Nutritional requirements of roses grown in peat

Trials were conducted in the greenhouse with Rose ‘America's Junior Miss’, grown in peat moss, to study the nutritional importance of N, S, P, K, Ca and Mg, using the method of systematic variations.The ideal proportion of the major elements in question, together with the corresponding optimal dose were investigated in terms of the fresh weight of marketable cut flowers. The nutrient contents of substrate extracts and plant leaves were analyzed for diagnostic interpretation. Highest yields were obtained with the ionic proportion (meq% anionic and cationic nutrients): 64 N, 18 S, 18 P, 38 K, 26 Ca and 36 Mg at an optimal dose of 510 meq/plant.Treatments of the above composition and showing a ratio anions/cations equal to 1.3 gave the most satisfactory results.     

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 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).     

Hydraulic characteristics of composted pig manure,perlite, and mixtures of them,and their impact on cucumber grown on bags

Composted pig manure (CPM), unmixed or in mixture with perlite, was evaluated as growing medium based on both physical characteristics and agronomic performance. The physical properties were determined in CPM, perlite (0.5–2.5 mm), and their 75:25, 50:50 and 25:75 mixtures by volume. It was found that unmixed CPM has a higher bulk density (BD) than perlite, a slightly lower air space at a suction of 10 cm, and a markedly higher content in easily available water (EAW), although the water content at a suction of 10 cm is the same in the two media. Mixing CPM with perlite by 50:50 seems to increase the actual water content and decrease the actual air content at container capacity, while the BD and the EAW score intermediate to those in the unmixed constituents. Simulation of the relative hydraulic conductivity (K_r) indicates a sharp decrease in the unsaturated hydraulic conductivity (K) of CPM, perlite and their mixtures as the media suction increases. The differences in the decrease rate of K_r between the tested substrates are rather small, with the most and least steep decrease being observed in perlite and the mixture by 50:50, respectively. The agronomic performance of CPM was assessed by growing greenhouse cucumber in bags filled with perlite up to 20 cm in height, CPM up to 10 or 20 cm in height, and their mixture by 50:50 up to the same heights as CPM. A media height of 10 cm in the bag resulted in appreciably higher yields than a height of 20 cm, regardless of the type of the substrate, while the latter had no significant effect on yield. This effect of media height was ascribed to the steep decrease in K, which was minimized in all media at higher suction levels than 10 cm, thereby severely restricting water availability in their upper layers (10–20 cm) when their height in the bag was 20 cm.     

连续施用磷钾镁肥对红壤温州蜜柑的效应

以枳砧温州蜜柑为试材,进行了长期定位施用磷、钾、镁肥试验。连续6年的试验结果表明,施用磷、钾、镁肥均有明显增产效果,并能提高叶片和果皮中相应元素的含量。其中,以在施用氮磷钾肥的基础上增施镁肥的增产优质效应最佳。长期施用氯化钾导致果实维生素C含量降低,总酸量增加。贮藏试验结果表明,果实耐贮性与施钾成正相关,与施镁成负相关,施磷对果实耐贮性亦有不利影响。     

库尔勒香梨萼端腐烂与Ca、Mg、K营养的关系

以冷藏后的库尔勒香梨健康果和发生顶端腐烂的果实为试材,采用原子吸收分光光度计测定方法,分析比较了健康果与发病果不同部位的Ca、Mg、K含量,以探讨这种病害发生的原因。结果表明:库尔勒香梨果皮、果肉、果心中Ca、Mg、K含量差异显著。患病果果皮和果肉中的Ca含量明显低于健康果,且顶部Mg、K含量低于健康果,但其差别小于Ca含量的差别。因此,库尔勒香梨萼端腐烂可能与果实果皮、果肉组织缺钙,以及顶部果皮缺Mg有关。     

榛仁中氮、磷、钾、钙与贮藏物质的相关性分析

以杂种榛优良品系为试材,分析氮、磷、钾、钙与贮藏物质的相关性。结果表明:氮、磷、钾和钙与脂肪显著或极显著正相关。氮、磷和钙与蔗糖显著或极显著正相关,‘82-11’品系中的磷和钾与可溶性总糖显著或极显著正相关,‘84-237’品系中的钙与可溶性总糖显著正相关,‘84-402’品系中的磷素与可溶性总糖显著正相关。     

