Midsummer crop production news at agricultural companies of Agrowill Group

A period of heavy rain, which flooded quite large areas of crops in some regions of Lithuania or saturated soil, has been followed by extremely hot weather (> 30ºC), which may stay for some 10 days. Such a sudden change in weather conditions causes severe stress on the growth and development of plants. High temperatures and very low relative humidity (<40%) have forced leaf stomata to close and have strongly slowed down the process of photosynthesis, as the closed leaf stomata have not only slowed down the process of transpiration, which protects plants from overheating, several times but have also prevented atmospheric air from passing into plants. Therefore, there is a risk that part of winter crops may suddenly dry out. This risk is higher in areas with a thicker dry soil crust. This would result in a significant drop in winter crop yields and affect the growth of spring crops. In order to ascertain potential cataclysms in crop production as a result of hot and dry weather, we have carried out expeditionary observations.
The land controlled by agricultural companies Grūduva and Agrowill Želsvelė in southern Lithuania is dominated by medium-heavy loam with high-level groundwater. Therefore, excessive rain has severely affected this area. Technological ruts in nearly all fields are filled with water.  Water even flooded crops in some parts of the fields. This is where a soil crust will form first as soon as a drought begins, preventing the access of oxygen to the root zone and thus impeding the absorption of nutrients. Such a phenomenon is very dangerous to spring crops as this is the time when the most intensive plant growth takes place. A crop inspection has shown that some 15% of spring rape, 17% of spring wheat and barley and some 12% of maize crops are in saturated soils and are at risk of “suffocation” (root fermentation). Meadows are excessively wet as well.
The land managed by Jonava and Jurbarkas district agricultural companies is dominated by light loam, and the soils in a smaller part of the land have a heavier granulometric composition. In addition, there is sandy loam and peaty soil. A survey of farm specialists has also revealed that there is excessive moisture content in nearly all soils of these companies and water has flooded some crops. According to our estimates, approximately 12.5% of winter crops, 7.5% of maize, 7–10% of spring rape and some 13% of spring crops are in saturated soils, i.e. at a higher risk of a decrease in yields.  
Soils in the areas controlled by Kėdainiai and Radviliškis district agricultural companies have very different physical characteristics and vary in the degree of cultivation. Therefore, the crop condition differs there. Like in other regions, up to 15–20% of crops have been affected by excessive moisture in soil. Nevertheless, some crops are in very good condition and are expected to produce record yields.
It has been established that root fermentation, which particularly intensifies in very warm weather and shortage of oxygen in the root zone, can be considerably slowed down by fertilising crops through the leaves with solutions of a mixture of macronutrients and boron. In this case, boron is also necessary for cereals as it stops the process of fermentation. Spring rape, spring wheat, sugar beat and maize are particularly drought-sensitive. The formed soil crust, which prevents the access of oxygen into the maize root zone, will do more harm to maize than lack of moisture. These plants in particular need to be fertilised through the leaves in the case of hot weather and drought.
Hot and dry weather will also have a negative effect on winter crops. The threshing of winter barley, which is the closest to full maturity, will start at the end of the third week of this month.  Therefore, the upcoming drought and hot weather will not have a significant effect on them any more. Although hot weather will make winter rape mature 4–6 days earlier, this will not have a considerable effect on seed yields either. However, it does not on any account mean that these plants require less attention from us. 

The current condition of winter rape crops: 
* following winter stress, the condition of winter rape left to grow has considerably improved, more inflorescences with many siliques have formed, which are at the early stage of yellow ripeness and are planned to be threshed at the end of the second decade or at the start of the third decade of July;
* our biometric measurements have shown that the average productivity per winter oilseed rape plant (seed weight in a plant) in fields where soil is not saturated is expected to reach at least 18–22 g, i.e. 10–15% more than usual, but the actual density of most crops has shrunk by the same percentage compared to the multiannual average;
* at least 2.0–2.5 tons of rapeseed/ha are expected to be threshed in winter oilseed rape fields with a density of some 12 plants per square metre, with 3 and more tons of rapeseed/ha planned to be threshed in denser fields; seed yields in very thin crops will be less than 1.5–1 t/ha;
* there are a lot of weeds that have outgrown oilseed rape in some fields, which will be a big obstacle during oilseed rape harvest; therefore, it is time to start spraying such crops with glyphosate;
* a large part of oilseed rape (some 16%)  has been affected by pests (weevil, banded slugs and other), with some 6–10% of plants affected by diseases (grey rot, black spot and white mould); therefore, oilseed rape crops will differ in maturity and yield losses may increase; they can be considerably reduced by spraying crops with Aventrol;
* rape siliques contain too little lignin and are therefore weaker and less resistant to fungal pathogens; for this reason, siliques may fall apart or open before time and spread seeds; such crops would have to be sprayed with Aventrol again.

If the hot weather forecast appeared to be wrong, winter wheat would fully mature in the middle of the first decade of August.  However, given very warm and dry weather, wheat would dry off in 12–15 days. This means that winter wheat may reach their technological maturity at the end of July. Marked differences in the purchase prices of wheat grain depending on the quality of grain are expected this summer. It is not late yet to influence the quality of winter wheat grain and, to a certain extent, their weight. Following a very cold winter, there were significant differences in the quality of winter wheat crops in spring. Some of them were reseeded while others were left to grow.

The current condition of winter wheat crops:
* A major part of winter wheat crops in agricultural companies Grūduva and Želsvelė are in the middle of the stage of lactic ripeness and their grains contain at least 60% of dry matter, while winter wheat in other holdings are just at the early lactic ripeness stage when dry matter contained in them accounts for up to 50% of their maximum content;
* the condition of winter wheat crops left to grow has significantly improved in all companies, they have become denser, their ears contain more grain than usual, and their final productivity will depend solely on the ability of farms to fertilise crops through the leaves on time and to prevent grain from excessive shrinking during the upcoming drought;
* a major part of winter wheat crops is affected by diseases or pests, some of them are weedy; such crops should be sprayed with glyphosate 7–10 days before harvest, as grains from dried crops are more resistant to diseases and their quality is therefore less affected;
*  in order to keep grains in wheat ears and increase protein content in them, the crops must be fertilised through the leaves with nitrogen fertilisers two more times even in later phases of grain maturity. 

Virgilijus Paltanavičius ir Albinas Šiuliauskas
12 July 2010

<< All news