Investigation on Diseases and Pests of Grape Under Rain Shelter Cultivation in Shandong Province

Xiujie LI Guixiang LI Yujin LIU Zhen HAN Ziguo ZHU Qingtian ZHANG Bo LI

Abstract In order to make clear the effects of rain shelter cultivation on the incidence of diseases and pests of grape in Shandong Province， with Summer Black as the material， the diseases and pests of grape under rain shelter cultivation and open field cultivation in Taian and Jining were investigated. The results showed that under the rain shelter cultivation condition， the phenological period of grape delayed 5-8 d. The types of grape diseases and pests under the rain shelter cultivation were the same as those in the open filed cultivation. The most serious pests were Apolygus lucorum， followed by Lycorma delicatula， Erythreura apicalis and Thrips tabaci. The most serious leaf disease was downy mildew， and the most serious disease of grape berries was grape sour rot. Compared with the open field cultivation， the rain shelter cultivation could effectively reduce the incidence of pests and diseases in grape leaves and fruit. At the end of May 2018 and 2019， the occurrence rate of grape pests under the rain shelter cultivation in Taian reduced by 57.69% and 60.47%， respectively， and those in Jining reduced by 72.22% and 62.50%， respectively. In the middle of July of 2018 and 2019， the incidence of grape fruit diseases under the rain shelter cultivation in Taian reduced by 62.49% and 50.07%， respectively， and that in Jining reduced by 49.96% and 100%， respectively.

Key words Shandong Province; Grape; Rain shelter cultivation; Open field cultivation; Phenological period; Diseases and pests

Received： February 23， 2021  Accepted： April 28， 2021

Supported by Key Research and Development Program of Linyi City （2020ZX010）; Agricultural Improved Variety Project of Shandong Province （2020LZGC008）; Agricultural Science and Technology Innovation Project of Shandong Academy of Agricultural Sciences （CXGC2021A11）.

Xiujie LI （1980-）， female， P. R. China， research assistant， master， devoted to research about viticulture physiology and breeding.

*Corresponding author. E-mail： sdtanlibo@163.com.

The grape cultivation area of Shandong Province is 38 000 hm which plays an important role in the poverty alleviation of farmers and the adjustment of industrial structure. The ripening period of grapes in Shandong Province coincides with the same season of rain and heat， and a little careless management will cause serious diseases and pests and difficult control of fruit cracking and rotten fruit. At present， agrochemicals are used in large doses and multiple batches in production， causing food safety hazards and soaring production costs. As people pay more and more attention to food safety， the research and development of green cultivation methods for reducing the occurrence of pests and diseases from sources has always been the focus of scientific and technical personnel.

Rain shelter cultivation is a simple facility cultivation method in which plastic film is covered on the facilities above the top of canopies during the grape growing season to prevent rainfall from affecting the growth and fruiting of grape， thereby ensuring the normal maturity of grapes[1-3]. Rain shelter cultivation can avoid rain splashing and flowing， reduce the temperature and humidity of the grape leaf curtain layer， and theoretically reduce the incidence of moisture-loving diseases. In recent years， rain shelter cultivation has gradually emerged in southern China[4]， and the promotion of this technology has turned the sub-suitable areas for grape planting in the south into efficient areas. Drawing on the experience of rain-shelter cultivation of grapes in the south， Shandong Institute of Pomology introduced rain shelter cultivation techniques into the main growing areas of table grapes such as Jinan， Taian， Jining， Liaocheng， etc.， in 2010. They conducted a systematic study on the rain shelter cultivation mode， construction cost， and the effects of rain shelter cultivation on the growth and development， fruit quality and micro-environment of grape[5-9]， and initially formulated the grape rain shelter cultivation technical regulations suitable for Shandong Province. Studies in Guangxi and other places have shown that rain shelter cultivation has a certain effect on the prevention and control of grape downy mildew[10-12]， gray mold[13] and white rot[14]. The occurrence of plant diseases and pests has regional characteristics. The occurrence time and types of plant diseases and pests in different regions are different. However， as of now， there is no report on the effect of rain shelter cultivation on the occurrence of diseases and pests in the cultivation of edible grapes in Shandong Province. For this reason， for two consecutive years from 2018 to 2019 in the main edible grape production areas in Shandong Province， the occurrence of grape diseases and pests under the two cultivation methods of sheltered and open fields was investigated， aiming to provide guidance for the prevention and control of diseases and pests of grape cultivated in sheltered areas and further improve the technical system of rain shelter cultivation of grape in Shandong Province.

Materials and Methods

Experimental materials

The grape variety was Summer Black.

