2020-2021年赣州市柑桔冻害调查分析

2020年12月-2021年1月,赣州市出现多次低温霜冻天气,对柑桔造成较严重冻害,为了解不同纬度、不同立地条件、不同品种、不同砧木、不同树势和不同防寒措施下的柑桔冻害情况,2021年2月对全市柑桔冻害进行了调查分析。结果表明,纬度方面,26°25′14″～27°2′44″之间的柑桔冻害最重;地形方面,洼地冻害最重,平地次之,坡地最轻;品种方面,抗冻性强弱为金秋砂糖桔>爱媛28（红美人）>纽荷尔脐橙>鸡尾葡萄柚,龙回红脐橙的抗冻性明显优于纽荷尔脐橙;砧木方面,枳砧纽荷尔脐橙的抗冻性强于枳橙的;树势方面,抗冻性强弱为强树>中庸树>弱树;采果时间方面,采果时间越早,抗冻性越强;树况方面,衰退病树冻害最重,黄龙病次之,正常树最轻;树龄方面,幼树冻害最重,老树次之,中年树最轻;防冻措施方面,树冠覆盖遮阳网、整园覆盖防虫网、薰烟+冻前灌水、单株套蛇皮袋+冻前灌水、主干刷白+冻前灌水等都有防冻作用,但相同防冻措施因所处区域和地形的不同,防冻效果存在较大差异。柑桔冻害主要发生在寒潮过后晴朗无风的凌晨,天气预报的最低温度高于果园实际的最低温度,当天气预报0℃左右时,晚熟柑桔果实即可能受冻。因此,赣州市纬度26°25′14″～27°2′44″区域,尤其是此区域的低洼地,不宜大面积发展脐橙和葡萄柚等不耐冻品种,全市大部分区域不宜发展果实需要越冬的晚熟品种。     

长寿区气象站与当地果园冬季温度的比较

【目的】长寿区是重庆市的重要晚熟柑橘基地,但近年来其丘陵地带的晚熟柑橘果实频繁遭遇冻害,而气象记录和预报的低温均不至于导致果实冻害,因此有必要了解冬季低温期间区气象站、果园观测站与柑橘树冠温度的差异,以及气象预报温度与柑橘树冠温度的差异。【方法】2013年12月至2014年2月,在长寿区龙河镇丘陵地带不同海拔高度的柑橘树冠上安装自动温湿度记录仪,在果园中部安置果园自动气象观测站,定时记录温度变化,将树冠实测温度与果园气象观测站、长寿区气象站记录的温度进行比较,利用线性回归建立相互间的温度关系模型。【结果】试验期间1月气象站、观测站实测温度与浅丘果园柑橘树冠日平均温度差异最大,晴天日平均温度差异明天大于阴雨天;测得的最低温度为气象站-0.1℃、观测站-2.0℃、浅丘上部树冠-3.4℃、浅丘中部树冠-3.7℃、浅丘底部树冠-4.3℃;测得出现低于-2℃的天数为气象站0天、观测站0天、浅丘上部树冠1.0天、浅丘中部树冠3.3天、浅丘底部树冠6.7天;果园不同海拔柑橘树冠温度（T）与气象站温度（Ta）的关系模型为浅丘上部树冠T1=1.104Ta-2.6437,浅丘中部树冠T2=1.1398Ta-3.2671,浅丘底部树冠T3=1.1883Ta-3.8931。当果园温度低于0℃时,气象站预报的最低温均明显高于树冠实测的最低温,而预报的最高温大多数低于树冠实测的最高温度。【结论】气象站最低温高于果园柑橘树冠最低温4.6℃、气象预报最低温高于果园柑橘树冠最低温6.7℃,当天气预报最低温为1.6℃左右时,浅丘底部的柑橘树冠最低温即可能低至-2℃而达到果实冻害温度,应采取防冻措施;而当气象站实测的最低温低于1.2℃并持续超过5h时,浅丘底部柑橘树上的果实即可能受冻。     

