Economic impacts of bird damage and management in U.S. sweet cherry production

Bird damage is a common and costly problem for fruit producers, who try to limit damage by using management techniques. This analysis used survey data from producers in five U.S. states to estimate bird damage to sweet cherry (Prunus avium) crops with and without the use of bird management. A partial equilibrium model was applied to the data to estimate the change in the marginal cost of production resulting from disuse of bird management. The model incorporates both decreased yield and elimination of management costs. A welfare analysis was conducted with short and long run supply elasticities derived from time-series data using geometric distributed lags. With no bird management, total surplus in the United States decreases by about $185 to $238 million in the short run and $21 to $29 million in the long run, indicating that bird management has a large impact on cherry production and associated market outcomes, including price and consumption.     

Bird damage to select fruit crops: The cost of damage and the benefits of control in five states

Fruit loss to birds is a long-standing and costly problem for many producers. We conducted a survey of Honeycrisp apple, blueberry, cherry, and wine grape growers in California, Michigan, New York, Oregon, and Washington to estimate costs of bird damage and benefits of bird damage management. We also assessed grower perceptions of impacts on profits and effectiveness of bird management techniques. Current yield-loss estimates provided by growers and market price data were used to monetize current bird damage in each crop and growing region. Data on expected damage without management were used to estimate the benefits of bird damage management as it is currently being employed in the different crops and growing regions. We estimated that current bird damage costs per hectare ranged from $104 in Oregon tart cherries to $7267 in Washington Honeycrisp apples. Estimated benefits of bird management ranged from $299 per hectare in Oregon tart cherries to $36,851 in California blueberries. Aggregate bird damage in the five crops and states was estimated at $189 million, and the aggregate benefits of managing that damage were estimated at $737 million to $834 million. Growers viewed most techniques for bird damage management as ineffective, or only slightly effective, and a majority of blueberry and sweet cherry growers viewed bird damage as having a significant impact on profits. Enhancing the effectiveness of bird damage management would increase both the efficiency and profitability of fruit production.     

Proportions of bird damage in tree fruits are higher in low-fruit-abundance contexts

Frugivorous birds impose significant costs on tree fruit growers through direct consumption of fruit and grower efforts to manage birds. We documented factors that influenced tree fruit bird damage from 2012 through 2014 with a coordinated field study in Michigan, New York, and Washington. For sweet cherries, percent bird damage was higher in 2012 compared to 2013 and 2014, in Michigan and New York compared to Washington, and in blocks with more edges adjacent to non-sweet cherry land-cover types. These patterns appeared to be associated with fruit abundance patterns; 2012 was a particularly low-yield year for tree fruits in Michigan and New York and percent bird damage was high. In addition, percent bird damage to sweet and tart cherries in Michigan was higher in landscapes with low to moderate forest cover compared to higher forest cover landscapes. 'Honeycrisp' apple blocks under utility wires were marginally more likely to have greater bird damage compared to blocks without wires. We recommend growers prepare bird management plans that consider the spatial distribution of fruit and non-fruit areas of the farm. Growers should generally expect to invest more in bird management in low-yield years, in blocks isolated from other blocks of the same crop, and in blocks where trees can provide entry to the crop for frugivorous birds.     

不同龙眼品种果实成熟时糖含量及其特征研究

通过测定37个龙眼品种果实成熟时假种皮中可溶性糖含量,比较不同龙眼品种的糖组分特点与差异。使用高效液相色谱法对糖组分含量进行测定,采用相关性分析和聚类分析法对数据进行分析,将37个龙眼品种进行分类。结果显示,37个龙眼品种果实假种皮在成熟时期TSS含量在16.84%~27.34%之间,假种皮中可溶性糖主要为蔗糖、葡萄糖和果糖,其中蔗糖含量明显高于含量相当的葡萄糖和果糖。相关性分析表明,龙眼果实可溶性固形物(TSS)含量与甜度和总糖含量呈极显著正相关,甜度和总糖含量亦呈极显著正相关。根据不同品种龙眼果实假种皮中蔗糖/己糖的比例可将37个龙眼品种分为蔗糖积累型、中间类型和己糖积累型。     

