Abstract only

Under the conditions of market economy, and due to the lack of material and technical resources and the deteriorating environment, the development of resource-saving environmentally safe cereal production technologies assumes special urgency. A system of agricultural practices for cereal growing will be an effective means of managing the growth and development of plants only if it complies with the changing crop requirements and weather conditions. The beginning of field operations in Azerbaijan is associated with the period when snow cover disappears and soil regains it plasticity. The average date falls on 29 April to 10 May in the highland zones, on 15-25 April in foothill zones and on 20 March -15 April in lowland zones. The average annual duration of the period from snow melting to the establishment of soil plasticity makes up from 15 to 25 days. During an early but prolonged and cold spring, soil mellows in 30-40 days. Generally, duration of the period depends upon the physical and mechanical properties of soil. Soil mellowness terms up to 10°C at the depth of 5 cm in the highland zones by years vary from 15 May to 10 June, in the foothills-from 20 April to 20 May, and in the lowlands -from 11 to 20 April. Thus, a possible date of starting field operations in various zones varies within a 50-day range. This uncertainty in the dates of the spring operations influences the sequence of the technological operations for soil preparation. A significant variation in the maturity dates of winter crops is also observable. Harvesting of winter crops may commence in the lowlands from 5 to 30 June, in the foothills -from 20 July to 15 August and in the highlands -from 20 August to 14 September (Table ). Harvesting is the most labor-consuming tec- hnological process of agricultural production. To en- sure the maximum harvest of the crop with the best grain quality, the best harvest management practices should be strictly observed. Technical tolerances and operation quality assessments are based on the main probability-statistical characteristics of a machine- tractor unit (MTU) and the processes performed thereby. The available crop management requirements to the operation of an MTU provide generally for a tolerance only for deviation of the average value of the process from the set (nominal or established) value X That is they are based on the comparison of the actual level of adjustment ~ with a tolerance for the unit adjustment ~ according to the value: L\; = 'X -XI/ I :$1L\~I¡¡ Fig 1 shows a change in the winter wheat productivity depending on the planting date t(a) and a change of losses L depending on the cut height h(b) in the lowland zone of the republic. Fig.1.Change in productivity U of winter whe- at depending on planting date t(a) and change of losses depending on the cut height h(b) in the lowland zone of Azerbaijan: 1 and 2- yield dis-tribution density upon the lesser and higher dispersion degree, respectively. Tolerance D for irregularity of the qualitative indicators of the technological process is based on the following criteria: 1. permissible value of utilizing product harvest per unit of area (Fig. 1 a) or a permissible value of losses upon product harvesting (Fig.1 b ); 2. changeable quality of operation due to the technical state of the unit, changed conditions and initial properties of the processed material; 3. qualitative indicators conditioned by the previous and subsequent practices or operations of the technological process. If harvest starts 6 days after full maturity, grain losses make 5 percent, while after 10 days the losses are as high as 20% and after 15 days rise to 30 percent. Therefore, cereals should be harvested within the shortest possible time and, generally, not later than 5-6 days after full maturity of grain. Farms in Azerbaijan lack enough grain harvesters. On average, about 130 ha of harvestable area fall per each harvester. Taking into account other unfo- reseen difficulties and shortages the harvesting often takes up to 20-30 days or even longer. Because of the delays, each year grain losses make up 30% out of the biologically predicted yield. Hence, we believe it is essential that cereal harvesting starts first in the lowland zone of the republic and then continues in the foothill and highland zones. This would make possible to complete harvesting in the shortest terms and avoid significant yield losses.

English

0409|AGRIS 0401|AL-Wheat Program

Juan Carlos Mendieta

CIMMYT Publications Collection