Recent progress and future prospects for mechanized harvesting of fruit crops with shaking systems

Mechanized harvesting technologies with shaking systems for fruit industry have been widely investigated and significantly developed over the past several decades which were presented by a large amount of literature.This paper reviews the research and development progress of mechanized harvesting of fruits systematically with a focus on the theoretical study,fruit crop variety,shaking system categories,abscission chemical agents,and their actual applications.Based on the comprehensive review,mechanized harvesting systems for different fruit crops appear multifarious shaking modes with various vibratory mechanisms and structural dimensions.Major advantages in the development of fruit mechanical harvesting with effective vibratory patterns and catching frames provide a series of economic and agronomic benefits,such as reducing labor costs,promoting standardized planting,and increasing productivity.However,fruit injury and tree damage are the main reasons why mechanical shaking systems are rarely used for fresh fruit harvesting because of tenderness and frangibility of the fruit crops.Therefore,more efforts should be concentrated on the innovative shake-and-catch system with suitable frequency and amplitude to achieve low fruit damage or even nondestructive harvesting for fresh fruit market.This overview summarized the advantages and bottlenecks of these shaking systems for fruit harvesting and proposed the challenges and some constructive prospective viewpoints aimed at the major issues of mechanical harvesting techniques.In addition,employing sorting technologies to classify the postharvest fruits provide a new direction for the further development of mechanized harvesting in high-value fruit crops,as well as bring more benefits to growers and increase their interest in equipment investment on the mechanical shaking harvester for the fruit industry.

Recent advances in fruit crop genomics

In recent years,dramatic progress has been made in the genomics of fruit crops.The publication of a dozen fruit crop genomes represents a milestone for both functional genomics and breeding programs in fruit crops.Rapid advances in high-throughput sequencing technology have revolutionized the manner and scale of genomics in fruit crops.Research on fruit crops is encompassing a wide range of biological questions which are unique and cannot be addressed in a model plant such as Arabidopsis.This review summarizes recent achievements of research on the genome,transcriptome,proteome,miRNAs and epigenome of fruit crops.

不同处理对大棚草莓连作土壤理化性质和果实品质的影响

为了探讨不同处理对大棚草莓连作土壤和果实品质的影响,以未处理为对照(CK),研究了甜玉米轮作、棉隆消毒、生物炭利用、菌渣混土等7个不同修复技术对处理后土壤理化性质、植株生长、果实品质、产量的影响。结果表明:甜玉米轮作处理(T1)土壤含水量、容重最高,EC值最低,养分含量除了全氮、全钾、碱解氮、有效锌外最低,盐分离子含量均低于CK;小麦秸秆炭处理(T3)土壤含水量、容重较低,EC值最高,pH值高于CK,有机质、全磷、有效磷、有效铜、有效锌含量最高,盐分离子含量除了F-和Cl-外均高于CK;T1草莓植株生长指标高于CK,单果重、单株产量高,果实硬度大,可溶性固形物含量高,糖酸比、固酸比最高。综上所述,T3可有效改善土壤板结和酸化,减少养分损失;T1土壤保水性好,养分利用率高,可消耗部分过多养分,减轻土壤富营养化,减缓连作土壤次生盐渍化,促进植株健康生长,提高果实品质和产量。

不同土壤处理对重茬地苹果幼树生长结果的影响

重茬栽培存在重茬障碍问题,严重影响苹果幼树的生长发育。作者研究不同土壤处理对重茬地苹果幼树生长结果的影响。结果表明,不同土壤处理均有较好效果,明显提高果树成活率、促进树体生长发育、提高果实产量和品质。其中,多菌灵+菌肥、棉隆熏蒸+菌肥、客土3个处理的效果最好,可在实际生产中推广应用。

Branched Secondary Alcohol Ethoxylate, Ammonium Thiosulfate, Calcium Polysulfides-Thiosulfate, and Fish Oil Effects on Blossom Thinning, Fruit Set and Quality of Peaches and Nectarines

