What Fertilizer Is Best to Apply at the Rice Heading Stage? Timing of Pesticide Application and Key Points for Pest and Disease Control

Heading is the phenomenon in which the fully developed ear of a cereal crop extends out from the top leaf as the stem elongates. It is the stage in which vegetative growth and reproductive growth advance vigorously together, and it is also the best period for topdressing. So, what fertilizer is best to apply at the rice heading stage? When should pesticide be applied? Key points for pest and disease control included!

1. What fertilizer is best to apply at the rice heading stage?

The application of ear fertilizer should be comprehensively considered according to variety, climate, soil, the expected requirements of a high-yield structure and the ideal growth conditions. Generally, early-maturing varieties may not need it; for ordinary medium- and late-maturing hybrid rice varieties, on the basis of early tillering fertilizer, ear fertilizer should also be applied, and it is especially necessary for sandy fields with low fertility levels and weak fertilizer retention capacity. Generally speaking, the amount of urea in ear fertilizer accounts for about 20-30% of the total nitrogen fertilizer, and potassium sulfate or potassium chloride accounts for about 40-50% of the total potassium fertilizer applied. For fields where early growth is not vigorous, leaf color is pale yellow at the jointing stage, leaves do not hold dew in the morning, and leaves stand erect at noon, flower-promoting fertilizer should be applied. If by the booting stage “second black” is not obvious, flower-preserving fertilizer should also be applied to increase the seed-setting rate and promote large ears.

2. When should pesticide be applied at the rice heading stage?

Pesticide should be applied at the rice heading stage within 5-7 days before the rice booting stage, which is the best period for controlling sheath blight, rice blast, rice planthopper and other pests and diseases. When applying pesticide, be careful to avoid the high-temperature period at noon, and generally spray before 10 a.m. and after 3 p.m. If it rains within three hours after application, it needs to be reapplied.

3. Key points for pest and disease control at the rice heading stage

1. Sheath blight

Application should be carried out when the diseased plant rate at the booting stage reaches 30%-4%. The solution should be sprayed on the middle and lower parts of the rice plants. With the splash irrigation method, a 3-5 cm water layer should be maintained in the field. When applying validamycin, it is best to do so after rain on a sunny day, or when there is no heavy rain within two hours after application. Use 100-150 ml of 5% validamycin aqueous solution per mu, or 25 g of high-concentration validamycin powder, choosing either one, and dilute with 100 kg of water for conventional spraying, or dilute with 400 kg of water for splash irrigation.

2. Rice blast

When rice blast is truly found to occur, correctly determine the type of rice blast, and based on the condition, strive to control its development at the initial stage and block the spread of the pathogen as much as possible. Adopt a treatment strategy using Fuji-one and chlorobromoisocyanuric acid soluble powder (50% concentration) to control the development of the disease and avoid greater damage.

3. Rice planthopper

(1) Oil-drop insect killing. Drip 400-500 g of waste diesel oil or waste engine oil per mu, keep a shallow water layer of 20 cm in the field, and manually drive the insects so that they fall into the water and die upon touching the oil. After treatment, replace with clean water. Do not use this method after the booting stage.

(2) Spread poisoned soil. Spread 1.5 kg of dimethoate powder and 2 kg of moist fine soil per mu.

(3) Spray with pesticide. Spray with 0.5 kg of 40% dimethoate emulsifiable concentrate added to 800-1000 kg of water.

4. Yellow stem borer

During the peak hatching period of the newly hatched larvae, the booting stage is the best period for controlling white heads. When 5%-10% have booted, apply pesticide once; if the insect population is large, apply 1-2 more times at an interval of 5 days.

It can be seen that the rice heading stage marks the transition of rice from the growth of roots, stems and leaves to flowering and grain formation. It is the most important key period determining rice yield, and also the period in which rice grows and develops fastest in its life and has the greatest demand for nutrients, water, temperature and light. Therefore, at this stage it is very important to do a good job in fertilization and pest and disease control management.