桃树耐旱、耐寒性研究初报

用电导法、组织含水量等方法,对丽秋、红芙蓉等12个桃品种的耐旱、耐寒性进行测定,将结果进行聚类分析.12个供试桃品种可分为抗逆性强、抗逆性中强、抗逆性中弱和抗逆性弱4类;抗逆性从强到弱依次为:中秋红＞瑞光4号＞莱山蜜＞阿布白＞沙红桃＞红芙蓉＞瑞光18号＞丽秋＞千年红＞瑞光28号＞瑞光22号＞瑞光27号.     

Prognosis and correction of iron chlorosis in peach trees and relationship between iron concentration and Brown Rot

This study investigates the possible correlations between bark, floral, and leaf iron (Fe) concentrations and SPAD measures to be used as early methods for prognosis of iron chlorosis in peach trees. The results showed that there were significant correlations between bark, floral and leaf Fe concentrations and SPAD measurements. This study shows for the first time the possibility of using bark analysis as an early predictive method of iron chlorosis in peach trees.Differences in mineral composition of leaves of peach trees, in relation to rootstocks were also found.This study also investigated the distribution of mineral elements in different parts of peach leaves. Tissue analysis of different leaf parts showed that the peripheral and petiole of leaves had the highest P, Ca, Mg, Zn, Fe, B and Cu concentrations. In contrast, the highest K concentration was found in the internal parts of leaves. High Mn concentration was found in the laminar of leaves, but was lower in the petioles.In other experiments, the effect of different sources of Fe application on the leaf Fe concentrations and development of Brown Rot in the year of application and one and 2 years later was also examined. No application increased significantly the leaf Fe concentrations in the year of application and 1 year later. Leaf Fe concentrations were significant higher in trees treated with FeSO₄·7H₂O + S 2 years after application.The possible effect of flesh Fe concentration to susceptibility of peach (cv. Sun Crest) to Monilinia laxa was also evaluated. The results showed no correlation between flesh Fe concentration and susceptibility of peach to M. laxa. Besides, no statistical difference was found in the susceptibility of peach to M. laxa collected from the cultivar Sun Crest grafted on different rootstocks.     

Relationship between environmental factor and maximum daily stem shrinkage in apple tree in arid region of northwest China

After measuring maximum daily stem shrinkage (MDS) of irrigated apple tree using dendrometer during the year 2007–2010 in arid region of northwest China, we analyzed the respective relationships between MDS and single plant physiological index and environmental factors to investigate whether MDS can indicate the water status of apple tree and to establish empirical multiple regression equation among MDS and environmental factors. Results show that MDS increased at the beginning and then decreased gradually during whole growing stage. The close relationships between MDS and stem water potential, predawn water potential, stomatal conductance were found, showing that MDS can indicate the water status of mature apple tree. The relationships between MDS and single meteorological variable were significant at the other growth stages except at the bud development and flowering stage, because the canopy structure was not developed, and the order of determination coefficient (r²) over the whole growing stage was maximum vapour pressure deficit > maximum air temperature > net radiation. There were also significant correlations between MDS and soil volumetric water content and reference crop evapotranspiration over the whole growing stage. However, the determination coefficient among MDS and meteorological variables and soil volumetric water content at 0–120 cm depth was higher than those between MDS and single variable. Thus the multiple regression equation among MDS and meteorological variables and soil volumetric water content at 0–120 cm depth can be used to estimate MDS under fully irrigated apple orchard.     

桃幼树光合年变化及落叶期早晚与营养生长的关系

试验以2个桃品种(南方早红和大久保)1 a生幼树为试材,研究了光合年变化和落叶期早晚与营养生长的关系。结果表明,2个品种桃6月份光合速率日变化呈双峰曲线,最高峰在11:00,次峰在14:00—15:00;8月份光合速率曲线呈单峰,最高峰在13:00。日光合总量的季节变化也呈双峰,分别在5月和8月。4—8月南方早红单位面积月光合总量占年总量的94.15%,大于大久保同时期的比值。南方早红落叶晚于大久保,且抽生新梢能力强于大久保。因而,南方早红9—10月光合面积的增大对单株年光合总量增加的贡献略高于大久保。实验认为,南方早红4—8月高的光合能力和9—10月落叶期晚对其旺盛的营养生长都具有重要的促进作用。     

