根據各地(di)冬后二化螟種(zhong)群基數調查(cha),結合(he)早(zao)稻(dao)布局、天(tian)氣趨(qu)勢預報等因素綜合(he)分析(xi),預計(ji)今年(nian)一代二化螟在(zai)早(zao)稻(dao)上(shang)中等偏(pian)重(zhong)發(fa)生,局部大發(fa)生,重(zhong)發(fa)區(qu)(qu)主要(yao)在(zai)金華、衢(qu)州(zhou)和臺州(zhou),以及其他(ta)早(zao)稻(dao)零星(xing)種(zhong)植區(qu)(qu),浙北杭、嘉、湖純單季(ji)稻(dao)區(qu)(qu)中等偏(pian)輕(qing)發(fa)生。發(fa)生期比去(qu)年(nian)遲(chi)5-6天(tian)左(zuo)右,接近常年(nian)。
冬后殘(can)留蟲量(liang):受去(qu)(qu)(qu)年(nian)(nian)(nian)水(shui)稻(dao)稻(dao)縱卷葉螟(ming)發生(sheng)重(zhong),防(fang)治(zhi)頻率高,以(yi)及今年(nian)(nian)(nian)1-2月低(di)(di)溫冰雪天(tian)氣的影響,今年(nian)(nian)(nian)二(er)化螟(ming)冬后殘(can)留蟲量(liang)較(jiao)上年(nian)(nian)(nian)明顯(xian)下降(jiang)(jiang)。據(ju)29個(ge)重(zhong)點病蟲測報站(zhan)(zhan)近期調查,冬后田(tian)(tian)間稻(dao)樁殘(can)留蟲量(liang)各類型(xing)田(tian)(tian)平均(jun)(jun)為(wei)127.56頭(tou)(tou)(tou)/畝,幅(fu)度為(wei)25-2700頭(tou)(tou)(tou)/畝,其中87%的站(zhan)(zhan)點比(bi)去(qu)(qu)(qu)年(nian)(nian)(nian)下降(jiang)(jiang)15%-98%之(zhi)間,且低(di)(di)于常(chang)(chang)年(nian)(nian)(nian)。但地(di)區(qu)間差異(yi)較(jiao)大,上年(nian)(nian)(nian)晚稻(dao)二(er)化螟(ming)發生(sheng)較(jiao)重(zhong)的金華和衢州稻(dao)區(qu)比(bi)去(qu)(qu)(qu)年(nian)(nian)(nian)增加(jia)10%-129%。如龍游縣為(wei)2543頭(tou)(tou)(tou)/畝,較(jiao)大發生(sheng)的去(qu)(qu)(qu)年(nian)(nian)(nian)增加(jia)123%,婺(wu)城區(qu)比(bi)上年(nian)(nian)(nian)增加(jia)6%,江山市增加(jia)20.6%。稻(dao)草殘(can)蟲量(liang)也比(bi)去(qu)(qu)(qu)年(nian)(nian)(nian)和常(chang)(chang)年(nian)(nian)(nian)低(di)(di),據(ju)蒼(cang)南、瑞安、臨海、椒江等站(zhan)(zhan)剝查,每(mei)50公斤稻(dao)草平均(jun)(jun)殘(can)蟲量(liang)在(zai)30.4-520頭(tou)(tou)(tou)之(zhi)間,均(jun)(jun)比(bi)去(qu)(qu)(qu)年(nian)(nian)(nian)低(di)(di)61%-94%。椒江站(zhan)(zhan)調查,平均(jun)(jun)殘(can)蟲量(liang)為(wei)142頭(tou)(tou)(tou),比(bi)2007年(nian)(nian)(nian)520頭(tou)(tou)(tou)減(jian)72.7%,比(bi)常(chang)(chang)年(nian)(nian)(nian)1301頭(tou)(tou)(tou)減(jian)89%,為(wei)歷年(nian)(nian)(nian)較(jiao)低(di)(di)年(nian)(nian)(nian)份。
發生期:據蒼(cang)南、瑞安、臨海、東陽、龍游、松陽等地調查(cha)(cha),越冬代二(er)化(hua)(hua)螟(ming)(ming)發育進度(du)比去(qu)年(nian)(nian)遲(chi)2-7天(tian)(tian)。瑞安站剝查(cha)(cha),化(hua)(hua)蛹(yong)高(gao)峰(feng)在(zai)4月(yue)10日(ri)(ri)(ri)左(zuo)右(you),發生期比去(qu)年(nian)(nian)推遲(chi)6天(tian)(tian)左(zuo)右(you);蒼(cang)南4月(yue)14日(ri)(ri)(ri)調查(cha)(cha),稻草二(er)化(hua)(hua)螟(ming)(ming)化(hua)(hua)蛹(yong)高(gao)峰(feng)在(zai)4月(yue)11-12日(ri)(ri)(ri),比去(qu)年(nian)(nian)遲(chi)3天(tian)(tian)左(zuo)右(you);龍游調查(cha)(cha),蛹(yong)高(gao)峰(feng)在(zai)4月(yue)17日(ri)(ri)(ri)左(zuo)右(you),比去(qu)年(nian)(nian)遲(chi)6天(tian)(tian);東陽4月(yue)15日(ri)(ri)(ri)剝查(cha)(cha),化(hua)(hua)蛹(yong)率為(wei)35.3%,預計化(hua)(hua)蛹(yong)高(gao)峰(feng)在(zai)4月(yue)20日(ri)(ri)(ri)左(zuo)右(you),接近常年(nian)(nian),較去(qu)年(nian)(nian)略遲(chi)。預計今年(nian)(nian)一代二(er)化(hua)(hua)螟(ming)(ming)羽化(hua)(hua)高(gao)峰(feng)期:臺州、金華、衢(qu)州為(wei)5月(yue)上旬前(qian)期,寧波、紹(shao)興為(wei)5月(yue)上旬后(hou)期至中旬。
天氣趨勢:據省氣候中心預計,4月中旬至5月上旬全省平均氣溫大部分地區接近常年或略偏高;總降水量浙北地區接近常年,全省其他地區接近常年或略偏多。預計4月中旬全省有1-2次明顯的降雨過程,旬雨量大部分地區較常年略偏多,旬氣溫全省較常年偏高,對浙江中部和南部已化蛹二化螟有一定影響。
來源:浙(zhe)江省植物保護檢疫局