沼泽地覆膜种稻栽培技术

本文阐述了沼泽地的特点及开发种稻的可行性,同时介绍了辽宁省桓仁地区利用沼泽地开发种稻覆膜栽培技术措施。     

Plant-parasitic nematodes in the potato growing areas of Maine

A study was conducted from October 1987 to November 1988 to accumulate data on the distribution of plant-parasitic nematodes, to examine rotation schemes and time of sampling in relation to nematode populations, and to assess the occurrence ofVerticillium spp.-Pratylenchus spp. in potato growing areas of the state of Maine.Pratylenchus penetrans andP. crenatus were encountered most frequently, with detection being 19% higher in early season (May–June) than late season (September–November). All rotation schemes supportedPratylenchus spp.Meloidogyne hapla was encountered in 14% of the early samples and 19% of the late samples. Oats-potato, potato-potato, and clover-potato supported the highestM. hapla population levels. Other nematodes detected in fewer samples and in lower numbers than the two above genera wereParatylenchus spp.,Criconemella spp.,Helicotylenchus spp. andTylenchorhynchus sp. Two plants from each of 27 fields were examined for nematode-fungus associations. Samples from 7 fields were positive forV. dahliae andP. penetrans only,V. alboatrum andP. penetrans were found in 1 field,V. alboatrum alone was detected in 1 field andP. penetrans,V. dahliae andV. alboatrum were found together in 2 fields. The detection of these nematode-fungus associations suggests that the potato early dying complex defined elsewhere in the United States may be occurring in Maine.     

茶区沼气设施的建造和使用

近几年我国茶区沼气能源发展和普及速度很快，不少省（市、区）茶区沼气普及率已高达80％以上。沼气的普遍应用，有效保护了茶区森林植被，改善了生态环境。本文特就茶区所使用沼气的性质、设施建造和安全使用知识等作一简单介绍。     

Protein and lysine digestibility and protein quality of cooked Filipino rice diets and milled rice in growing rats

The protein quality of typical rice-based menu of Filipino preschool child and adult and cooked milled rice was assessed for true digestibility (TD), biological value (BV) and net protein utilization (NPU) in growing rats. Lysine and energy digestibilities were also determined. For the preschool child diet, TD was 88.8%, BV 90.0%, and NPU 79.9%. For the adult diet, TD was 87.3%, BV 86.6%, and NPU 75.5%, whereas cooked rice had 90.0% TD, 82.5% BV and 74.3% NPU. Lysine digestibility was 95.4% for preschool child diet, 95.7% for adult diet, and 100.0% for rice. Digestible energy was 91.3% for preschool child diet, 93.0% for adult diet, and 95.3% in rice. Amino acid scores were 100.0% for preschooler diet, 92.1% for adult diet, and 62.2% for rice. Protein quality based on amino acid score corrected for TD was 88.8% for preschool child diet. 80.4% for adult diet, and 56.0% for rice. If based on lysine digestibility instead of TD, protein quality would be 7.1% higher.     

Imidacloprid concentrations in paddy rice fields in northern Vietnam: measurement and probabilistic modeling

Paddy and Water Environment - Uncertainties associated with pesticide exposure forecasts arise from many sources such as spatial and temporal variability of factors influencing pesticide behavior,...     

Genetic diversity and population structure of rice blast fungus in China

Rice blast resistance has been unreliable insome cases with the field breakdown of previ-ous resistant cultivars occurring within a fewyears.To eventually develop better breedingstrategies,we combine MGR—DNA finger-printing and pathotyping to determine the pop-ulation structure of the pathogen and the rela-tionship between the structure and virulencediversity of the pathogen in China.The MGR—DNA fingerprints of 40 isolates collectedfrom 108 different sites among 12 provinces(municipality)during 1980—1994 have beenstudied with a dispersed repeated sequenceprobe MGR586/EcoR 1 digest combination.The fingerprint data document a generalizedgenetic organization.Forty—five pathotypesof P.ricsea could be distinguished into 54 sepa-rate lineages based on MGR—DNA fingerprint     

Plant diversity and composition of rice field bunds in Southeast Asia

Which plant species can be found on rice field bunds and what are the prevailing life forms? Which plant communities occur and what are the main environmental drivers and phytogeographic patterns shaping these communities? How do species diversity and composition differ between bunds and paddies? To answer these questions, 133 vegetation relevés using the Braun-Blanquet method were collected in lowlands and uplands of Vietnam and the Philippines between 2012 and 2015. Soil samples were collected and farmers were interviewed. Properties of soil, climate, and geography were assessed, further structural parameters, landscape heterogeneity, seasonality, management and intensity of cultivation. Hierarchical UPGMA cluster analysis and NMDS ordinations were performed to visualize variation in plant community composition and the determinants. We found 302 vascular plant species, of which 94 species are red listed by the IUCN (under category “Least concern”). Therophytes and helophytes are the prevailing life forms. Six clusters of plant communities were classified, and temperature, soil acidity, land use intensity and nutrient availability were identified (according to relevance) as explanatory variables. Bunds revealed higher species richness than paddies and bunds in mountain areas were more species-rich than those in the lowlands. We conclude that the composition of bund communities provides valuable information on environmental and biogeographical conditions of the local rice landscapes, and that it is probably the best applicable and most reliable indicator of management intensity.     

油菜茬单季稻免耕直播高产高效栽培技术

阐述了湖南省双季稻主产区,现存10万hm^2单季稻低效种植面积.引进免耕直播轻型栽培技术以后,重点抓了选用适宜的品种、大田清茬除草与整平等8项技术措施,获得了油菜和水稻高产高效.免耕直播水稻667m^2产出稻谷612 kg,比移栽稻增产3.12%,油菜增产4.68%,而且省工省力.     