榛子主干横截面积和产量关系的研究

对5个榛子品种的产量与主干横截面积和产量关系进行了调查研究,结果表明,达维和辽榛8号产量稳定且丰产,辽榛9号产量低,辽榛1号与玉坠前期产量低,后期增长快,也有发展前途。榛子主干横截面积与产量有显著的直线回归关系,在生产和科研中还需长时间观察。     

Effect of pruning and plant spacing on the growth of cherry rootstocks and their influence on stem water potential of sweet cherry trees

Summary

The aims of this work are to describe the effects of pruning and planting density on growth and water relations of ungrafted and grafted sweet cherry trees. A trial with cherry rootstocks ‘Prunus avium’, ‘CAB 11E’, ‘Maxma 14’, ‘Gisela 5’ and ‘Edabriz’ was begun in 1997. Pruning severities were applied to the rootstocks (0, 30, 60 and 90% of the vegetative growth was removed corresponding to P1, P2, P3 and P4 treatments, respectively) after planting to two plant spacings (S1 = 0.25 × 1.0 m and S2= 0.45 × 1.5 m). Canopy, root growth and leaf water potential (ψ_leaf) were quantified throughout the growing season. Pruning significantly affected root length and root weight of the rootstocks. Uncut plants (P1) showed a heavier and expanded root biomass (231 g and 108 m) than the intensively pruned plants (P4) (187 g and 75 m). The greater root biomass was obtained with the spacing/pruning combination, S1/P1 (285 g), and the smaller with S1/P4 (180 g) and S2/P4 (176 g). ψ_leaf varied significantly between the rootstocks and plant spacing but not with pruning. ‘Maxma 14’ and ‘P. avium’ attained the lowest values of midday ψ_leaf, –2.28 and –2.04 MPa, but the highest values of predawn ψ_leaf, –0.29 and –0.25 MPa, respectively. Generally, with high density (S1), the rootstocks exhibited lower predawn and midday ψ_leaf. In 1998, cultivars ‘Burlat’, ‘Summit’ and ‘Van’ were grafted onto rootstocks and a trial was installed in 1999. Predawn and midday stem water potential (ψ_stem) on cherry trees, measured in 2002, were affected significantly by the rootstock/genotype combination. Cultivars grafted on ‘P. avium’ and ‘Maxma 14’ showed the less negative midday ψ_stem, –1.36 and –1.42 MPa respectively, so these rootstock genotypes perhaps induced a higher drought resistance to the scion. Recorded data show that the scion-rootstock interaction with regard to production performance under water deficits may be an important consideration in cherry tree planting strategies.     

西瓜品种叶部特征与抗旱性的关系

为探讨西瓜叶片特征与抗旱性的关系,找寻能表征西瓜品种抗旱性的叶部特征,通过盆栽试验研究了9个已知抗旱性强弱的西瓜材料叶片结构、水分生理和气孔特性。结果表明:利用西瓜材料单叶面积、叶片解剖特征(栅栏组织/海绵组织、上表皮、下表皮和栅栏组织/叶片厚)和气孔特性(气孔的长/宽、气孔密度、气孔导度、气孔开口大小、单位叶面积气孔相对面积)隶属函数值判定的耐旱级别与大田直接鉴定所得的耐旱等级正相关。西瓜叶片的解剖特征和气孔特性可用于品种抗旱性鉴定,但单一指标不能准确判断西瓜品种的抗旱性。     

The effect of trunk electric vibration on the growth,yield and fruit quality of peach trees (Prunus persica [L.] Batsch)

To determine the effect of electric vibration on the growth, yield and fruit quality of peach electric vibrators that provided intermittent perturbation of 6500 rpm for 15 min every 6 h were firmly attached to the trunks of peach trees. Electric vibration resulted in the reduction of shoot length by 80% but had no significant effect on fruit weight, acid content and Brix. In another experiment, electric vibrators (for 15 min every 2 h) were attached to the branches after summer pruning. The regenerated shoots from the treated branches showed more than 500% reduction in length compared to the untreated ones. Even the regenerated shoots of untreated branches nearby the vibrator showed 60% reduction in length. Ethylene production and ACC content in the shoot tips of treated branches were greater than that from control ones.     