Total crop load has an inverse relationship with fruit size, while larger fruit size is often demanded by the peach and nectarine markets. Hand-thinning is extremely expensive, and thus, crop load adjustment, using blossom thinners is a crucial practice to ensure production of commercially acceptable fruit size and yield efficiency in stone fruit. In this study, the influence of branched secondary alcohol ethoxylate (Tergitol TMN-6) and/or ammonium thiosulfate (ATS), Crocker Fish Oil (FO), and a mixture of calcium polysulfides and thiosulfate (lime sulfur) on fruit set and quality attributes in peaches (Prunus persica) and nectarines (P. persica var. nectarina) were studied. All blossom thinners reduced fruit set in “Summer Lady” peach in both 2016 and 2017. Fruit sets in “Summer Lady” peach trees with a double application of Tergitol TMN-6 at the rate of 7.5 or 10 mL ·L¯1, each rate applied at 40% and 80% bloom, were lower than those receiving the same rates of this chemical only at 80% bloom, but they were similar to those receiving a single Tergitol TMN-6 spray at 15 mL·L¯1 at 80% or 100% bloom. “Summer Lady” peach trees receiving FO at 20 mL·L¯1 plus lime sulfur at 25 mL·L¯1, once at 40% bloom and again at 80% bloom had lower fruit set as compared to Untreated Control but the fruit set was higher than those with any Tergitol-TMN-6 spray. Tergitol TMN-6 at 12 m·L¯1 at 100% bloom or 10 mL·L¯1 all stages of bloom reduced fruit set in “Zee Lady” and “Snow Giant” peaches. In “Snow Giant” peach, trees receiving Tergitol TMN-6 at all concentrations and blossom stages had significantly higher fruit weight as compared to the trees of Un-treated Control. Applications of Tergitol TMN-6 at all concentrations at 80% bloom reduced fruit set in “Red Globe” and “Elberta” peaches in Utah. ATS and FO slightly reduced fruit set in peaches but they were less effective than Tergitol TMN-6 in all cases. Overall, it is concluded that efficacy of blossom thinners depends on the rate of thinners, temperature, cultivar and stage of bloom development.

Growth simulation and yield prediction for perennial jujube fruit tree by integrating age into the WOFOST model

Mathematical models have been widely employed for the simulation of growth dynamics of annual crops,thereby performing yield prediction,but not for fruit tree species such as jujube tree(Zizyphus jujuba).The objectives of this study were to investigate the potential use of a modified WOFOST model for predicting jujube yield by introducing tree age as a key parameter.The model was established using data collected from dedicated field experiments performed in 2016-2018.Simulated growth dynamics of dry weights of leaves,stems,fruits,total biomass and leaf area index(LAI) agreed well with measured values,showing root mean square error(RMSE) values of 0.143,0.333,0.366,0.624 t ha^-1 and 0.19,and R2 values of 0.947,0.976,0.985,0.986 and 0.95,respectively.Simulated phenological development stages for emergence,anthesis and maturity were 2,3 and 3 days earlier than the observed values,respectively.In addition,in order to predict the yields of trees with different ages,the weight of new organs(initial buds and roots) in each growing season was introduced as the initial total dry weight(TDWI),which was calculated as averaged,fitted and optimized values of trees with the same age.The results showed the evolution of the simulated LAI and yields profiled in response to the changes in TDWI.The modelling performance was significantly improved when it considered TDWI integrated with tree age,showing good global(R2≥0.856,RMSE≤0.68 t ha^-1) and local accuracies(mean R2≥0.43,RMSE≤0.70 t ha^-1).Furthermore,the optimized TDWI exhibited the highest precision,with globally validated R2 of 0.891 and RMSE of 0.591 t ha^-1,and local mean R2 of 0.57 and RMSE of 0.66 t ha^-1,respectively.The proposed model was not only verified with the confidence to accurately predict yields of jujube,but it can also provide a fundamental strategy for simulating the growth of other fruit trees.

