Management techniques of summer sowing oil sunflower in the middle and later stage

After the summer sowing oil sunflower enters the middle stage, it mainly manages the bud stage, flowering stage and grain filling stage. The specific management techniques are as follows:

I. Management of bud period

1. Intertillage fertilization, trenching soil cultivation: the third intertillage before and after budding, combined with intertillage urea 8 kg per mu, fertilization depth should be 8-10 cm, and root soil cultivation combined with intertillage.

two。 Watering in case of drought, drainage in case of waterlogging: abundant rainfall in summer, generally do not need watering before budding, if Rain Water is too large to pay attention to drainage, the ground can not have stagnant water, in case of drought years, it should be watered.

Management of the period from flowering to grain filling

1. Timely watering: we often form autumn drought weather after the Beginning of Autumn, which is extremely disadvantageous to the formation of yield. during flowering, we must ensure an adequate supply of water. In case of drought, we should irrigate the last water for the last time within 15 days after the final flowering.

two。 Foliar fertilizer spraying: foliar spraying with 0.3% boron fertilizer solution and 0.2% potassium dihydrogen phosphate solution before flowering, with two sprayers of water (30kg) per mu, once every 10 days, for 2-3 times.

3. Pest control: the main diseases are Sclerotinia sclerotiorum, downy mildew, leaf spot, Verticillium wilt, gray mold, black spot, powdery mildew, rust and so on. Pests are mainly cotton bollworm, borer, as well as underground insects, thrips and so on.

4. Forking and artificial pollination: some sunflower varieties have branching characteristics, which affect the development of the disk of the main stem, so when the plant appears bifurcation, it should be knocked out in time. Sunflowers are mainly pollinated by bees. Release bees to pollinate, 5-7 mu of land need to put a box of bees. In places where there is a lack of bee sources, artificial pollination is needed to improve the seed setting rate. The time of artificial pollination can be carried out around 9-11:00 in the morning. At this time, there are many pollen grains, the vitality is exuberant, and the pollination effect is good. The method of artificial pollination is to gently rub the two plates together at the peak of flowering, or gently rub them on each disk with a round powder puff made of cardboard with a diameter of 5-10 cm with a clean towel and do it every other day, thus increasing production significantly. The seed setting rate is 85%.

III. Timely harvest

The harvest time is in the middle and late September. It can be harvested when 4-5 leaves and stems in the upper part of the plant and the back of the disk turn yellow and the seeds harden. Li Jinzhong