Salinity effects on strawberry plants grown in rockwool. II. Fruit quality

Fruit development and quality in strawberry cv. Rapella were influenced by salinity (+NaCl) treatments applied to the roots of plants growing in rockwool under heated glasshouse conditions. As salinity increased from 2.5 to 8.5 mS cm-1, fruit yield decreased. Analysis of the fruit showed that the reduction in yield was due to reduced water content, reflected by increasing dry matter percentage (8.32% at 2.5 to 9.78% at 8.5 mS cm-1). The concentration of reducing sugars and acids remained the same on a dry-weight basis after salinity treatment but, on a fresh weight basis, the decreasing water content increased their relative concentrations. Salinity levels had no significant effect on instrumental texture and colour measurements. Sensory evaluation of the colour, texture and flavour of strawberries showed significant differences in colour and flavour but no difference in texture.     

Effects of salinity on various growth stages of muskmelon cv. Revigal

Salt tolerance of muskmelon cv. Revigal was assessed during germination, seedling growth and growth in hydroponic culture. First, germination tests were conducted using four salinity treatments (0, 390, 780 and 1560 mS irf'). At the second stage, seedling growth was studied at salinities of 225,550,775 and 1000 mS m“1. Finally, the influence of salt on the size and organoleptic characteristics of fruit and on the content of various elements in the leaves was studied at salinity levels of 250,500 and 750 mS m'1. Abilities of the seed to germinate and of the seedling to grow adequately were determined under saline conditions of up to 780 mS m_l and 550 mS m“1, respectively. During the last stage, a slight decrement in yield was observed at 500 mS nT1 and fruit mean weight reached 82% of the control. Results suggest that this cultivar is moderately salt-tolerant and can be grown, in principle, at salinities of up to 500 mS m‘. An interesting relationship has been established between the influence of salinity on leaf area of the seedling and on the yield obtained during hydroponic culture; we are therefore proposing seedling leaf area as a major indicator of salt tolerance.     

Effect of interplanted rice on the growth of tomato in deep solution culture and on the response to salinity

Summary

Tomatoes were grown for 66 d in deep solution culture (a) without aeration, (b) with interplanted rice and (c) with air bubbled through the solution, in factorial combination with two electrical conductivities (4 and 8 mS cm^?1). Root growth was seriously restricted in the poorly aerated solutions (a) and (b). Interplanted rice stimulated shoot growth compared with the un-aerated treatment, and increased the total dry weight, leaf area and fruit yield (fresh weight) by up to 26, 34 and 22% respectively. The total dry weight of plants grown with rice was only 60% of that of the aerated ones but the area of corresponding upper leaves was 73%. Water and nutrient uptake were reduced by poor aeration but, after allowing for the uptake by the interplanted rice, only the uptakes of P and Ca by tomatoes in that treatment were significantly higher than those of the un-aerated plants. The higher salinity reduced growth and the uptake of nutrients. No interaction between aeration and salinity was found.     

Effect of Leaf Number and Area on the Fruit Growth of Regular and Biennial Bearing Mango (Mangifera indica L.) Grown Under North Indian Conditions

Abstract

The optimum leaf number required for normal fruit growth in the regular bearing mango cultivar ‘Amrapali’ and the biennial bearing cultivars ‘Chausa’, ‘Dashehari’ and ‘Langra’ were studied by isolating individual fruits with known numbers of supporting leaves by shoot girdling at the time of fruit set. There were significant differences in the leaf area (249.01-1817.10 cm2), fresh weight (7.0-77.0 g) and dry weight (3.7-50.0 g) of leaves on shoots having 30, 20, 10 and 5 leaves as compared with control in different cultivars. In both types of cultivars, there was a progressive reduction in fruit size in terms of total fruit, pulp, peel, and seed weight with decreasing numbers of supporting leaves, however, a minimum reduction (2.4%) in fruit growth in ‘Amrapali’ was noticed with 30 supporting leaves. A nonsignificant difference in photosynthetic rate with varying number of leaves was found but its efficiency in leaves was higher in ‘Amrapali’ as compared with biennial bearing cultivars. Starch accumulation in the leaves was reduced by shoot girdling. The stomatal resistance of the leaves of girdled shoots was comparable with that of leaves on control shoots. In all the cultivars except ‘Amrapali’ it was observed that 30 leaves, the maximum retained on a shoot, could not support the growth of a single fruit to normal size. The data on rate of photosynthesis in different pool size of leaves and fruit growth in girdled and nongirdled shoots clearly show that fruit development depends not only on the current assimilates but also to a great extent on reserves. A 14CO2 feeding experiment showed a higher rate of carbon fixation in the leaves of girdled shoots than in the control shoots, but the translocation of 14C assimilated to the developing fruits on the girdled and control shoots was comparable. The results also indicated that developing fruits are major sinks for current photosynthates as more than 60 percent of the 14C exported from the treated leaf was found in the fruit in all instances.     

