Wheat cultivation benefits agricultural production systems in Central Brazil

The appreciation of wheat in the last harvest and the advantages offered by the crop in production systems in the Cerrado in the central region of the country have aroused the interest of producers in the region, especially those who rotate crops under irrigation. With improved management, producers have been able to explore the potential of cultivars such as those developed by Embrapa, obtaining average yields exceeding 100 sc/ha. This was the backdrop to the Irrigated Wheat Field Day, held on September 18th by the Agricultural Cooperative of the Federal District Region (COOPA-DF) and Embrapa on the Jolmir Cenci property, in PAD-DF, Federal District. The event brought together 250 people, including regional producers and technicians.

Technical responsible for COOPA-DF, Claudio Malinski said that the cooperative needs to encourage the cultivation of wheat in the region not only to obtain quality raw material for the mill, but also so that the rural producer can have the benefits that the crop indirectly brings to the other cultures that succeed it. “We must produce around 400 thousand bags (of flour) and we are paying R$982 per ton of BRS 254 and R$910 per ton of BRS 264”, he highlighted. Around 40 members, representing a planted area of ​​approximately 8 thousand hectares, supply wheat to COOPA-DF. The expected production in this harvest for irrigated wheat should be around 750 thousand sc, with an average productivity of 93,75 sc/ha. 

The BRS 254 cultivar is the cooperative's flagship wheat crop. “We are favoring the cultivar because it is the most interesting wheat for the mill. Any other product produced in Brazil, when mixed with BRS 254, will produce quality flour for the industry. The other materials are good, but more care is needed when choosing to make the blend as there are some limiting factors”, explained Malinski. He recalled that BRS 254 also requires attention to the risk of lodging (falling or arching of plants). “But he has an advantage. The cycle is longer and, if it gets cold, it is possible to increase production to 8 tons/ha (or 133 sc/ha)”.

To update and answer questions from Field Day participants, Embrapa researchers presented information about the cultivars developed by the Company's research adapted to the Cerrado of Central Brazil and made available to the market. They also addressed the management of wheat cultivation and diseases that affect crops.  

Embrapa Cultivars 

Launched in 2015, the irrigated wheat cultivar BRS 394 It can also be recommended for the rainfed system (safrinha wheat). It combines high productivity (above 120 sc/ha in an irrigated system and 60 sc/ha in the off-season) and greater tolerance to lodging in relation to, for example, BRS 254. It is an early material, with wide adaptation to planting time, being harvested in 110 to 115 days. The lax (dilated) ear, with greater spacing between the spikelets, facilitates the preventive control of blast, the main disease that affects wheat fields in the Brazilian tropical region. In well-managed soils, roots can reach two meters deep, as seen in commercial crops.

The cultivar has hard grain and is classified in the industry as bread wheat. “To have liquidity when selling to the mill, you need quality wheat for the production of bread, mainly”, argued researcher Júlio Albrecht, from Embrapa Cerrados (DF), remembering that 70% of wheat flour production in Brazil is destined for the bakery industry, with the remainder used in the production of biscuits and pasta. In this sense, BRS 394 presents high gluten strength* (320 x 10-4 J average), well above the 250 x 10-4 J required by the industry. Another difference is the stability** of 20 minutes, higher than the 12 minutes required. “This is excellent for both the mill and the baker who will make the bread,” he added.

When commenting on the precocity of the variety, the researcher highlighted that the best planting time to achieve the highest productivity with irrigated wheat in the region is the first fortnight of May. “If you plant earlier, in April, you run a greater risk of blast. Excessive rain in February and March is a harbinger of blast. But if the rains are normal during this period, you can plant from April 15th with less risk of the disease”, he recommended. 

BRS 264 wheat, launched in 2005, is the most planted variety in the region. “If we walk through the Cerrado of Mato Grosso, Bahia, Goiás and DF, 80% of the wheat area is planted with this cultivar. We will hardly be able to take it off the market because in addition to having high productivity (120 sc/ha), it is one of the materials that is very early. After 90 days it is ready for farming, with significant water savings”, commented the researcher. The cultivar has moderate resistance to lodging and is resistant to threshing.

Also made of hard grain and classified as bread wheat, with an average gluten strength of 255 x 10-4 J, stability over 20 minutes and an average hectoliter weight (PH)*** of 80 kg/hl. “It is one of the few varieties with which it is possible to make bread without adding others. Mills buy with their eyes closed due to this flexibility in the production of flour for baking and the flour yield, which reaches 66,5% on average, one of the best. Even bakers say that making bread with this variety is almost magical”, said Albrecht.

