Water Management of pollution-free Ponkan cultivation

The water management of mandarin fruit trees requires timely irrigation when water is needed, timely drainage in case of flood, and no stagnant water in root system. Irrigation water should be pollution-free and should meet the requirements of NY/T5016.

1. Irrigation

The main results are as follows: (1) the effect of water on the growth and fruit of ponkan.

Water accounts for 80%-85% of Ponkan fruit and more than 60% of branches, leaves and roots. Trees play a key role in physiological changes such as nutrient absorption, transport, maintenance of cell expansion, transpiration and photosynthesis. Due to the uneven distribution of annual rainfall in Ponkan producing areas, Ponkan fruit trees should be irrigated when they need water.

(2) Water requirement law of Ponkan.

Ponkan has different water demand in different growth stages of the year, and has the law of transpiration water consumption. Transpiration water consumption was the lowest from December to February of the following year, increased gradually after March, and reached its peak from July to August. There was a positive correlation between air temperature and transpiration (r = 0.9165). The leaves take water from the fruit for evaporation.

(3) Irrigation quantity

The best way to determine the amount of irrigation is to measure the soil water content first, and then use the following formula to calculate.

Irrigation water = 667 × soil capacity × root depth × [0.8 × (maximum field capacity-soil water content before irrigation)] (cubic meter / mu)

(4) Irrigation period

It is too late to irrigate when the leaves of Ponkan are curled. During the specific irrigation period, it is commonly used to determine the diurnal variation of leaf transpiration, soil water content and fruit diameter.

Standard for irrigation of soil: Sandy soil