全程机械化生产对双季稻病虫草发生及产量的影响

为探索不同翻耕栽植方式对双季稻病虫草发生和产量的影响，对旋耕-机插、旋耕+牛耕-机插、牛耕-机插、旋耕-手插等4种翻耕栽植方式进行了比较试验。结果表明，未施药区4种翻耕栽植方式早稻主要病虫草为纹枯病（Rhizoctonia solani）、稻纵卷叶螟（Cnaphalocrocis medinalis）、鸭舌草（Monochoria vaginalis）和稗草（Echinochloa crusgalli），晚稻主要病虫草为纹枯病、稻纵卷叶螟、稻飞虱（Sogatella furcifera，Nilaparvata lugens）、鸭舌草和稗草。在肥水管理相同的条件下，早、晚稻纹枯病病情指数孕穗期分别为8.25～13.31和17.60～23.10，乳熟期分别达13.75～20.90和20.02～23.76，其中旋耕-手插方式重于旋耕-机插方式，牛耕-机插方式重于旋耕-机插方式。早稻二代稻纵卷叶螟发生较重，卷叶率为15.03%～16.67%；晚稻四代和五代稻纵卷叶螟发生较重，卷叶率分别为29.67%～33.48%和60.09%～65.45%，4种翻耕栽植方式早、晚稻稻纵卷叶螟发生量差异不显著。晚稻稻飞虱前期虫口密度偏低，齐穗期为425～550头/百丛，至乳熟期达1 200～1 600头/百丛，其中以旋耕-手插处理虫口密度最高，旋耕-机插虫口密度最低。早稻稻田杂草有鸭舌草、稗草、矮慈姑、千金子、水竹叶等，均以鸭舌草和稗草为优势种群，分别占总草的68.00%和29.70%；晚稻稻田杂草有鸭舌草、稗草、节节菜、千金子、香附子、空心莲子草等，均以鸭舌草和稗草为优势种群，分别占总草的69.60%和17.40%。早、晚稻以牛耕-机插处理杂草发生量最大，其次分别为旋耕+牛耕-机插和旋耕-机插处理，旋耕-手插处理杂草发生量最小。测产对比方差分析表明，4个种翻耕栽植方式产量差异不显著。在病虫草发生初期，选用适当的农药可有效控制不同翻耕栽植方式病虫草发生，早、晚稻平均增产10.00%和7.88%。该研究为双季稻区水稻全程机械化生产病虫草防治技术的推广提供参考。

Effects of techniques of paddy field production mechanization on occurrence of diseases, insect pests, weeds and yield of double-cropping rice

Abstract: Four patterns such as mechanized rotary tillage-mechanized transplanting method, mechanized rotary with cattle tillage-mechanized transplanting method, cattle tillage-mechanized transplanting method and mechanized rotary tillage-manual transplanting method were tested in order to investigate the effects of different plowing-transplanting methods on diseases, insect pests, weeds and yield of double-cropping rice. Results showed that major diseases, insect pests and weeds were sheath blight disease Rhizoctonia solani, Cnaphalocrocis medinalis, Monochoria vaginalis and Echinochloa crusgalli in early rice with four plowing-transplanting methods in no using pesticide areas, and sheath blight disease, C medinalis, rice planthopper (Sogatella furcifera and Nilaparvata lugens), M. vaginalis and E. crusgalli in late rice. Under the same conditions of fertilizer and water management, the sheath blight disease indexes of early and late rice were 8.25-13.31 and 17.60-23.10 at booting stage, 13.75-20.90 and 20.02-23.76 at milky stage, respectively, which was more serious using mechanized rotary tillage-manual transplanting method than that using mechanized rotary tillage-mechanized transplanting method, and more serious using cattle tillage-mechanized transplanting method than that using mechanized rotary tillage-mechanized transplanting method. The second generation of C. medinalis occurred seriously in early rice, and its curled leaf rates were 15.03%-16.67%. The fourth and fifth generation of C. medinalis in late rice occurred seriously, and its curled leaf rates were 29.67%-33.48% and 60.09%-65.45%, respectively. The occurrence difference of C. medinalis was not significant between four plowing-transplanting methods in early and late rice. The population density of rice planthoppers in late rice was low at early stage, 425-550 heads/100 clusters at full heading stage, 1200-1600 heads/100 clusters at milky stage, which was highest using mechanized rotary tillage-manual transplanting method, and lowest using mechanized rotary tillage-mechanized transplanting method. There were M. vaginalis, E. crusgalli, Sagittaria pygmaea, Euphorbia lathyris, Murdannia triguetra and so on in early paddy field, which M. vaginalis and E. crusgalli were the dominant species, 68.00% and 29.70% of the total grasses, respectively. There were M. vaginalis, E. crusgalli, Rotala indica, Euphorbia lathyris, Cyperus rotundus, Alternanthera philoxeroides and so on in late paddy field, which M. vaginalis and E. crusgalli were the dominant species, 69.60% and 17.40% of the total grasses, respectively. The weeds' density was highest in early and late paddy fields with cattle tillage-mechanized transplanting method, followed by mechanized rotary with cattle tillage-mechanized transplanting method and mechanized rotary tillage-mechanized transplanting method, and lowest with mechanized rotary tillage-manual transplanting method. Variance analysis indicated that there was no significant difference in the yield among four kinds of plowing-transplanting methods. The diseases, insect pests and weeds in early and late rice under different plowing-transplanting methods could be controlled effectively by applying appropriate pesticides during the early days of pest occurrence. The average yields were increased 10.00% and 7.88%, respectively. The study provided a reference for the extension of control technology on diseases, insect pests and weeds of double-cropping rice in paddy field production mechanization.