Relationship between tipburn and leaf mineral composition in strawberry

Malformation of emerging leaves with distortion of leaf tips, a condition known as tipburn, is frequently observed in strawberry. Calcium (Ca) deficiency has been considered the main cause of tipburn. The aim of the present study was to analyse the relationship between leaf mineral composition and the incidence of tipburn in three short-day strawberry (Fragaria x ananassa Duch.) cultivars (‘Ventana’, ‘Camarosa’ and ‘Candonga’) submitted to different concentrations of Ca. The studies were conducted in a hydroponic system in a greenhouse. Calcium was added as Ca(NO₃)₂ at 2 mM, 3 mM, 4 mM and 5 mM. A completely randomized block design (4 Ca concentrations × 3 cultivars) with three replications was used. Each replicate consisted of 12 plants grown in a polyethylene bag (100 cm × 18 cm × 3 cm) filled with coconut peat. Crown diameter and tipburn incidence were evaluated throughout the experimental period, and at the end of the experiment leaf mineral composition was assessed. In general, plants with larger crown diameters had a greater incidence of tipburn. The ‘Candonga’ cultivar had the smallest incidence of tipburn, while the ‘Camarosa’ and ‘Ventana’ cultivars were more susceptible. There was no correlation between level of Ca applied and incidence of tipburn. The incidence of tipburn was associated with foliar K:Ca and K:Mg ratios. Ratios above 3.40 for K:Mg and 1.77 for K:Ca represented a risk of more than 50% of tipburn incidence, when overall means for all cultivars and levels of Ca were used.     

The influence of relative humidity and nutrition on leaf tipburn of strawberry

Leaf tipburn of strawberry, a localised calcium deficiency causing malformation of emerging leaves, was induced by high relative humidity and alleviated by diluting the nutrient solution or by reducing the level of potassium, magnesium or nitrate in otherwise standard solutions. Increasing the phosphate content of the solution had no effect, while supplementing the calcium nitrate to above sufficiency levels of calcium increased tipburn. Leaf calcium (% dry weight) decreased temporarily during leaf emergence and was lower in affected emerging leaves than in comparable healthy ones     

The relationship between leaf growth,calcium accumulation and distribution,and tipburn development in field-grown butterhead lettuce

The change in calcium (Ca) concentration with time, the distribution of Ca within various leaves, and leaf and tipburn development were studied in field-grown lettuce (Lactuca sativa L.) cultivar ‘Cobham Green’.Ca distribution between and within leaves followed two distinct patterns. The average concentrations in the outer leaves were always higher than in the inner leaves. The concentrations at the periphery of the outer leaves was always greater than in the midrib, whereas for the inner leaves the converse was true.Tipburn only occurred in the inner leaves; it developed on only those leaves and those parts of the leaf which expanded most rapidly.Thus, tipburn development appears to depend on the supply of Ca relative to the rate of leaf growth.     

The effect of boron on tipburn and auxin activity in lettuce

Lettuce plants (Lactuca sativa L.) grown in a boron deficient nutrient medium developed tipburn. Their leaves showed no overall increased auxin activity compared with those of control plants until they were 66 days old, when boron deficient plants showed a relative increase in the activity of one auxin. It is postulated that tipburn in lettuce may be caused by interacting factors including calcium and boron deficiences, and the ontogenetic age of the plant. Environmental and cultivar effects on the incidence of tipburn indicate that agronomic or genetic control measures may become feasible, if the mechanism controlling its expression can be further elucidated.     

几种有机肥料在温室草莓上施用试验

目前,生产上应用有机肥料改善果实性状已成为重要的栽培技术之一.有机肥料是一种完全肥料,不仅含有大量元素和许多微量元素,还含有一些植物生长所必须的激素和多种有益土壤微生物,能够改善果实品质,提高产量,改良土壤等.为了摸清有机肥对草莓生长发育的影响,我们于2006年12月-2007年5月以草莓新品种'甜查理'为试材进行施肥试验,现总结如下.……     

Fruit calcium content and lipoxygenase activity in relation to albinism disorder in strawberry