Salinity effects on some postharvest quality factors in a commercial tomato hybrid

Summary

The commercial F1 tomato hybrid (Lycopersicon esculentum L. Mill) cv. Radja (GC-793) was cultivated with low (control), moderate (70 mM NaCl) and high (140 raM) salinities under greenhouse conditions for 14 weeks. The effects of different salinity levels on fruit weight and major chemical components determining fruit quality were assessed. Red ripe fruits were harvested to determine fruit weight, size and composition. The water content and mineral composition were determined in whole fruits; the carbohydrate, organic acid and soluble protein contents were analyzed in pericarp tissue. Moderate salinity reduced the fresh and dry fruit weights by only 10 and 13%, respectively, while high salinity reduced them by 40 and 33% compared with control fruits. The water content was not significantly affected by salinity. Thus, fruit weight does not seem to be limited by the water supply under these conditions. The amount of Na⁺ significantly increased only at high salinity, while Ca²⁺ and Mg²⁺ contents were not affected. K⁺ content, which represents more than 70% of the mineral composition, vends to increase with salinity. The citric acid content slightly increased at moderate salinity, while both citric and malic acids contents were reduced at high salinity, increasing the citric/malic ratio. The pH values were always about 4. The low content in soluble proteins was reduced by high salinity, while moderate salinity increased it. In pericarp tissue of moderately treated fruits, the fructose and glucose contents were three times and twice as high as control and highly salinized-ones. Starch, sucrose and myo-inositol also accumulated under salinity. Hexoses and starch accounted for 20, 66 and 42% of the pericarp dry matter in control, moderate and highly salinized fruits, respectively.     

果树缺铁性黄化植株诊断方法的研究进展

该文主要评述了果树缺铁性黄化诊断中叶分析的不足和花分析的可行性。通过对国内外文献分析可知,叶分析存在滞后性和矛盾性两方面不足,而花分析能更好地了解果树铁营养状况,比叶分析具有一定的优越性。今后应加强花诊断指标和采样部位的研究。     

Effects of humidity,Ca and salinity on the accumulation of dry matter and Ca by the leaves and fruit of tomato (Lycopersicon esculentum)

Tomato plants were grown at four humidities in factorial combination with two levels each of Ca (150 and 300 mg 1^-1) and salinity (5 and 7 mS cm^-1) in the nutrient solution applied to the rockwool substrate. The humidity treatments, defined as vapour pressure deficits, were 0.15, 0.25, 0.43 and 0.65 kPa (held constant day and night) in Experiment A, and high (0.21 kPa) or low (0.47-0.55 kPa) humidity during the day in combination with high (0.16 kPa) or low (0.45-0.50 kPa) humidity at night in Experiment B. High humidity reduced the dry weight of the leaves, as did the higher salinity. The Ca content (%) and the total amount of Ca (mg) accumulated by the leaves always decreased at high humidity, this response being greater at night than during the day, and always increased with the higher level of Ca. Accumulation of Ca by the fruit was markedly reduced by low humidity during the day, increased by the higher Ca level, and was decreased by high salinity at the lower Ca level. High humidity during the day appears to promote Ca movement into the young fruit, irrespective of the humidity at night.     