荔枝资源果实成熟进程中糖、酸变化

为探讨荔枝品种资源果实成熟期间的糖、酸变化特点,对15份荔枝品种资源果实成熟进程中假种皮的糖、酸含量变化及其完熟果的还原糖、蔗糖含量进行分析。结果表明,15份荔枝资源果实成熟进程中的糖的变化可分为还原糖积累型和蔗糖积累型2大类,其中还原糖积累型又可分为4个亚类;不同品种资源间,完熟果的还原糖、蔗糖含量差异显著,还原糖的含量在67.50~118.63 mg/g,蔗糖的含量在13.60~93.27 mg/g,大部分的荔枝资源其果实主要积累还原糖;荔枝果实假种皮的可滴定酸含量在成熟的前期急剧下降,后期变化趋缓;以完熟果的各糖分指标进行聚类分析可将15份荔枝资源分为2个类群5个组群。     

几种植物生长物质对毛叶枣果实品质的影响

用浓度分别为20,50mg/L的GA3,NAA,ABA,6-BA涂抹谢花40 d后的毛叶枣(Zizyphus mauritiana Lam.)幼果.果实成熟后,测定果实的相关品质.结果表明:(1)20mg/LAA能够显著提高毛叶枣果实维生素C、可溶性固形物、蔗糖和有机酸的含量,但对单果重没有影响;20mg/L 6-BA也能提高果实维生素C、可溶性总糖和蔗糖的含量,但降低了单果重、葡萄糖和果糖的含量;20 mg/L ABA能促进果实增大,提高果实可溶性总糖和有机酸的含量;20 mg/L GA能增加有机酸的含量,但降低了含糖量、单果重及维生素C.(2)50 m/LNAA处理能提高果实所有品质的含量;50 mg/L ABA和6-BA都能提高含糖量及有机酸,但降低了单果重和维生素C含量;50mg/L GA能增加单果重、有机酸,但降低了含糖量和维生素C.综合结果表明,20mg/L浓度处理优于50 mg/L,而且NAA处理对提高毛叶枣果实品质效果比GA3,ABA,6-BA的好.     

毛叶枣果实发育过程中糖分的积累规律

研究高朗1号、新世纪、蜜枣和缅甸长果4个毛叶枣品种果实发育过程中可溶性糖分的组成及其变化.结果表明:毛叶枣果实可溶性糖组分主要是蔗糖、葡萄糖和果糖;在果实发育初期,糖含量少,果实中蔗糖积累始于果实膨大中后期,直至成熟期;高朗1号、新世纪果实中果糖与葡萄糖的积累规律较相似,其含量变化不明显;蜜枣和缅甸长果果实中果糖的积累速度明显快于葡萄糖的.     

菠萝果实发育过程中糖积累与其代谢酶的关系

以菠萝[Ananas comosus(L.)Merr.]"巴厘"和"台农11号"两个品种为试验材料,测定不同发育时期果实中蔗糖、葡萄糖和果糖含量以及蔗糖代谢相关酶--酸性转化酶(AI)、中性转化酶(NI)、蔗糖合成酶(SS)和蔗糖磷酸合成酶(SPS)的活性,并对果实中糖积累与酶活性的关系进行分析.结果表明:2个品种果实中糖积累动态十分相似,即果实发育前期,糖积累缓慢;进入成熟期,蔗糖迅速积累,而己糖"巴厘"果实中前期变化较少,后期稍有积累,"台农11号"果实中前期稍有积累,后期基本不变.2个品种果实中蔗糖含量与SS和SPS活性相关系数分别达到正的显著或极显著水平,NI活性与2个品种果实中蔗糖含量呈极显著负相关,蔗糖含量与AJ的活性相关性品种间差异明显.     

