Evolving splines and seasonal unit roots in weekly agricultural prices

The univariate statistical properties of agricultural price series need to be examined as a first step in the analysis of price transmission mechanisms. However, in the case of weekly price series, increasingly available, the testing procedures usually applied in this step are not suitable to deal with evolving seasonal effects. In this study, a method of testing for seasonal unit roots in weekly series of agricultural prices is described. When the deterministic seasonal component does not remain constant over time, the restricted evolving spline model (RESM) is shown to be a useful parametric formulation to capture the deterministic seasonal pattern. Therefore, the RESM model should be included as a deterministic component in auxiliary regression for unit root tests at seasonal frequencies. This proposal is applied to three weekly series of Canary Islands banana prices. From the standard seasonal unit root tests, the null hypothesis is failed to be rejected at the 5% or 10% significance level at some seasonal frequencies for each one of the series. Once critical values are obtained by simulation exercises when the RESM model is included, the hypotheses of unit root are rejected at each one of the seasonal frequencies for all of the three series.     

某公司租用土地开发香蕉项目综合效益分析

A comprehensive evaluation is made in this article on the eco-benefit, social benefit, and economic benefit from banana planting of a company in three planting bases in Xinping County. Before the banana is planted, the land is classified into sloppy land, woodland and arable land We carefully study the three types of land, analyze the various effects and benefits made by banana planting on these types of land, and make a comprehensive comment.     

CARBAP and innovation on the plantain banana in Western and Central Africa

Plantain is considered as a major staple food in Central and Western Africa with a production estimated at approximately 8 million tons (Lescot, 2007). But almost all small producers do not have access yet or do not use the innovations from research, and yields are thus very low. CARBAP (African Research Centre on Banana and Plantain) is a novel example of a regional research partnership for plantains and bananas across Western and Central Africa and particularly Cameroon, Democratic Republic of Congo, Côte d'Ivoire, Ghana, Guinea and Nigeria. It links researchers, creates novel platforms, undertakes training and disseminates materials. It encourages mass propagation by farmers—after training, some 10 million new disease-resistant plants were spread to farms over two years.     

香蕉假茎机械化切块还田的工艺价值分析

通过运用价值工程的分析,提出香蕉假茎先分段再切块还田的工艺思想。对比当前的人工砍切香蕉假茎废弃方式、切碎还田的工艺,与切块还田工艺等进行价值的功能成本分析与评价,确定了香蕉假茎切块还田工艺,更切合蕉区实际的香蕉假茎还田工作。     

几种废弃物作添加料养殖黄粉虫的试验

试验分别用西瓜皮、香蕉皮、水浮莲与麦麸按不同比例混合养殖黄粉虫高龄幼虫．探讨不同处理对黄粉虫生长繁殖的影响。结果表明：添加50％比例西瓜皮、香蕉皮的配方养殖黄粉虫总体效果最好。     

香蕉酒生产工艺研究进展

香蕉酒作为一种具有独特风味的果酒逐渐受到市场的追捧。香蕉酒的传统工业生产工艺简单,随着市场对果酒酒品的追求,发酵工艺研究的改进越来越受到重视。本文总结了香蕉酒的传统工业生产工艺,通过对香蕉酒工艺优化发展的概述,并结合相关酒品评价方法,总结了香蕉酒的工艺优化方法,提出了改进发酵工艺的措施。     

两岸香蕉标准对比分析

文章对两岸香蕉的标准数量、质量等级标准、农药残留限量标准进行了比较分析，旨在为订立两岸香蕉的共通标准提供技术参考。     

Perceptions and outlook on intercropping coffee with banana as an opportunity for smallholder coffee farmers in Uganda

Coffee and banana are important cash and food crops in Uganda and the surrounding East African highland region. Production is dominated by smallholders that have limited arable land and often coffee and banana are intercropped. No significant research and development efforts have been undertaken over the last few decades on this coffee/banana intercropping system. Because recent studies suggest that this system could be a practice with high benefits to the farmers, we decided to study the perceptions of stakeholders along the coffee value chain starting with farmers. Perception analysis based on open-ended interviews following interview guides revealed that a major limitation for the sustainability of this system was poor soil fertility conditions. Perceptions on the benefits of intercropping differed little among coffee actors; that is, banana intercropping provides additional food and income from smallholders’ limited land and helps farmers reduce risks related to drought, pest/disease attacks and coffee price volatility. However, farmers’ desire to minimize risks does not match the objective of stakeholders higher up the coffee value chain to maximize coffee production. Furthermore, research by public institutes, both national and international, is primarily organized for single crops and not systems. We conclude that the institutional setting of the coffee sector hampers the promotion of intercropping, despite the benefits for the farmer.     

我国香蕉秸秆回收利用现状研究

香蕉属于热带水果,起源于亚洲东南部,是国际性大宗水果,具有生长周期短和产量高等特点,每年收获大量香蕉产品的同时也产生几乎等量的香蕉秸秆等农业废弃物。为此,香蕉秸秆如何进行回收利用已成为一个热议的科学课题。本论文结合研究现状,对我国香蕉秸秆回收利用的现状进行阐述。     

Implications of efficiency and productivity change over the season for setting MEY‐based trigger targets

The banana prawn component of Australia's Northern Prawn Fishery (NPF) is currently managed through the use of annually updated trigger catch rates as a means of achieving maximum economic yield (MEY) in the fishery, taking into account the estimated price and cost components for that season. The estimation of these target catch rates is based on the assumption of relative homogeneity of the fleet in terms of efficiency, productivity and cost structure. In this study, these assumptions are examined through the estimation of a stochastic production frontier. While technical efficiency varies between vessels, average efficiency is relatively constant over the fishing season. However, average productivity of the fleet increases, with smaller vessels (in terms of engine power) exiting the fishery earlier. This would likely increase the average cost of fishing towards the end of the season, with implications for setting the target catch rate. Based on a standard assumption as to the relationship between costs and vessel size, we find that the MEY target catch rates are most likely currently underestimated. However, the implementation of a precautionary minimum catch rate (which is above the MEY target catch rates for recent years) has maintained the fishery at a profitable level.