Experimental methods

Experimental design

From 2018 to 2019， in the main table grape producing area of central Shandong Province represented by Taian and the main table grape producing area of southwest Shandong represented by Jining for 2 consecutive years， the occurrence of grape diseases and pests under the two cultivation methods of sheltered and open fields was investigated. Specifically， the Taian pilot project was selected at the Jinniu Mountain Experimental Demonstration Base of Shandong Institute of Pomology， Daiyue District， Taian City， Shandong Province. The grape vines were planted in 2014， with a north-south direction， a row spacing of 2 m×6 m， and shaped with T-shaped frames. The Jining pilot project was selected in Jining Qufu Nishanhong Ecological Agriculture Co.， Ltd. The grape vines were planted in 2016， and the planting method and frame type were the same as the Taian pilot. In the same pilot， a comparative experiment design was adopted， and two methods of rain shelter cultivation and open field cultivation （CK） were set up.  The rain shelter facilities were simple multi-span rain shelters with a height of 2.6 m and a span of 6 m， and the top was covered all year round. The two pilots were all irrigated by drip irrigation， and had good drainage and irrigation conditions and a high level of grape management.

Before budding， lime sulfur mixture （3-5 Baume degrees） was sprayed once throughout the orchards to eliminate overwintering eggs and adults. After budding， no pest control measures were taken， and the fruit was not bagged， so as to observe the occurrence of fruit diseases and pests. Other field management measures were the same as usual.

Investigation items and methods

The main types of pests and diseases and the degree of damage

Starting from the budding of grape in spring， 20 normally-growing grape plants were randomly selected for each treatment， and the types of diseases and pests were investigated in the field. The areas of diseased leaves and fruit were visually inspected， and referring to the method of Fu et al.[15]， combined with the control experience of local fruit farmers， the degree of pest damage was graded.

Grading standards for disease severity： +： sporadic occurrence， which generally does not require prevention; ++： mild occurrence， which needs to be treated with concurrent treatment measures， and will cause certain losses if no prevention and treatment measures are taken; +++： moderate occurrence， which needs special prevention; ++++： serious occurrence， which needs a variety of measures and prevented and controlled multiple times.

Grading standard of pest severity： +： mild occurrence， which generally does not require prevention; ++： moderate occurrence， which needs to be treated with concurrent treatment measures， and will cause certain losses if no prevention and treatment measures are taken; and +++： serious occurrence， which needs special prevention， and will cause obvious losses if no prevention and treatment measures are taken.

Phenological phase

In spring， 10 normal plants were randomly selected， and the phenological period was recorded according to the growth of plants.

Incidence rate of leaf diseases and pests

The leaf pest investigation was carried out in mid April for the first time， and thereafter once every month， and a total of five investigations were carried out. Twenty grape plants were randomly selected， and three leaves in the middle of shoots were randomly selected from each plant to investigate the number of leaves with pests and diseases， and calculate the incidence of leaf diseases （pests） （number of damaged leaves/total number of investigated leaves×100%）.

Incidence rate of fruit cluster diseases

The fruit disease investigation was conducted on June 1  for the first time， and once every 15 d thereafter， and a total of six investigations were carried out. Twenty grape plants were randomly selected， and three fruit clusters were randomly selected from each plant to investigate the number of diseased or rotted fruit clusters and calculate the incidence of fruit cluster diseases （number of damaged fruit clusters/total number of investigated fruit clusters × 100%）.

Results and Analysis

Effects of rain shelter cultivation on the main pests and diseases of grape and the damage degree

Disease types and harm degree

The investigation results for 2 consecutive years （Table 1） showed that the types of diseases that occurred in grape cultivated in sheltered areas were basically the same as those of grape cultivated in open fields. In Taian and Jining areas， downy mildew and sour rot occurred severely， of which downy mildew was the most harmful to leaves， and sour rot was the most harmful to mature fruits; white rot， grapevine anthracnose and gray mold occurred mildly and had certain harm; and powdery mildew， grape spot anthracnose and rust occurred sporadically and generally did not need to be controlled. Among leaf diseases， downy mildew occurred the most serious. Once it occurred， the disease spread quickly and was usually difficult to control. Among the fruit diseases， sour rot was the most serious. When the disease was severe， the orchards smelled sour， and the rotten grape juice flew down the fruit bags and caused dark pollution， which seriously affected the fruit quality and the beauty of the orchards. White rot disease occurred mildly， and it was also harmful to the fruit， so attention should be paid to prevent it in advance.

Pest types and damage degree

The investigation results for 2 consecutive years （Table 2） showed that the types of pests that occurred in sheltered grape were basically the same as those in open-field grape. In Taian and Jining areas， Apolygus lucorum occurred severely， and the damage was the most severe. The leaves were the most severely damaged by A. lucorum in April and May each year， and the damaged leaves showed irregular holes， and shrank in severe cases. Lycorma delicatula， Erythroneura apicalis and Thrips tabaci occurred moderately and caused serious damage. Among them， T. tabaci mainly damages the young fruits， and the damaged parts formed small black spots， which seriously affected the appearance of the fruit. Planococcus ficus and Parthenolecanium corni occurred mildly and generally did not need to be controlled.