腐植酸浸种对盐胁迫下小麦萌发种子及幼苗生理特性的影响

为研究盐胁迫下腐植酸浸种对小麦幼苗生理特性的影响,采用春小麦品种龙麦26和克旱16为试验材料,分别用清水和腐植酸浸种,测定了NaCl胁迫下萌发种子的α-淀粉酶活性、幼苗根系和叶片的总可溶性糖、蔗糖和果糖含量,以及浸出液的电导率。结果表明,盐胁迫下萌发种子的α-淀粉酶活性降低,幼苗根冠比增加,但幼苗整体鲜重降低,叶片和根系浸出液电导率增大,总可溶性糖含量增加,叶片蔗糖和果糖含量增加,根系蔗糖含量降低。腐植酸浸种降低了α-淀粉酶活性,增加了叶片总可溶性糖和根系蔗糖含量,减少了根系总可溶性糖和叶片蔗糖含量,降低了叶片和根系浸出液电导率。推测腐植酸浸种可能是通过调控果糖浓度变化,缓解了盐胁迫下小麦幼苗的质膜损伤。     

3个品种香蕉果实中糖酸组分及含量的比较分析

用高效液相色谱(HPLC)法测定皇帝蕉(贡蕉)、巴西蕉和粉蕉成熟果实中糖酸组分及含量。结果表明,成熟果实中均含有蔗糖、葡萄糖和果糖,并以积累蔗糖为主,皇帝蕉(贡蕉)、巴西蕉和粉蕉果实中蔗糖含量分别占总糖的59.76%、66.18%、68.69%,总糖含量大小表现为,皇帝蕉>巴西蕉>粉蕉;均含有11种有机酸,以苹果酸为主,含量分别占总酸的51.71%、47.30%、46.68%,同时含有大量的柠檬酸,分别占总酸的18.13%、19.62%和19.96%,并富含多种有机酸,总酸含量大小是粉蕉>巴西蕉>皇帝蕉。     

不同龙眼品种果实退糖特性分析

退糖在龙眼果实过熟时出现,是影响龙眼果实品质的重要原因之一,不同品种龙眼果实过熟时退糖的速度不同。本研究通过比较32个龙眼品种果实退糖的时间和退糖过程中糖含量的变化,利用统计分析进行分类并分析这些龙眼品种果实的退糖特性。结果表明:(1)根据退糖发生时间可将32个龙眼品种分为四大类型:极快退糖、快退糖、慢退糖和极慢退糖品种,其退糖时间分别为5~8、10~11、15~16 d和20 d;(2)成熟时龙眼果实TSS含量的高低与退糖速度无关;(3)龙眼果实的退糖主要是由于蔗糖含量的大幅度下降;(4)依据蔗糖含量的下降速率进行聚类,可将32个品种龙眼分为3个类型:极快退糖型、快退糖型、慢退糖型,3个类型品种与按退糖时间的分类基本相似。     

遮荫对胡椒主花期叶片碳代谢及成花量的影响

为探明胡椒主花期适宜光照强度,以确定胡椒主花期与搭配作物适宜间作密度,研究分析4种荫蔽度条件下,胡椒主花期完全展开叶的光合作用、可溶性糖、蔗糖、淀粉等的积累,相关代谢酶活性及成花量,探究光照和碳水化合物积累对开花量的影响。研究结果表明：30％荫蔽度处理下胡椒主花期开花量没有被显著抑制,而且在树体恢复期和主花期前期可溶性糖积累明显增加,相关性分析显示,花枝上叶片糖积累对随后的成花有极显著正效应,而糖积累与蔗糖磷酸合成酶活性呈显著负相关。研究认为,在树体恢复期和主花期前期,搭配作物对胡椒遮荫的荫蔽度为30％左右时,可以促进糖积累,为花芽发育提供充足的物质基础,以保证胡椒与搭配作物间作时主花期花量。     

A review and synthesis of bird and rodent damage estimates to select California crops

A comprehensive literature review was conducted to identify the magnitude of bird and rodent damage to 19 economically important crops in California. Interviews with agriculture experts provided additional information about damages. Monte Carlo simulations were used to derive summary estimates of damages to each crop. A meta-analysis indicated that summary damage estimates from expert interviews were higher than estimates from field studies and surveys. It was also found that there has been a downward trend over time in damages to almonds and grapes. The results of our study indicate that damages from bird and rodents remain high for many crops and are likely to be economically significant within the state of California.     

