Relationship between Leaf Area Index and Yield of Hybrid Rice

In the research, 20 indica hybrid rice varieties were investigated under high-dense and low-amount, mid-dense and mid-amount and low-dense and high-amount fertilization conditions in order to explore correlation between LAI in ful heading stage with yield and to analyze yield differences, yield components, material accumulation and transferring, as wel as correlation between key cultivation factors and yield. Final y, approaches and key technology for yield breakthrough were dis-cussed, which provides theoretical and technological references for rice high yield.

Conservation of Traditional Rice Varieties in a Globally Important Agricultural Heritage System (GIAHS):Rice-Fish Co-Culture

The traditional rice-fish farming system is selected as a ＂globally important agricultural heritage system＂ （GIAHS） by the Food and Agriculture Organization （FAO）,United Nations Development Programme （UNDP）,and Global Environment Facility （GEF）,etc.In Zhejiang Province of China,where the pilot site for this GIAHS farming system is located,we compared the use of traditional rice varieties in rice-fish co-culture and rice monoculture.Further,we determined how traditional rice varieties were performed in this rice-fish system.Only 19% of the farmers who practiced rice monoculture planted traditional varieties while 52% of farmers who practiced rice-fish co-culture planted traditional varieties.Traditional varieties represented 13% of the total land cultivated under rice in the rice-fish system but only 2% in the rice monoculture system.In the rice-fish system,yield was lower for traditional rice varieties than hybrid varieties but application of fertilizers and pesticides was also lower.In a field experiment in the rice-fish system without pesticides,rice planthopper numbers and sheath blight incidence were lower from three traditional varieties than one hybrid variety;yields were 8 to 32% lower from the traditional varieties than the hybrid.Our results showed that traditional rice varieties can be preserved through conserving GIAHS rice-fish co-culture.Our study also indicated that traditional rice varieties can survive in the rice-fish system because these varieties are helpful to the whole system and beneficial to the farmers.

Influence of Weeding on the Performance of White Maize Varieties

The experiment was conducted at agronomy farm of Sher-e-Bangla Agricultural University, Dhaka from November 2017 to April 2018 to investigate the influence of weeding regimes on the performance of white maize varieties. The experiment comprised two varieties viz. YANGNUO-3000 and PSC-121, designated as V1 and V2 respectively combined with four weed control treatments viz. T0 = No weeding, T1 = One hand weeding at 60 DAS (days after sowing), T2 = two hand weeding at 40 DAS and 60 DAS and T3 = Weed free after 40 DAS. The experiment was laid out in RCBD (factorial) with three replications. PSC-121 showed the superior performance in terms of plant height, leaf number plant-1, number of grains cob-1 (468.75), 100 grains weight (35.0837 g), grain yield (8.28 t ha-1), stover yield (6.56 t ha-1) and harvest index (55.58%) over YANGNUO-3000. In the case of weed control treatments, the highest plant height, leaf number plant-1, number of grains cob-1 (464.54), 100 grains weight (37 g), grain yield (9.25 t ha-1) and stover yield (7.46 t ha-1) were reported from T3. All the parameters studied were found lowest with T0. However, in terms of interaction, no single interaction was superior to other alternatives. But in most of the cases V2T3 showed the highest values regarding the maximum plant height, leaf number plant-1, number of grains cob-1 (494.97) and 100 grains weight (38 g). V2T3 showed the highest grain yield (9.33 t ha-1), whereas, V1T0 showed the lowest grain yield (5.49 t ha-1). The lowest weed density and weed biomass (12.17 no. m-2 and 4.33 g·m-2) was recorded from T3. The highest weed control efficiency (94.38%) was also recorded from T3. In the case of variety V2 showed better performance in terms of weed density, weed biomass and WCE (46.32%).

Breeding of a New Fruit Radish Variety"Sheng Qing Yi Hao"

"Sheng Qing Yi Hao",a new fruit radish F1 hybrid,which was bred from HSR54 A,a self-bred sterile line,and HS1356,an excellent male parent.The flesh of the roots is emerald green,delicate,sweet and crisp.The skin of the roots is little spicy.It takes about 70 d from sowing to maturity.The fleshy roots have a length of 22-27 cm,a diameter of 6-8 cm,and a root weight of 0.8-1.1 kg.The F1 hybrid has stronger resistance to soft rot disease in the field the control group‘Chengyangqing’.It is suitable for cultivation in greenhouse in spring and open field in autumn in north China.