Sunflower in the off season?

Sunflower cultivation, despite the plant having been domesticated by man around 5 thousand years ago, was only introduced in South America in the 1990th century, with Argentina emerging as one of the largest producers in the world. In Brazil, it was introduced, first in the south of the country, by European immigrants, due to the habit of consuming roasted almonds. From the beginning of the XNUMXs, there was a significant increase in demand for sunflower oil, considered healthier due to its higher content of polyunsaturated fats and also a higher level of linoleic acid, essential for the human body.

This growth in demand in recent years has led to a tendency for supply to increase and a consequent reduction in the price differential in relation to soybean oil, which has favored an increase in consumption from 4 thousand tons in 1993 to around 40,9 thousand tons in 1997.

Low prices

As the prices paid to farmers for the grains produced continued to be discouraging, this growing demand was basically met with imported products, mainly from Argentina, meeting national production for just 4,5% of consumption. Fortunately, 37% of imports in 1997 are represented by crude oil, destined for refining and distribution by the national industry, which reduces competition from foreign brands and generates a demand for domestic production of grains for grinding and oil extraction. To meet potential demand, it is enough to solve the equation of raw material prices, in order to allow profits to the farmer and, at the same time, the production cost of national crude oil that makes it competitive with imported oil.

In the current circumstances, it seems that only the cultivation of “autumn” sunflower, in February-March, in succession to large crops, could become a good alternative for the farmer, since it does not impose absolute risks, as it is intended to the increase in income from agricultural activity and not to the formation of this income, which is the responsibility of the large summer crop. It could also be an alternative for using sugarcane renovation areas or traditional “safrinha” corn areas which, due to loss of the planting season or due to adverse conditions, are only bearable for sunflower cultivation as it is more tolerant to cold. intense and dry, in some phases of its cycle.

crop rotation

In the case of succession, there tends to be a benefit for both crops, as is the case with corn-sunflower, in which there may be a decrease in the incidence of pests, due to the allelopathic effect of the sunflower, a reduction in diseases and an improvement in the physical conditions of the crop. soil for both, with the possibility of an increase in corn productivity of up to 30%, and also in the case of sunflower soybeans, in which there may be an increase of up to 15% in the productivity of both crops.

According to surveys, the costs for sunflower production, analyzed under the conditions of January 1998, and with their values ​​transformed into the North American dollar, at a rate of R$1,20, in force at the time, totaled US$229,40 per hectare , for “autumn” planting, which takes place in February-March. Considering that, in 1999, the price trend for grains placed in the industry was US$160,00 to US$170,00 per ton, the profitability of the crop, for a productivity of 2000 kg/ha, without discounting the cost transportation costs, it could reach US$ 90,60 to US$ 110,60 per hectare.

These calculations indicate that, although sunflower cultivation represents an alternative to increase income, by taking advantage of the normally idle season (February-July), there is a need for a careful analysis of transport costs which, due to the low volumetric weight of the grains of sunflower, vary significantly, from farmer to farmer, with the distance between the crop and the industry, and can become an impediment.

In the case of small independent producers, the artisanal and cooperative extraction of crude oil through simple pressing and filtration, for regional sale, can become a viable option, which is why ITAL developed a continuous press called “Mini-40 ”, with a processing capacity of 40 kg per hour. This portable press is only recommended for processing grains with an oil content above 40%, as is the case with many sunflower varieties.

The first series of tests with sunflower in the shell, using this equipment, was carried out with 900 kg of raw material, obtaining an extraction efficiency, considered satisfactory, of 24 to 26,5% of oil per kilogram of grains, with a simple operation. When processing using the Mini-40, prior cleaning is necessary to remove soil, stones and other impurities, by sieving and shaking.

Considering that the press yield, for cultivars whose grains have between 40% and 42% oil content, is around 400 to 500 liters of product per hectare, if the productivity is 2 t/ha, we will have the possibility to generate, in addition to the cake, an income of US$240,00 to US$375,00 per hectare, from which we must deduct the costs of extracting, packaging and selling the product.

Lately, the use of sunflower silage has increased, probably because it generates a greater quantity of moist plant mass per unit area, better product quality and lower production costs in autumn crops, when compared to corn. Your silage becomes even more advantageous when the corn grain market is a buyer.

how to plant

The appropriate population of sunflower plants, in crops, is 30.000 to 60.000 per hectare, depending on the cultivar and soil conditions, which suggests spacing between rows between 50 and 90 cm, depending on the harvester to be used, looking for - have three plants per linear meter. For the most common cultivars, it has been observed that the recommendation is 40.000 to 45.000 plants per hectare.

When sowing, carried out when soil moisture is at a level sufficient for good germination, the seeds must be distributed as evenly as possible and completely covered with a maximum of 5 cm of soil. These measures prevent the occurrence of uneven spacing in the row and prolongation of emergence for more than 10 days, which would mean that plants with less available area, or delayed emergence, suffer competition, developing little and producing less.

With regard to the climatic conditions for cultivation, the sunflower plant adapts very well to low temperatures in different phases of its life, except for the time when the flower bud is formed, due to its burning, which can give rise to several flowers without economic importance, and in pollination, when the viability of pollen grains and the number of pollinating insects are seriously affected by intense cold, causing a reduction in pollination efficiency and consequent flower abortion. Sunflower also grows reasonably well at high temperatures, but the grains produced will have poorer quality oil due to the lower linoleic fatty acid content.

Plants in sunflower crops, installed at the appropriate times, develop quickly after 30 days of emergence, easily dominating possible invaders, and making the need for weed control limited to the initial period of the crop cycle. This makes it possible to use herbicides with a short residual effect and a broad spectrum of action.

Crop diseases

Sunflower is generally attacked by diseases caused by fungi, the occurrence of which is one of the main factors to be taken into account when choosing a regional option for installing the crop, as production losses, depending on climatic conditions, can be large, with reports of a reduction of up to 60% in production estimates. Of the pests, the main ones are caterpillars, which can be controlled with biological insecticides, as their effect is only curative and by contact, initially causing the interruption of feeding and, after about three days, the death of the caterpillars. Chemical control should be avoided during flowering, as it causes damage to pollinating insects, especially bees.

The attack of beetles and stink bugs, when harmful, can also be controlled with organophosphate insecticides, but before the flowering season, so as not to destroy bees and other pollinating insects, causing the elimination of grain production, a greater harm than that. caused by kitties.

Depending on the time of year, depending on the availability of food in the region, many birds, including sparrows, parakeets and parrots, attack the heads during the grain filling phase, destroying them partially or completely. The severity of the attack can be limiting in the case of small crops, as there is no chemical treatment permitted by law.

Control can only be done with the use of devices that scare away birds during the graining season combined with the early harvest of the crop, with the grains still very moist, at the point of physiological maturity, between 5 and 6 weeks after flowering, after the which no longer incorporates dry matter, and physical maturation is completed via drying in a yard or dryer.

Mechanical harvesting can be done using corn or soybean harvesters, with minor modifications, or using machines with a sunflower platform. The harvesting speed, in the case of using an adapted corn harvester, is up to 9 km/hour, while in the case of a soybean harvester it is 4 km/hour.

The moment for mechanical harvesting is when the plants are dry, brown in color and the heads are dark brown, indicating that the grains have reached a moisture content between 14 and 17%, and the entire area must be harvested before it reaches 10%. .

Early harvesting, when the degree of moisture in the grains is higher, requires greater care in adjusting the machines, aiming to avoid seed breakage and an increase in the amount of impurities in the harvested product.

Antonio Carlos Angelini

CATI

Maria Regina G. Úngaro

IAC

Jane M. Turatti

ITALY