He also recalled that BRS 264 is very responsive to planting density. The recommendation is to use 200 kg/ha of seeds to reach the cultivar's productive potential – anything less will result in lower productivity. “It's worth spending a little more on seeds and getting 20 to 30 sc/ha more than other cultivars, as it responds well to sowing density,” he pointed out.

BRS 254, also launched in 2005, can be planted a little later (due to a third crop, for example), although the best planting time is also the first fortnight of May. Furthermore, it tolerates rain better during harvest compared to BRS 264, as it has a more closed and harder grain. It has an early/medium cycle and a productive potential of 100 sc/ha (there are producers exceeding 120 sc/ha), being resistant to threshing and moderately resistant to lodging, demanding greater attention to the amount of nitrogen in coverage and when applying the regulator of growth.

Considered a standard wheat by COOPA-DF, it has an average gluten strength of 330 x 10-4 J, reaching 400 x 10-4 J, and stability of 25 to 32 minutes, being classified as improving wheat. “As it is very strong, it is used to improve wheats with low gluten strength and low stability in the production of flour for baking. That’s why it’s so important for the mills”, he explained.

Finally, the dry wheat cultivar BRS 404, launched in 2015, is tolerant to drought and heat and suitable for the rainfed system (safrinha), with planting best suited for the month of March. The average productive potential is 60 sc/ha in rainfed (with producers having already reached 80 sc/ha) and just over 100 sc/ha in an irrigated system, for which it can also be recommended, as, according to Albrecht, it is well responsive with little water. It is an early cycle cultivar, resistant to threshing and moderately resistant to lodging. Classified as bread wheat, the variety has high gluten strength (320 x 10-4 J) and stability for over 12 minutes, ensuring good liquidity when sold to mills.

Management recommendations

According to researcher Jorge Chagas, from Embrapa Trigo (Passo Fundo, RS), the diversity of irrigated systems in the region makes it difficult to generate management guidelines that fit perfectly in all cases. “We make an overview of the situations encountered and generate a basic management recommendation so that the producer does not make mistakes that lead to loss of productivity and is successful in managing the crop”, he explained. He presented recommendations for the most important components of the management of Embrapa's wheat cultivars based on results of trials in producer areas in the Federal District, Cristalina (GO) and Unaí (MG).

The first factor to be observed is sowing, which can be broadcast or in a row, using a seeder. The second option is the most recommended because it has several advantages, such as more adequate planting depth, saving seeds, greater efficiency in the use of fertilizers, conservation of direct planting, possibility of using pre-emergent herbicides and, mainly, greater uniformity of the plant arrangement. “Most of the seeds sown are shallow. At the time of grain filling, there may be losses due to lodging, because the plant will be poorly anchored to the soil”, observed Chagas.

The sowing time recommended by the Ministry of Agriculture, Livestock and Supply (MAPA), based on agricultural zoning studies of climate risk for irrigated wheat in the region, is from April 11th to May 31st. However, research has led to the indication of a window from May 5th to 20th, dates that are less favorable to blast. If the producer decides to sow after May 20th, he must use the BRS 394 or BRS 254 cultivars, which are more tolerant to possible rain during harvest, in September.

By showing that the same cultivar can have different response curves to the same sowing density on different farms, Chagas highlighted that the research seeks to generate recommendations for average sowing density to best perform the cultivars' potential. Therefore, the recommendation is 300 to 350 viable seeds/m² for BRS 254, with 51 to 60 plants/linear m; from 340 to 390 viable seeds/m² for BRS 394, with 58 to 66 plants/linear m; and 400 to 450 viable seeds/m² for BRS 264, with 68 to 76 plants/linear m at a spacing of 17 cm between rows.

The researcher paid attention to checking the Weight of a Thousand Seeds (PMS), in grams. “We have found great variation in seed lots of the same cultivar. If you plant with a generic recommendation of 200 kg/ha of seeds, for example, and the PMS is 35g, you will be using 20% ​​more seeds than recommended. This will result in almost 500 plants per m², with a greater tendency to lodging,” he explained.

If the crop has already been planted with a seeding density above that recommended for the cultivar, the recommendation is to lower the nitrogen dose. And in case of error when applying the growth regulator at the end of the cycle, it is necessary to adjust irrigation management to avoid lodging before grain filling. “Lodging is perhaps the main problem with irrigated wheat (in the region) after blast. We have to manage the crop in such a way that it does not become dormant or only becomes dormant at the end”, said Chagas.