Survey of potato spindle tuber viroid in seed potato growing areas of the United States

Fourteen United States (U.S.) seed potato certification agencies surveyed all U.S. seed potato growing areas for presence of the potato spindle tuber viroid (PSTVd). The survey included general surveillance, which involved searching for the occurrence of PSTVd in state seed potato certification records from 1990 through 2000, and a field survey, which involved testing selected crops for PSTVd infection by nucleic acid dot blot hybridization during 1999 through 2001. No PSTVd incident was documented in any of the state certification records, nor was PSTVd detected in the field surveys. All U.S. seed-growing areas were determined to be free of PSTVd. It is concluded that PSTVd has been eradicated and freedom from potato spindle tuber viroid has been successfully maintained in all of the seed potato growing areas in the United States.     

Opportunities to increasing dry season rice productivity in low temperature affected areas

Rice is a major source of food for more than 2.7 billion people and planted on nearly 130 million hectares in which 10% is subjected to low temperature problems. Dry season (DS) rice cropping has been expanding in the high altitude lands in Asia and the low temperature is one of constraints to rice production. This study aims to quantify the potential for growing irrigated rice in DS, particularly in high altitude areas in northern Lao PDR where temperatures are low and pose problems for seedling establishment. Research focused on identifying sowing times to avoid the detrimental effects of low temperature, the optimal seedling age for transplanting, the potential of plastic covers and half burnt paddy husk layer to protect nursery seedbeds from low temperature and varieties suitable for this environment. Studies were conducted over 5 years and were examined at six locations. In two locations, where temperature was favorable for rice production throughout the DS, time of sowing was not critical. In higher altitude areas in northern Lao PDR, however, low temperature caused establishment problems in nurseries. In these areas, mid-November sowing before the onset of winter reduced the low temperature effects on seedling establishment while sowing in mid winter (December and January) increased the risk of failure. There were no significant effects of seedling age (25-, 35- and 45-day old) for transplanting on yield for DS rice. Using clear plastic to cover the nursery increased minimum temperatures on average by about 4 °C, which improved seedling growth and resulted in higher grain yield. The mean minimum temperature of 12 °C for 30 days after seeding is critical and temperature below 12 °C resulted in high risk of crop failure due to poor germination, poor seedling growth or insufficient seedlings. Rice needs to be sown at times where the mean minimum temperature exceeds 12 °C or plastic covers are required to protect seedlings. The current popular varieties did not show significant tolerance to extreme cold temperature.     

Genetic diversity and association mapping for salinity tolerance in Bangladeshi rice landraces

Breeding for salinity tolerance using Bangladeshi rice landraces and understand genetic diversity has been limited by the complex and polygenic nature of salt tolerance in rice genotypes. A genetic diversity and association mapping analysis was conducted using 96 germplasm accessions with variable response to salt stress at the seedling stage. These included86 landraces and 10 indica varieties and lines including Nona Bokra, from southern Bangladesh. A total of 220 alleles were detected at 58 Simple Sequence Repeat(SSR) marker loci randomly distributed on all 12 rice chromosomes and 8 Sequence Tagged Site(STS) markers developed for genes SKC1, DST, and SalT. The average gene diversity was 0.5075 and polymorphism information content value was 0.4426, respectively. Cluster analysis revealed that 68 and 21 accessions were clustered into 2 distinct groups, possibly corresponding to indica and japonica groups, respectively and the remaining 7 landraces were classified as an admixed group. In addition to Wn11463, the STS marker for SKC1, RM22418 on Chr. 8 was significantly associated with salinity tolerance, at the location of a QTL detected in previous studies. Our findings of favorable alleles associated with salinity tolerance in Bangladeshi rice landraces, as well as the development of STS markers for salt tolerance genes, will be helpful in future efforts to breed salinity tolerance in rice.     

Genetic diversity of rice sheath blight isolates (Rhizoctonia solani AG-1 IA) from different rice cultivars

Rhizoctonia solani AG 1 IA, the non specific, soil borne, and plant casual agent of rice sheath blight, occurring world widely in rice fields, has become a major disease to rice. In this study,relationships among R. solani AG 1 IA isolates, collected from different rice cultivars were reported.     

早稻无盘旱育抛秧技术在湘北地区应用初报

2005年在杂交早稻上试验无盘早育抛秧技术，表现秧苗素质好，大田分蘖快，有效穗增加．单产提高，具有显著的经济效益，与对照比较,增产10．2％，纯收入增加24．3％。由于未使用塑料软盘，对保护农业生态环境也有较好的作用。     

水的垂直渗透对水稻生长发育的影响研究

通过研究水的垂直渗透对水稻返青、水稻分蘖、水稻产量的影响,提出通过完善排水工程、设施,定期深耕田地,改善土壤渗透性,为水稻高产奠定基础。     

苏北沿海地区灰飞虱生规律及影响因素分析

灰飞虱在射阳地区一年发生五代,越冬代及一代危害麦子等夏熟植物,夏熟植物成熟后,一代成虫迁飞到水稻等秋熟植物繁殖二、三、四代.麦子出苗后,四代若虫转移到麦苗上越冬.影响因素主要有水稻品种布局的变化、耕作方式、种植制度、水稻育秧方式、春季气候.     

穴株数对水稻生长发育及产量的影响

本试验对2株/穴、3株/穴、4株/穴、5株/穴、6株/穴的生育进程进行跟踪调查,结果表明,每穴插秧株数以3～4株为宜,产量水平较高,经济效益较佳。