CO2 enrichment of strawberry and cucumber plants grown in unheated greenhouses in Israel

Strawberries and cucumber plants were grown in ambient atmospheric CO₂ concentrations of 300 v.p.m. and at elevated levels of 900, 1500 and 3000 v.p.m. during winter and early spring in 10 unheated greenhouses in the coastal plain of Israel. Co₂ enrichment averaged 7 hours per day between the end of November and the second half of April.Strawberry plants of cultivar ‘Tioga’ yielded 31, 43 and 51 % more than the control when subjected to a 3-, 5- and 10-fold increase in CO₂ concentration, respectively.Cucumber plants of cultivar ‘Elem’ grown at 3000 v.p.m. CO₂ yielded 26 % more over the whole picking season than those grown at 300 v.p.m. Yield during the first month of picking was doubled by both a 3- and a 10-fold increase in aerial CO₂ concentration.     

钾、镁相互作用对龙眼幼苗生长的影响

在酸性土壤中进行了龙眼幼苗钾、镁肥不同施用量的盆栽试验，结果表明，钾与镁均显著影响龙眼幼苗的生长，且钾、镁之间存在明显的交互作用；当钾肥与镁肥的施用比例为2：1时，能获得龙眼幼苗的最高生物量，由此得出龙眼叶片K／Mg的适宜比值为2．43。     

植物卷材中氮磷钾的流失及多效唑对植物的影响

以种植紫穗槐(Amorpha fruticosa Linn.)的植物卷材试件为研究对象,研究了植物卷材中紫穗槐氮磷钾的利用流失规律;采用5个多效唑浓度梯度(0.004、0.020、0.040、0.060、0.080g·L~(-1)),研究了多效唑对植物卷材中紫穗槐的氮磷钾利用和生物量产生的影响。结果表明:氮磷钾在成分单一的植物卷材基质中随冲刷的流失速度较快。在7次破坏试验中,基质中氮的损失量为22.4%,磷的损失量为15.9%,钾的损失量为25.4%。多效唑对植物利用固定氮磷钾的效应和对其生物量的影响有明显不同。紫穗槐(Amorpha fruticosa Linn.)在多效唑浓度为0.080g·L~(-1)时固定利用的氮磷钾最多,但此浓度并非紫穗槐营养生长最旺盛的浓度,反而多效唑浓度为0.040g·L~(-1)时,紫穗槐的生物量最大。     

甜菜氮、磷、钾肥配合施用效应及推荐用量

运用＂3414＂肥料效应田间试验方案,研究甜菜氮、磷、钾肥配合施用效应及推荐用量。结果表明,合理配施氮、磷、钾肥,有利于提高甜菜的产量、产糖量及投入产出比,甜菜的最大产量达到80458.33 kg/hm2,比无肥区增产44.94%,最大产糖量达到12978.47 kg/hm2,比无肥区增产38.97%;根据一元二次效应方程式,获得最佳产量、最佳产糖量的N∶P2O5∶K2O分别是1∶1.4∶1和1∶1.7∶1,这与前人研究基本一致。     

Effects of CO2 on leaf conductance and canopy transpiration of greenhouse grown cucumber and tomato

The effects of carbon dioxide (CO₂) on stomatal opening and canopy transpiration were investigated in cucumber (Cucumis sativus L., cv. Jessica) and tomato (Lycopersicon esculentum Mill., cv. Calypso). Stomatal opening (i.e. leaf conductance, g) was measured with a porometer, and canopy transpiration rate (E) with weighing lysimeters on intact plants in large greenhouses. Regression analysis was applied to account for the effects of radiation, air humidity, leaf temperature and CO₂ on g. The effect of CO₂ on E, which is primarily through g and secondarily through adjusted air humidity, was investigated by combining the regression equation for g with the Penman-Monteith equation for E. The relative effect of CO₂, as calculated with the fitted regression equations, was a decrease of about 4% in g for cucumber and of about 3% for tomato, per 100 μol mol-1 increase in CO₂, in the range of about 300 to 1200 μmol mol^?1 CO₂. The effect of CO₂ on E was smaller than on g and the extent of the effect depended on the conditions, mainly ventilation rate. The ratio K (relative change in calculated E divided by relative change in calculated g) was estimated at less than 0.2, except at low radiation. In reality, K will be even lower, because feedback mechanisms enforce the reduction in g and counteract the reduction in E. So the reduction of the transpiration rate of greenhouse cucumber and tomato caused by moderate CO₂ enrichment is small and mostly negligible, except under low light conditions.     

