International Water & Irrigation

33 Introduction The Helianthus Annuus or Sunflower, is a globally popular plant, not only because of its attractive round flower head and rich golden colouring, bearing a strong resemblance to the sun. Apart from being pleasant to the eye, the Sunflower is amongst the top main world oil-producing plants. Sunflower oil is not only a renowned source of both nutrients and vitamins for human consumption feed as well as feed for animals. In the years of spiralling oil prices, sunflower oil was recognized for its potential of becoming amongst the principal raw materials in biodiesel production. Sunflower plants are cultivated in each of the World’s continents., with global production reaching more than forty-four million tonnes annually. While close to two-thirds of all sunflowers cultivated annually come from Europe, South America take a share of the industry, particularly Argentina with around three million tonnes with Mexico lagging not that far behind. In Brazil, less than 200,000 tonnes are cultivated annually, with the industry centralized in the states of Mato Grosso, Minas Gerais and Goias. Over the years considerable research has been implemented to ascertain the ideal Sunflower variety. When choosing the right varieties for a particular function, various factors must be taken into consideration particularly during the initial implementation phase of the sunflower crop, with considerable challenges caused as a result of poor interaction between plants and their environment. Selection of the most suitable crop varieties for a particular location needs to take into account several important parameters to assess their maximum agricultural potential. These take into account: • Crop yield, • Plant growth (phytomass accumulation) or the primary process of CO2 assimilation, • Transpiration rate, • Water potential in the plant and growth rate. The financial viability of cultivating sunflower crops in the semi-arid regions of Brazil semiarid region, typified by above-average temperatures and high rates of luminosity can be related to the selection of adapted varieties to the region as well as efficient irrigation management. The region’s growers have to relate their crop efficiency levels to the balance soil, water, plant and atmospheric conditions to optimize what is known as the morph physiological processes of the plant and increase its yield. To receive the maximal results, growers in the region carried out a series of tests designed to evaluate the morph physiological and productive characteristics of sunflower varieties grown under drip irrigation in the Sub-Mid Sao Francisco River Valley region of Brazil. Material and methods The assessments were at a branch of the BrazilianAgricultural Research Corporation situated in the State of Pernambuco, in the North East of Brazil, The region’s climate is “typically tropical”, with its rainy season running through the winter delivering an annual average precipitation of less than 800 mmwhich is irregularly distributed. Local annual average temperature can range between 23° to 27 °C, with annual evaporation levels running at around 2,000 mm and annual relative humidity of approximately 50%, To precipitate the field trials, the field was portioned using a randomized block experimental design with four replications used. Trials were carried out using 21 varieties and hybrids of sunflower (See Table One) . The plot was separated into six six meter long rows, spaced 70 cms apart, with the plants Evaluating the productive responses of irrigated sunflower varieties in Brazil In the years of spiralling oil prices, sunflower oil was recognized for its potential of becoming amongst the principal raw materials in biodiesel production