Research On Regional Distribution Of Citru Based On Huanglongbing In Guangdong Province

Guangdong province is a large production site of citrus and has a long history of planting.The citrus industry is agricultural pillar industry in Guangdong.Huanglongbing(HLB)is the most crushing disease to citrus,which has caused different levels of economic losses to the global citrus industry for many years.The damage of HLB is increasing in recent years and seriously restricts the development of citrus industry in Guangdong.In this study,based on relevant statistical data,we analyzed the present situation of citrus production and the occurrence of HLB in China and in the world as well.After visiting the department of agricultural administration in many cities of Guangdong province and citrus planting base,we have found out the related situation of citrus production and the occurrence of HLB.Then we analyzed the cultivation and adaptation of citrus and also analyzed the planting area in Guangdong province.1.The citrus planting area is maintained at about 240,000 hectares and the citrus yield is at about 3900,000 tons in recent years in Guangdong province,which makes Guangdong to be one of the most important producing areas.Among these areas,Zhaoqing city has the largest planting area,reaching to about 59,200 hectares,followed by Meizhou,Qingyuan and Yunfu city.The yield of citrus of both Meizhou and Zhaoqing city exceed 1 million tons.Among these areas of county level,Longmen county of Huizhou,Yunan county of Yunfu and Meixian county of Meizhou have the largest planting area and all the three counties have planting areas exceeding 20,000 hectares.Meixian county of Meizhou has the most yields,reaching to 623,489 tons,followed by Deqing county of Zhaoqing city,whose yields reach to 412,630 tons.Both Longmen county of Huizhou and Yunan county of Yunfu have yields exceed 300,000 tons.2.The area of HLB reaches to about 59,700 hectares in Guangdong province in 2017,which covers ca.25% of the total planting area and causes serious threat to citrus production.Among these areas,Qingxin district of Qingyuan and Yunfu city have the largest epidemic area,and both exceed 5,000 hectares.3.Based on natural resource conditions in Guangdong province and patterns of growth and development of citrus,we conclude that most of the areas in Guangdong have the suitable climate conditions for citrus planting,except for a few mountain areas in the north,which will encounter low temperature climate,such as frost,freezing and so on in a few years.Therefore,Guangdong has regional advantage in developing citrus production.4.Based on the climate and geographical features of Guangdong province,combining with the present citrus varieties,planting scale and occurrence of HLB,we analyzed the planting area of citrus in Guangdong province.We divided the planting area of citrus in Guangdong into four dominant citrus areas,including eastern Guangdong,western Guangdong,northern Guangdong and the Pearl River Delta.Each area has its central region,potential region and radiant region.Then we device the citrus varieties and developing direction for each area,to make sure that the planting area will be stable at 240,000 hectares in the whole province in 2020.5.In this paper,we have discussed the comprehensive prevention and control measures for citrus HLB,and provide guarantee for the implementation of compartment.