Weeding techniques in transplanted and direct wet-seeded rice in Pakistan

Field studies were undertaken to explore the weed management strategies for transplanted and direct wet-seeded rice in the Dera Ismail Khan district of North-west Frontier Province, Pakistan. The experimental design was a randomized complete block with a split plot arrangement. The main plots consisted of two planting techniques (transplantation and direct seeding), while weed control practises assigned to the subplots included the use of the granular herbicide Sunstar 15WG (ethoxy sulfuron), Machete 60EC (butachlor), conventional hand weeding, and the weedy check (untreated control). Data were recorded on weed dynamics and the agronomic parameters of the rice crop. Economic analyses on the data were also run. The weed density and biomass were lower in the transplantation plots than the direct-seeding plots. The herbicides ethoxy sulfuron and butachlor reduced the density over the weedy check, with a density comparable to hand weeding in 2002, but slightly higher in 2003. As a result of weed management by hand weeding and herbicides, the paddy yield and its components were significantly higher for the transplanted method compared to the direct-seeded method. The comparable yield of herbicides with hand weeding offers an option for the use of herbicides as an alternative management tool. In light of our findings, it is concluded that for good economic returns, rice crops may be transplanted rather than direct-seeded. The herbicides ethoxy sulfuron and butachlor offer a weed control cover comparable with hand weeding under the transplantation method, while butachlor is good for controlling weeds even under the direct-seeded conditions in the agroclimatic conditions of the area.     

以电导法配合Log istic方程确定茶梅‘小玫瑰’的抗寒性

 摘　要: 以不同处理时间、不同低温处理下茶梅‘小玫瑰’叶片的电解质外渗率(REC) 变化作曲线,并结合Logistic方程分别计算茶梅的半致死温度(LT50 ) , 结果发现在低温处理6 h以上, 茶梅叶片的REC均随着处理温度的降低而呈“S”形上升, 由此计算出“S”形拐点对应的温度即为茶梅叶片的LT50 , 其温度值在- 1215℃至- 14℃之间, 这可认为是茶梅抗寒能力的重要指标。关键词:     

Estimation of daily and total lactation milk yield of Chios ewes from single morning or evening records

Linear models were developed and evaluated for the estimation of daily (24 h) and total lactation milk yield of dairy sheep from single morning (am) or evening (pm) milking records. A total of 22,908 individual test-day milk records of 5110 ewes of the Chios breed, raised in 46 flocks, were used. Depending on the model, different daily milk yield estimates were derived for each ewe, accounting for lactation number, stage of lactation, season of previous lambing and interval between successive milkings. Daily milk yield was also estimated from doubling the single am or pm record. Actual and estimated yields were compared using root mean square errors (RMSEs), mean absolute differences, an accuracy parameter defined as the ratio of the actual yield variance over the sum of the variances of actual yield and absolute difference, and the product moment correlation between estimated and actual yield. Results were validated on independent datasets. Linear models resulted in less biased and more accurate estimates of the daily milk yield than simply doubling the am or pm record. Root mean square errors decreased by 7-37% and the mean absolute difference was reduced by 1-4% of the average daily yield. Higher accuracy and correlation were obtained from linear model application than doubling. Total lactation milk yield was predicted based on actual daily yield and compared to predictions based on estimated daily yield from am or pm records, as well as directly on single milking records. Root mean square errors obtained when daily yield had been estimated with linear models were 26-35% lower compared to doubling the am or pm yield and 0-13% lower compared to estimating the total lactation yield directly from single milking records. Linear model application also resulted in lower mean absolute difference and higher accuracy and correlation than doubling the am or pm record. Recording the yield of a single milking (am or pm) instead of both can benefit milk recording by reducing its cost and increasing farmer participation. In this context, linear models developed in the present study can be used for the accurate estimation of daily (24 h) and total lactation milk yield from single milking records.     

硝酸钙和IAA对温州蜜柑果实钙含量及其品质的影响

在花期、花后1周、3周、采前2周对龟井蜜柑进行Ca(NO3)2、IAA和IAA+Ca(NO3)2喷布处理,同时测定了不同发育时期各处理果实钙含量及其采后果实的主要品质,并与采后浸钙处理和完熟采收果实品质进行了对比分析,结果表明:1)各处理的果皮钙含量在花后51d和112d均有所提高,但此期整个果实钙含量并无显著性差异,采收时各处理整个果实和果肉钙含量均显著高于对照;2)采收时各处理果实的可溶性固形物和可滴定酸均显著低于对照,可溶性糖、单果重、果皮色差值和相对电导率与对照无显著性差异,各处理糖酸比显著高于对照;3)采后30d时IAA+Ca(NO3)2喷布和采后浸钙处理果实的维生素C及完熟采收果实的可溶性固形物和可溶性糖均显著高于对照和其他处理。     

京郊露地蔬菜平衡施肥产量和养分数据库的建立

蔬菜施肥推荐需要了解作物的养分需求和收获部分带走的养分量。根据京郊地区露地蔬菜生产的调查结果,结合已有的相关文献和专家意见,建立了京郊露地主要栽培蔬菜的包括目标产量、经济产量、残茬产量、养分需求量、经济产量部分养分含量、作物残茬养分含量等内容的数据库。     

罗汉果生产技术研究的思路与发展对策

探讨了罗汉果生产技术研究思路，提出选育、引进优良品种，培育茎尖脱毒壮苗，建立种薯基地，采用容器无土栽培、平地栽培、设施栽培，施用天敌真菌、接种VA菌根真菌防治根结线虫等技术建议。     

H5亚型禽流感灭活疫苗免疫后鸡血凝抑制抗体动态变化观察

选择国家指定的两个厂家生产的禽流感灭活疫苗(H5亚型,N28株)进行无母源抗体来航鸡的免疫试验.通过鸡免疫后血凝抑制(HI)抗体的动态性检测,对两个疫苗的免疫效果进行了观察.研究结果表明,两个疫苗均具有良好的免疫效果,但也存在一定程度的差异;加强免疫可以明显提高抗体水平,延长免疫保护时间.     

辣椒红色素的检测方法

综述辣椒红色素的多种检测方法,即溶解性试验、显色反应、分光光度测定法及薄层层析法。     

辣椒新品种镇江3号的选育

中晚熟杂交一代辣椒镇研3号是以江苏本地羊角椒自交系Y9007为母本,由甘肃酒泉引进的甜椒自交系T9218为父本配制的一代杂交组合。镇研3号为中熟辣椒品种,果形为牛角形,纵径15cm,肩横径5.0cm、肉厚0.40cm,单果平均重42g。果面光滑,青熟果绿色、味微辣,风味佳,适宜在长江流域或南方保护地栽培种植,667m2产量约为4200～5000kg。     

陕西线辣椒病毒病病原检测简报

在陕西省线辣椒主产区多点随机取样,采用酶联免疫吸附法对陕西线辣椒病毒病毒原进 行了鉴定。结果表明,陕西线辣椒病毒病毒原有BBWV、PMMV、CMV、ToMV、TMV、PVY和 CVMV。优势毒原是BBWV、PMMV和CMV。