GB/T 15797-2011Rules for monitoring and forecast of the wheat rosette dwarf (Wheat Rosette Stunt Virus) (English PDF)

2.1 Mediator propagation vectortransmission

The virus is attached to other organisms and communicates and infects through its activities.

2.2 The vector of the virus

Spread the virus of the body, many types, mainly insects, mites, nematodes, fungi, dodder, etc., to insects is most important.

Note. Laodelphaxstriatella (Falén) is the main drug carrier of wheatrosettest virus (WRSV).

Gray planthopper once poisoned for life can be poisoned, but not by the egg poisoning. When the virus is caught in winter, the virus can overwinter in the nymphs. Gray planthopper,

Virus in the body to take a period of time to pass the virus.

2.3 Severity of severity

The degree of disease of the plant or organ.

Note. The severity of wheat dwarf dwarf, the overall dwarfing degree of the plant, the degree of yellowing and reduction of leaves, the degree of tiller increase, whether heading and spikelets

And other elements of the division, divided into four levels. 0 --- normal disease-free; 1 --- plant dwarf, height less than 30% less than the plant, leaves have retreat green bars or

Grain, can spike, but the spike less than the normal spike less than 5; 2 --- plant dwarf, height about 50% lower than the plant, leaf thinning, yellow, tiller

3, the plant is heavily dwarfed, the leaves are small, the color is very yellow, the tiller is not a joint or a few can be jointed

But can not spike, or spike no grain or no more than the grain.

2.4 Disease rate of the lesion

The ratio of the number of wheat plants to the total number of animals surveyed.

2.5 Disease index

Disease occurrence of the prevalence and severity of the comprehensive indicators to indicate the average level of disease occurrence, according to formula (1) calculation.

I = sigmai × l () i

L × 3 × 100 (1)

Where.

I - disease index;

i - the severity level;

li --- the severity of the corresponding value of the number of strains;

L - the total number of plants (in this standard refers to the single stem).