Sweet potato (Ipomoea batatas) is one of the stable tuber crops consumed by many households in Nigeria. It can be found in different varieties and exist in many colours of skin and flesh. The production of this important crop is still very low, thereby compromising food security. Sweet potato is one of the target commodity crops under the Nigerian Agriculture Sector Investment Opportun...

The aim of this work is studying the use of copulas and vines in numerical optimization with Estimation of Distribution Algorithms (EDAs). Two EDAs built around the multivariate product and normal copulas, and other two based on pair-copula decomposition of vine models are studied. We analyze empirically the effect of both marginal distributions and dependence structure in order to show that bo...

The carotenoid content was examined in leaf and berry tissues of grapevines (cv. Cabernet Sauvignon) grown either under ambient conditions or under a polyester film to reduce UV light by 98%. Total carotenoids in leaves were less in vines grown under the UV screen. Levels of beta-carotene decreased with berry development around veraison. This effect was more pronounced in vines grown under redu...

—The use of automated grape harvesters in the Cape Wine Growing region has resulted in controversy regarding their effect on the chameleon Bradypodion pumilum. We investigated densities of B. pumilum during harvesting at a vineyard near Stellenbosch, South Africa. During dedicated surveys, no chameleons were found in vines, while vegetation surrounding the vines contained densities as high as 1...

With the economic pressures for high yields and production efficiency, there has been increasing use of the method of minimal or mechanical pruning due to its reduced inputs and higher yields. Yet, many times the yields on minimally-pruned vines may be too high for the juice Brix and quality required by the industry. Since this production method changes many of the basic relationships we have d...