部分梨砧木的叶片组织结构与抗旱性的关系

为了评价西南喀斯特山区常用梨砧木的抗旱力强弱,了解其叶片组织解剖结构和保水力参数与抗旱性的关系,以川梨(Pyrus pashia Buch.-Ham.)、滇梨(P.pseudopa shia Yu)、砂梨(P.pyrifolia Nakai)和杜梨(P.betulaefolia Bge.)为材料,采用测定旱害指数的方法鉴定其抗旱力强弱,分析几种梨砧木叶片组织解剖结构和保水力参数与抗旱性的关系。结果表明,供试梨砧木的实际抗旱力强弱顺序为杜梨>川梨和滇梨>砂梨。梨砧木叶片栅栏组织与海绵组织的厚度比、叶肉组织结构紧密度(CTR)和水分临界饱和亏的大小,与砧木种间的旱害指数呈极显著的负相关,与抗旱性呈极显著的正相关;叶肉组织结构疏松度(SR)和失水速率的大小,与旱害指数呈极显著的正相关,与抗旱性呈极显著的负相关。杜梨的抗旱力极强,川梨和滇梨抗旱力强,砂梨的抗旱力中等。用叶片组织解剖结构参数指标鉴定梨砧木抗旱性可靠性较强,用叶片失水速率和水分临界饱和亏等指标鉴定梨砧木抗旱性与实际抗旱性具有较高的吻合度。     

桃枝条梢端生长及其与温度,叶水势和比叶重关系的研究

以金冠、汉瑞、红港、卡尔红为试材，探讨了桃枝条梢端生长与环境温度、叶水势和比叶重之间的关系及其昼夜变化规律。表明：在试验条件下枝条梢端生长速率与环境温度呈显著正相关，与一天中早、晚碳水化合物积累也呈显著相关，而与叶片水势变化无关。梢端生长速率昼夜总的变化趋势与气温变化相吻合，最大值出现在平均气温最高的傍晚（１６：００～２０：００），最小值出现在平均温度最低的凌晨（０：００～８：００）。在２５±０．５℃恒温条件下，梢端生长速率最大值出现后，并不随即下降，而是保持这个生长速率直至午夜，尔后逐渐降至最低值。太阳升起后，生长速率又逐渐回升。     

袋控缓释肥对桃幼树生长发育的影响

袋控缓释肥根据果树树体较大的特性,结合果树养分需求特性,采用纸塑材料做成的控释袋包裹掺混肥料,袋上针刺微孔,利用微孔控制养分释放,达到供肥和养分需求相一致。大田试验结果表明,施肥后袋控缓释处理土壤Nmin比撒施稳定,土壤Nmin含量维持在60mg/kg左右,养分释放缓慢、平稳,能满足幼树生长发育需要;1次撒施处理施肥2周后土壤Nmin含量达100mg/kg,随后急剧下降,8周后降至不施肥水平;2次撒施处理每次施肥2周后土壤Nmin含量达80mg/kg,即2个高峰。袋控缓释处理桃树根系含有大量的毛细根,与其它处理差异显著,但不施肥处理根系分布范围最广。袋控缓释处理桃树地上部树势中庸,不旺长;撒施处理在第2次施肥前以1次撒施地上部长势最旺,第2次施肥后以2次撒施地上部长势最旺。袋控缓释处理2007年开花观察时,开花数和坐果量均最高;2008年休眠期观察时,单位枝条长度花芽数量最多。     

9个海棠品种锈病发生情况调查

对邻近桧柏的苹果资源圃内9个海棠品种的锈病发生情况进行调查表明,海棠距离桧柏近感染锈病重、距离桧柏远感染锈病轻;综合分析9个海棠品种与桧柏距离不同叶片病斑数不同的调查结果认为,白兰地海棠、草原海棠、BMO、草原玫瑰抗锈病力强,乙女海棠较抗锈病,圆叶海棠、垂枝富尔顿、红哨兵海棠及W112不抗锈病。     

A comparison of the combined effect of water stress and crop load on fruit growth during different phenological stages in young peach trees.

