Crop rotation sequencing to minimize yield losses of summer-irrigated lowland rice in Myanmar caused by the rice root-knot nematode Meloidogyne graminicola     

Pa Pa Win  Pyone Pyone Kyi  Zin Thu Zar Maung  Yi Yi Myint  Dirk De Waele 《国际虫害防治杂志》2020,66(4):319-331

Abstract

The effect of different rice-based crop rotation sequences on the population densities of Meloidogyne graminicola and on the yield of rice was evaluated in a microplot experiment under lowland rice field conditions. Ten treatments of cropping sequences were grown in four successive growing seasons: continuous growing of the susceptible rice cultivar Thihtatyin (rice-rice-rice-rice), four treatments of 1- season crop rotation sequences (rice-rice-chickpea-rice, rice-rice-black gram-rice, rice-rice-soybean-rice, rice-rice-cowpea-rice), and five treatments of 2-season crop rotation sequences (groundnut-rice-chickpea-rice, green gram-rice-black gram-rice, cowpea-rice-soybean-rice, sesame-rice-cowpea-rice, sunflower-rice-sesame-rice). Population densities of M. graminicola recovered from the rice plants and the nematode multiplication factors (Mf) in the soil in the continuous rice cropping sequence (rice-rice-rice-rice) was the highest among the ten cropping sequences. Lowest nematode Mf in the soil was observed in the 2-season crop rotation sequence sunflower-rice-sesame-rice and the highest was observed in the 1-season crop rotation sequence rice-rice-cowpea-rice among the nine crop rotation sequences. Highest rice yield was obtained in the 2-season crop rotation sequences green gram-rice-black gram-rice, sesame-rice-cowpea-rice and sunflower-rice-sesame-rice, which were about 2 times higher compared with the 1-season crop rotation sequences and about 3 times higher compared with the continuous rice cropping sequence.  相似文献   

Intragastric and intracoelomic injection challenge models of tilapia lake virus infection in Nile tilapia (Oreochromis niloticus L.) fingerlings     

Felipe Pierezan  Susan Yun  Win Surachetpong  Esteban Soto 《Journal of fish diseases》2019,42(9):1301-1307

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五种植物生长调节剂对甘草生长的影响   总被引：4，自引：2，他引：4  

谢建军  蔺海明  王瑞芳  刘婷  安文芝  祝玲敏 《甘肃农业大学学报》2008,43(3)

通过对甘草喷施1 000倍液爱多收、1 000倍液植物动力2003、500倍液多效唑、0.4%的精肥王和200倍液钾天下进行田间试验,旨在探明不同植物生长调节剂对甘草干物质积累、株高、根长及芦茎的影响.结果表明,5种植物生长调节剂对甘草生长发育均有不同程度的促进作用,综合评价最好的是0.4%的精肥王,其次是1 000倍液爱多收,而500倍液多效唑基本没有促进作用.  相似文献   

作业环境微气候对伐木作业人员及作业效率的影响   总被引：1，自引：0，他引：1  

王立海  尹奉月 《森林工程》1995,11(3):32-36

本文从人类工效学的角度对作业环境微气候对伐木作业人员及作业效率的影响进行了理论分析和部分实例探讨。首先,作者对高温作业 环境的影响进行了热平衡分析和实例分析研究;其次,作者又对低温作业环境对作业人员及作业效率的影响进行了较深入的理论分析和实例探讨。结果表明,作业环境微气候对伐木作业效率有较为显著的影响。对北方林区而言,夏季高温环境(较正常环境)影响伐木作业效率幅度约为20％—30％,冬季低温影响幅度约为15％—25％。  相似文献   

Pathological changes induced by three myxosporeans in the intestine of cultured tiger puffer, Takifugu rubripes (Temminck and Schlegel)     

Tin Tun  K Ogawa  & H Wakabayashi 《Journal of fish diseases》2002,25(2):63-72

Pathological changes in cultured tiger puffer, Takifugu rubripes , with emaciation disease in Kyushu, Japan were studied histologically. In most cases, diseased fish were heavily infected with at least one of three myxosporeans ( Myxidium fugu , Myxidium sp. and Leptotheca fugu ) and two unidentified hyperparasitic microsporeans, attached to, or in, the intestinal epithelium. Myxidium fugu attached to the surface of the epithelium, caused no noticeable effects on the host tissue, irrespective of its infection with the hyperparasite. Myxidium sp., which proliferated in the epithelium, induced severe pathological changes including accumulation of cell debris between the epithelium and lamina propria and resultant detachment of the epithelium. Leptotheca fugu, another histozoic myxosporean, induced degeneration of the epithelium, associated with massive infiltration of macrophages into the epithelium to encapsulate parasites. When L. fugu was infected with its hyperparasitic microsporean, shortened villi were also observed. This is probably because passage of macrophage-parasite aggregates through the basement membrane of the epithelium severely damaged the epithelial structure. It is evident histologically that, unlike epicellular M. fugu , histozoic Myxidium sp. and L. fugu with or without hyperparasitic microsporeans, were highly pathogenic to host fish. This strongly suggests that they are causative agents of the emaciation disease.  相似文献   

Distribution and structural variation of arabinoxylans in common wheat mill streams   总被引：6，自引：0，他引：6  