Nutrient elements and lipoxygenase (LOX) activity were determined in strawberry fruit to establish a relationship, if it exists, between nutrient ratios (N/Ca and K/Ca), and lipoxygenase activity with albinism disorder. About 33% strawberry fruit were affected by albinism. Etna had highest incidence of albinism (48.6%) and Sweet Charlie the lowest (16.2%). Dry matter content (%) was lower in albino fruit (5.23%) than normal fruit (7.36%). The concentration of N, P, and Mg did not differ significantly, but that of K (1.87 mg g⁻¹ fresh weight) was notably higher and of Ca (0.105 mg g⁻¹ fresh weight) was lower in albino fruit than normal fruit. Consequently, the nutrient ratios, N/Ca (9.78) and K/Ca (16.96) were higher in albino fruit than normal fruit. Cultivars differed widely in respect to dry matter (%), mineral content and nutrient ratios. LOX activity determined on dry weight or fresh weight basis was significantly higher in albino fruit than normal fruit, with significant differences among cultivars. Positive correlations existed between nutrient ratios and albinism incidence (r = +0.338), LOX activity and albinism incidence (r = +0.412), and LOX and nutrient ratios (r = +0.448). Thus, it appears from the study that calcium and LOX activity may not the basic cause of albinism in strawberry, but these may be involved in senescence or fruit ripening process, as LOX activity was lower in albino than in normal fruit.     

The effect of trickle irrigation,misting and row position on the incidence of tipburn of field lettuce

The effect of trickle irrigation, with and without additional applications of night mist, just before maturity on the incidence and severity of tipburn in field lettuce was investigated. The mean incidence of tipburn for all treatments was much higher (84%) on the outer 2 rows of beds than on the inner 2 rows (47%). On the outer rows irrigation and misting had virtually no effect on tipburn, whereas on the inner rows irrigation reduced it from 72% (in control plants) to 39%, misting to 63% and misting + irrigation to 16%. It is believed that the combination of night misting and trickle irrigation of inner rows resulted in conditions conductive to root-pressure flow which translocated calcium ions to heart leaves of lettuce plants, thereby reducing tipburn injury. It is suggested that the increased severity and incidence of tipburn in the outer rows could have resulted from soil compaction in wheelings which would reduce root growth, soil aeration and root pressure.     

~(60)Coγ辐射对不同品种草莓离体叶片再生及芽生长的影响

以丰香和章姬草莓的无根无菌苗为试材,用10～40Gy 60Coγ射线辐照处理,以未辐照为对照,研究了60Coγ射线辐射对草莓叶片再生及植株继代增殖的影响。结果表明,叶片对辐射敏感,且丰香叶片比章姬叶片敏感,叶片再生的半致死剂量为10～20Gy;辐照后不同时间取叶接种,丰香叶片的不定芽再生率在剂量10Gy呈上升趋势,而其他剂量则几乎未见有变化,章姬在剂量10～30Gy,叶片的不定芽再生率提高较大,40Gy仍表现轻微下降;适宜的辐射剂量对草莓试管苗增殖有促进作用。     

Pre-harvest foliar application of calcium and boron influences physiological disorders,fruit yield and quality of strawberry (Fragaria × ananassa Duch.)

Studies were conducted in ‘Chandler’ strawberry to determine if pre-harvest foliar application of Ca, B or their combination influences physiological disorders, fruit yield and quality or not. For this, treatments consisted of (i) five sprays of calcium as CaCl₂ (first spray was performed at the petal fall stage and later at 7 days interval), (ii) three sprays of boron as boric acid (first spray at the beginning of flowering and later at 15 day interval), (iii) combination of (i) and (ii), and (iv) plants sprayed with water served as the control. Results indicated that fruit harvested from plants, which were sprayed either with Ca or Ca + B had significantly lesser incidence of albinism (6.7 and 6.5%), and grey mould (1.3 and 1.2%) than those harvested from plants sprayed either with B alone or in control. Although, B alone could not influence the incidence of albinism and grey mould, but it reduced fruit malformation (3.4 and 3.1%) significantly. Further, Ca, B or their combination had not influenced the individual berry weight, but marketable fruit yield differed significantly. The lowest marketable fruit yield (149.3 g/plant) was recorded in plants under control, and the highest (179.2 g/plant) in plants sprayed with Ca + B. Similarly, such fruit were firmer; had lower TSS, higher acidity and ascorbic acid content at harvest than those in control. Similarly, such fruit after 5 days storage were firmer and brighter, and have significantly lower TSS (7.9 and 7.8%); higher ascorbic acid content (43.7 and 45.0 mg/100 g pulp) and acidity (1.08 and 1.07%) than those in control or those receiving B alone. Incidence of grey mould was significantly lesser in fruit, which received Ca (2.2%) or Ca + B (1.9%) than those, which received either B (8.1%) alone or those in control (8.4%). Our studies indicated that pre-harvest foliar application of Ca + B is quite useful for reducing the incidence of disorders and getting higher marketable yield in ‘Chandler’ strawberry.     