Another key factor is fertilization, as the crop demands balanced soil. It is important to check the history of the area, the recommended base saturation and whether the aluminum is neutralized. For planting fertilization, the recommended doses of phosphorus must be observed (80 to 100 kg/ha); potassium (40 to 60 kg/ha); boron, to avoid sterility of the spikelets; zinc, mainly in plantations after corn; in addition to calcium and sulfur, which can be supplied by limestone and agricultural gypsum.

The recommended nitrogen application is 20 to 40 kg/ha at the base and the remainder as cover, from planting to 15 days after germination. When growing after corn, nitrogen should be increased by around 15%. Late application of nitrogen, aiming to increase quality, should not be done. “Our cultivars already have the quality for baking, even with zero nitrogen application”, he pointed out. According to the researcher, the higher the sowing density and nitrogen, the greater the chance of lodging, which is why the producer must be aware of this relationship between these factors and the growth regulator. “Surrounding this tripod results in high productivity. But if you start with the wrong density, with excess nitrogen and even mistime the application of the growth regulator, the chance of having a “bedded” crop with productivity losses is very high”, he taught.

According to studies on farms, the best responses to nitrogen applied as top dressing (with 20 kg base) were at total doses (top dressing plus base) of 100 to 120 kg/ha in BRS 254, from 120 to 140 kg/ha in BRS 264 and 110 to 130 kg/ha in BRS 394. “By applying more nitrogen than that, the plant becomes susceptible to lodging. It is important to respect these responses”, explained Chagas.

As for the growth regulator, the recommendation is to apply 0,5 L/ha to the first visible node or two applications of 0,3 L/ha – one to the first visible node and another, six days later, to the second visible node. “Many producers have adopted the application divided into two doses of 0,3L/ha because it is easier to hit the point of the first visible node”, he commented. The application should take place during the mildest temperatures of the day and with little wind, avoiding re-applying the spray bar. The product should not be applied to plants under stress, especially due to herbicides, and must wait five days. There should also be no applications of other products up to five days after applying the growth regulator. Irrigation should only be carried out again two to three days after applying the regulator, to avoid washing the product and ensure efficiency.

Irrigation management can be done with the help of the page Irrigation Monitoring in the Cerrado. Simply select “Annual Crops” and then “Embrapa 42” for BRS 394 and BRS 264 or “Embrapa 22” for BRS 254. The page shows step-by-step irrigation management, starting from the emergence date of the informed crop, calculating the day's evapotranspiration based on data collected from a network of climatological stations and providing the water depth to be applied and the irrigation shift.

Chagas also commented on the BRS 404 cultivar, highlighting that dry wheat does not compete with off-season corn in the system, as it is planted in a different window – from March 5th to 20th. BRS 404 has a low cost, requiring fewer seeds (250 to 300 viable seeds/m², equivalent to 130 to 140 kg/ha) and, when planted after soybeans, requires a maximum of 30 kg/ha of nitrogen in coverage. On the other hand, it presents the risk of losses from blast in the event of rain. “We have to look for the dry season and pay attention to the weather forecast, as there are still no cultivars resistant to blast,” he added.

Integrated disease management

One of the main items of integrated disease management in wheat and other agricultural crops is crop rotation. Researcher Angelo Sussel, from Embrapa Cerrados, explained that the formation of wheat straw has positive and negative effects. “The straw prevents weeds from coming in the next crop, leaving the area clean after the wheat harvest. But it also contains the inoculum for all the diseases that occurred in the area that year. Only by placing other crops later can this straw rot and no longer be present in the next wheat cultivation cycle. This is the importance of crop rotation”, he highlighted, adding that the absence of straw reduces spot infection in the following wheat crop.

In addition to crop rotation, the producer must observe whether the cultivar to be sown is resistant to diseases and whether it has been validated in the region and in a year favorable to the occurrence of these diseases. “Cultivar resistance is the cheapest technology for disease management. It is not worth working with a cultivar that is not resistant in an environment highly favorable to the occurrence of diseases, especially in the case of rainfed wheat, which has greater disease pressure”, he explained. 

The seeds must be healthy, which can be verified by phytosanitary analysis carried out by laboratories. The level of infection of the seeds will indicate whether they can be used for planting, whether treatment with fungicides will be necessary to reduce the inoculum (if the level of infestation is low) or whether they will have to be discarded and sold as grains. The researcher highlighted the importance of seed treatment to reduce the presence of the inoculum, but that the measure will only be effective if the area is clean. “There is no point in having a treated seed if the area still has straw and in the previous year there was an incidence of stains and blast, where the inoculum is already present”.