不同滴灌带布设方式对苹果-大豆间作系统土壤化感物质与微生物的影响

为探究不同滴灌带布设方式对果农间作系统土壤酚酸类物质、酶活性和微生物分布特性影响,初步探明间作滴灌条件下,土壤酚酸类物质与土壤生物因子的相互关系。以晋西黄土区典型的苹果—大豆间作系统为研究对象,设置3种(L1、L2、L3)滴灌带间距,分析不同水分分布下土壤酚酸类物质、酶活性和微生物数量的空间分布变化,并在相关性基础上利用逐步回归模型,分析3个土壤因子之间的相互关系。结果表明:除苯甲酸和间苯三酚外,滴灌带间距对酚酸类物质分布影响显著(p<0.05),除过氧化氢酶外,滴灌带间距对酶活性、微生物数量分布有显著影响(p<0.05)。在垂直方向上,不同滴灌带布设方式使酚酸更多地分布在深层土壤,微生物数量和部分酶活性在L1、L2处理中随土层加深而先减后增;在水平方向上,不同滴灌带布设方式对土壤酚酸类物质、细菌和真菌分布影响与间作对照处理一致,随距树距离增加而增加。滴灌条件下,除对羟基苯甲酸外,酚酸类物质受脲酶、过氧化氢酶和放线菌的抑制作用显著,间作处理土壤酚酸总量较单作有所减少。L1处理土壤酶活性、微生物总量最高,L2处理土壤酚酸类物质累积量最低。其中L2处理在酚酸累积量最低的基础上,土壤酶活性也处于较高水平,因此,建议在果农间作系统中采用隔行大豆布设滴灌带模式,改善土壤微生态环境的同时可缓解化感物质的抑制作用。

不同负载量对金陵黄露桃产量和果实品质的影响

为探讨不同负载量对桃产量和果实品质的影响,以自然开心形树形的金陵黄露桃为试材进行了连续3年的试验。试验采用随机区组设计,设4个处理:T1,留果约150个/株;T2,留果约250个/株;T3,留果约300个/株;T4,留果约350个/株,单株重复,每处理重复6次。结果表明:T4处理产量较高,但单果重最低;T1处理产量最低,但单果重最高;T2处理产量相对较低,但单果重相对较高;T3处理产量相对较高,但单果重相对较低。T1处理果实可溶性固形物含量和糖酸比均较高。T2和T3处理果实内在品质均略低于T1处理。负载量对果实着色程度影响不显著。可见,盛果期金陵黄露桃负载量为每株约150个果实时(每667 m^(2)产量约1300 kg),产量较低,但可生产出较大果个的果实,品质较好;每株250~300个果实时(每667 m^(2)产量2000~2400 kg),可保证较高的产量和较大的果个。

Indigenous Fruit Trees of Tropical Africa: Status, Opportunity for Development and Biodiversity Management

Tropical fruit trees constitute important biological resources in the global agrobiodiversity context. Unlike the tropical fruit trees of American and Asian origin, indigenous fruit trees (IFT) of tropical Africa have scarcely achieved the status of international recognition in commodity markets and research arena outside Africa. This paper presented a critical review of the status of IFT in the Tropical African sub-regions (of West Africa, Central Africa, East Africa, Southern Africa and the Indian Ocean Islands) in relation to the introduced naturalised fruit trees from tropical America and Asia, threats to the diversity and sustainable use of IFT, analysis of the opportunities and challenges of developing IFT, as well as targets for crop improvement of the rich IFT of Tropical Africa. Domestication programme via relevant vegetative propagation techniques for priority IFT of the sub-regions was examined and advocated, in addition to the adoption of complementary conservation strategies, including Field GeneBanks in the management of the continent’s IFT diversity.

