Effects of irrigation deprivation during the harvest period on yield determinants in mature almond trees

Effects of irrigation deprivation during the harvest period on yield determinants in mature almond (Prunus dulcis (Mill.) D.A. Webb cv. Nonpareil) trees were investigated during a 3-year field experiment. Return bloom and fruit set were measured on 2185 individually tagged spurs. Water stress resulting from irrigation deprivation during the harvest period, which purportedly coincides with the time of flower initiation, had no effect on the percentage of spurs that flowered or set fruit during subsequent years. Although water stress had no apparent effect on spur mortality, 66% of the tagged spurs died within 3 years. In addition, many spurs were vegetative by the third year, indicating the importance of spur renewal for sustained fruit production. Reductions in nut yield were evident after two successive years of irrigation deprivation during the harvest period. Regression analysis indicated a loss in yield of 7.7 kg tree(-1) in response to each 1 MPa decrease in stem water potential below -1.2 MPa during the previous seasons. The number of fruiting positions per tree (estimated indirectly for whole trees based on weight of current-year shoots > 5 cm in length) was negatively associated with water stress. Yield reduction in response to water stress during harvest appears to be a compound, multiyear effect, associated with reduced annual growth and renewal of fruiting positions.     

Spur behaviour in almond trees: relationships between previous year spur leaf area, fruit bearing and mortality

In mature almond (Prunus dulcis) orchards, the majority of crop is borne on spurs (short, proleptic shoots) that can live for several years and can produce from one to five fruits. Previous research has led to the hypothesis that spur longevity is related to spur light exposure, cropping and age. However, limited quantitative data are available to substantiate these hypotheses. The objective of this study was to determine spur characteristics that were most highly correlated with spur productivity and longevity in mature, bearing almond trees. Previous year spur leaf area was strongly related to spur viability and flowering; the greater the leaf area in the previous year, the higher the probability of spur survival into the next year and the higher the probability for the spur to bear one or more flowers. Previous year bearing also appeared to influence viability and return bloom, especially in spurs with low leaf area. These results suggest that spur source-sink balance is basic to the life cycle of almond spurs. Furthermore, the results are consistent with the hypothesis that spurs are semi-autonomous organs with respect to carbohydrate balance for much of the growing season. Finally, this information provides general thresholds for maintaining spur viability and productivity that will be useful for developing and evaluating tree training systems and orchard management practices.     

红荷包杏的开花坐果习性

红荷包杏是当前国内自然形成的成熟最早的杏树良种，但对其开花坐果习性一直缺乏系统、科学的研究，生产上误解甚多。结合多年实践及科学设计研究方案，初步摸清了其不同树龄、不同树势、不同结果部位及不同结果枝类的败育花率和开花坐果习性。结果显示：红荷包杏坐果率的高低与树龄、树势、结果枝类、结果部位和开花批次有密切关系．红荷包杏幼树的早期丰产比较困难，其丰产稳产的时期在五年生以后才能达到；盛果期正常生长的红荷包杏树，以短果枝及花束状果枝结果为主；虫媒和人工授粉对红荷包杏的授粉、坐果起着决定性的作用，风媒对红荷包杏的授粉基本不起作用；红荷包杏白花坐果率不是零．     

杉木种子园无性系结实遗传与变异研究

杉木[Cunninghamia lanceolata(Lamb.)Hook]是我国特有的主要用材树种,对其生长性状(如树高、胸径、材积等)遗传与变异的研究,已有很多的报道,而对其结实的研究却很少。随着国内林业生产的发展,对杉木良种需求的数量愈来愈大。因此有必要对杉木结实的遗传与变异进行研究,为种子园营建及经营管理提供依据。     

湿地松种子园无性系间开花结实差异分析

湿地松种子园内无性系间的生长，开花和结实等性状存在着显著差异，无性素水平和单株水平上的性状相关分析结果基本一致，雌花量与结实量，球果长与宽有较密切的相关关系，而无性素的雌花量与雌花量存在负相关关系。     

