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1.
以北京7号桃树为研究对象,低温强度为主导指标、≤0℃温度持续时间为辅助指标,建立桃树盛花期霜冻害指标体系。采用大田试验,低温霜箱模拟,并结合霜冻历史调查资料分析的方法,得到北京7号桃盛花期花器发生轻霜冻(受冻率≤30%)、中霜冻(受冻率31%～60%)、重霜冻(受冻率61%～80%)和特重霜冻(受冻率≥81%)不同强度霜冻灾害的温度指标分别为最低气温≥-1.8、-1.9～-3.2、-3.3～-4.1、≤-4.2℃;气温≤0℃持续时间分别为≤2.6、2.7～5.2、5.3～7.0、≥7.1h。 相似文献
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宁夏苹果花期霜冻敏感性指标研究 总被引：2，自引：0，他引：2
苹果花期霜冻指标是果园霜冻预报预警、防御的基础,本文运用人工模拟霜箱,以富士、嘎啦和乔纳金苹果为试验对象,设置过冷却模拟试验设5个温度梯度和4个持续时间共计20个试验处理,模拟研究了苹果花期霜冻敏感性指标。结果表明:苹果花苞期花瓣、盛花期花瓣和子房以及幼果期的幼果平均过冷却点在-3.51℃~-3.27℃,结冰点变化范围在-2.94℃~-2.65℃。苹果花期低温敏感范围在-2.5℃~-3.5℃之间,不同花器官、不同品种、不同低温持续时间和不同发育阶段之间有所差异,其中,在苹果花的花瓣、子房、雄蕊和雌蕊等不同花器官中,花瓣最不耐冻,子房和雌、雄蕊随温度降低变异较大;不同类型花耐受冻顺序为花苞半开花全开花;-2.5℃~-3.0℃温度处理下,致死率随持续时间增加明显,温度高于或低于这个范围,持续时间对致死率影响不大;3个苹果品种中,富士最不耐冻,其次是乔纳金和嘎啦。 相似文献
3.
冰核活性细菌与植物霜冻的研究概况 总被引：3，自引：0，他引：3
长期以来认为植物霜害是零度以下低温(-2—-5℃)和霜敏感植物生理特性所引起的冻害。近年来,国外研究证明,植物体上广泛存在的具冰核活性的细菌(简称INA)是植物发生霜害的关键因素,这类细菌可在-2—-5℃诱发植物细胞水结冰而发生霜冻;也有研究证明,由于细胞水具过冷却作用(supercooling),在没有冰核细菌存在的条件下,能耐-7—-8℃低温而不发生霜冻。这些新发现,揭示了冰核活性细 相似文献
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基于生理指标确定河套灌区玉米春霜冻的气象指标 总被引：1，自引：0，他引：1
霜冻是河套灌区发生频率较高的农业气象灾害之一。本文以河套灌区广泛种植的玉米中晚熟品种科河8号为试验材料,以常温(20℃左右)为对照,设置5℃~-5℃的低温环境,对玉米幼苗分别进行1 h、3 h、5 h处理,对比观测试验前后玉米各项生理指标的变化情况。逆境生理研究能更好地理解不同程度的低温胁迫下植物的生理生化变化,可基于此确定霜冻预报的气温指标。研究结果表明:随着处理温度的降低和低温胁迫时间的延长,玉米幼苗叶绿素含量呈稳定下降的趋势;可溶性糖含量、SOD活性、丙二醛含量先升高后下降,最高值出现在-2℃和-3℃。通过对以上3个指标变化特点的分析表明:4叶玉米幼苗比3叶的抗寒性更强;可溶性蛋白含量先下降后上升,最低值出现在-2℃;各低温处理均导致玉米幼苗的净光合作用速率、气孔导度、单叶水分利用率下降。参照本文及过冷却点的试验结果,制定河套地区玉米春霜冻的最低气温指标如下:轻霜冻,0℃~3.0℃;中霜冻,-2.5℃~0℃;重霜冻,-2.5℃。 相似文献
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为提高宁夏桃园布局合理性及霜冻监测预测、评估和防御能力，以‘华玉’和‘瑞光39号’桃品种为研究对象，采用野外霜冻试验箱模拟低温环境，于2022年4—5月开展霜冻原位试验，于盛花期、豆果期和幼果期各设置4个处理温度，分别持续0.5 h,以自然状态下的花朵和幼果为对照，跟踪调查不同低温处理下2个桃品种各发育期的受冻率，并结合室内显微观测及过冷却点，最终确定宁夏2个桃品种花(幼果)的霜冻等级指标。原位霜冻模拟试验结果表明，果树受冻害温度可能略高于其过冷却点。桃不同发育期霜冻指标有显著差异，桃抗冻能力开花期>豆果期>幼果期。不同品种抗冻能力差异显著，开花期‘瑞光39号’与‘华玉’抗冻能力基本相当，但豆果期和幼果期其抗冻能力明显弱于‘华玉’。‘华玉’豆果在-1.10℃时轻度受冻，在-2.68℃重度受冻，而‘瑞光39号’在-0.96℃时轻度受冻，低于-2.16℃低温时重度受冻。‘华玉’幼果在-1.75～-0.48℃轻度受冻，低于-2.40℃则重度受冻；‘瑞光39号’幼果在温度达到-0.52℃时轻度受冻，遇-1.41℃低温则遭受重度受冻。 相似文献
6.
