番茄裂莖是咋回事? 番茄裂莖怎么防治?

番茄裂莖,植株易從開(kai)裂處折斷,影響(xiang)生(sheng)長。露(lu)地、保(bao)護地番茄都(dou)有(you)發(fa)生(sheng),高溫期更常見,多是在(zai)定植后(hou)20~30天(tian)發(fa)生(sheng)在(zai)第三(san)花穗附近。發(fa)病初期莖裂部分壞(huai)死變褐,7~14天(tian)后(hou)莖部異常,在(zai)節間出現縱(zong)溝凹陷,逐漸形(xing)(xing)成(cheng)孔洞(dong)。輕微時,只(zhi)形(xing)(xing)成(cheng)縱(zong)溝或線形(xing)(xing)、“Y”字形(xing)(xing)縫隙。嚴重時,縱(zong)溝深凹成(cheng)洞(dong),并穿透莖形(xing)(xing)成(cheng)中(zhong)空,狀如(ru)“天(tian)窗”,癥狀不僅(jin)出現在(zai)主枝,腋芽也有(you)發(fa)生(sheng)。莖裂一旦(dan)發(fa)生(sheng),發(fa)生(sheng)部位的(de)節間就顯(xian)著(zhu)縮短(duan),葉對生(sheng),花穗弱,往(wang)往(wang)坐果不良。