the issue of convergence or divergence of productivity has important policy for regional poverty reduction and increasing standards of living. if productivity converges to a common level without intervention, there will be little need for explicit policies in lagging regions to promote the catch up. on the other hand, if productivity undergoes a divergence trend, then explicit policies would be...

This study examines, using quantile regression, the linkage between food security and efforts to enhance smallholder coffee producer incomes in Rwanda. Even though in Rwanda smallholder coffee producer incomes have increased, inhabitants these areas still experience stunting and wasting. This study examines whether the distribution of the income elasticity for food is the same for coffee and no...

an indirect tarns-log production function was employed to estimate the demand functions for such inputs as: fertilizer, seed, pesticide, water recourse and machinery as subject to budget constraint and while using data related to cotton producers in the three provinces of north khorasan, khorasane razavi, and south khorasan in 2007-8. lagrange coefficients with relation to cotton producers in t...

With an assumption that the larvae of cabbage looper, Trichoplusia ni (Hübner), a secondary pest of cotton, Gossypium hirsutum (L.), could move between cotton plants in the field, we conducted a series of laboratory experiments to determine the larval movement, food choice, consumption, survival, and development on Bt (Bollgard II expressing Cry1Ac and Cry2Ab) and non-Bt cotton. On non-Bt cotto...

As regards decreasing cotton cultivation in Iran during these years, the degree of risk taken by a cotton cultivator in the agricultural part is important. The studies showed that the cotton crop yield during the past years did not have enough growth and the cotton cost product in the period of study cotton production costs, has increased. In this paper, the risk orientation of cotton cultivato...

We use a regulatory model with resistance evolution in two pests to insecticidal Bt cotton and pyrethroids (a conventional insecticide) to examine non-Bt cotton (refuge) planting requirements designed to manage Bt-resistance evolution in the midsouth. Our analysis suggests that reduced refuge requirements would enhance producer profitability, sprayed refugia are more cost effective than unspray...

Aphids are infected with a wide variety of endosymbionts that can confer ecologically relevant traits. However, the bacterial communities of most aphid species are still poorly characterized. This study investigated the bacterial diversity of the cotton aphid Aphis gossypii associated with Bt cotton in northern China by targeting the V4 region of the 16S rDNA using the Illumina MiSeq platform. ...

Transgenic cotton that has been engineered to produce insecticidal toxins from Bacillus thuringiensis (Bt) and so to resist the pest cotton bollworm (Helicoverpa armigera) has been widely planted in Asia. Analysis of the population dynamics of H. armigera from 1992 to 2007 in China indicated that a marked decrease in regional outbreaks of this pest in multiple crops was associated with the plan...