施肥对红松无性系种子园母树结实效应研究

通过在红松无性系幼龄种子园进行的氮肥、磷肥和钾肥3种肥料,每种肥料设置4个水平的施肥试验,研究分析了氮肥、磷肥和钾肥3种肥料,以及每种肥料的不同施用数量,对促进红松无性系种子园幼龄母树结实的效果,提出促进红松无性系幼龄植株结实的适宜施肥数量。     

幼龄枣树叶幕形成规律观察

通过对5年生幼龄枣树叶幕形成全部过程的观察,初步掌握了在咸阳市渭北地区的自然条件下,枣树叶幕形成受外界气温和枣股的发育营养状况影响,及不同年龄枣股上抽生冬吊及着叶特点,从而为幼龄枣树早果、丰产栽培技木提供了参考依据。     

Variations in dendrometric and fruiting characters of <Emphasis Type="Italic">Vitellaria paradoxa</Emphasis> populations and multivariate models for estimation of fruit yield

The fruit of Vitellaria paradoxa is an ideal raw material in cosmetic, pharmaceutical and confectionery industries. There are no accurate data on annual fruit yield due to the lack of objective assessment tools. The objectives of this study were to develop fruit yield prediction models based on dendrometric and fruiting variables, to examine variations in these variables between upland and lowland populations in Burkina Faso, and associations between these variables. A total of 191 fruiting trees were selected according to crown accessibility, and 17 dendrometric and fruiting variables were recorded. The fruit yield, expressed in number of fruits per tree, fresh and dry weights of fruits, was assessed by collecting fruits dropped overnight until the end of the fruiting period. Fruit yield prediction models were derived for each population using partial least squares regression. The results showed significant differences in dendrometric and fruiting variables between populations (P < 0.01). The lowland population had the highest values for most of the dendrometric variables while fruiting variables were the highest for the upland population. A strong significant correlation (P < 0.01) was found between number of shoots and fruiting variables. Within individual trees, fruit yield was lowest for the bottom part of the crown and the section of the crown with north-east orientation. Fruit yield parameters were successfully predicted based on selected dendrometric and fruiting variables (prediction error = 0.092 and 0.125 for upland and lowland populations, respectively). All fruiting variables, number of shoots and crown attributes had the highest influence on the models.     

油茶大小年结果及其生物学特征

将油茶个体分为大年树、小年树、连年小年树和稳产树4个类型,调查研究了油茶大小年结果的生物学特性。研究表明:花芽数量是产生大小年的直接原因,座果量与上年花芽数量呈抛物线关系,y=-0.0193x~2+0.8687x-1.1039;着果量与其并存的花芽数量呈指数函数关系,lny=0.7879ln l/x+2.7286。此外还研究了各结果类型树的春梢枝、春梢叶和果的生长动态特征。     

墨西哥柏实生种子园营建及其优树子代测定的研究

通过种子园与子代测定相结合的方式,在位于滇中的石林林场建立了含102个优树(家系)的墨西哥柏实生种子园,从中探讨了墨西哥柏实生种子园的营建途径。对该种子园的52个墨西哥柏自由授粉优树子代测定的结果表明,墨西哥柏速生,10年生树高、胸径、材积、冠幅的年均生长量分别为1.04 m、1.43 cm、0.009 6m3和0.22 m。生长性状和结实性状家系间的差异达显著水平。树高、胸径、材积、冠幅、结实量的家系遗传力分别为0.76、0.66、0.68、0.74和0.65,单株遗传力分别为0.27、0.16、0.18、0.23和0.16,其生长性状和结实性状呈显著的负相关。从该种子园中评选出了9个优良家系,22个优良单株,其材积遗传增益平均为13.47%和25.2%。此外,还揭示了墨西哥柏10年生期间的生长规律。     