荔枝果实发育过程中果皮颜色形成的相关分析

以着色较差的妃子笑(LitchichinensisSonn.cv.Feizixiao)和着色较好的白糖罂(LitchichinensisSonn.cv.Baitangying)果实为材料,研究了二者果实发育过程中叶绿素、花色素苷、可滴定酸、pH和糖的变化规律,探讨了这些指标与果实着色之间的关系。结果表明:果实发育中后期,白糖罂果实的着色指数一直高于同期的妃子笑果实。白糖罂花色素苷含量增加早且含量高,叶绿素含量下降快且含量低,花色素苷与叶绿素含量比值高。果实发育过程中,2个品种果皮的可滴定酸、可溶性糖、还原性糖、葡萄糖含量总体呈下降趋势,而pH、果糖含量呈上升趋势。果实发育后期,白糖罂可溶性糖、蔗糖含量比妃子笑低。可滴定酸和pH与果皮着色指数极显著相关,果糖、葡萄糖及还原性糖分别与妃子笑果皮色素的1种或几种及着色指数显著或极显著相关,但糖的变化与白糖罂色素含量及着色指数没有显著相关关系。     

云南蔗区3个主栽品种霜冻后的糖分变化

对2013年云南省弥勒市朋普蔗区3个主栽品种ROC22、闽糖69-421和云蔗03-258在霜冻轻度冻伤后的糖分变化进行了检测分析。结果表明,经霜冻轻度冻伤40d内,闽糖69-421的蔗糖分最高,云蔗03-258的最低；闽糖69-421还原糖分最低,ROC22最高。闽糖69-421在霜冻后糖分下降较云蔗03-258快,云蔗03-258还原糖增加较闽糖69-421快,ROC22的糖分则继续增加,还原糖也继续下降。本研究结果可为霜冻对不同甘蔗品种的影响研究提供新的数据,同时为甘蔗生产管理提供参考依据。     

不同渗糖技术对龙滩珍珠李果脯品质及果实细胞结构的比较

本文以龙滩珍珠李为原料,采用常压、真空、微波和超声波4种渗糖技术加工果脯,研究不同渗糖技术对龙滩珍珠李果脯感官品质、理化营养品质、质构特性以及对龙滩珍珠李果实细胞结构的影响。结果表明：真空渗糖制备的龙滩珍珠李果脯色泽最佳、褐变度最低（1.95）,Vc含量最高（58.33 μg/g）,总糖含量较低,但组织状态和口感差;微波渗糖得到的果脯色泽最差,褐变度最高（3.18）,Vc含量最低（41.34 μg/g）,且均与常压处理存在显著性差异（P<0.05）,硬度、咀嚼性、弹性和胶着性均最低,分别为508.33 g、10.57 mJ、3.44 mm和256.33 g;超声波渗糖获得的龙滩珍珠李果脯感官总分、总糖含量、硬度、咀嚼性、弹性和胶着性均为最高,分别为82.13分、49.22%、868.33 g、16.00 mJ、3.68 mm和452.33 g,显著高于常压处理的（P<0.05）,复水率最低（106.48%~128.66%）,且明显降低了对龙滩珍珠李果实细胞结构的破坏。可见,超声波渗糖技术对龙滩珍珠李果脯品质及果实细胞结构的保护效果最好。     

硫酸钾不同施肥方法对菠萝果实发育过程中糖含量及相关酶活性的影响

以栽培管理条件一致的‘巴厘’菠萝为试材,研究钾肥的不同处理对菠萝果实发育过程中糖分组成、含量以及蔗糖代谢相关酶活性的影响。结果表明,钾肥处理提高了菠萝果实内果糖、葡萄糖和蔗糖含量。果实不同发育时期,不同处理对果实蔗糖代谢酶的变化具有不同影响,但总的变化趋势是一致的,均表现为随着果实的逐步成熟、糖逐渐积累,转化酶活性、蔗糖合成酶(SS)活性由低到高逐步上升,蔗糖磷酸合成酶(SPS)活性先升高后降低。不同处理均增加了果实转化酶和蔗糖合成酶分解活性,降低了果实的蔗糖磷酸合成酶和蔗糖合成酶合成活性。其中以喷施K2SO4和土施K2SO4混合使用对果实糖含量和相关酶活性的影响效果最好,其次为喷施K2SO4,土施的效果不明显。表明,在土施和喷施2种方法一起使用时,果实是通过改变4种酶的活力来提高库强度。果实库强度增加的同时,相应地促进了同化产物的运输。     