The manual elimination of plants with inoculum (“charcoal”), according to Sussel, is extremely necessary, as the spores of disease-causing fungi spread easily with the wind, reaching other ears and infecting the seeds. The planting time must be observed mainly for blast management. Planting before the recommended dates increases the risk of infection due to greater amounts of rain and dew. “Rain and dew cause the presence of water on the surface of leaves and ears. And water is the facilitating agent for any infection,” said Sussel.

Balanced nutrition and irrigation management are factors that save fertilizer, water and energy. The researcher recommended periodic soil analysis in the area to accurately replace the nutrients needed by the plants. “In a poorly nourished plant, resistance genes will have less response. In a well-nourished plant, these genes will respond better, it will be more resistant and will explore its maximum potential,” he commented. 

As for irrigation, only the recommended amount of water should be added for the crop. “If you can make a greater depth (of water) during the bottling period****, before the ears are issued and, after this period, leave as much time without irrigation as possible, resulting in fewer wet days, you will reduce the chance of blast in the area”, he suggested, not excluding the need for preventive fungicide spraying.

Disease monitoring must occur since planting, but must be intensified from the first visible node, when the four leaves that guarantee maximum productivity of the plant will be exposed – the flag leaf and the three below it. To protect them throughout the cycle, you must observe the weather conditions (rain, temperature and dew), and whether there are already stains in the area. Sussel stressed that the use of fungicides is the last resort to be used.

The main wheat crop diseases in the region, in addition to blast, are powdery mildew, leaf spots and rust. “Powder mildew and rusts are mainly controlled with resistant cultivars, which will ensure a reduction in the application of fungicides. For leaf spots, crop rotation is extremely important to reduce the occurrence, in addition to seed treatment,” he explained.

As for blast, fungicide spraying must be started during the budding and heading period, when the flag leaf is exposed. “If spraying is carried out, the flag leaf and the lower leaves will be protected, in addition to reducing the inoculum for the following week, in which the ears are being emitted. By reducing inoculum and irrigation during this period, the possibility of blast occurrence will be lower,” he said. Another measure is to monitor the crop and neighboring areas, in addition to checking whether the weather conditions are favorable to the disease.

Blast management, according to the researcher, is always preventive. “The fungicide applied protects, but does not cure. If the cob has already been infected, it will die. There is no recovery of tissue that has already been infected,” he said. Another important point is the application technology, in which the rotation of the chemical groups of the fungicides (and not just the molecules) must be observed, which contributes to maintaining the effectiveness of the active ingredients; the recommended volume of syrup; the sprayer tips, which must have two angles of attack; the recommended dose of adjuvants for the fungicide; and the time of application, avoiding periods of the day with lower relative humidity and higher temperatures.

The researcher recalled that rainfall averages in March and April 2019 were above the historical average, with more rainy days, and that losses in safrinha wheat crops were significant. “Those who monitored wheat diseases and sprayed early on were able to harvest dry wheat. Those who did not monitor were unable to control the diseases,” he said. 

At the time, some producers suspected that a new bacteria was harming wheat fields. Sussel recalled that Embrapa promoted a task force, in which researchers collected samples from several farms in the region. “There was no new bacteria. What some saw was a supporting bacteria, which was there simply because it was opportunistic. The problem was leaf spot and leaf blast. The wheat planted earlier ended up dying, probably due to excess water and diseases, in addition to inadequate management”, he concluded, warning again to check the adaptation of cultivars for planting in the producer's region.

Producers highlight advantages

Producer in Cristalina (GO) Helcio Wander planted 190 ha of irrigated wheat this harvest. The 130 ha pivot with the BRS 264 cultivar obtained an average of 125 sc/ha. The harvest of the 60 hectares with BRS 254 had started on the eve of Field Day, and the expectation was for productivity above 100 sc/ha. 

He observed crop performance much better than in previous years. “The weather helped a lot, with cold days during the cycle,” he said. On the property, wheat is used in crop rotation – this summer, it will give way to soybeans in the pivot where the BRS 264 cultivar was harvested. Next year, it should be followed by corn and, the following year, by fruit and vegetables. “We do this rotation to minimize soil diseases, such as nematodes, as much as possible,” he explained.

As for blast, Wander says that at first he was apprehensive because of the attack on dry wheat crops in the first half of this year. “After we planted the wheat in the pivots, we thought it would be a lot of trouble. Luckily it got quite cold. We applied products and managed to overcome (the blast)”.