Salinity effects on strawberry plants grown in rockwool. I. Growth and leaf water relations

Comparison of four everbearing or day-neutral cultivars of strawberry (Rapella, Ostara, Fern and Selva) grown under glasshouse conditions in rockwool showed Rapella to accumulate the greatest shoot dry weight and leaf number together with the production of few stolons but many relatively large fruits per inflorescence. Subsequent studies with cv. Rapella found that increasing the salinity of the irrigation supply from 2.5 to 5.7 and to 8.5 mS cm"1, by the addition of NaCl, progressively reduced leaf number emerged and final leaf area by up to 36% and 48% respectively, after 100 d of treatment. Shoot dry weight, excluding fruits, was reduced by up to 47%. The number of crowns (lateral branches) was reduced from 11 in the lowest salinity to 8 and 7 at the higher salinity levels. Leaf water potential, \)/w, was reduced by up to 0.23 MPa in young leaves and 0.36 MPa in older leaves. Leaf osmotic potential, xj/^, was decreased by up to 0.14 MPa in younger leaves following salinity treatment at 8.0 mS cm-1. Consequently leaf turgor was reduced more in older than in younger leaves. Inflorescence number was reduced from 27 to 20 and 17. Within the remaining inflorescences however, flower numbers, fruit numbers and duration of fruit ripening were not affected. A marked decrease in the fresh weight of the fruit was detected in both higher salinity treatments but fruit dry weight was only slightly reduced.     

Salinity and shading effects on leaf water relations and ionic composition of strawberry plants grown on rockwool

Summary

Strawberry plants were grown in rockwool under glasshouse conditions at NaCl salinities of 2.6,5.9 and 8.6 mS cm^-1 and at total irradiances of 2.1 and 4.9 MJ m^?2d^?1. Increasing salinity and irradiance reduced leaf water potential (ψω), osmotic potential (ψπ) and turgor potential (ψτ). There was an interaction between salinity and irradiance on with the lowest ψπ recorded for the unshaded leaves. Increased salinity altered the ionic composition of the leaf. Chloride concentration was increased from 0.03 to 0.61 % (D.W.) while NO₃ content in the leaf sap was reduced from 10.51 to 3.60 mg ml^-1 as salinity increased from 2.6 to 8.6 mS cm^?1. Expressed on a fresh-weight basis, the concentration of K was reduced at high irradiance whereas Ca and Mg were enhanced. On a dry-weight basis K, Na, Ca and Mg were unaffected by salinity treatment. Net photosynthesis was reduced by high salinity but only in plants grown in unshaded conditions.     

Relationship between light,fruit and leaf mineral content with albinism incidence in strawberry (Fragaria x ananassa Duch.)

A study was conducted in strawberry to establish a relationship between shading, mineral nutrient of leaves and fruits with albinism incidence. Plants grown under shade produced albino fruits in higher proportion than those grown in open fields. Similarly, plants under shade produced smaller sized fruits and have lower fruit yield. Among cultivars, Etna had highest incidence of albinism (49.6%) and Sweet Charlie the lowest (14.4%). Dry matter content (%), concentration of five major nutrients, viz. N, P, K, Ca, Mg, S and N:Ca and K:Ca nutrient ratios did not differ significantly in the leaves of plants producing normal or albino fruits. However, in contrast, the concentration of K was notably higher (1.97 mg g⁻¹ fresh tissue weight) and that of Ca was lower (0.098 mg g⁻¹ fresh tissue weight) in albino fruits than normal ones. Consequently, the ratios of N:Ca (11.34) and K:Ca (20.08) were higher in albino fruits than normal ones. Cultivars also differed widely in respect to dry matter (%), mineral content and nutrient ratios. Thus, it appears that lower light intensity favours the development of albinism in strawberry, and it seems that calcium is not the basic cause of albinism, but increased vigour associated with overuse of N and K might be positively associated with it.     

日光温室条件下桃、草莓、葡萄套栽技术

日光温室桃树下间作草莓,边行套栽葡萄,可充分利用温室内土地面积,也可有效利用温室边空闲地,是立体栽培的新模式,高产高效的新技术。     

The production of strawberry plants by in vitro micro-propagation

In the presence of 6-benzylaminopurine strawberry plants produce many axillary buds which grow into shoots bearing more axillary buds. Rooted plantlets, however, are only formed in the absence of added cytokinins. A technique that can be used to multiply large numbers of strawberry plants very quickly is described.     

