手機版
ruqiuhoudeqiwensuizhelengkongqidepinfanruqinermingxianjiangdi，youqishizaiqinglangwufengdeyejianhuoqingchen，fushesanrezengduo，dimianhezhizhubiaomianwenduxunsuxiajiang，dangzhizhutiwenjiangzhi0℃以yi下xia時shi，植zhi株zhu體ti內nei細xi胞bao會hui脫tuo水shui結jie冰bing，遭zao受shou霜shuang凍dong危wei害hai。我wo們men通tong常chang把ba秋qiu季ji第di一yi次ci發fa生sheng的de霜shuang凍dong稱cheng為wei初chu霜shuang凍dong，因yin為wei初chu霜shuang凍dong總zong是shi在zai悄qiao無wu聲sheng息xi中zhong就jiu使shi作zuo物wu受shou害hai，所suo以yi有you農nong作zuo物wu“秋季殺手”的稱號。溫度降得越低，霜凍的威力就越大，造成的損失也越嚴重。
霜凍對農作物的危害
霜凍能使作物受害，主要是由於0℃以yi下xia的de低di溫wen使shi作zuo物wu細xi胞bao間jian隙xi的de水shui形xing成cheng了le冰bing晶jing，並bing且qie冰bing晶jing不bu斷duan地di吸xi收shou細xi胞bao的de自zi由you水shui使shi冰bing晶jing逐zhu漸jian增zeng大da，這zhe就jiu使shi細xi胞bao內nei水shui分fen減jian少shao而er導dao致zhi細xi胞bao質zhi脫tuo水shui，使shi細xi胞bao質zhi膠jiao體ti物wu質zhi發fa生sheng凝ning固gu和he細xi胞bao枯ku萎wei。在zai冰bing晶jing形xing成cheng和he增zeng大da的de過guo程cheng中zhong，對dui細xi胞bao也ye產chan生sheng機ji械xie壓ya力li而er導dao致zhi機ji械xie損sun傷shang。如ru果guo霜shuang凍dong較jiao輕qing，農nong作zuo物wu還hai沒mei有you死si亡wang，霜shuang凍dong過guo後hou溫wen度du逐zhu漸jian上shang升sheng，細xi胞bao慢man慢man解jie凍dong，還hai可ke以yi恢hui複fu生sheng命ming活huo動dong。
玉米、大豆、棉花等秋收作物在成熟前對霜凍非常敏感。玉米如果在灌漿期遭受早霜凍，不僅影響品質，還會造成減產。當氣溫降至0℃時(shi)，玉(yu)米(mi)發(fa)生(sheng)輕(qing)度(du)霜(shuang)凍(dong)，葉(ye)片(pian)最(zui)先(xian)受(shou)害(hai)。玉(yu)米(mi)灌(guan)漿(jiang)的(de)養(yang)料(liao)主(zhu)要(yao)是(shi)葉(ye)片(pian)通(tong)過(guo)光(guang)合(he)作(zuo)用(yong)產(chan)生(sheng)的(de)，受(shou)凍(dong)後(hou)的(de)葉(ye)片(pian)變(bian)得(de)枯(ku)黃(huang)，影(ying)響(xiang)植(zhi)株(zhu)的(de)光(guang)合(he)作(zuo)用(yong)，產(chan)生(sheng)的(de)營(ying)養(yang)物(wu)質(zhi)減(jian)少(shao)。由(you)於(yu)養(yang)料(liao)減(jian)少(shao)，玉(yu)米(mi)灌(guan)漿(jiang)緩(huan)慢(man)，粒(li)重(zhong)降(jiang)低(di)。如(ru)果(guo)氣(qi)溫(wen)降(jiang)至(zhi)零(ling)下(xia)3℃，就(jiu)會(hui)發(fa)生(sheng)嚴(yan)重(zhong)霜(shuang)凍(dong)，除(chu)了(le)大(da)量(liang)葉(ye)片(pian)受(shou)害(hai)外(wai)，穗(sui)頸(jing)也(ye)會(hui)受(shou)凍(dong)死(si)亡(wang)。這(zhe)樣(yang)不(bu)僅(jin)嚴(yan)重(zhong)影(ying)響(xiang)玉(yu)米(mi)植(zhi)株(zhu)的(de)光(guang)合(he)作(zuo)用(yong)，而(er)且(qie)還(hai)切(qie)斷(duan)了(le)莖(jing)稈(gan)向(xiang)籽(zi)粒(li)傳(chuan)輸(shu)養(yang)料(liao)的(de)通(tong)道(dao)，灌(guan)漿(jiang)被(bei)迫(po)停(ting)止(zhi)，常(chang)常(chang)造(zao)成(cheng)大(da)幅(fu)減(jian)產(chan)。
初(chu)霜(shuang)凍(dong)出(chu)現(xian)時(shi)，如(ru)果(guo)作(zuo)物(wu)已(yi)經(jing)成(cheng)熟(shu)收(shou)獲(huo)，即(ji)使(shi)再(zai)嚴(yan)重(zhong)也(ye)不(bu)會(hui)造(zao)成(cheng)損(sun)失(shi)，而(er)我(wo)國(guo)北(bei)方(fang)地(di)區(qu)常(chang)因(yin)初(chu)霜(shuang)凍(dong)出(chu)現(xian)早(zao)，秋(qiu)收(shou)作(zuo)物(wu)還(hai)沒(mei)有(you)完(wan)全(quan)成(cheng)熟(shu)就(jiu)遭(zao)受(shou)霜(shuang)凍(dong)危(wei)害(hai)，造(zao)成(cheng)大(da)麵(mian)積(ji)減(jian)產(chan)。
初(chu)霜(shuang)凍(dong)發(fa)生(sheng)在(zai)作(zuo)物(wu)成(cheng)熟(shu)前(qian)期(qi)，直(zhi)接(jie)影(ying)響(xiang)產(chan)量(liang)，受(shou)災(zai)後(hou)即(ji)使(shi)采(cai)取(qu)補(bu)救(jiu)措(cuo)施(shi)也(ye)很(hen)難(nan)挽(wan)回(hui)損(sun)失(shi)，所(suo)以(yi)在(zai)初(chu)霜(shuang)凍(dong)危(wei)害(hai)較(jiao)重(zhong)的(de)地(di)區(qu)，應(ying)該(gai)選(xuan)用(yong)耐(nai)寒(han)和(he)早(zao)熟(shu)品(pin)種(zhong)，合(he)理(li)調(tiao)整(zheng)播(bo)種(zhong)期(qi)，加(jia)強(qiang)田(tian)間(jian)管(guan)理(li)，確(que)保(bao)作(zuo)物(wu)在(zai)霜(shuang)凍(dong)來(lai)前(qian)充(chong)分(fen)成(cheng)熟(shu)。
做好對初霜凍的防禦工作
可用熏煙法、灌溉法、噴霧法、防護林法、覆蓋法等物理、化學方法增溫或減緩降溫速率；選用抗旱品種、早熟品種、適時播種、培養壯苗、改良土壤等農業方法來防禦霜凍、減輕危害。