Summary

The combined effect of fruit load and water stress on fruit water content and dry-matter accumulation was analysed for three phenological stages of fruit growth. Irrigation treatments were no irrigation during Stage I (NI-SI), Stage II (NI-SII), or Stage III (NI-SIII) compared with a fully irrigated control. Three thinning treatments were imposed within each irrigation treatment resulting in fruit loads ranging from low to high. Fruit harvests at the end of Stage I, II and III were used to determine total tree fruit fresh and dry matter after each stage of fruit development. Fruit water accumulation was highly sensitive to the effect of water stress at high fruit loads in all fruit developmental phases, but reductions in fruit water content were more apparent during Stages II and III than during Stage I. On the other hand, fruit dry-matter accumulation was relatively insensitive to water stress at any fruit load level and developmental stage. However, reductions in dry-matter accumulation were obtained during Stage III from those trees that were not irrigated during Stage I (NISI). Since these reductions occurred only for mid-to-high fruit load conditions, the decreases in fruit growth during Stage III appeared to be related to a carbon source limitation. The possible reasons for this source limitation are discussed.     

Investigating the relationship between various measuring methods for determination of establishment success of urban trees

Establishment is a key concept in urban forestry but it is currently inconsistently defined and measured. Thus, several different methods are being used to determine establishment success but their consequences and applications are rarely discussed. With this paper we would like to stimulate an increased discussion regarding these concepts both in relation to a theoretical definition but also to their practical use. The problem was approached through an experiment using sweet cherry (Prunus avium L.) and northern red oak (Quercus rubra L.) trees and the most common methods used for determination of establishment success. The trees were studied during the first three years after transplant and the association between the different measuring methods was examined. A Principal Component Analysis showed that terminal and lateral shoot length were strongly correlated, and that midday- and pre-dawn shoot water potential, and stomatal conductance were strongly correlated. We developed an index for nightly recovery of water status, which showed that terminal shoot growth was not related to nightly recovery until the third year after transplanting. Our results suggest that successful tree establishment is determined differently depending on which method is used for determination but that the differences might decrease with time. The lack of a firm definition of the term establishment may complicate communication, both within the scientific community and in practice.     

The effect of irrigation and crop load on stem water potential and apple fruit size

Summary

The effect of irrigation rate under various crop loads on the fruit size of apple (Malus domestica Borkh cv. Golden Delicious) was investigated in three field experiments in 1993–1995. During the first two years the field experiments evaluated the effects of various crop loads on yield, fruit size and midday stem water potential under 40% deficit irrigation. In 1995, the effects of five irrigation levels (0.42–1.06 of USDA Class A evaporation pan) and four crop loads (100–450 fruits per tree) were studied in a factorial experiment. Midday stem water potential increased with irrigation level and decreased with crop load in 1993 and at the lowest irrigation level in 1995. Daily fruit growth rate decreased with midday stem water potential in 1993 and at the lowest irrigation level in 1993. The effect of crop load on fruit growth rate was associated with limited soil water availability. A reduction in yield and average fruit size were associated with midday stem water potentials lower than –1.3 MPa. Taking an additional 0.1 MPa as a safety factor, –1.2 MPa could serve as a reasonable threshold for irrigation control in the orchard.     

Influence of temperature and bark injuries on the development of Phytophthora cactorum and P. Citrophthora on peach trees

The effect of temperature and bark injuries on the occurrence of crown rot of peach trees caused by P. cactorum and P. citrophthora were examined in field and laboratory. Lesions developed at 35 °C (the complete range of temperatures tested) but maximum development occurred at 20–25 °C. Greatest growth of these fungi on cornmeal agar (CMA) also occurred between 15 and 30 °C. Both pathogens could infect injured trees up to 20 days after wounding, but could not infect uninjured plants or plants wounded 40 and 30 days before inoculation, respectively. This study showed that temperature is a critical factor for the development of Phytophthora crown rot of peach trees. In addition, crown rot developed from recent wounds inoculated with agar plugs of Phytophthora.     

Effect of salinity and water table on the mineral content of plum and peach

The effects of combinations of salinity and water table on the mineral content of plum and peach were studied in lysimeters.Chloride content (Cl) in the leaves and the roots of plum and in the leaves of peach increased with salinity, whereas Cl in peach roots was not affected. Leaves of peach contained higher amounts of Cl than the leaves of plum. The opposite trend was observed in the roots.Sodium content (Na) increased with salinity in plum, whereas in peach it was not affected.The effect of salinity on calcium content (Ca) was not consistent in plum and peach.Potassium content (K) in the leaves of plum and peach decreased with salinity, whereas in the roots it was not affected.The Ca/K ratio in plum leaves increased with salinity, whereas in peaches it decreased in the 4000 p.p.m. treatment.Leaf phosphorus content (P) in the plum and the ‘Balady’ peach decreased with salinity, while in ‘Mit Ghamre’ peach it was not consistently affected. In plum root, P increased with salinity, whereas the effect was the opposite in peach.Magnesium content (Mg) was not significantly affected.The depth of the water table had no consistent effect on the Cl, Na, Ca, K, Ca/K ratio, P and Mg contents in the leaves and roots of plum or peach.The interaction between salinity treatments and water table levels was not significant in most cases.     

