World Plant and Soil Science Congress
Samarkand state university, Uzbekistan
Title: New techniques for evaluation of water stress and drought effects in crop and rangeland plants
Biography: Muhtor Nasyrov
Temperature and water regimes are the main factors that affect the growth, development, and yield of plants growing in arid and semi-arid regions. Consequently, any change in climate will likely have a major influence on plants growing in these areas. For example, a 1-3 0C rise in temperature can shift growth to 5-14 days earlier, which may result in growth initiation during the last week of February. This shift may be critical for the growth of vegetation where growth would be shifted to a period of more intensive rainfall and lower air temperatures, resulting in declines in total biomass production. This may be particularly important for sedges (Carex spp.), a main fodder crop in Central Asia, which have previously been shown to exhibit considerable reductions in height during the last 30 years.
To precisely evaluate the effects of water stress on plant growth, it is often desirable to grow plants under controlled conditions such as greenhouses and growth chambers. Controlled environments minimize variability within experimental treatments and allow for the precise testing of hypotheses related to environmental effects on plant growth. However, plant growth in pots in a greenhouse or growth chamber can be problematic because soil water dynamics in pots can differ significantly between plants grown in pots or small containers compared to field plots. Use of deep soil columns for evaluation of water stress effects on plant growth represent an improvement over pots because soil columns are deeper, hold more soil, and better approximate field water dynamics. Generally, the deeper the soil column in relation to the surface area of column, the closer actual field water dynamics can be simulated. A small soil column surface area for soil columns compared to the column depth allows the development of realistic water stress effects in a greenhouse or controlled environments. As a result, several randomized treatments can be effectively established with soil columns within a small area. In addition, new techniques using Watermark sensors have been developed to more precisely monitor levels of water stress in soil columns. The combination of these techniques will allow careful statistical comparisons to be made to precisely evaluate water stress effects in arid plants.