Prediction of the occurring amount of whitebacked planthopper(WBPH) on early rice by sea temperature

Whitebacked planthopper (WBPH) is a kind of long-distance migratory pest. Its occurring amount is closely related to the climate change of large sphere. In recent years many researches have reported that the climate of large sphere was affected by the Pacific sea temperature (ST). We studied the long-range forecast of the occurring amount of WBPH by using data provided by State Meteorological Administration, China. Taking the highest amount per 100 hills in main injurious generation of WBPH on early rice in Ganzhou Prefecture, Jiangxi Province as the object of forecast (y), and dividing y into six grades,i.e. 1-6 grades means the sequence of 1,000,1,001-3,000, 3,001-5,000, 5,001-10,000,10,001-20,000, and over 20,000 heads in order. Three regions were selected from the 286 grid points in the northwest Pacific. Region A was the maritime space between Black Tide Region and California Cold Flow Region, 160°E-130°W,

Performance of Five Early Indica Rice Varieties under Direct Seeding in Jiangbei District

Comparative experiments were conducted on five conventional indica rice varieties,including Yongxian 15,Zhongzao 39,Shunda 135,Zhongzu 143,and Zhongzu 18.Under direct seeding conditions,their growth period and yield performance were investigated.The results showed that the yield of Zhonggang 143 and Shunda 135 was higher than that of Yongxian 15(CK),and Zhonggang 143 had the highest yield of 7.494 t/hm 2,followed by Shunda 135(7.467 t/hm 2);Yongxian 18(CK)has a yield of 7.326 t/hm 2.Taking into account factors such as field growth,yield,and growth period,Zhongzu 143 and Shunda 135 can be further promoted to optimize the early rice variety structure in Jiangbei District.

Effects of different mechanical direct seeding methods on grain yield and lodging resistance of early indica rice in South China

Direct seeding of rice has become a main planting method due to the low labor input and high economic benefit in South China.Dry direct seeding(DDS)has been widely used for single-season rice planting establishment.However,few studies have examined the performance of early-season indica rice under mechanical dry direct seeding.A two-year field experiment was conducted with two indica rice cultivars(i.e.,Zhongjiazao 17 and Zhuliangyou 819)to study lodging characteristics and grain yield formation under DDS,flooded direct seeding(FDS)and wet direct seeding(WDS)patterns.The results showed that the annual grain yield in DDS was higher by 14.42–26.34%for cultivar ZLY819 and 6.64–24.58%for cultivar ZJZ17 than in WDS and FDS,respectively,and these increases were mainly attributed to the improvement of the panicles.The DDS pattern significantly increased the seedling emergence rate of early indica rice cultivars,and increased total dry weight and crop growth rate.Meanwhile,shorter basal internodes,better stem diameter and stem wall thickness and lower lodging index were found in DDS in contrast to FDS and WDS.In particular,DDS improved the stem lodging resistance.Our results suggested that the appropriate direct seeding method was beneficial for improving the grain yield and lodging resistance of early indica rice.

Resistance Evaluation of Some Hybrid Rice, Conventional Early Indica and Late Japonica Rice to Magnaporthe grisea

Thirty isolates of Magnaporthe grisea collected from 18 provinces/cities representing 21 pathotypes and 9 different lineages were inoculated to rice varieties with known resistance genes and some hybrid rices, conventional early indica and late japonica varieties cultivated recently in China. Virulence spectrum of the 30 isolates was very different, showing that they recognize numerous different resistance genes. Varieties also revealed very different resistance patterns showing that they carry different resistance genes or combinations of resistance genes. On the basis of comparisons with international differential varieties with known resistance genes, resistance genes in certain Chinese varieties could be speculated. The results indicated that some of them were resistant to most of the isolates tested and that they could be of interest as resistance sources for hybrid parents or to be planted in the field directly.

Performance of Soft Rice (Oryza sativa L.) Grown in Early Season in China

Eating quality is of paramount importance to rice(Oryza sativa L.)consumers and soft rice with low amylose content has become popular in China.This study was conducted to evaluate the performance of soft rice grown in the early season(ES)dominated by non-soft rice.Field experiments were conducted in Yongan and Santang,Hunan Province,China from 2016-2018.Results showed that grain amylose content in soft rice cultivars was consistently lower in the ES compared to the late season(LS).The lower grain amylose content in the ES compared to the LS was partly attributed to higher average daily mean temperature during grain filling.No significant relationship was observed between grain yield and seed amylose content in ES rice.Soft rice cultivars produced a similar average grain yield to non-soft rice cultivars in the ES.These results encourage breeders to develop more ES rice cultivars with soft texture to meet the consumer demand for this type of rice.

An early maturing rice variety of high quality—Zhefu 218

Early maturing rice variety of high quality "Zhefu 218" was developed by prof XIA Yingwu, Zhejiang Agricultural University, Hangzhou, China. The growth period of the new rice variety is 106 d and its average yield is about 5.25-7.08 t / ha. It has the speciality of early-maturing combined with good quality. Not only the grains of "Zhefu 218" are of excellent cooking, but also of nutritive quality. The flavour of the cooked rice of"Zhefu 218" is considerably better than those of the ordinary rice cultivars here.

The impacts of timing and insecticides at early stage of late rice on the population development of brown plant hopper(BPH)

Field experiments were carried out in northern Zhejiang Province. Three insecticides (methamidophos,Shachongshuang and triazophos) were used to control the rice leaffolder Cnaphalocrocis medinalis and rice striped stemborer Chilo suppressalis in rice fields during 18—27 days after transplantating. The impacts of timing and insecticides on the population development of brown planthopper Nilaparavata lugens was surveyed by direct counting on the plants or by tapping method.

Simulation of Potential Productivity of Early Season Rice Varieties in Different Reqions of South China

Rice is a staple food crop in China.Since the 1950’s,many new varieties havebeen used and resulted in great increase ofyield.However there were still some barriersin the nationwide extension of new varietiesdue to the insufficient information about thecharacteristics of varieties.So,it is impor-tant to find ways of determining the potential

Analysis of Super-high Yield Population in Rice Zhongzao 39

[Objectives] The paper focused on the way how to promote yield of early indica rice Zhongzao 39. [Methods] At different yield levels, the yield components of super-high yield population in Zhongzao 39 were analyzed. Correlation analysis, regression analysis and path analysis were performed to analyze the relationship among traits and their contributions to yield. [Results] The performance of ear, grain and weight in Zhongzao 39 showed significant differences among different yield levels. It showed that the direct contributions of main economic traits to yield were determined to be 1 000-grain weight〉effective ears〉seed setting rate〉filled grains per ear. [Conclusions] The super-high yielding and effective cultivation techniques were suggested as follows： on the basis of the increasing number of effective ears and the remaining of grain weight, a stable seed setting rate should be considered.

Breeding and application of Jiafuzhan,a new elite early indica rice cultivar in China

After 20 years of dedicated research,Jiafuzhan has been successfully developed under the new technologies in breeding high-quality early indica rice cultivars.Its rice quality has almost reached the A-level Editable Rice of Agriculture Department of China,and its average production reaches 400-500 kg/(666.7 m^(2)).This new cultivar also has other characteristics such as enhanced resistance of blast and fallen,steady productivity,and strong adaptability.Jiafuzhan has been put into production of over 11.4×10^(4)hm^(2)in Fujian Province and has been introduced and extended in other Provinces like Jiangxi,Guangdong,and Guangxi,China.The successes of breeding Jiafuzhan is a solution to the existing perennial problems in the rice industry,such as poor grain quality of big-grain rice and early indica rice,low productivity,and poor blast resistance of elite rice.