根据河北省1971-2010年冬小麦春季霜冻害灾情资料、逐日气象资料,建立了以气温稳定通过12℃为临界期的冬小麦霜冻害判别指标;分析了霜冻害时空变化特征;根据灾害风险分析原理,建立了霜冻害风险指数,进行了相应的风险区划,并初步探讨了霜冻害对冬小麦产量的影响。结果表明:河北省霜冻害以轻度为主,90年代以后发生霜冻害的站点数年际间变化幅度较90年代以前明显增大,站点数量明显增多;霜冻害总站点数存在明显的4a、7a和11a周期,90年代中期以后7a周期消失,11a周期逐渐缩短为8a周期;霜冻害高发区分布在邯郸、邢台、保定西北部以及沧州和衡水两市的部分地区,低发区分布在唐山、秦皇岛地区;霜冻害风险以中度和低度为主,中度风险区分布在邯郸西部、邢台大部、沧州南部、保定西北部,其它麦区大部为低风险区。霜冻害影响冬小麦产量的形成,发生强度与冬小麦气象产量呈负相关(r=-0.346)、与减产率呈正相关(r=0.342)。 相似文献
7.
为有效防御桃园花期晚霜冻危害,2012年4月在秦安县进行早春覆黑膜桃园花期气象效应及防霜效果试验。试验得出：早春桃园地表覆黑膜后,其较好的增温保墒作用,能使桃树地表层和桃树冠层内保持相对较高的温湿度条件,桃园土壤浅层0～40 cm和桃树冠层50～150 cm处平均温度较无膜桃园分别偏高0.3～0.4 ℃和1.3 ℃,平均土壤相对湿度提高2～6个百分点,较好的水热资源配置,能够增强树势,提高桃树抗霜冻能力。在晚霜冻主要危害时段的夜间增温最为明显,增温幅度分别为0.8～0.9 ℃和1.0～1.1 ℃,冠层最低温度层50 cm处增温1.2 ℃,温度梯度温差降低0.4 ℃,相对较高的夜温条件能为花期提供一定的热量条件,并有效缩短了桃树花期,可减轻其遭受春季晚霜冻危害几率和危害程度。通过对2012年4月12-13日覆膜桃园盖膜防霜和烟熏两种试验,出现轻霜冻时段的04：00-07：00时桃树冠层100 cm处最低温度4.2 ℃和2.1 ℃,较无盖膜防霜桃园偏高1.2 ℃和0.9 ℃;较无膜无防霜桃园偏高5.0 ℃和2.9 ℃。虽然熏烟防霜是一种传统的方法,具有一定的效果,但就目前来说,不符合生态保护的理念。因此,覆膜桃园盖膜防霜不仅体现了极佳的防霜效果,而且有利于生态保护,便于操作,易于推广。 相似文献
8.
陕西省富士系苹果花晚霜冻指标研究 总被引：4，自引：0，他引：4
为解决现有的陕西省富士系苹果晚霜冻指标与实际情况有出入的问题,以人工气候箱试验方法为主对指标进行研究。试验发现:陕西省富士系苹果花晚霜冻临界温度为-2℃,且温度越低、持续时间越长,苹果花的受冻率就越高;剧烈的升降温变化,更易造成苹果花遭遇冻害影响;苹果花受冻与其开放程度密切相关,开放程度越大,受冻越重,但受冻害程度与其是中心花还是边花关系不明显。基于此,建立了包含受冻等级、极端最低气温、0℃以下低温持续时间、受冻率及受冻表现共5要素在内的陕西省富士系苹果花晚霜冻指标,并通过检验发现,该指标对实际灾情的吻合率和基本吻合率大于70%,可投入业务使用。 相似文献
9.
