剂进行了田间处理试验。     

种植年限对设施蔬菜土壤养分和环境的影响

为了给设施蔬菜地合理施肥提供依据,研究了不同种植年限设施蔬菜地土壤理化性质、微生物数量及酶活性变化,以露地土壤为对照(CK),采集种植1 a(年)、3 a、5 a、7 a、9 a、11 a、13 a、15 a、17 a、20 a以及20 a以上的0~20 cm设施蔬菜土壤样品,采用常规土壤理化性质检测方法测定了土壤理化性质和酶活性,采用平板计数法,分析土壤微生物数量。结果表明,设施菜地种植年限与土壤容重呈正相关,与土壤孔隙度呈负相关;设施菜地土壤pH值随种植年限的增加逐年降低,两者呈显著的负相关性;土壤EC值、土壤有机质和速效磷含量都随种植年限的增加而逐年增高,并与种植年限呈显著的正相关性;与CK相比,种植13 a的蔬菜样地土壤全氮和速效钾含量均显著地增加;连续种植20 a以上,设施蔬菜土壤含盐量比对照土壤显著地增加了486.49%。土壤细菌和放线菌数量、过氧化氢酶和碱性磷酸酶活性呈现出先增加后减少的趋势,且都在种植年限为11~13 a时达到最大;真菌数量随着种植年限的增加而增加,而土壤脲酶活性则随种植年限的增加呈下降趋势;转化酶活性随着种植年限的增加保持不变。土壤微生物数量与酶活性之间存在一定程度的相关关系,其中土壤真菌数量与土壤酶活性之间的相关性最为显著。综上所述,种植年限不同的设施菜地,土壤养分失衡,呈现酸化趋势,盐分含量逐年增加,土传真菌病害潜在发生,对设施蔬菜生产不利。     

连作对设施甜瓜生长和光合作用以及养分吸收和产量品质的影响

【目的】探明连作对设施甜瓜的影响。【方法】以在连作0、1、3、5、7、10 a(年)土壤中种植的‘豫甜香’品种为研究对象,分别测定其生长、光合作用及果实产量、品质等。【结果】植株长势随连作年限的增加而减弱,且根部发育受阻。植株净光合速率、叶绿素总量、蒸腾速率和气孔导度均随连作年限的增加而下降,但叶绿素a/b比值升高。伸蔓期叶片、蔓和根中的全氮(N)含量均随连作年限的增加而下降,而花期和坐果期则增加。连作条件下磷(P)基本稳定。全钾(K)含量随连作年限的增加而下降。长年连作条件下果实的总酸含量明显升高,而可溶性固形物和总糖含量则降低。【结论】设施甜瓜种植3~5 a时出现连作障碍问题。长期连作不利于甜瓜生长,使根发育受阻,不利于光合作用及根部等养分的吸收积累,使果实产量下降、口感变差。因此,设施甜瓜最好不要连作超过5 a。     

Effects of air and soil temperatures on the growth of gerbera

The effect on gerbera cultivar ‘Fredaisy’ of air and soil temperatures in the range 11–21°C has been studied in home-made growth-cabinets providing a sufficient thermal insulation between air and soil. Certain characteristics of the plants in cabinets were compared to those in a greenhouse.Amongst the growth characteristics, the length of the maturation period of the flower and the elongation rate during the early stage of the stem growth were more influenced by air temperature; the interval of appearance of new buds, the final stem length, and the elongation rate at the end of the stem growth, were more influenced by soil temperature.The elongation rates allowed a reasonably accurate prediction of the thermal zero of vegetation.     

不同砧木嫁接对番茄生长及品质的影响

为了探讨不同砧木嫁接对番茄产量和品质的影响,以'粉霸2000'番茄为试验材料,选择'美砧一号"砧霸一号'托鲁巴姆'强力砧'新纳姆'5个砧木品种进行比较试验,'美砧一号'砧木嫁接番茄成活率达90.67%,果实品质与对照无显著差异,单果质量0.24 kg,667 m~2产量7 002.79 kg,比自根苗分别增加了41.17%,58.97%。综合评价认为,'美砧一号'砧木嫁接番茄不仅成活率高,而且能显著促进植株生长,提高番茄产量,可作为番茄嫁接砧木选择的参考品种在盐城地区推广。