全州县优质芦笋高产栽培技术

芦笋味道清香鲜美,肉质脆嫩可口,含有丰富的维生素和氨基酸,是一种营养价值极高的药食兼用高档保健蔬菜。广西全州县生产的芦笋色泽浓绿、脆嫩香甜、营养成分含量高,远销南宁、柳州及湖南、广东等省市,产品供不应求,发展前景较好。本文从优良品种选择、营养钵培育壮苗、深层均匀施肥、无公害除草、科学合理留母茎、茎枯病综合防治六个方面入手,介绍了全州县芦笋标准化高产栽培的技术要点,以期指导广西及周边地区芦笋种植业的高效发展。     

果树嫁接的优势及关键技术

嫁接是果树无性繁殖的方法之一,即采取优良品种植株上的枝或芽接到另一植株的适当部位,使两者结合而生成新的植株。文章总结了嫁接在保持品种优良形状、丰产和提高抗逆性等方面的优势,介绍了常见的三种嫁接方法(T型芽接、木质芽接、插皮舌接);在此基础上提出了选择合适嫁接材料、注意嫁接时间、选择合适的嫁接方法、选取合适的生长点等提高嫁接成活率的措施。     

四川南部稻区稻瘟病发生危害及防治对策

该文报道了四川南部稻区稻瘟病发生危害特点,提出了不同生态区稻瘟病的防治对策及配套技术。     

大黄鱼苗淀粉卵涡鞭虫病的诊断及防治方法

淀粉卵涡鞭虫是大黄鱼苗种培育危害最大的寄生虫之一.本文对大黄鱼苗淀粉卵涡鞭虫病发生的临床症状和防控方法进行了研究,除常规防治方法外,利用双氧水与高锰酸钾合用也可起到杀灭虫体,减少寄生数量的效果.同时,本文分析和比较了发生寄生虫病的育苗池水与正常池水的水质理化因子,为有效诊断和防治大黄鱼苗淀粉卵涡鞭虫病提供基础材料.     

Technical efficiency of carp production in Nepal: An application of stochastic frontier production function approach*

Abstract

Modern aquaculture is a relatively new activity among Nepalese farmers and a small contributor to the economy. Given the abundance of water resources and fish species, rising demand for fish, and its high profitability, aquaculture has potential for future expansion if it is given appropriate attention from the government. In Nepal, productivity in aquaculture is much lower compared to other countries in the region, which suggests that there is potential for increased fish production through technological progress and improvement in farm‐level technical efficiency. However, no formal analysis has yet been conducted to assess the productive performance of Nepalese aquaculture and its potential for future improvement. Against this background, this paper examines the technical efficiency and its determinants for a sample of fish pond farms from the Tarai region of the country using a stochastic production frontier involving a model for technical inefficiency effects. The estimated mean technical efficiency is 77%, with intensive farms being more efficient than extensive farms. The adoption of regular fish, water, and feed management activities has a strong positive effect on technical efficiency.     

玉米单交种豫玉27号高产栽培措施研究

采用单因素随机区组设计对豫玉27号（原名洛单94-1）进行密度试验，结果表明：该品种对密度具有广适性，适宜种植密切为45000-75000株/hm^2。采用N、P、K三因素旋转组合设计，通过计算机模拟寻优，建立了豫玉27号的产量-施肥量数学模型；分析了N(x1)、P(x2)、K(x3)的主效应及交互效应与产量的关系，它们对产量的影响大小依次为N、P、K。筛选出玉米产量大于等于108000kg/hm^2的最优方案为：N393.15-399.15kg/hm^2、P2O5171.90-175.05kg/hm^2、K2O167.25-174.60kg/hm^2，其比例为：2.3：1：1。     

黑龙江省大豆产业发展的方向与策略

黑龙江省发展优质大豆产业化生产,具备天时、地利、人和的有利条件,建设优质大豆产业化生产基地、发展大豆经济,在发展方向上要抓住“一个为主、三个面向”,在发展策略上要抓住“三张王牌”和“两个一起抓”,在具体措施上要发挥“两个优势”、建设“两个基地”、实现“两个改变”、做到“两个加强”。     

旱作大豆综合农艺栽培措施与产量关系模型及产量构成分析

针对内蒙古大豆主产区,以蒙豆5号品种为试验材料,在旱作条件下,通过对不同施氮、磷、钾量和密度四项农艺栽培措施与产量形成的关系研究,建立了四项农艺措施与产量关系的数学模型.通过对数学模型的优化解析,提出了单产175kg/667m2以上目标产量的优化农艺栽培措施组合方案,即密度以2.05-2.19×104株/667m2、施磷(P2O5)量4.0-5.5kg/667m2、施钾(K2 O)量3.7-4.4kg/667m2、施氮(N)量4.0-4.7kg/667m2.经田间试验验证,模型和提供的优化方案可行,对生产实践具有重要的理论意义和应用价值.除单株荚数随着密度降低而增加外,单株粒数、荚粒数、百粒重及产量均随密度、施肥量增加而呈单峰曲线变化.     

Inhibiting soil loss and runoff from small plots induced by an individual freeze-thaw cycle using three rangeland species

This study investigated the role of three rangeland species viz. Agropyron trichophorum, Medicago sativa, and Lolium prenne on mitigating of effects of a freeze-thaw (FT) cycle on runoff generation and soil loss from small experimental plots. Small plots (0.5 × 0.5m) were prepared in three replicates for control (i.e., under a FT cycle only) and treatments (i.e., individually planted with the study species and subject to a FT cycle). The treated plots were then placed at a slope of 20% and subjected to simulated rainfall with intensity of 70 mm h⁻¹ and 30 min duration. The results of the study showed a significant effect (P < 0.05) of the plants on controlling runoff and soil loss after a FT cycle. Also, the detrimental effects of the FT cycle due to performance of ice lenses and formation of an active melting layer in the soil surface were ameliorated by the presence of litter on the soil and root-binding effect of the plants. Time to runoff increased by 54, 111 and 10%, runoff volume decreased by 27, 68 and 0.4% and soil loss changed by −34, −62, and +6.5% in the plots planted with A. trichophorum, L. prenne and M. sativa, respectively. The results of the current study indicated that L. prenne had the maximum benefit on reducing runoff and soil loss from the plots undergoing a FT cycle.