北方主要落叶果树对在土壤中施用不同量的PP333的反应

对苹果、桃、樱桃和葡萄进行了盆栽土施不同剂量PP333的试验。结果表,由于PP333在植物体内移动缓慢,PP333的抑制效果不能立即表现出来。PP333在植物体内的移动速度在苹果中较慢,在桃和樱桃中较快,葡萄介乎二者之间。 PP333对加长生长的抑制作用主要表现为节间的缩短和较早地停止生长,以及由此产生的节位数的减少。此外还表现在茎粗,单叶面积,叶片总面积,茎及叶的鲜,干重的降低以及副梢数目的减少和长度的降低上。PP333对根系也有抑制作用,但比地上部小,从而改变了根/冠比。土施PP333 1.0ppm以上的剂量有强烈的抑制作用,PP333抑制生长的强度与使用的浓度呈指数曲线相关关系。PP333促使新老叶片加厚。     

纽荷尔脐橙果实对源叶光合作用的影响

在纽荷尔脐橙果实膨大期,选取1年生双果枝、单果枝和营养枝,晴天测定源叶净光合速率(Pn)、气孔导度(Cond)、蒸腾速率(Trmmol)、胞间CO2浓度(Ci)和叶面温度(Tleaf)等生理指标,探讨挂果对源叶光合特性的影响。结果表明,挂果水平对源叶Pn、Cond、Trmmol有显著影响,对Ci和Tleaf无明显影响;上午以挂果多的枝条的源叶Pn、Cond、Trmmol峰值更低,下午则呈相反的趋势。不论枝条挂果多少,源叶Pn日变化呈典型的"双峰"曲线;Pn与Tleaf呈抛物线相关,当叶温达36℃左右时叶片光合作用最强。     

Relationship of leaf necrosis and defoliation to phosphorus and potassium concentrations in selected tissue and to certain fruit quality parameters of pecan

Pecan [Carya illinoinensis (Wangenh.) K. Koch] trees developed necrotic areas in the leaves late in the growing season. July samples indicated that leaf P (0.114% DW) and K (0.62% DW) were low, but other elements were within accepted sufficiency ranges. Relationships between leaf P and K concentrations with nut quality and return bloom were determined. Trees were rated for leaf necrosis 1 October using a 1 (none)–5 (severe) scale. Fruit were harvested and analyzed for weight/nut, kernel weight, and kernel grade. Leaflet pairs collected 1 October from fruit bearing shoots were analyzed for N, P and K. Return bloom was determined on branches that bore fruit the previous year. Necrosis ratings were positively related to leaf N and negatively correlated with weight/nut; kernel, shuck and leaf P concentrations; and kernel and leaf K concentrations. Leaf, kernel and shuck P concentrations were positively correlated with weight/nut and percentage number 1 kernels. Leaf K was positively correlated with return bloom and weakly negatively correlated to weight/nut. Phosphorus was the primary element limiting fruit development and K shortage substantially reduced return bloom. Data support minimum pecan leaf standards in July for fertility recommendations of 1.0% K and 0.14% P.     

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.     

Einfluss von blattappliziertem Bor auf Boraufnahme und Fruchteigenschaften von Kulturheidelbeeren (Vaccinium corymbosum)

In 2003, highbush blueberry (Vaccinium corymbosum) cultivars ‘Brigitta Blue’ and ‘Nelson’ were treated with a foliar boron-containing, ascofol spray (Wuxal^®). After blossoming, the plants were sprayed three times with 0.5% ascofol solution. Control plants were sprayed with tap water. Fruit harvest of each cultivar was on July 19 and 30, respectively. Leaf samples were taken on June 4 and August 7. The boron content of fruits and leaves was analyzed along with fruit yield and single berry weight. The potential absorption rate of applied boron (boron increase in leaves and fruits) was calculated. Foliarly applied boron was readily taken up by the leaves of both cultivars and translocated to the fruits. A potential boron absorption rate of 2.4% was calculated for ‘Nelson’. Foliar application of boron did not increase fruit yield in either cultivar. However, ‘Nelson’ showed a slight increase of berry weight in the second harvest, associated with the boron treatments.     