负载量对高接瑞香红苹果果实生长和品质的影响

【目的】通过探究负载量对苹果新品种瑞香红高接树的果实生长、果实品质以及经济效益的影响,为高接瑞香红苹果树的适宜负载量提供依据。【方法】以高接第5年的瑞香红苹果树为材料,应用干截面积法设计3种负载量处理,以最大负载量为对照,T1:3.0个·cm^(-2)TCSA(树干横截面积,trunk cross-sectional area);T2:2.0个·cm^(-2)TCSA;T3:1.3个·cm^(-2)TCSA;CK:4.3个·cm^(-2)TCSA,测定每种负载量下果实纵横径增长速率、果实外观与内在品质、果实香气物质含量,根据果实产量与分级标准预估每种负载量下的经济效益。【结果】随着负载量降低,果实生长速率、大型果所占比率、平均单果质量、翌年开花数量、果面a值,以及可溶性固形物、果糖、葡萄糖、香气物质含量均表现出增加趋势;果实的产量、硬度、蔗糖含量表现出降低趋势;果实的果形指数、果面L值、果面b值、可滴定酸含量无显著变化;预估经济效益先增高后降低。【结论】低负载量下果实生长速率较快,果实品质较好,但产量与经济效益较低;提高负载量虽然能增加产量,但会降低果实品质,综合来看,高接第5年的瑞香红苹果树以3.0个·cm^(-2)TCSA的负载量较为适宜。

园艺作物果实苹果酸代谢与转运及其调控研究进展

番茄、苹果、梨、枣等园艺作物是典型的苹果酸型果实,其果实酸度主要取决于液泡中苹果酸的积累量。苹果酸不仅决定果实的风味品质,还可作为呼吸底物为植物体提供必需的物质和能量,在调节植物细胞渗透势、酸碱平衡、抗逆性等方面起着重要作用。苹果酸代谢途径比较复杂,涉及众多结构催化酶的参与,而苹果酸主要贮存于液泡中,从细胞质向液泡的跨膜运输和储存是复杂的生物学过程,需要多种转运蛋白、质子泵的参与。总结了苹果酸型果实酸度性状遗传研究、转运蛋白及质子泵在苹果酸跨膜转运中的作用,并将转录因子对苹果酸的代谢调控进行了概述,以深入理解苹果酸代谢调控网络,为园艺作物品质育种提供理论基础。

三种胡麻生长模型对现蕾期和青果期干旱胁迫响应能力的比较

本研究利用不同胡麻品种、不同干旱程度的大田试验数据,检验、评估3种作物模型干旱胁迫效应算法的精确性,及其在现蕾期、青果期干旱胁迫处理下对胡麻蒸腾速率、气孔导度、叶面积指数及籽粒产量4个指标的模拟预测能力。模拟结果表明,干旱胁迫使胡麻蒸腾速率、气孔导度、叶面积指数和籽粒产量降低。3种作物模型干旱胁迫效应算法可以模拟出胡麻生理生化指标在各干旱处理下的变化趋势,但模拟效果不够理想。3种干旱胁迫效应算法均低估了籽粒产量。综合考虑,WOFOST模型干旱胁迫效应算法对籽粒产量、蒸腾速率的模拟效果最好,APSIM模型干旱胁迫效应算法对气孔导度的模拟效果最好,DSSAT模型干旱胁迫效应算法对叶面积指数的模拟效果最好。

基于深度学习的苹果图像语义分割方法研究

针对现有语义分割方法存在分割速度慢、精度低等不足,通过结合MobileNet模块、深度可分离卷积DSC以及CBAM注意力机制,提出一种基于改进的DeepLabv3+网络的苹果图像分割方法,可用于苹果自动化采摘工作中苹果果实的定位。通过实验探究腐坏程度、腐坏位置、苹果品种以及复杂背景等因素对苹果图像语义分割性能的影响,同时验证该方法的鲁棒性。

水分胁迫对果树光合作用及同化代谢的影响研究进展

综合有关文献从水分胁迫对果树的净光合速率、干物质积累和分配、气孔反应、光抑制、光合色素、光合酶活性、氧化物质代谢、呼吸以及叶绿素荧光等几个方面的影响进行了分析总结。并认为今后应加强多因子相互作用、多循环胁迫的研究;还应扩大研究对象,筛选适宜的树种(品种)和抗水分逆境的生理指标;同时还要加强与呼吸作用和荧光反应生化分析等方面研究的结合。

