高溫
危害 高溫熱害對蔬菜生長發育和產量形成帶來不利影響,是形成蔬菜供應“秋淡”的基本原因。例如,番茄在開花初期遇40℃以上的上表溫度會引起落花,持續時間愈長,坐果率愈低;菜豆在30℃以上授粉率大大降低;黃瓜在32℃以上也不利於果實生長。
防禦措施 一是夏季多種植耐熱蔬菜,如冬瓜、絲瓜、豇豆、空心菜等。在海拔較高(600米以上)delengliangshanqujianlixiajigaowendanjibugeishengchanjidi,taozhonggaoganzuowuzheyangjiangwen,ruqieziyutianjiaojianzhong。ershishishijiaoshui,tongguozhengfasanrejiangwen。gaowenganhanjijiecaiyongpenguanxiaoguozuijia,danyingbimianzaizhongwuqianhougaowenshijiaoshui,yinweituranjiangwenhuigeishucaizaochengshenglizhangai。sanshicaiquzheyangzaipei。xiajicaiyongzheyangwang(涼爽紗)覆蓋栽培,可防止太陽直接輻射灼傷蔬菜,可比露地栽培降溫3℃~5℃,有利於喜涼蔬菜越夏。四是施用生長調節劑,控製落花。如用2,4-D浸花和對氧苯氧乙酸噴花,可防止番茄和茄子因高溫落花。
暴雨
危害 播(bo)種(zhong)後(hou)遭(zao)遇(yu)暴(bao)雨(yu)衝(chong)擊(ji),種(zhong)子(zi)被(bei)衝(chong)散(san)至(zhi)溝(gou)底(di)或(huo)露(lu)於(yu)土(tu)表(biao),造(zao)成(cheng)缺(que)苗(miao)。出(chu)苗(miao)後(hou)表(biao)土(tu)遭(zao)遇(yu)暴(bao)雨(yu)衝(chong)刷(shua),使(shi)根(gen)係(xi)暴(bao)露(lu),轉(zhuan)晴(qing)後(hou)暴(bao)曬(shai),菜(cai)苗(miao)萎(wei)蔫(nian)枯(ku)死(si)。各(ge)類(lei)菜(cai)苗(miao)受(shou)暴(bao)雨(yu)機(ji)械(xie)損(sun)傷(shang),會(hui)導(dao)致(zhi)長(chang)勢(shi)下(xia)降(jiang),產(chan)量(liang)降(jiang)低(di),上(shang)市(shi)量(liang)少(shao),形(xing)成(cheng)“菜少價高”現象。
防禦措施 一是大力興修水利,疏通河道,加固河塘海堤,改造易澇窪地,實行深溝、高gao畦qi耕geng作zuo,植zhi樹shu造zao林lin保bao持chi水shui土tu,田tian間jian溝gou渠qu要yao溝gou溝gou相xiang通tong,排pai灌guan自zi如ru。二er是shi當dang多duo雨yu天tian氣qi時shi,要yao及ji時shi開kai溝gou排pai水shui或huo機ji械xie排pai水shui,受shou淹yan植zhi株zhu要yao及ji時shi洗xi去qu莖jing葉ye上shang的de淤yu泥ni,除chu去qu黃huang爛lan葉ye片pian,扶fu直zhi植zhi株zhu。土tu壤rang稍shao幹gan後hou及ji時shi中zhong耕geng鬆song土tu追zhui肥fei。三san是shi深shen耕geng改gai土tu,多duo施shi有you機ji肥fei,能neng改gai善shan土tu壤rang物wu理li性xing質zhi,提ti高gao土tu壤rang滲shen水shui能neng力li,對dui減jian輕qing雨yu澇lao濕shi害hai有you一yi定ding效xiao果guo。
熱雷雨
危害 夏xia季ji,由you於yu太tai陽yang輻fu射she強qiang烈lie,地di麵mian急ji劇ju增zeng溫wen,促cu使shi大da量liang濕shi熱re空kong氣qi猛meng烈lie上shang升sheng,常chang產chan生sheng較jiao強qiang的de雷lei陣zhen雨yu,這zhe就jiu叫jiao熱re雷lei雨yu。它ta多duo發fa生sheng在zai午wu後hou,並bing且qie越yue是shi悶men熱re無wu風feng的de天tian氣qi越yue容rong易yi發fa生sheng。熱re雷lei雨yu常chang帶dai來lai較jiao大da危wei害hai,對dui黃huang瓜gua、茄子、葉菜類蔬菜都有較大影響,特別是對幼小菜苗危害更甚。
防禦措施 最(zui)好(hao)的(de)辦(ban)法(fa)是(shi)在(zai)雨(yu)後(hou)及(ji)時(shi)澆(jiao)水(shui),采(cai)用(yong)噴(pen)灌(guan)更(geng)好(hao)。因(yin)為(wei)澆(jiao)水(shui)後(hou)可(ke)使(shi)耕(geng)作(zuo)層(ceng)完(wan)全(quan)飽(bao)和(he),水(shui)分(fen)帶(dai)進(jin)氧(yang)氣(qi),排(pai)出(chu)了(le)有(you)毒(du)氣(qi)體(ti),根(gen)的(de)呼(hu)吸(xi)就(jiu)會(hui)好(hao)轉(zhuan),吸(xi)水(shui)功(gong)能(neng)增(zeng)加(jia)。澆(jiao)透(tou)水(shui)後(hou)還(hai)可(ke)降(jiang)低(di)溫(wen)度(du),有(you)利(li)於(yu)蔬(shu)菜(cai)生(sheng)長(chang),不(bu)利(li)於(yu)病(bing)菌(jun)繁(fan)殖(zhi)。澆(jiao)水(shui)還(hai)可(ke)以(yi)衝(chong)洗(xi)去(qu)濺(jian)在(zai)葉(ye)麵(mian)上(shang)的(de)汙(wu)泥(ni),有(you)利(li)於(yu)光(guang)合(he)作(zuo)用(yong)的(de)進(jin)行(xing)。
手機版