Evaluation of Salinity Tolerance of Some Selected Almond Genotypes Budded on GF677 Rootstock

ABSTRACT

In order to evaluate the tolerance of some almond genotypes to salinity, a factorial experiment was carried out based on completely randomized design (CRD), with two factors: genotypes in 11 levels (Tuono, Nonparaeil, Mamaie, Shokoufeh, Sahand, ‘Ferragnès,’ 1–16, 1–25, A₂₀₀, 13–40 budded on GF₆₇₇ rootstock, and GF₆₇₇ (without budding)) and irrigation water salinity in five levels (0, 1.2, 2.4, 3.6, and 4.8 g/l of natural salt (equal electrical conductivity 0.5, 2.5, 4.9, 7.3, and 9.8 dS/m, respectively) and with 4 replication for each treatment in research greenhouse of Seed and Plant Institute in years 2013 and 2014. The results showed that with increasing salinity concentration, growth indicators include the branch height, branch diameter, number of total leaves, percentage of green leaves, leaf density on the main branch, leaf area and leaf area ratio, relative humidity content, chlorophyll index, chlorophylls a, b, total, scion fresh and dry weight, root fresh and dry weight have been reduced in the all genotypes studied, but percentage of necrotic leaves, percentage of downfall leaves, root fresh and dry weight ratio to scion fresh and dry weight, relative ionic percentage, and cell membrane injury percentage of leaves were increased. The results of chlorophyll fluorescence showed that salinity stress affected on the young trees by increasing the amount of minimum fluorescence (F_O) and decreasing the maximum fluorescence (F_m) and reduced variable fluorescence (F_v) in the plants and reduced variable fluorescence ratio to maximum fluorescence of 0.83 in the control plants to 0.72 in Sahand cultivar and GF₆₇₇ rootstock. The result showed that type of scion was affected in obstruction of Na⁺ absorption by the roots and their transported to leaves, as well as was affected in increasing uptake of K⁺ by the roots and their transported to leaves. In this research, GF₆₇₇ is well tolerated to water salinity to 4.9 dS/m but with higher range of salinity showed stress effects. The result showed that type of genotypes budded on GF₆₇₇ rootstock was very effective in tolerant to salinity. Overall, ‘Ferragnès’ was recognized as the most tolerant cultivar to salinity stress. This cultivar could tolerate salinity 3.6 g/l (Ec: 7.3 dS/m). Also, Sahand was recognized as the most sensitive cultivar to salinity stress.     

Influence of fruit load on dry matter and N-distribution in sweet pepper plants

The influence of fruit load on the leaf characteristics and on the distribution of dry matter (DM) and nitrogen (N) in sweet pepper (Capsicum annuum L., cv. Cornado) plants was investigated under Mediterranean glasshouse conditions during a winter–spring production cycle (from December till June). DM weight of all organs (roots, stems + petioles, leaves and fruits) and N content were determined throughout the growing cycle over a 3-week interval. The results showed that the cyclic fruit load pattern (production flushes) was associated with strong variations of N-leaf content on an area basis and specific leaf weight, SLW. On a whole plant scale, the value of SLW dramatically decreased (≈30%) with increasing fruit load; the reverse held true as long as the fruit dry weight remained low (<30 g pl⁻¹). The decline in SLW was coincident with a shift in distribution of DM and N in the plant, both preferentially diverted to the fruits. The time evolution of DM and N fractions in organs exhibited periodic fluctuations, with a duration close to the length of a fruit growth cycle (about 70 days, from anthesis to harvest). Linear relationships were found between the fraction of dry mass and N in fruits, and those of the other organs. The slope of these relationships was considered as an indicator of the response and sensitivity of the organ growth to an increase in fruit load. The root dry mass fraction was the most affected by increases in fruit load (slope of −0.75), while the N fraction in roots and in leaves was affected to a similar extent (slope of −0.50 and of −0.40, respectively). We conclude that, in the sweet pepper, the cyclic pattern of fruit load induces opposite cyclic patterns of dry matter and N content in the other aerial organs as well as in the roots, thereby reflecting close shoot–root coordination in the allocation of carbon and nitrogen resources among the organs. Finally, we discuss the possible implications that could derive from these findings for modelling dry matter partitioning in plants subjected to continuous fruit harvesting.     