用基因操作法改良糖甜菜（英）

甜菜的产糖量占世界蔗糖产量的４０％，从碳同化角度来说，甜菜是极高效的温带作物之一，但用基因操作法仍有提高其产质量的潜力。对甜菜贮藏器官发育过程的解剖、生理和蔗糖积累的研究，为制定增加产量和减少环境对甜菜生长影响的策略奠定了理论基础。为促进对发育操作过程以达到上述这些目标，必须增强对细胞分裂的调节机制的认识。我们先研究植物激素限定细胞分裂的方式，随后研究调节细胞分裂的一些分子生物学特征。目前，我们已分离和鉴定了一些与甜菜细胞周期相关的基因序列，并用甜菜细胞悬浮培养对这些与细胞分裂调节相关的基因表达进行了研究，细胞分裂调节基因特定位点表达的策略已被确定，进一步优化甜菜转化系统的研究正日趋完善。通过这个途径，有希望获得高根产、高含糖、高汁液纯度和低环境影响的甜菜植株。     

低温胁迫对嫁接苦瓜幼苗渗透调节物质的影响

为研究低温胁迫对苦瓜嫁接苗渗透调节物质的影响,以中原共荣与苦砧 2 号 2 个南瓜品种作为砧木与翠柳2号苦瓜分别靠接的嫁接苗为试材,对照采用苦瓜自根苗,使用人工气候培养箱进行低温处理,对低温下两种不同砧木嫁接苗的冷害指数及可溶性蛋白、游离脯氨酸、可溶性总糖、葡萄糖、果糖、蔗糖含量的变化进行测定。结果显示：在低温胁迫下,嫁接苗的冷害指数极显著低于自根苗,说明嫁接可以缓解幼苗所受的低温伤害。在冷胁迫期间,可溶性蛋白、游离脯氨酸以及可溶性总糖嫁接苗显著高于自根苗;在冷胁迫前期,嫁接苗葡萄糖含量显著高于自根苗;果糖含量嫁接苗与对照差异不显著;蔗糖含量在低温胁迫过程中,嫁接苗均显著高于自根苗。苦砧 2 号在可溶性蛋白,游离脯氨酸以及可溶性糖的含量上均高于中原共荣,综合表现上苦砧 2 号的抗冷性优于中原共荣以及自根苗,说明嫁接苗在低温胁迫时能有效地提高此 3 类渗透调节物质含量,以此提高苦瓜幼苗的耐冷性,而在冷胁迫前期正向响应的可溶性糖中的主要成分是葡萄糖,蔗糖在整个耐冷胁迫期间均表现了正向作用。     

Cues used by house finches for detecting methiocarb-treated grapes

Laboratory tests were conducted to determine how house finches (Carpodacus mexicanus) detect and avoid bunches of grapes treated with the repellent methiocarb and to determine whether the presence of a visual tag paired with methiocarb-treated bunches facilitates this detection and avoidance. Individually caged birds were offered one untreated and one treated grape bunch during a series of 2 h preference feeding trials, and each bird's total consumption and its preference for the treated bunch were measured. When the positions of the treated and untreated bunches were alternated during successive feeding trials, house finches took just as much from the methiocarb-treated bunch as from the untreated bunch, but their total consumption declined. When the positions of the treated and untreated bunches were kept constant, total consumption initially declined but increased again to pretreatment levels as the birds learned to feed from the non-treated bunch. Consumption from the grape bunch on the side of the cage where the birds had previously encountered the repellent remained low even after methiocarb treatments ended. The visual tag had little effect on either total consumption or grape bunch preference. The implications of these findings for controlling bird damage to ripening grapes are discussed.