Root asphyxia

Water stresses (of different frequencies and types) which affect both soil and soil crops are grouped together under the name “root asphyxia” (drowning, water wilt). Note that they can occur very occasionally, for example following heavy rains or ruptures of irrigation pipes, during the deficiency of solenoid valves In this case, the water more or less submerging a crop, accumulating in the areas which form a basin, saturating a substrate, puts a transient stress on the plants. The latter often see their leaves at the apex thinning, wilting and curving more or less. If these asphyxiating conditions persist, the leaf blade eventually turns yellow and necrosis.

Water stress can be involuntarily repeated over time with each irrigation. This is the case, for example, when a producer does not fully control the irrigation of plants and tends to add too much water to each watering. Tomato irrigation is an agro-cultural intervention which is not trivial and can lead to critical situations when it is poorly controlled. This succession of root asphyxia also leads to the appearance of symptoms comparable to those described above. In this case, they may be preceded by more limited plant growth, and wilting will instead affect the lower leaves. A comparable situation will also be encountered, but more locally, in certain plots containing areas of heavier soil or in basins.

Whatever the nature and frequency of water stress, the effects on plants are fairly comparable. The tomato, like many other cultivated plants, does not cope well with its root system being completely submerged for a long period of time. Such a situation leads to a lack of oxygen: it follows a more or less important destruction of roots, largely explaining the wilting. This telluric phenomenon could sometimes be amplified by the proliferation of anaerobic microorganisms which would contribute to the denaturation of the roots.

In general, significant damage is especially observed in poorly drained plots, with heavy soils and during periods of hot weather which promote anaerobic microorganisms, accelerate plant transpiration, and therefore wilting.

In plots where asphyxiation occurs fairly regularly, the soil should be drained. We should also be wary of certain rather asphyxiating substrates. In all cases, it will be necessary to rectify the frequency and the quantities of water added to each irrigation. Remember that the tomato has significant root regeneration capacities which should allow you, either by blocking the plants, or by regulating irrigation, to restore certain asphyxiating situations.