水分胁迫对‘赤霞珠’不同叶龄叶片光合特性的影响

【目的】探究水分胁迫对葡萄不同叶龄叶片光合及荧光变化规律的影响。【方法】以3 a(年)生‘赤霞珠’葡萄(Vitis vinifera‘Cabernet Sauvignon’)为试材,由黎明前叶片水势(ψb)反映胁迫程度,设置对照(无水分胁迫,CK)、中度水分胁迫(T1)和重度水分胁迫(T2)三个处理,测定‘赤霞珠’葡萄新梢不同叶龄叶面积、叶片光合参数、叶绿素荧光参数及Ru BP活化酶和果糖-1,6-二磷酸酯酶活性。【结果】葡萄叶片叶龄为80 d时,叶面积趋于稳定,T2显著降低了各叶龄叶片的面积,T1与CK无显著性差异;葡萄叶片SPAD值随叶龄的增加而增大,且T1增加了各叶龄叶片SPAD值,T2则降低;Pn、Gs、Tr、Ru BP活化酶和果糖-1,6-二磷酸酯酶活性随葡萄叶片叶龄的增加均呈先上升后下降的趋势,并且随水分胁迫程度的增加下降程度增大;水分胁迫不同程度地降低了各叶龄叶片Fv/Fm、Yield、ETR、q P,而Fo显著增加,T2增加了各叶龄叶片的NPQ,但随着叶龄的增加,T2叶片NPQ又显著低于其他两个处理。【结论】随‘赤霞珠’葡萄叶片叶龄的增加,光合能力呈先上升后下降的趋势,当葡萄叶片叶龄为60~90 d时,光合能力最强。水分胁迫降低了各叶龄叶片的光合效率,重度水分胁迫会阻碍葡萄幼龄叶片的正常发育,并加速老龄叶片的衰老。     

营养液EC值对基质栽培番茄 产量和品质的影响

为探索营养液EC值对基质栽培番茄产量和品质的影响,在番茄植株第3穗果坐住后,设置不同的营养液EC值进行灌溉。结果表明:高EC值营养液灌溉抑制植株生长及产量形成,随着EC值的提高,番茄植株株高、茎粗、叶长、叶宽、坐果数、单果质量、产量明显降低,4.0、5.0 mS/cm高EC处理667 m~2产量较对照3.0 mS/cm分别降低35.6%和42.2%;番茄果实的VC、可溶性糖、可溶性固形物含量及糖酸比显著提升,但5.0 mS/cm处理可溶性糖及糖酸比显著低于4.0 mS/cm处理。综合分析,EC值4.0 mS/cm的营养液适合番茄成株期生长,且有利于提高其品质,适用于高品质番茄栽培。     

Effects of multiple applications of methyl jasmonate on fruit ripening,leaf gas exchange and vegetative growth in fruit trees

Summary

Multiple applications of methyl jasmonate (Me-J), at 10.mM, enhanced the rate of fruit ripening in peach ‘Redhaven’. The effect of Me-J on red colour development and fruit firmness was most pronounced in fruit treated six times with Me-J. Lower concentrations of Me-J had no effect of fruit colour. Me-J, at 10.mM, significantly reduced stomatal conductance, photosynthetic rate and transpiration rate of crabapple leaves, but had no effect on these parameters in peach leaves. The short-term inhibitory effects of Me-J on leaf gas exchange in crabapple persisted for up to 24 h. Fourteen applications of Me-J over a period of 28 days resulted in a 60% decrease in the concentration of chlorophyll in leaves. These Me-J applications also reduced the length of new branches, leaf number and leaf fresh weight by 65%, 31% and 47%, respectively. In peach, Me-J induced some leaf chlorosis and early leaf senescence within two weeks of the treatments which resulted in significant reductions in shoot length.     