Rodrigo Werlang, producer at PAD-DF, has used wheat in the production system since 1988, having planted different Embrapa cultivars. This year, he chose to plant BRS 404 second-season wheat to produce seeds for COOPA-DF in an area of ​​45 ha with irrigation. A pivot that has water restrictions was used, hence the choice of a rainfed cultivar, which requires less water. “We follow an irrigation schedule in the DF in which the pivot irrigates for two days and stops for one day. So, he was a perfect fit for this material.” 

Planting was delayed by a few days due to operational issues at the farm, which ended up helping the crop escape the blast. “We closed an average of 93 sc/ha of this second-season wheat in the pivot, with a hectoliter weight of 84 kg/hl. It is a material that we had never planted. It requires care due to the risk of lodging, which grows a lot, and it is necessary to get the right point of the growth reducer”, he commented. 

In the Werlang system, after soybeans in the summer, corn, wheat or beans are planted in a staggered manner in the pivots where off-season corn will not be grown. For next year, the producer is still analyzing what he will do. “When we define the off-season, we will see what will go into the pivots, whether beans or wheat. One thing that limits us a lot is the issue of water. If it’s a year that doesn’t rain much, we’ll plant beans, which require a little less water consumption,” he explained. 

The producer points to the formation of straw as the main advantage of wheat in the system. “As we have a problem with having little straw for direct planting, it allows for fantastic planting. And even though it is a pivot area, in January, in a summer season, irrigation is more difficult because evapotranspiration is very high. We noticed that straw holds more (moisture). This will impact productivity down the road”, he analyzed.

William Matté, is a producer at PAD-DF and Cristalina. He planted 55 ha of wheat under pivot, half of the area with BRS 254 and the other half with BRS 264. The idea was to compare the performance of the materials. The producer had planted BRS 254 in 2018 and, this year, wanted to discover BRS 264. 

“It is a crop to participate in the crop rotation of our irrigated production system. It has a different root system, with very interesting roots for the Direct Planting System, as well as a lot of straw, forming dry matter,” he said. After wheat, soybeans will be planted in the summer, as last year. The idea is to increase the irrigated area for next year, keeping 20% ​​with wheat for crop rotation. “The straw has a very good carbon-nitrogen ratio, decomposition is a little slower, and lasts longer in the system,” Matté pointed out.

Paulo Bonato planted wheat on 102 hectares under pivot on the property in Cristalina, half of the area with BRS 254 and half with BRS 264. In this harvest, yields were 126 sc/ha with BRS 254 and 128 sc/ha with BRS 264, reaching 143 sc/ha with the latter in some areas of the crop. “The expectation was for even higher productivity depending on how the crops were in the field. But the quality of the wheat is very good, the hectoliter weight is around 85 kg/hl, a value that is difficult to achieve. I’m satisfied,” said the producer.

For Bonato, wheat fits perfectly into the farm's irrigated crop rotation system, which involves soybeans, beans and seed corn. “I rotate the pivot and between the pivots, so that I don’t have leftover crops the next time I plant. Wheat straw is persistent and takes a long time to decompose. If I plant wheat this year on a pivot, I will only plant it again in two years on that pivot,” he explained. According to the producer, the advantages of using wheat are mainly the deep root system, quality straw and diversification of income sources. “This provides financial stability, cash flow. The cooperative sets the price together with the producers. It needs the raw material and can pay them better by not having to pay shipping from Paraná or Argentina”, he commented, also praising the adaptability and productivity of the varieties developed by Embrapa.

Despite having planted during the recommended period, he had to carry out more fungicide sprays than in other years due to the high blast pressure observed in the region's off-season wheat crops in the first half of the year. “For blast, control is preventive. You can’t see it, but if you let it appear, it’s over, it has already caused damage at the site of infection,” he recalled.

Bonato, who has always been a wheat farmer, observed that every year there are climatic situations that interfere with the development of the crop. “If I had known that this year would be hotter in the initial phase of farming, I would have increased the number of plants per m², which would have increased the production level. In a warmer period, wheat does not tiller as much. But if you work with a larger number of plants, during the coldest period there will be lodging. So, it’s very difficult to equalize,” he said. “You have to monitor the culture daily, observing what can be improved for the following year,” he added.

*Represents the work of deforming the dough and indicates the baking quality of the flour (strength of the flour). 

**Provides a measure of the dough's tolerance to mixing and is related to the strength of the dough. 

***It is the mass of 100 liters of wheat, expressed in kg/hl. It is influenced by grain uniformity, shape, density and size and by the content of foreign matter and broken grains in the sample. It serves as an indication of the health of the grain. 

**** Development stage of the wheat plant that occurs before heading, being very sensitive to water and thermal stress (frost and heat), as it coincides with meiosis (division) of the pollen grains' mother cells.