Influence of branch autonomy on fruit,scaffold, trunk and root growth during stage III of peach fruit development

We studied the influence of branch autonomy on the growth of reproductive and vegetative organs by establishing different patterns of fruit distribution within and between large branch units (scaffolds) in mature peach trees (Prunus persica (L.) Batsch cv. 'Elegant Lady'). Different patterns of fruit distribution were established by defruiting either whole scaffolds (uneven fruit distribution between scaffolds; US) or several selected hangers (small fruiting branches) per tree (uneven fruit distribution between hangers; UH). The effects of these patterns were compared with the effects of an even fruit distribution treatment (EVEN) in which fruits were thinned to achieve maximum uniformity of fruit distribution within the canopy. The desired fruit loads were obtained by differentially thinning the remaining bearing parts. On a tree basis, the response of mean fruit mass to fruit load was strongly affected by fruit distribution. The steepest mean fruit mass to fruit load relationship was found in US trees, whereas the relationship in UH trees was intermediate between the US and EVEN trees. On a scaffold basis, differences in fruit size between EVEN and US trees with similar fruit loads, though statistically significant, were relatively small, indicating that scaffolds were almost totally autonomous with respect to dry matter partitioning to fruit during the final stage of peach fruit growth. Hangers also appeared to exhibit significant autonomy with respect to the distribution of dry matter during the final phase of fruit growth. Branch autonomy was evident in scaffold growth: defruited scaffolds in the US treatment grew more than fruited scaffolds, and fruit distribution treatments had little impact on scaffold cross-sectional area on a tree basis. On the other hand, as observed for fruit growth, branch autonomy did not appear to be complete because the fruited scaffolds grew more in US trees than in EVEN trees under heavy cropping conditions. However, the effect of fruit distribution occurred only over short distances, and was negligible on organs located farther away from the source of heterogeneity (fruits), such as the trunk and roots.     

药用植物母猪果的生长发育特性

药用植物母猪果为山龙眼科山龙眼属的常绿阔叶树。2004年和2005年在云南省墨江县设置标准地和抽样调查得出:母猪果主要分布在海拔1600-2000 m,零星生长于常绿阔叶林和针阔混交林林地内;总状花序生于多年生枝条和树冠外围枝条的叶腋间,未开的花为浅黄色,开时为白色,具香味。花被4裂,雄蕊4枚,子房无毛,1室。果实为稍扁球形,果皮木质,内含1粒种子,花粉扁球形,极面观三角形边直或稍凹;花5-6月开放,果实发育从6月开始,生长较缓慢,到11月上中旬果实横径约1 cm左右;果实需到次年的5-6月才能成熟,在同一植株上可出现既有花又有果的现象。母猪果大小年结果和隔年结果现象极为明显,大部分植株当年结果后,次年就不开花结果。     

银杏枝叶生长规律与两次采叶试验研究

本文对栽植后两年的银杏嫁接幼树的枝叶生长规律进行了观察，发现银杏新梢具有春梢和夏梢两种；新梢生长有４种方式；短枝亦分春季展叶生长和夏季展叶生长两种，其中春季展叶生长发生于所有短枝顶芽，而夏季展叶生长一般只发生在顶生短枝顶芽。试验证明，采用全采的方式能有效地刺激所有短枝顶芽全部进行夏季展叶生长；采用两次采收方式能使银杏采叶园的产叶量较传统采收方式（一次采收方式）的产叶量提高１倍。     

早酥梨叶枯病危害损失与防治指标研究

梨叶枯病是在早酥梨上发现的一种新病害，病原菌为Ｍｙｃｏｖｅｌｌｏｓｉｅｌｌａ ｐｙｒｉｃｏｌａ。通过调查早酥梨叶枯病在田间的消长动态，实测不同病情指数下１年生早酥梨苗的高、粗生长量、７－８年生结果树平均单果重、单株产量，建立了苗期生长量和结果树产量损失估计模型，推算出该病害防治指标病指苗期为１２．７４％，结果树为１３．８４％。     