1958-2006年河西走廊极端天气气候事件变化特征 总被引：3，自引：1，他引：2
利用1958-2006年甘肃河西走廊18个观测站大雨、干旱、≥35℃高温、≤-20℃低温、霜冻、大风、沙尘暴、雷暴、冰雹等极端天气气候事件的年发生日数资料,采用多项式法、线性倾向、M ann-Kendall法、滑动t检验及Morlet小波等统计学方法诊断分析其变化特征。结果表明:近49年来,河西走廊大风、沙尘暴、低温、霜冻、雷暴和冰雹呈显著减少趋势,高温呈显著增多趋势,其中大风、沙尘暴、高温和霜冻分别于1996,1989,1996年和1998年前后发生突变;大雨和干旱频数总体变化不显著。20世纪90年代初,低温和霜冻由多趋少,高温、大雨和干旱由少趋多,与河西走廊突变增暖时间基本吻合。干旱和高温存在长期性变化周期,沙尘暴、雷暴存在阶段性变化周期,其余极端天气周期变化不明显。 相似文献
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J. Hinrichs-Berger 《Gesunde Pflanzen》2004,56(2):48-54
Painting the trunks of deciduous fruit trees white prevents frost injuries. Frost cracks in the bark are important entry sites to the trunk for many plant pathogens such as Pseudomonas syringae, which causes decline of fruit trees. Frost damage and the epiphytic Pseudomonas population on trunks were significantly reduced by painting trees with white paint before the first frost in autumn. A copper compound (Funguran) was added to the paint. This sort of protection from frost injuries relies primarily on the physical effect that the sunlight does not warm the bark, since it is reflected by the white colour. Heating up the bark on the sunny side of the trunk during frost periods leads to tension cracks. A number of products were tested for their stability on bark and their ability to cover trunks and reflect sunlight. Some colours were stable for the whole observation period (more than 100 days) and guaranteed effective heat protection. In conclusion, painting the trunks of deciduous fruit trees white effectively controlled frost cracks. Moreover, the results of a 2-year field trial indicate that trunk infections of Pseudomonas syringae were prevented by using a white paint to which a copper compound was added. 相似文献
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The desorption of ethylene dibromide (EDB) residues from fumigated Shamouti citrus fruits is fitted by a single exponential equation at 17 and 22°C, and by an equation with a double exponential term at 5°C. Establishing the rate constant enables calculation of the initial concentration of EDB residues in the peel, thereby obtaining information on conditions during fumigation and on the possibility of peel injury development in the fumigated fruit. Healthy, harvested Shamouti citrus fruit evolve ethylene at a low rate, which is increased by EDB fumigation. Fumigated fruit in which EDB caused peel injury evolved ethylene at a higher rate than fumigated fruit in which peel injuries did not develop. This information could be used for predicting peel injuries and in studies aimed at a better understanding of the processes leading to the development of peel injuries in fumigated citrus fruit. 相似文献
14.
Z. Klement 《EPPO Bulletin》1977,7(1):57-68
Bacterial canker and dieback (Pseudomonas syringae van Hall) of apricot is a widespread disease in Europe, except for the Mediterranean areas. Cankers usually develop at pruning wounds or other points of injury. Phloem and cambium become susceptible from just after leaf drop until budding. If the phloem necrosis does not girdle the branch or trunk, cankers develop by the middle or the end of summer. In early summer, the bacterium actually dies out in the infected tissue, and the tree remains resistant during the summer. During this period, the pathogen lives epiphytically on the surface of the leaves, without causing any symptoms. The extent of bacterial necrosis of the phloem depends on the severity of winter frost. Without winter frost, bacterial induced tissue necrosis does not occur. Necrosis is found only if P. syringae has enough time to proliferate before the onset of frost. The most effective method of control is to carry out spring rather than winter pruning. 相似文献
15.
1960-2011年新疆初终霜日及无霜期的变化特征 总被引：4，自引：0，他引：4
利用1960-2011年新疆51个地面气象站逐日最低气温观测资料,运用线性趋势、距平分析、5 a滑动平均等方法,分析了初、终霜日和无霜期的基本特征及其变化趋势。结果表明：新疆初霜日推迟11 d,终霜日提前7 d,无霜期延长17 d。北疆、南疆和天山初、终霜日及无霜期与新疆整体变化趋势一致,但变化程度不同。天山地区变化最显著,其次是北疆,最后是南疆。初、终霜日的出现和无霜期的长短与地理因素和温度密切相关,随着海拔的升高,纬度的增加,初霜日提前,终霜日推迟,无霜期缩短。而随着温度的升高,初霜日逐渐推迟,终霜日逐渐提前,无霜期延长;从影响程度而言,最低气温的影响要大于平均气温和最高气温的影响。 相似文献
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终霜和春季低温冷害对新疆棉花播种期的影响 总被引：20，自引：1，他引：20
傅玮东 《干旱区资源与环境》2001,15(2):38-43
终霜冻和春季低温冷害是造成新疆棉区大面积严重缺苗、毁种重播的主要原因之一。全疆大部棉区棉花在播种期间均发生过霜冻害 ,其中多发区分布在北疆沿天山一带棉区及和田、且末棉区。且棉花早播与终霜冻害和低温冷害成正比。统计分析不同播期植棉的棉苗遭受霜冻及低温冷害影响的概率可确定各地棉区的最佳播期 相似文献
17.
