Site description
This study was conducted at National high quality red plum apricot
demonstration area,which is located at the Shanghuang Eco-experiment
Station in the semiarid Loess hilly region (35°59′- 36°02′ N, 106°26′-
106°30′ E) in Guyuan, Ningxia Hui Autonomous Region of China, Institute
of Soil and Water Conservation of Chinese Academy of Sciences, with the
altitude of the station ranges from 1,534 m to 1,824 m. Precipitation
here is absent in the periods from January to March and from October to
December, and the rainfall from June to September makes up more than
70% of the annual precipitation. Mean rainfall measured between 1983
and 2001 was 415.6 mm with a maximum of 635 mm in 1984 and a minimum of
260 mm in 1991. The frost-free season is 152 days. The Huangmian soil
having developed directly from the loess parent materials, consists
mainly of
loamy
porous loess (Calcaric Cambisol, FAO1988) with wide distribution in the
semiarid hilly region of the Loess Plateau. Red plum apricot tree is a
kind of fine variety apricot (Armeniaca vulgaris Lam.). The
experiment was conducted in 23-year-old red plum apricot garden planted
in 1996 and 1-year-old red plum apricot garden planted 2018 .
Generally, some 2- year-old red plum apricot trees start to bear fruit.
3 -year-old red plum apricot forest has some yield and the yield of 4
-year-old red plum apricot forest have reached a certain level after
planting red plum apricot tree. An adult red plum apricot tree start to
bloom in the end of March and are in full bloom in the first ten-day
period of April, red plum apricot fruit is in the expansion period of
fruit from the second ten-day period of May to the second ten-day period
of June, and fruit mature in the first ten-day period of July, and leaf
drop in the middle and last ten-day period of September. Once serious
drying happens in the Fruit expansion stage, leaf of red plum apricot
tree change colour from green to yellow or croci, and drop earlier. The
size of red plum apricot fruit is smaller than normal fruit, which
influence the yield, quality and economic benefits of red plum apricot.