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吉林省中西部盐碱洼地水稻直播稻田草害非常严重,因而影响了直播水稻的发展。1985～1988四年时间里,作者对该地区杂草发生规律进行了大量的调查研究,确认该地区直播稻田主要杂草有7科16种,其中危害极重的有3种,局部危害的有5种,分布普遍、危害轻的有8种。并明确了①开荒种稻三年以上的地杂草基本形成水田立体群落。②水稻生育期间杂草发生的三次高峰期是6月上中旬,稗草发生总量达45～75％;6月中下旬,扁杆藨草达总发生量的42～73％,慈菇、泽泻等达60～84％;7月初眼子菜、小茨藻发生量达总量的79～87％。③稗草种子广泛分布于5厘米土层中,1.5厘米以上的种子量占90％,萌发早、出苗快,危害最大;扁杆蔗草平均每平方米块茎达886.75个,15厘米以下块茎占93.4％。7月5日之前发生量占总量的72.11％。④根据直播稻田草的发生规律,确定最佳的防治时期及最优的配方4个,除草效果均在90％以L。
In the salinized depressions of central and western Jilin Province, direct seeding of paddy rice is very serious, which affects the development of direct seeding rice. During 1985 ~ 1988 four years, the author carried out a large number of investigations on the law of weeds in the area, confirming that there are 7 families and 16 species of weeds in direct seeding rice fields in the area, of which 3 species are extremely harmful and some are 5 species, widely distributed, the hazard of light 8 species. And clear ① land reclamation paddy three years above the basic formation of paddy weeds three-dimensional community. The third peak of weed occurrence during rice growth was in the middle of June and the total occurrence of barnyardgrass was 45-75%. In the middle and late June, the percentage of total barley was 42-73% Alisma, such as up to 60 ~ 84%; early July Ocimum vegetables, small algae occurred in the total amount of 79 to 87%. ③ The seeds of barnyardgrass were widely distributed in 5 cm soil layer, the amount of seeds more than 1.5 cm accounted for 90%, early germination, rapid emergence, the most harmful; flat bar cane an average of 886.75 square meters tubers, tubers 15 cm 93.4%. July 5 occurred before the amount of 72.11% of the total. ④ According to the law of occurrence of direct seeding rice field grass, the best control period and the best formulation were determined, and the weeding effect was 90%.