In article the sampling technique for definition of a condition of rewintering of plants of winter crops is described.
The winter present stood out the warm. But despite it behind crops of winter crops it is necessary to conduct continuous supervision: we should know, how winter crops wintered.
Winter hardiness – important biological property of grades of winter crops, opredeyolyayushchy their suitability for production.
And to define in what condition of a plant are during the winter period from a field periodically take samples (monoliths) and put them in a warm room for growth.
Tests take in the following terms:
On January 25 and on February 23, if rewintering went to this period normally, but then there came the adverse weather conditions, capable to cause damage of crops, it is necessary to take in addition samples in 10 days after a proyavyoleniye of an adverse factor.
Tests on growth take in the form of monoliths: in the length (along crops ryadok) 25-30 cm, width in two adjacent a ryadka and depth see it is necessary to Take not less than 20 carefully not to damage a plant.
Before a capture of test measure thickness of snow cover then snow ostoyorozhno delete and start monolith cutting down by an axe or a metal shovel.
Boxes with monoliths it is necessary to hold the first 2-3 days indoors with t ° 5-10 °, ukryv them bags, canvas. After thawing monoliths transfer for 12 days to a light warm room with t ° 18-20 °. If the soil of monoliths appears dry, it is necessary to water it voyody room temperature.
Calculation of results carry out for the 15th day after sampling in the field. For calculation all plants take out from the soil, wash out water and then separately count up in a kayozhdy monolith quantity live (given new backs and leaflets) and lost, not given growth.
On the basis of results of calculation calculate percent of death of plants in test on the following formula:
dx100
R =———— where d - number of plants not given growth
and and – total number of plants in test
It is possible to apply the simplified method of an otrashchivaniye to identification of a condition of winter crops. On the specified method of test take not the whole monolith, and separate pieces if only the most part of plants, especially their knots of a kushcheniye, wasn’t damaged. The taken plants immediately place in a box and cover with a bag. Boxes with tests bring for an otyotaivaniye in a room at air temperature near a minus 10 °. After soil thawing carefully separate plants of each test from the earth and wash out them water of room temperature. Then at them cut off roots so that the piece from knot a kushcheyoniya to a place of a cut equaled 3-4 see Otmerzshiye of a part of leaves also cut off. Roots sleduet to cut only at the plants, started to cluster. Otrashchivaniye lead in the plates half filled with water. The cut plants display along the edges of plates so that roots and the lower part of knots of a kushcheniye were shipped in water. Plates with rasteyoniya put in the light room, which temperature about 20 °.
The accounting of results of an otrashchivaniye is carried out for the 7th day.
L.Tishchenko, manager of Goseksperttsentr’s Soviet strong point.