Effects of the application of ‘cash’ on the growth,fruit yield,and nutrient status of tomato (Solanum lycopersicum L.) grown in reclaimed saline soil

Summary

The effects of ‘cash’ [a novel 2:5:1 (w/w/w) mixture of calcium sulphate, ground sunflower heads, and humic acid] as a soil amendment on the growth, fruit yield, and leaf nutrient status of tomato (Solanum lycopersicum L.) grown on reclaimed saline soil (EC = 9.4 dS m^–1) were investigated. A glasshouse experiment was performed in a completely randomised design with six treatments (0, 10, 20, 30, 40, or 50 g ‘cash’ kg^–1 soil) each with four replicates. The results indicated that ‘cash’ increased both the shoot dry weight (DW) plant^–1 and the root DW plant^–1, the free proline contents of leaves, and leaf chlorophyll contents. The use of ‘cash’ also increased the number of fruit plant^–1, fruit yield pot^–1, and fruit vitamin C contents, although total soluble solids (TSS) contents were not affected. The contents of nitrogen (N), potassium (K), and calcium (Ca), and the Ca:Na ratios of leaf tissues increased with all application rates of ‘cash’. Leaf phosphorus (P) contents showed no response to any applied level of ‘cash’. Leaf sodium (Na) contents declined gradually with an increase in the level of ‘cash’ applied to the soil. We concluded that ‘cash’ has a pronounced positive effect on the growth and fruit yield of tomato plants grown in reclaimed saline soil. ‘Cash’ therefore has the potential to be used as a soil amendment for vegetable crops such as tomato to overcome the adverse effects of salinity in newly-reclaimed soils.     

The effect of node origin on the development of cuttings of the tea plant (Camellia sinensis (L.) O. Kuntze)

The growth of roots and shoots of cuttings taken from nodes 3 to 9 on the parent stem, counting from the apex, have been compared. Comparisons also included dry weight of parts of the cuttings and leaf areas.

The number of cuttings with roots was unaffected by node origin; the weight of roots was similarly unaffected with the exception of one doubtful case.

Shoot growth, on the contrary, was found to be much more advanced in cuttings from older nodes, presumably because the buds were more highly developed. The cutting buds produced the flush-type growth and leaf forms typical of a mature tea bush.

The effect of node position on dry weights of cuttings was irregular. The greater loss of original leaves among cuttings from older nodes appeared to counteract the expected greater dry weight of these cuttings.     

Drying half of the root-zone from mid fruit growth to maturity in ‘Hass’ avocado (Persea americana Mill.) trees for one season reduced fruit production in two years

We tested the effect of extended drying of half the root system on fruit yield and fruit Ca concentration, an indirect measure of fruit quality, in avocado (Persea americana Mill. cv Hass). In a field experiment on a sandy soil, withholding irrigation and plastic sheeting was used to dry the root-zone beneath the whole canopy (DD) or half the canopy (WD), compared with well-watered trees (WW). The irrigation water contained added nutrients and was slightly saline. Yield, shoot growth, leaf conductance, leaf and fruit water status and mineral concentrations of leaves and fruit were studied. The responses of treated trees were assessed in the following season during which normal irrigation practices were restored. With respect to yield, the WD treatment behaved the same as the DD treatment. It reduced yield by more than half and proportionately more than the reduction in water supply thus reducing irrigation efficiency. Re-watering did not restore yield of WD or DD-trees in the next season. The WD and DD treatments had no effect on the concentration of Ca in the fruit mesocarp and so are unlikely to affect fruit quality. The main impact of reduced water supply on the trees was fruit abscission and this was linked to dry soil around the roots rather than the water status of the leaves or fruits. We conclude that extended drying of half of the root-zone in one season reduced irrigation efficiency for two seasons by promoting the abscission of developing fruit to the same extent as occurred when the whole root system was exposed to extended drying.