Farmers prepare to start growing the corn crop. At this time, it is very important to plan actions to ensure good production and profitability. Check out the guidance from researchers at Embrapa Milho e Sorgo (Sete Lagoas-MG). Crop care begins before planting and directly influences productivity. See how some measures can guarantee better results.
What criteria should the producer take into account when choosing corn seed?
Seed is the main input for a crop and its choice must deserve the farmer’s full attention. The producer must always be aware of the characteristics of the materials most adapted to their region, mainly in relation to productive potential, stability, resistance to diseases, suitability for the production system in use and climate and soil conditions. Furthermore, it is necessary to observe whether the batch of seeds purchased is within its expiration date and whether the germination rate (also identified on the label) is close to 100%.
The annual survey carried out by Embrapa Milho e Sorgo showed that for the 2016/17 harvest, 315 corn cultivars were made available.
The guideline for producers is to seek information in their region about the most planted hybrids and also about the results of regional corn trials, which are very common in most producing regions. The results of these tests serve as good indicators for choice, mainly due to the 'price x productivity and stability' relationship.
Several hybrids that have good productivity and stability can be found in conventional versions and also with transgenic events. This information can also be valuable for choosing the material to be planted.
In addition to choosing the most suitable hybrid, the producer must not give up planting the refuge if he chooses to sow any material with transgenic technology. The refuge, when done correctly, following technical guidelines, allows the reduction of crop production costs, due to less application of products to control caterpillars, in addition to being the most appropriate way of maintaining transgenic corn technology. .
What is important in preparing the area for corn cultivation?
Even in a scenario full of uncertainty, the main guideline for producers who will plant corn is to have PLANNING. The farmer needs to be assertive in his choices to be able to save as much as possible while trying to harvest as much as possible.
In this sense, to optimize the use of inputs (reducing production costs) and seek to minimize the effects of possible water restrictions, the producer must first select the plots with the best fertility history and, consequently, productivity, and start sowing. through these areas.
When the producer sows without taking this factor into account, areas with lower production potential considerably reduce profitability, as the profit obtained in areas with greater potential ends up “paying” for the loss that may arise from areas with restrictions. By following this area selection strategy, even when sowing in a smaller area, the producer has a greater chance of success, in addition to optimizing the use of inputs, combining lower costs with a higher rate of profitability.
Other areas, with a history of lower fertility or other restrictions on maximum corn productivity, can be sown later.
Another very important criterion for the success of corn, but neglected by producers, is the sizing of the planting area based on operational capacity, that is, the size of the area must be defined considering the machines and implements available for all mechanized operations.
In many producing regions, the window for planting is short. In the scenario in which corn presents good price prospects in the future market, the producer decides to plant the largest area possible. However, if the machinery available for planting is insufficient to meet the ideal cultivation window depending on the area to be sown, the producer adopts the strategy of increasing the work speed of both the seeders and sprayers. This option directly affects the plant stand and its distribution in the cultivation line, causing failures or competition between plants that are very close together.
For spraying, this premise is also valid, since, in the case of pest or disease pressure that requires tractor application, the increase in work speed implies greater losses and less operational effectiveness.
What cultural treatments should be carried out at the time of planting or immediately afterwards to ensure greater productivity?
Fertilizing
Corn fertilization is based on expected productivity. The best strategy is to always carry out fertilization following the soil analysis, the expected productivity (the producer can achieve this based on the history of previous years) and the most important premise: adopting the criterion of using the right source, at the recommended dose, at the time of greatest requirement of the plant and in the appropriate location (soil or foliar, broadcast or in the furrow, depending on the nutrient and dose).
Broadcast fertilization to optimize operational yield during planting may not be the best strategy in some situations, especially when it comes to phosphate fertilization and in years where the chance of water restriction tends to be more severe. Broadcast fertilization normally results in more superficial root growth, predisposing crops to suffer early stress during summers.
It is always important to remember that the supply of nutrients must be dimensioned based on the requirements of all the crops that make up the system in rotation or succession. Thus, every time the farmer fertilizes corn with quantities below those necessary to replace what is exported at harvest, there is an impoverishment of the nutrient reserves available in the 'soil+straw' environment.
Although at first this problem may not be perceived as influencing productivity (for example, in soils with high built fertility), the recurring use of deficient fertilization in corn over the course of some harvests will end up compromising the yield of the following crop.
Therefore, it is essential to try to calculate the nutrient balance in the crop system practiced on the farm (for example, soybeans – off-season corn), weighing inputs (fertilization) and outputs (exports) according to fertilizer management and productivity achieved throughout of crops. Otherwise, management errors could be incurred, with insufficient or unbalanced fertilization in relation to the nutritional requirements of the crops involved.
Efficient management of soil fertility begins with the establishment of a good direct planting system, which allows for greater straw accumulation and deeper root growth, key factors for better crop performance in conditions subject to water deficit. Therefore, a soil profile with corrected acidity and good nutrient availability at greater depths, as well as greater crop diversification, including plants for straw production (for example, corn – brachiaria consortium), should be the objectives of farmers who They wish to move forward in the search for greater production stability in the face of climate change in the Cerrado region.
Weed management
It is important to control competition between corn and invasive plants until the eighth leaf is emitted, as before this stage of development, corn is defining its productivity potential, and any competition compromises yield.
The producer must pay attention to the rotation of products with different active ingredients, as the resistance of weed plants to some herbicides is becoming increasingly common. Many producers rotate different commercial products but which, in some situations, have the same active ingredient. Constant monitoring by the agronomist is necessary so that these decisions can be more assertive.
Pest management
Integrated pest management is the cheapest technology and the one with the highest return for the producer. Monitoring using traps to capture insects brings several operational benefits, as a single technician can visit the areas to count and identify caterpillar adults. Therefore, in addition to monitoring, the producer can choose to use technologies with lower costs and less impact on the environment, such as, for example, biological control.
By carrying out this monitoring, the producer gains the option of choosing technologies that allow him to reduce costs with “calendarized” applications. It is important to highlight that, in the case of insecticides, chemical control must be initiated based on the level of economic damage to the crop, that is, the use of these products will always be curative. The use of chemical products to control pests at low levels of infestation or on a preventive basis is not recommended, and generates unnecessary costs.
Pests such as aphids and stink bugs, which until a few years ago were not a cause for concern for corn producers, have caused problems in crops. In the case of summer corn, the proximity to soybean crops can increase the incidence of attack and requires specific management for its control, always based on crop monitoring.
Disease management
It is also important to know the symptoms of the main diseases and the phase in which they tend to appear to define control strategies. Normally, preventive applications of fungicides are made, as once the disease is present in corn at high intensity, applications of products for curative control are inefficient.
The incidence and severity of many diseases are related to the cultivar sown and the climatic conditions during the development of the crop. Many hybrids are resistant to certain diseases and this resistance can be an interesting criterion for choosing the material to be sown.
Success in corn cultivation depends on good climatic conditions and good crop management, using appropriate technologies. History has shown that only by achieving high yields can the producer minimize price fluctuations, especially for the corn market, which has two major harvests (summer and off-season) within the same year.
Source: Embrapa