氮磷钾及有机肥配施对胡萝卜中胡萝卜素含量的综合影响

通过二次正交旋转回归设计,探讨了氮、磷、钾及有机肥对胡萝卜中胡萝卜素的综合影响。结果表明:影响胡萝卜素含量的一级(2因素)和三级(4因素)交互作用显著,二级(3因素)交互作用不显著;氮磷、氮钾、磷钾、钾与有机肥、磷与有机肥互作有利于胡萝卜素的积累,氮、磷、钾和有机肥合理配施(1∶0.84∶2.15∶725)可明显促进胡萝卜素的积累;在该试验条件下,有利于胡萝素积累的最佳施肥方案为:N(8.56～9.03kg/667m2)、P2O5(6.99～7.2kg/667m2)、K2O(18.37～19.41kg/667m2)、有机肥(6 159～6 596kg/667m2)。     

苹果茎痘病毒病原学研究初报

对从苹果上获得的苹果茎痘病毒的分离物ASPV—MX进行了研究 ,人工接种 4科 13种草本指示植物 ,发现ASPV—MV易由汁液摩擦接种 ,能侵染一种藜 (Chenopodiummurale)、西方烟 (Nicotianaoccidentalis - 37B)、西方烟亚种 (Nicotianaoccidentalissubsp‘obligua’)、鸡冠 (Celosiacristata)、千日红 (Gomphrenaglobosa) ,尤其在西方烟及西方烟亚种上症状明显 ,这 2个西方烟可以作为ASPV的鉴别寄主和繁殖寄主 ,在这 2种烟草的接种叶上均产生坏死枯斑 ,在西方烟的系统叶上主要产生明脉现象 ,而在西方烟亚种上的系统叶上产生线纹坏死。通过试验测得ASPV的致死温度为 6 2℃ ,稀释限点为 1× 10 -2 ,体外存活期为室温约 2 4h。     

Growth,allocation of N and carbohydrates,and stomatal conductance of greenhouse grown apple treated with prohexadione-Ca and gibberellins

Summary

Potted M.26 apple (Mahis domestica) liners were treated with the gibberellin biosynthesis inhibitor prohexadione-Ca (Apogee®) at 0 to 500 mg l”¹ as a foliar spray. Apogee inhibited stem elongation, leaf formation, total leaf area and shoot dry weight, while significantly increasing specific leaf weight, root dry weight and root: shoot ratio, regardless of rate. Foliar application of gibberellin A4₊₇ (GA4₊₇) at 200 mg l”¹ to Apogee-treated plants one day later reversed these effects, especially stem elongation, root dry-matter production and root: shoot ratio. Apogee increased N concentration in stems but not in leaves and roots. There was no effect on the pattern of N allocation amongst organs. GA4+7 increased leaf N concentration but decreased stem and root N concentrations compared with untreated controls, with N allocation shifting from roots to stem. Total nonstructural carbohydrates (TNC), expressed either on a concentration or content basis, increased in all parts of the Apogee-treated plants, due to increased levels of starch rather than soluble sugars, without altering allocation pattern. Conversely, GA4₊₇ reduced TNC levels (mainly starch levels) in all parts, with the pattern of allocation slightly shifted from roots to stem. The afternoon decline in stomatal conductance occurred earlier in the Apogee treated plants, measured 10 d after stem elongation had ceased. Starch buildup in the Apogee-treated plants appeared to be associated with this effect, suggesting an involvement of a feedback inhibition of photosynthesis in the Apogee-induced stomatal control.     