长白落叶松种子园各无性系结实量及播种品质差异研究

通过对长白落叶松种子园各无性系结实量、种子产量及播种品质等因子的定点研究,基本上掌握了长白落叶松种子园各无性系结实量及播种品质差异,选择出17个优质高产无性系,用选出的优质高产无性系构成新的生产群体,种子产量提高1.3~1.6倍,种子发芽率达到60%(国家Ⅰ级种子标准);各无性系间种子产量、播种品质等因子差异极大。     

美国山核桃在云南的引种适应性报告

1974～2000年美国山核桃在云南省漾濞、永平、昌宁等地进行引种试验和扩大引种试验表明，该树种生长量以第7年最大，金华和绍兴品种结果多，产量高；山站2号和兴林13号各项丰产指标均低，株产量少；结实大小年明显，金华品种为2年一周期，绍兴为3年；与原产地浙江相比，品质较好；在中亚热带生长和开花结实表现很好。美国山核桃与国内外在良好管理条件下的产量和质量基本相同，适宜于云南省栽培。从而为云南省增添了一个新的经济林木树种，填补了核桃分布下限没有好的油料干果树种可供发展的空白。     

不同修枝措施对樟子松母树生长与结实的影响

通过对樟子松无性种子园的母树进行截顶、疏枝、截轮枝处理,改变树木的形态结构,促进树势的恢复.结果表明,疏枝处理对樟子松的高生长、胸径生长及结实量均有一定促进作用,有利于樟子松的后续生长.     

湿地松无性系种子园生长及结实性状初步分析

为提高湿地松种子园的产量,以荆门市彭场林场一代去劣湿地松无性系种子园为研究对象,对其生长状况和结实性状进行调查,分析不同无性系生长和结实性状的差异性,并筛选出高结实无性系。结果表明：不同无性系间胸径、冠幅、球果长度、球果直径、球果径高、单株球果总产量和单个鲜果重均存在极显著差异(sg＜0.01),而单果出种量的差异不显著(sg=0.366);选出排名前3位的高结实无性系,结实量较均值提高了2倍多;根据差异分析的结论,为现阶段优良无性系初步筛选提供方向。     

间作花生对幼龄栗园生态因子影响的研究

】本文对幼龄板栗——间作花园生（样地）和单一板栗园（对照地）进行生态因子的同步测定，结果表明，间作花生有利于改善栗园生态环境，能促进幼龄栗树正常生长、早期丰产、结果。     

史密斯桉实生种子园建设初报

史密斯桉实生种子园由该树种的家系试验林经疏伐改建而成。在史密斯桉种源、家系选择试验阶段评选出优良种源2个，优良家系20个，优良种源中选率28．6％，优良家系中选率22．7％。种源蓄积量遗传力0．869，家系蓄积量遗传力0．609，单株遗传力0．986，进行单株、种源选择优于家系选择。优良种源遗传增益0．246，优良家系遗传增益0．276，家系平均实际增益45．3％。优良家系与较差家系木材密度无显著差异。家系试验林经两次疏伐改建为种子园后，每公顷保留林木340株左右。种子园促进史密斯桉植株开花结实试验的结果表明，经施肥及施用开花促进剂处理的家系开花结实率为对照的3倍，施肥及施用开花促进剂使植株开花结实提前，增加开花结实量有较好的作用。7．5年生，种子园个体平均开花结实率为24．6％，预计开花结实率每年将以15．5％的速度增加。开花结实率高的是18676、18688较差种源，开花结实率低的是18682、17131优良种源，较差种源开花结实率是优良种源的2．1倍。优良家系开花结实率65％，为全体家系平均开花结实率(28．6％)的2．3倍。较差种源比优良种源开花结实早，而在家系内是优良家系开花结实较早。