新疆野杏树干液流变化与环境因子的关系

对新疆伊犁新源野果林野杏树干液流进行监测,与环境因子结合分析,揭示野杏树干液流与环境因子的关系。结果表明:野杏树干液流有明显的昼夜变化,树干液流速率日变化表现为昼高夜低,在不同天气下树干液流速率呈现的规律为晴天>阴天>雨天;树干液流在7月的液流量达到最大,为2012.29L,整个生长阶段日均液流量均值为46.63 L;环境因子与野杏树干液流的变化有着密切的关系,其中太阳辐射在整个生长季中与树干液流均呈现极显著正相关,在7月相关系数最大,为0.802,而空气相对湿度一直呈现负相关关系。     

Influence of rate and method of application of superphosphate on the growth and nutrient status of newly planted peach trees

A field experiment was carried out with newly planted peach trees to determine the influence of both rate and method of application of superphosphate on tree growth and nutrient status during the first growing season. Superphosphate was applied at planting at rates ranging from ¼ to 9 lb per tree, and applications were made either to the soil surface, in the planting hole, under tree roots, or in a band around the tree at a depth of 6 inches. Trees were grown under straw mulch and were irrigated as required.

Results showed that, in this soil of low initial ? content, trees receiving 9 lb superphosphate on the soil surface or in a ring band grew significantly larger than trees receiving ¼ lb superphosphate per tree (this applied for butt circumference only on surface-treated trees), but high rates of superphosphate in the planting hole or under tree roots resulted in tree death. No significant differences in growth were recorded at harvest between surface and ring-banded treatments at any phosphate rate, but leaf analysis in midsummer and tree analysis at harvest showed that the phosphate status of surface-treated trees was significantly higher than that of ring-banded trees.

At low rates of superphosphate (¼ and 1 lb per tree), surface treatment tended to give larger trees at the end of the growing season than band treatment, but differences were not significant. It is thought that this differential response occurred because the phosphate-fixing potential of the soil increased sharply with depth and hence band applications were inefficient unless very high rates of superphosphate were used.

The tree damage observed when high rates of superphosphate were applied in the planting hole or under tree roots was probably due to a combination of osmotic stress, acidity damage to the roots and possibly toxic nutrient levels in tree tissues. Hence high rates of superphosphate should not be placed close to tree roots at planting.

Leaf analysis in midsummer and tree analysis at harvest showed that the main effect of superphosphate application was on the ? status of the trees, and maximum tree growth in the surface and band treatments corresponded to a value of approximately 0.28% ? (dry weight basis) in the leaves. The efficiency of uptake of applied superphosphate was very low at all rates of application and was especially so at high rates. However, positive growth responses were recorded to 9 lb superphosphate per tree in surface and banding treatments. It is suggested that, although most of the applied superphosphate could not be utilized, tree growth rate was proportional to the concentration of ? in the soil zone which could be exploited by the roots.     

Effect of xylem blockage on stem resistance and water potential in Triplochiton scleroxylon K. Schum. cuttings

Summary

Cuttings of the tropical hardwood species Triplochiton scleroxylon K. Schum. may be extremely difficult to root, depending on the physiological status of the parent plant and propagation conditions. This study examined the importance of xylem blockage in limiting the water supply to unrooted stem cuttings. Stem resistance was greatest in Node 1 cuttings (youngest node) of stock plants, and decreased basipetally. Resistance increased to a maximum, and water potential reached a minimum, 6 d after transfer to rooting medium.The primary site of blockage occurred within 1 mm of the stem base, suggesting an excision-induced wounding response. Histological studies revealed that gums of carbohydrate origin were deposited in some protoxylem elements near the stem base. The influence of these factors in determining cutting survival is discussed.