眉山晚熟柑橘冻害调查研究

2020年我国柑橘产区罕见遇到多年未有的低温天气,导致其树体和果实均遭受了不同程度的冻害。为了弄清不同区县、不同地形和不同品种柑橘树体和果实的冻害情况,我们于2021年2月对眉山5个区县不同果园和不同品种树体和果实进行了冻害调查,并与对应5个区县气象数据进行对比分析研究。结果表明,5个区县的冻害程度与低温密切相关,同期以仁寿县温度最低（-3.7℃）其柑橘树体和果实冻害最重,而丹棱县（-1.2℃）且日温差较差小冻害最轻。不同地形的树体和果实冻害程度由高到低依次为低洼>平地>山地。对于不同的地区和立地条件以及不同柑橘品种在低温来临前,采取不同的防寒措施促使树体和果实安全越冬。     

宜昌市柑橘冻害发生的气象特点及柑橘不同品种在冻害中表现和冻后恢复比较

【研究目的】全球升温趋势之下,极端温度变幅加大和低温造成的灾害性天气频率不减反增,2008、2011和2012宜昌柑橘产区部分或大面积发生不同程度柑橘冻害。本研究旨在增强人们对于冻害发生天气情况的了解,为柑橘产区品种规划及防寒减灾提供参考资料【方法】通过对宜昌市夷陵区历次柑橘冻害发生的气象资料统计和冻后实际调研情况分析,对最近几年冻害发生过程中不同柑橘种类和品种的表现及冻后恢复情况进行比较。【结果】发现历次大冻均发生于1月5日至1月31日之间,冻害程度与低温强度及低温持续时间呈现正相关。比较了柚、杂柑、椪柑、温州蜜柑和甜橙等不同柑橘种类在冻害中的表现,结果表明,受冻程度由重到轻依次为：杂柑→柚类→橙类→椪柑→温州蜜柑,离大水体远的果园受冻严重;坡向、坡位对冻害程度有影响。冻后恢复情况与树体冻害程度和冻后恢复能力有关,甜橙和柚冻害较重,但恢复能力较强,椪柑受冻虽然较甜橙和柚为轻,但冻后恢复较慢,而温州蜜柑冻害发生轻、冻后恢复也最快。【结论】在柑橘栽培北缘地区,因地制宜选择适宜品种、合理进行规划布局对柑橘产业健康发展极为重要。     

广西柑桔冰冻灾情调查及恢复措施

2008年1月12日至2月18日,广西壮族自治区连续遭受低温雨雪冰冻天气袭击。这次灾害性天气影响范围广、强度大、持续时间长,对柑桔生产造成极大的影响。广西柑桔受冻害主要在柳州市以北地区,晚熟柑桔果实直接受冻,树体受不同程度冻害,部分柑桔园甚至遭受毁灭性破坏。     

陕西·城固县柑桔冻后春季科技大培训工作全面展开

本刊讯(特约通讯员王博)去冬今春以来,城固县出现了31年一遇的寒冷天气,低温持续时间长达30余天,柑桔主产区最低气温达到-5℃以下有7天,最低气温达到-7℃有3天,极端最低气温达-7.9℃左右,给柑桔产业造成了严重伤害。据初步调查统计,目前全县因受冻发生枯枝干叶的桔园面积达到4533.33hm2,约占全县柑桔总面积的30.3%。其中平地桔园冻害较为严重,受冻面积达到3533.33hm2,约占平地柑桔面积的66%;坡地果园受冻面积1000hm2,约占坡地柑桔面积的10%。本次冻害在我县各柑桔主产区均有不同程度发生。从受冻情况看,各品种均有不同程度的冻害。成熟期越早的品种,采摘后树体     

