Although traditional knowledge on the medicinal properties of Boerhavia diffusa L. of the family Nyctaginaceae is known, production potential, assimilate partitioning to economic yields and agronomic requirements for commercial cultivation are poorly understood. Consequently, the objective of this study was to identify agronomic practices that could partition more assimilate to economic components to obtain optimum yield from cultivation. A factorial experiment was carried out at the University of Peradeniya Experimental Station, Dodangolla, Sri Lanka from July 2006 to August 2008. Treatments include two types of planting materials, five types of fertilizers and five harvesting methods. The results revealed that the seedlings performed better than cuttings in all studied parameters. Among types of fertilizers, the recommendation for Ipomoea batatas (L.) Lam. (Sweet potato) was the best for production of below ground dry matter in seedling plants. The optimum rate of below ground dry matter was attained at 8 months after planting (MAP) in seedlings. Organic or inorganic fertilizer recommendation for Trianthema portulacastrum L. (Sarana) was the most suitable for harvesting of above ground dry matter of seedling plants. The study also showed that B. diffusa could be managed by repeated harvesting of above ground dry matter as a leafy vegetable at two month intervals up to six months followed by harvesting the entire plant at eight MAP for medicinal as well as a leafy vegetable. Implications of research findings are discussed | S Arulmageswaran, 'Effects of Some Agronomic Practices on Dry Matter Partitioning of Boerhavia diffusa L', vol. 20, pp.366-375, 2008

Despite the agronomic importance of potato (Solanum tuberosum L.), the interaction of atmospheric carbon dioxide concentration ([CO₂]) and drought has not been well studied. Two soil-plant-atmosphere research (SPAR) chamber experiments were conducted concurrently at ambient (370μmolmol⁻¹) and elevated (740μmolmol⁻¹) [CO₂]. Daily irrigation for each chamber was applied according to a fixed percentage of the water uptake measured for a control chamber for each [CO₂] treatment. We monitored diurnal and seasonal canopy photosynthetic (A G) and transpiration rates and organ dry weights at harvest. Plants grown under elevated [CO₂] had consistently larger photosynthetic rates through most of the growth season, with the maximum A G at 1600μmolphotonsm⁻² s⁻¹ 14% higher at the well-watered treatments. Water stress influenced ambient [CO₂] plants to a larger extent, and reduced maximum canopy A G, growth season duration, and seasonal net carbon assimilation up to 50% of the control in both [CO₂] treatments. Water use efficiency increased with water stress, particularly at elevated [CO₂], ranging from 4.9 to 9.3gdrymassL⁻¹. Larger photosynthetic rates for elevated [CO₂] resulted in higher seasonal dry mass and radiation use efficiency (RUE) as compared with ambient [CO₂] at the same irrigation level. This extra assimilate was partitioned to underground organs, resulting in higher harvest indices. Our findings indicate that increases in potato growth and productivity with elevated [CO₂] are consistent over most levels of water stress. This work can support various climate change scenarios that evaluate different management practices with potato.

It is widely accepted that a healthy diet is an important factor in preventing chronic diseases, and in improving energy balance and weight management. Studies have shown strong inverse correlations between tomato consumption and the risk of certain types of cancer, cardiovascular diseases and age-related macular degeneration. Because tomato is the second-most important vegetable in the world after potato, this horticultural crop constitutes an excellent source of health-promoting compounds due to the balanced mixture of minerals and antioxidants including vitamins C and E, lycopene, β-carotene, lutein and flavonoids such as quercetin. Improvement in phytonutrients in tomatoes can be achieved by cultivar selection, environmental factors, agronomic practices, stage of ripeness at harvest, and appropriate handling and conditioning all the way from the field to the consumer. The purpose of this paper is to review the recent literature of the main factors that can improve the nutritional quality of tomato and consequently their beneficial role in human diet. The importance of genotype selection and the optimization of environmental conditions (light, temperature, humidity, atmospheric CO₂ and air pollutants) for high nutritional value is outlined first, followed by the optimization of agricultural practices (soil properties, water quality, mineral nutrition, salinity, grafting, pruning, growing systems, growth promoters, maturity, and mechanical and pest injuries). The review concludes by identifying several prospects for future research such as modelling and genetic engineering of the nutritional value of tomato.

In the context of sustainable and less energy-dependent agricultural biomass production, an energy balance was developed for a conventional rotation of winter wheat (Triticum aestivum L.), sugar beet (Beta vulgaris L. subsp. vulgaris), adzuki bean (Vigna angularis (Willd.) Ohwi & Ohashi) and potato (Solanum tuberosum L.) under the highly fuel-dependent and material-intensive farming systems in the Tokachi region of Hokkaido, northern Japan. As annual energy inputs, tractor operations, truck transportations and grain drying for adzuki bean and winter wheat consumed the equivalent of 6.09 and 11.50GJha⁻¹ year⁻¹ in fossil fuels, respectively. Input-output table estimates of the energy consumption resulting from the use of materials necessary to agricultural production (chemical fertilizers, biocides and agricultural machines) ranged between 11.01±0.26GJha⁻¹ year⁻¹ for winter wheat and 24.38±0.35GJha⁻¹ year⁻¹ for sugar beet. Thus, total annual energy inputs for fuel and materials consumed in cultivation and transportation steps amounted to 22.51±0.26, 32.97±0.35, 20.71±1.58 and 24.44±0.41GJha⁻¹ year⁻¹ for winter wheat, sugar beet, adzuki bean and potato production, respectively. Chemical fertilizer consumption contributed significantly to the energy use, representing 25-43% of the total energy inputs. Based on regional crop production statistics (1999-2003), total energy outputs as yield and crop residue biomass were estimated at 151.3±18.1, 346.1±17.9, 42.0±18.1 and 163.8±11.6GJha⁻¹ year⁻¹ for winter wheat, sugar beet, adzuki bean and potato production, respectively, resulting in regional conventional cropping energy output/input ratios of 6.72, 10.50, 2.03 and 6.70. Sugar beet is the most promising biomass-derived energy feedstock crop in this region, due to its high energy output/input ratio and net energy gain (energy output-input). However, for the full sugar beet-based bioethanol production system, a much lower energy output/input ratio and net energy gain were expected, given the greater energy inputs required in the transformation process. In addition to altering agronomic practices, transformation technologies less dependent on fossil fuels are crucial to developing sustainable bioethanol production systems in northern Japan.