Experience in field management of sugar orange in October

1. Field management

Grass management in ① orchards: choose measures that you think are economical and effective to control weed growth. Grass control in this period is beneficial to exposure to light, ventilation, reduction of air humidity and disease prevention in orange orchards.

② strengthened the control of nitrogen and quality of fruit in the later stage: the fruit quality of citrus was most affected by tree potential in the later stage. Most of the photosynthates were converted into nitrogen-containing organic compounds to form shoots and consumed, while the fruits showed large coarse fruit, green skin, poor color conversion, low fruit juice content, low soluble sugar content and poor quality. Regulation measures, the first is to control the amount of nitrogen application, followed by topdressing should be applied early, supplemented by ring cutting, in order to control the tree potential. If the above measures are not effective, organic matter with high carbon content can be applied to the soil 60 days before fruit ripening (such as unripe manuscripts or 5 liters per square metre of tree shade with 2% Murray 4% sugar solution) to reorganize the excess inorganic nitrogen in the soil, inhibit the excessive absorption of nitrogen by roots before fruit ripening, and help to reduce the level of inorganic nitrogen in soil and leaves. So as to promote coloring, increase sugar and reduce acid, timely ripening, and improve fruit quality.

2. Disease and pest control

The main pests harmful to citrus in October are red and yellow spiders, rust mites, whitefly and fruit-sucking armyworm, etc. Pest control should pay attention to the safe interval of pesticide harvest, and biological pesticides and physical destructive pesticides should be selected in general. For example, avermectin + sulfur gel suspension is used in the later stage, which has the effect of isolating pathogen infection and promoting pericarp color. In this period, the control of diseases and insect pests is thorough, which is beneficial to reduce the storage decay.