花期叶面喷施B和Ca对油橄榄完全花比率和坐果率的影响

【目的】在油橄榄花期叶面喷施硼和钙肥,研究叶面喷施硼、钙及硼-钙交互作用对油橄榄完全花和坐果率的影响。【方法】选甘肃陇南主栽的3个油橄榄品种(‘莱星’‘鄂植8’‘城固32’),采用完全正交试验,在花期前、中、后分别喷施不同浓度硼和钙的叶面肥,调查完全花比率和坐果率,并观察了硼和钙对花粉萌发的影响。【结果】花期叶面喷施硼和钙对各品种油橄榄完全花及坐果率的交互影响均不显著。但‘鄂植8’和‘城固32’在0.10%的硼酸因素下,完全花比率较对照分别提高了8.9%和11.5%;‘城固32’在0.05%的硼浓度下的坐果率较对照提高了154.2%;‘鄂植8’和‘城固32’在0.00%、0.25%的钙浓度处理下,其坐果率均显著高于更高浓度的处理,高浓度的钙反而对果实坐果率有显著抑制作用;‘莱星’的处理间差异均不显著。培养基50~75 mg·L~(-1)的硼酸对油橄榄花粉萌发促进作用最好,而培养基添加钙则抑制花粉萌发,且硼和钙存在一定的拮抗作用,因此高浓度的钙不利于油橄榄花受精和果实坐果。【结论】油橄榄不同品种对花期喷施硼和钙的响应程度不同,适量的硼(0.5%~1.0%)对油橄榄开花坐果有促进作用,而高浓度硼(大于1.00%)和高浓度钙(大于0.25%)均不利于油橄榄开花坐果,在油橄榄花期的叶面施肥中应谨慎使用外源高浓度钙。     

The effects of some chemical treatments on leaf water conductance of cut,flowering stems of Chrysanthemum morifolium

The leaf water conductance of cut, flowering stems of Chrysanthemum morifolium was measured by diffusion porometry. The stems were placed in solutions of chemicals which have commonly been used in flower preservatives, or which might be expected to affect the physiology of the leaves.In the environmental conditions of our experiments (18° C; 0.8 kPa; 5 W m^?2 visible radiation for 8 h) sucrose (6 %) and abscisic acid (0.001 %) lowered leaf water conductance. Silver nitrate (0.003 %) or 8-hydroxyquinoline sulphate (0.02 %) either had no effect or increased leaf water conductance. We conclude that the latter two substances increase the vase life of cut flowers by affecting the physiology and pathology of the stem rather than the stomatal physiology of the leaf. The leaves of stems standing in high concentrations of sucrose accumulated sucrose and were frequently damaged as a result.The results are discussed with regard to the water relations of the cut flower and the possible use of anti-transpirants.     

美国黑莓大棚高产高效栽培技术

美国黑莓,群众俗称黑草莓,为蔷薇科黑莓属多年生藤本鲜食水果.原产北美,是第3代新兴水果,目前风靡欧美.1995年从美国引种成功,1997年被枣庄市科委列为农业重点开发项目.1999年进行了黑莓大棚栽培试验,结果表明果实、果色、风味与露地栽培较为相似,667m2(1亩)产量达820 kg,浆果成熟期比露地栽培提早86天左右,售价比露地栽培增长10倍(40～60元/kg),经济效益显著.     

11个草莓品种在河南郑州栽培比较试验

以引进的10个草莓品种‘甘露’‘山东二号’‘天仙醉’‘章姬’‘久香’‘香野’‘红颜’‘白雪公主’‘宁玉’‘艳丽’和河南省主栽品种‘甜查理’为试验材料,研究了11个品种的植株生长特性、果实经济性状、物候期、抗病虫性及产量。结果表明:‘香野’和‘甘露’抗病虫性强、果实品质好、产量较高,适合在河南省郑州市自采园区种植;‘山东二号’和‘宁玉’在果实可溶性固形物含量、果实硬度、产量、抗病虫性及果实成熟期方面表现较好,可作为‘甜查理’的替代品种栽培。     

简易大棚葡萄间作草莓栽培技术

在浙江杭州地区采用简易的大棚栽培葡萄,并且棚内套种草套,2月初盖膜保温,草莓于4月初上市,葡萄比露天栽培提前半月上市,经合理的夏季修剪,使葡萄的二次果也获得高产,于10月底成熟上市。     

四季草莓赛娃在新疆伊犁地区的栽培表现

2001年自山东引入四季草莓赛娃试种,表现良好。平均单果重36g,最大单果重94g,可溶性固形物含量为11．1％～13．5％。平均单株周年产量900g。适应性强,抗寒、抗病性强。