Delcour JA  Van Win H  Grobet PJ 《Journal of agricultural and food chemistry》1999,47(1):271-275

In 19 wheat-milling fractions total pentosan content, calculated as 0.88 x (% L-arabinose + % D-xylose), varied between 1.44 and 30.66% on dry matter (dm). It increased with ash content once the latter exceeded 0.6% (dm basis). Water-extractable arabinoxylans were recovered by saturating water extracts to 65% ethanol. Their contents in the milling fractions varied between 0.35 and 1.38%, and above 0.6% ash content also increased with this parameter. Their L-arabinose-to-D-xylose ratios ranged between 0.65 and 0.39, with the lowest values found for the fractions with highest ash content, indicating that the ash-rich tissues contain more arabinoxylans that are less branched. (1)H NMR spectroscopy revealed that the decrease in L-arabinose-to-D-xylose ratio was accompanied by an increase in unsubstituted xylose residues and a decrease in disubstituted xylose residues, while the contents of monosubstituted xyloses were virtually constant.  相似文献   

Remote sensing analysis of forest damage by selection logging in the Kabaung Reserved Forest, Bago Mountains, Myanmar     

Rosy Ne Win  Reiji Suzuki  Shinya Takeda 《Journal of Forest Research》2012,17(2):121-128

Selection logging is a principal management scheme in natural teak-bearing forests in Myanmar. Monitoring the spatial extent and intensity of selection logging is important for sustainable forest management. This study applied the normalized difference vegetation index (NDVI) image differencing method using two SPOT-5 pan-sharpened images (2.5 m spatial resolution) taken in October 2007 and January 2009 to analyze canopy changes associated with damage from forest harvesting. According to the pixel-based analysis, NDVI changes were larger in most logging road/log landing points whereas smaller NDVI changes were seen in most unlogged points. NDVI changes in teak stump areas were related to distance from a logging road and the number of stumps within the estimated crown area (a circular area with a 10 m radius from the center of each stump). A Fisher’s exact test showed that one of the main factors causing the high NDVI change in teak stump areas was the effect of road construction. The distribution pattern of teak stumps indicated that teak stumps with estimated crown areas that contained more than one stump had high mean change in NDVI. The spectral difference between before and after logging revealed that logging roads had a greater effect on canopy changes than teak stumps.  相似文献   

Effects of option mitigating ammonia volatilization on CH4 and N2O emissions from a paddy field fertilized with anaerobically digested cattle slurry     

Khin Thawda Win  Ryoko Nonaka  Koki Toyota  Takashi Motobayashi  Masaaki Hosomi 《Biology and Fertility of Soils》2010,46(6):589-595

A lysimeter experiment was carried out to evaluate the effects of the NH₃ volatilization mitigation by adding anaerobically digested cattle slurry (ADCS) alone, with wood vinegar (WV) or with a higher level of floodwater (HFW), on emissions of CH₄ and N₂O from a paddy soil planted with fodder rice. We have carried out the following treatments: (1) chemical fertilizer, (2) ADCS, (3) ADCS + WV, and (4) ADCS + HFW; the height of floodwater was 10 cm in the latter treatment, and it was 3 to 4 cm in the other treatments just before fertilizer applications. Nitrogen fertilizer rate added to soil in each treatment was 30 g NH₄⁺–N m⁻² (split in one basal and two top-dressing additions). Ammonia volatilization in the ADCS treatment was 2.7 g NH₃–N m⁻² throughout the growing season, and it was significantly reduced by 79% and 55% in the ADCS + WV and ADCS + HFW treatments, respectively. The total amount of CH₄ emitted in the ADCS treatment in the growing season was not significantly enhanced by the mitigation of NH₃ volatilization either by adding wood vinegar or by increasing the height of the floodwater. Negligible N₂O emissions were observed in all treatments during the growing period.  相似文献   

New sampler for dry deposition in forest canopy     

Chisato Takenaka  Win Ko Ko 《Journal of Forest Research》1998,3(1):19-24

A new type of sampler for dry deposition in a forest canopy was designed and tested to confirm its usefulness. The new sampler is made of Teflon chips packed in a nylon net, and tied on a rod like a branch in the canopy. The validity and characteristics of the new sampler were checked by comparing it with the conventional bucket sampler and the foliar extraction method using hinoki (Chamaecyparis obtusa) trees. The comparison between the deposited amounts on the dummy branch and those on the bucket indicates that the dummy could trap gaseous matter more effective than the bucket. From a comparison with the foliar extracting method, it is concluded that the trapping of particulate matter by the new dummy branch is comparable to that of natural needle leaves. However, its efficiency for gaseous matter is relatively small. This disadvantage should be improved by applying other materials to the dummy. Moreover, it is found that the uptake of gas especially SO₂ through the stomata is an important point in the discussion about dry deposition. To evaluate the amounts of dry deposition in the forest canopy more precisely, combination with the additional method should be useful. This study was supported in part by a grant-in-aid for Scientific Research from the Ministry of Education, Science, Sports, and Culture, Japan.  相似文献   

Minimal risk of tilapia lake virus transmission via frozen tilapia fillets     

Worrayanee Thammatorn  Pattarasuda Rawiwan  Win Surachetpong 《Journal of fish diseases》2019,42(1):3-9

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