宁夏黄瓜新品种及主栽品种对白粉病的抗性评价

通过盆栽接种试验和田间自然发病调查相结合的方式进行了10个黄瓜新品种和2个黄瓜主栽品种(‘博美626‘’德尔88’)对白粉病的抗性鉴定,旨在明确不同黄瓜品种对白粉病的抗性水平,为黄瓜抗病品种的筛选和农业防治提供科学依据。试验结果表明,除‘德尔100’易感白粉病外,其他11个品种均对白粉病具有不同程度的抗性,其中‘津早3号‘’粤青1号‘’德尔80‘’德尔11‘’德尔12’达到高抗,而宁夏主栽品种‘博美626‘’德尔88’只达到中抗;从不同黄瓜品种生长指标和产量测定结果来看‘,德尔11‘’德尔80‘’津早3号’均表现出了优势,其产量均高于主栽品种,而‘德尔12‘’粤青1号’长势相对较差,产量低于主栽品种。总体来讲,新品种‘德尔11‘’德尔80‘’津早3号’在宁夏具有推广价值,可进一步进行大面积试验示范。     

氮钾营养对青花菜生长,花球产量与光合生理的影响

高氮低钾处理的青花菜植株生长最好，花球产量最高；低氮低钾、低氮高钾和高氮高钾处理均较低。高氮低钾处理比其他处理的叶片叶绿素与氮含量高，糖含量居中。钾素水平相同时，高氮能提高核酮糖－１，５－二磷酸羧化酶／加氧酶羧化活性；而在氮素水平相同时，高钾则降低ＲｕｂｉｓＣＯ羧化活性，提高ＲｕｂｉｓＣＯ加氧活性。低钾时高氮降低ＲｕｂｉｓＣＯ加氧活性；高钾时高氮则提高ＲｕｂｉｓＣＯ加氧活性。ＲｕｂｉｓＣＯ羧化活性     

N、K元素交互作用对基质栽培西葫芦生长、产量及品质的影响

为阐明施肥与西葫芦产量、品质的关系,更加有效地提高肥料利用率,以西葫芦品种‘小王子’为试验材料进行基质栽培,基质栽培中营养液以日本山崎配方中的N、K元素为对照,改变其元素水平采用交互组合试验设计,探讨N、K互作对西葫芦生长发育、产量及品质的影响,对其植株高度、叶绿素含量、养分分布、根系特性、产量及品质进行了分析。结果表明:处理2(N1=215.1 mg·L-1,KO=234.3 mg·L-1)的根长、根表面积、根平均直径分别高出对照44.99%、47.31%、46.3%;其可溶性蛋白与维生素C含量分别高出对照25.42%与77.19%,且产量高出对照11.5%,说明适合的氮钾比能有效控制地上部与地下部的发展趋势、调控营养生长与生殖生长的关系、提高西葫芦的产量并改善果实品质。     

几种物质对蓝莓土壤pH及有效N、P、K的影响

以4年生盆栽"灿烂"兔眼蓝莓为试材,研究了硫磺、硫酸钾和食用醋对土壤pH及有效N、P、K含量的影响。结果表明:在土壤中施入一定量的硫磺、硫酸钾和食用醋后,能显著降低土壤pH,增加土壤有效N、P、K含量。其中食用醋能迅速降低土壤pH至蓝莓生长最适的4.0~4.8范围,硫磺也能调整土壤pH至4.0~4.8,但改良效果较食用醋慢,3种物质中硫酸钾改良土壤pH的效果最差,同时土壤中有效N、P、K含量随pH降低而增加。综合分析表明,食用醋是一种见效快,易于施用的土壤pH改良物质。     

氮磷钾配施对温室秋冬茬番茄产量的影响

采用"3414"回归设计,研究了氮磷钾配施对温室秋冬茬番茄产量的影响。结果表明:温室番茄最高产量施肥量是氮肥(N)259.3 kg/hm2,磷肥(P2O5)196.6 kg/hm2,钾肥(K2O)190.5kg/hm2,最高产量是76 029 kg/hm2;最佳产量施肥量是氮肥(N)249.3 kg/hm2,磷肥(P2O5)186.8kg/hm2,钾肥(K2O)183.4 kg/hm2,最佳产量是75 987 kg/hm2。