2018年采用田间调查法对陕西关中地区20个县(区)小麦冻害率及受冻畸形麦穗上赤霉病的发病率进行了调查,并对畸形麦穗上的病原菌进行分离鉴定,分析了冻害的成因和畸形麦穗感病的原因,提出了预防策略。结果显示,陕西关中不同地区小麦受冻害程度不同,西北部地区冻害程度严重,冻害率最高可达24%;由室内鉴定可知,受冻麦穗易感染赤霉病菌引发赤霉病,且相同地区的不同品种及相同品种在不同地区的发病率有较大的差异,西部较湿润地区冻害穗赤霉病发病率达80%以上,东部旱塬地区基本在70%以下。表明小麦冻害及冻害穗上赤霉病严重程度存在地区与品种差异性。 相似文献
18.
In a 4-year study, the incidence of various types of injuries (caused by insects, birds, growth cracks, mechanical wounding, and other, unidentified factors) was assessed in relation to brown rot development (caused by Monilinia fructigena) on fruit of three apple cultivars (Prima, Jonathan, and Mutsu) in integrated and organic blocks of two apple orchards in Hungary. In addition, populations of male codling moths (Cydia pomonella) were monitored with pheromone traps season-long in both management systems. On average, injury incidence on fruit at harvest was 6.1 and 19.2% in the integrated and organic treatments, respectively. Insect injury, which was caused primarily by C. pomonella, had the highest incidence among the five injury types, accounting for 79.4% of the total injury by harvest in the organic blocks and 36.6% in the integrated blocks. Levels of all other injury types remained close to zero during most of the season, but the incidence of bird injury and growth cracks increased markedly in the final 3 to 5 weeks before harvest in both production systems. Brown rot developed more slowly and reached a lower incidence in the integrated (6.4% final incidence on average) compared with the organic blocks (20.1% average incidence). In addition, the disease developed later but attained higher levels as the cultivar ripening season increased from early-maturing Prima to late-maturing Mutsu. Overall, 94.3 to 98.7% of all injured fruit were also infected by M. fructigena, whereas the incidence of brown-rotted fruit without visible injury was very low (0.8 to 1.6%). Correlation coefficients (on a per plot basis) and association indices (on a per-fruit basis) were calculated between brown rot and the various injury types for two selected assessment dates 4 weeks preharvest and at harvest. At both dates, the strongest significant (P < 0.05) relationships were observed between brown rot and insect injury and between brown rot and the cumulative number of trapped C. pomonella. At the harvest assessment, two additional significant correlations were between brown rot and bird injury and between brown rot and growth cracks. In every case, correlation coefficients were larger in organic than in integrated blocks. Although it is well established that brown rot in pome fruits is closely associated with fruit injuries, this is the first study to provide season-long progress data on different injury types and quantitative analyses of their relative importance at different times in the growing season and across two distinct management systems. 相似文献
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近44a宁夏霜冻特征 总被引：4，自引：0，他引：4
根据宁夏20个气象观测站1961~2004年的日最低气温和地表0厘米地温资料,组合建立具有一定代表性的霜冻指标。研究表明:近44a宁夏霜冻发生次数呈明显下降趋势,春霜冻发生几率明显高于秋霜冻,大多数站终霜日的绝对变率大于初霜日;霜冻发生频次和各地拔海高度呈正相关关系,生长季、年均日最低温度与霜冻发生次数呈负相关关系;全区累积发生连续2d以上霜冻几率占发生总数的1/3以上,最多持续时间在5~6d;过程性霜冻主要表现为局地性霜冻,虽然全区性霜冻发生几率不到1/5,但危害很大;春、秋霜冻随地域在农事关键期的发生几率差异较大。 相似文献
20.
甜瓜种质资源苗期抗旱性生理鉴定指标测定 总被引：3，自引：1，他引：2
以6个甜瓜品种为试材,测定其株高胁迫指数(PHSI)、干物质胁迫指数(DMSI)、叶片水分饱和亏(WSD)、相对含水量(RWC)、束缚水含量、组织水含量、自由水含量、电解质渗出率、干旱处理伤害率、离体叶片抗脱水能力等指标,并对各指标进行显著性测验,评价各品种的抗旱性。结果表明:鉴定甜瓜品种抗旱性,苗期可应用株高胁迫指数(PHSI)、干物质胁迫指数(DMSI)、叶片水分饱和亏、电解质渗出率、干旱处理伤害率等指标。 相似文献