2018年宜昌市柑橘冻害情况分析及对策建议

2018年1月,宜昌市出现两次低温雨雪天气,导致宜昌各县市区的柑橘受到不同程度的冻害。本文调查了宜昌市所辖县市区柑橘冻害情况,分析了冻害发生特点,提出科学建园、适地适栽,设防护林、改善小气候,树体保护、减轻冻害,加强管理、增强树势,冻后管理等对策建议。     

白沙枇杷皱果影响因素调查及其防治技术研究

本研究以当地主栽品种‘软条白沙’和‘宁海白’为试材,从防控白沙枇杷皱果入手,采用田间调查的方法,进行白沙枇杷皱果影响因子研究。结果表明：品种、果实着生方位、果园土壤肥力水平、果实负载多沙均与皱果有关,‘宁海白’抗皱果性强于‘软条白沙’;着生在南面的果实比东、西、北易皱果,树体表面的果实比树冠内膛的果实易皱果;重施基肥的果园抗皱性能强于肥力低的果园;结果枝和营养枝成一定比例、叶果比大的树抗皱性强于叶果比小的树。经过幼果早期套袋、转色期覆盖遮阳网遮阳布、树冠喷水、树盘覆盖反光膜等防皱试验比较,幼果期早期套袋是白沙枇杷防皱果的一种经济有效的实用方法,值得生产中大力推广。白沙枇杷皱果的阈值温度是田间气温在35.3℃以上,阈值湿度在48.3%以下,持续1：30以上。     

三峡库区晚熟脐橙果实粒化的原因及对策

2012年4月中旬以来,三峡库区的奉节县晚熟脐橙果园不同程度地出现果实粒化现象,严重地影响三峡库区柑橘（特别是晚熟柑橘）产业的持续健康发展。笔者针对这一情况,到当地的康乐镇、大树镇、公平镇、永乐镇等6个晚熟脐橙主产乡镇果园进行了实地调查,初步找到了晚熟脐橙果实产生粒化的原因,并提出了相应对策。     

龙眼防寒冻六大措施

1　园地选择　选西坡、北坡中下部开阔地带 ,冷空气不易沉积 ,日夜温差较小 ,冻害发生较轻的地方。尽量避免在低洼地、山窝和海拔较高的东、南坡地。2　培养防冻树冠　同一株成年树 ,通常外围受冻较重 ,内膛和下层枝叶受冻较轻。因此 ,在栽培管理上 ,通过修剪把树冠培养成分枝多、叶层厚、冠幅大的理想树型 ,减轻或避免霜冻为害。3　控冬梢　对于 10月中下旬抽发的晚秋梢 ,要株施复合肥或尿素 0 5ｋｇ ,促进新梢整齐快速生长。对于 11月上旬后抽生的冬梢 ,要强抑硬控 ,年底前不让抽梢。在严格控制水肥的条件下 ,采用断根、晾根或刻伤、环剥…     

Phase I evaluation of CCNU (lomustine) in tumor-bearing cats

1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.     

Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects

Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.     

Prevalence of gastric lesions in racing Alaskan sled dogs

Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.     

The Epidemiology of Gastrointestinal Nematodes of Dairy Cattle in Central Kenya

The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.     

Diversity of Ectoparasites in Sheep Flocks in Sa~o Paulo,Brazil

The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.     

Evaluation of biohydrogenation rate of canola vs. soya bean seeds as unsaturated fatty acids sources for ruminants in situ

An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.     

Serum biochemical values and mineral element contents of tissues in yaks

Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein     

Avian brood parasitism — a growing research area in behavioral ecology (part Ⅱ)

正We are pleased to publish the second special issue on avian brood parasitism and to be responsible guest editors for the two special issues of Chinese Birds (Vol. 3, No. 4, 2012 and Vol. 4, No. 1, 2013), entitled "Avian Brood Parasitism - A Growing Research Area in Behavioral Ecology". The first issue was published in December 2012. The goal of the two special issues is to publish accumulated knowledge and some of the recent developments in     

Internal Parasites and Haematological Values in Cattle Slaughtered in Buea Subdivision of Cameroon

Tropical Animal Health and Production -