落叶果树需冷量及其机理研究进展

落叶果树需冷量的准确估算是果树栽培尤其是果树促成栽培中的一个关键因素,直接关系到果树促成栽培的成败。综合有关文献,介绍了落叶果树需冷量的概念、估算方法、研究现状、生物学机制和存在问题。低温可以诱导休眠,休眠解除需要低温积累,从植物生理学和分子生物学角度阐述了落叶果树需冷量的机理。并对缩短落叶果树自然休眠期的可能途径从育种、施用外源化学药剂、环境调控3个方面进行了初步探讨。

我国果树多倍体育种研究进展

综合有关文献对主要果树多倍体的现状、果树多倍体育种的途径及其取得的成就、果树多倍体的鉴定、果树多倍体育种中应注意的问题进行了系统的阐述。果树多倍体育种的途径主要有利用对自然变异的选择获得多倍体、利用人工诱变获得多倍体、利用有性杂交培育多倍体、利用胚乳培养获得多倍体和利用原生质体融合培育多倍体;对多倍体的鉴定可以从形态特征、解剖结构、生理生化特性和染色体数目观察等方面来考虑;在今后的果树多倍体育种中应注意确定合适的倍性作为育种目标、重视多倍体种质资源的创新与应用、重视对多倍体嵌合类型的分离纯化、注意利用现代新技术提高育种效率、要加强对多倍体育种中有关问题的研究。

矮生樱组3个野生种果实性状的变异

对分布于山东胶东昆嵛山区的欧李、麦李及郁李3种野生樱桃207个实生单株果实性状的变异进行了初步研究,旨在为资源的保护与利用提供科学依据。结果表明:(1)欧李和麦李果实成熟期主要集中在7月中、下旬,个别早熟或晚熟类型的果实成熟期分别在7月初和9月中下旬,而郁李果实成熟期主要集中在9月份,个别晚熟类型在10月下旬成熟;(2)3个种果实(果核)纵径和横径及果(核)形指数在种内的变异系数均小于15%,是相对稳定的植物学性状;(3)单果质量、果柄长度、果实Ca与可溶性固形物含量在种内不同类型间存在较大的遗传变异,变异系数均在20%以上,遗传多样性极为丰富。

盐胁迫对果树光合生理的影响

结合我们相关的研究结果综述了盐胁迫对果树光合作用的影响。总体来说盐胁迫导致果树净光合速率下降,且这种作用受树种、品种、砧木以及盐的种类、浓度和处理时期的影响;盐胁迫还使叶片干物质积累下降并影响碳水化合物的组成。盐逆境所产生的渗透胁迫和离子毒害而引起的气孔性限制和非气孔性限制则是果树叶片净光合速率下降的原因。此外,盐胁迫使果树叶片的叶绿素荧光效率下降。文章最后还提了出今后研究果树盐胁迫与光合作用的关系应与实际的生产环境相结合。

赤霉素在落叶果树生产中的应用

赤霉素在落叶果树上应用范围很广,具有诱导无子果实的形成、提高座果率、改善果实品质、防止落花落果、促进果实早熟、延迟果树花期、增加果品贮藏能力和打破休眠的调控作用。文章对其研究进展和作用机理进行了简要概述。

一种木本果树基因组DNA提取方法研究

研究了一种可有效排除细胞内多酚类等杂质污染的简便、快捷、经济的果树基因组ＤＮＡ提取方法．其改良策略是：在细胞核被裂解前去除细胞质中的多酚类等杂质，防止多酚类物质被氧化，从而排除多酚类等杂质的干扰．利用这一方法提取的柑桔、枇杷、梨、苹果、湖北海棠、桃、樱桃等７种果树基因组ＤＮＡ均能被限制性内切酶完全消化，获得理想的Ｓｏｕｔｈｅｒｎ杂交结果，也可作为ＰＣＲ模板应用，成功地进行特异性基因扩增和ＲＡＰＤ．