Effect of rain shelter cultivation on the phenological period of grape

The investigation results for 2 consecutive years （Table 3） showed that the phenological period of grape cultivated in sheltered areas in Taian and Jining was generally delayed compared with grape cultivated in open fields， and the phenological period of grape in Jining area was slightly earlier than that in Taian area. In the experimental years， the budding period， the initial flowering period， the full bloom period， the color turning period and the berry maturity period of grape cultivated in sheltered areas in Taian were   2-3， 3-4 and 5-7 d later than those of the grape in open fields， respectively， and the budding period， the initial flowering period， the full bloom period， the color turning period and the berry maturity period of grape cultivated in sheltered areas in Jining were 0- 3-4，  2-6 and 8 d later than those of grape in open fields， respectively. From the perspective of the phenological periods in the two pilots， in the same year， the budding period， the initial flowering period， the full bloom period， the color turning period and the berry maturity period of grape under the open field cultivation mode in Jining area were 1-3， 2-3，  0-2 and 3-4 d earlier than those in Taian respectively， and the budding period， the initial flowering period， the full bloom period， the color turning period and the berry maturity period of grape in Jining area under the rain shelter cultivation mode were 2-3，  3-4， 0-1 and 0-3 d earlier than those in Taian， respectively.

Effect of rain shelter cultivation on the incidence of diseases and pests in grape

Incidence rate of leaf diseases

The investigation results for 2 consecutive years （Table 4） showed that the rain shelter cultivation had little effect on the incidence of leaf diseases in the early stage of grape growth， but it could effectively reduce the incidence of leaf diseases in the middle and late stages of grape growth. In the experimental years， in the early stage of grape growth， the occurrence of leaf diseases in open-field grape in the two pilots was less， and the incidence of leaf diseases in grape under sheltered cultivation was not much different from that in open-field grape. Since the end of June， with the increase of rainfall， the leaf disease rates of grape under the open field cultivation mode in the two pilots gradually increased， and there was a concentrated outbreak of diseases after the end of August. At the end of October 2018 and 2019， the incidence of leaf diseases of open-field grape in Taian area was 91.67% and 78.33%， respectively， and the incidence of leaf diseases of open-field grape in Jining area was 75.00% and 70.00%， respectively; and under the rain shelter cultivation， the incidence of grape leaf disease in Taian area （36.67% and 31.67%， respectively） decreased by 60.00% and 59.57%， respectively， and the incidence of grape leaf disease in Jining area （75.00% and 70.00%， respectively） decreased by 48.89% and 33.33%， respectively.

Incidence rate of leaf pests

The investigation results for 2 consecutive years （Table 5） showed that the rain shelter cultivation could effectively reduce the incidence of pests on grape leaves in the early stage of growth. From April to the end of June in the experimental years， the leaf pests of grape under the open field cultivation in Taian and Jining areas were severe， while the incidence of leaf pests in grape cultivated under rain shelters was significantly reduced. At the end of May 2018 and 2019， the incidence of leaf pests in open-field grape in Taian was 86.67% and 71.67%， respectively， and the incidence of leaf pests in open-field grape in Jining was 60.00% and 53.33%， respectively; and under the rain shelter cultivation， the incidence of grape leaf pests in Taian （36.67% and 28.33%， respectively） decreased by 57.69% and 60.47%， respectively， and the incidence of grape leaf pests in Jining area （16.67% and 20.00%， respectively） decreased by 72.22% and 62.50%， respectively. Since the end of July， the damage caused by pests to the leaves of grape cultivated in open fields gradually decreased; and the incidence of pests on the leaves of grape cultivated in sheltered areas was not much different from that of grape cultivated in open fields.

Incidence rate of fruit cluster diseases

The investigation results for 2 consecutive years （Table 6） showed that the rain shelter cultivation could effectively reduce the incidence of grape cluster diseases. As the fruit matured， the incidence of fruit cluster diseases of grape grown in open fields was on the rise. When the fruit began to mature in mid July 2018 and 2019， the incidence of fruit cluster diseases of open-field grape in Taian area was 13.33% and 6.67%， respectively， and the incidence of fruit cluster diseases of open-field grape in Jining area was 13.33% and 5.00%， respectively; and under the rain shelter cultivation， the incidence of grape cluster diseases in Taian area （5.00% and 3.33%， respectively） decreased by 62.49% and 50.07%， respectively， and the incidence of grape cluster diseases in Jining area （6.67% and 0， respectively） decreased by 49.96% and 100%， respectively. In mid August， that is， the fruit was hung on the trees for one month after maturity， compared with the open field cultivation， the incidence of fruit cluster diseases of grape cultivated under rain shelters in Taian area was reduced by 69.24% and 78.27%， respectively， and the incidence of fruit cluster diseases of grape cultivated under rain shelters in Jining area was reduced by 70.58% and 75.01%， respectively.

Conclusions and Discussion

From 2018 to 2019， the investigation results in Taian and Jining regions of Shandong Province for 2 consecutive years showed that the types and periods of occurrence of leaf and fruit diseases and pests in grape cultivated in sheltered and open fields were basically the same. Pests caused greater damage to the leaves of grape in the early growth stage than in the middle and late growth stages. The main pests were A. lucorum， L. delicatula and E. apicalis， among which A. lucorum was the most harmful pest to the leaves in the early stage of grape growth. Studies have found that since 2017， the population of A. lucorum has increased sharply and has become the main pest in the early stage of grape growth. Improper control can cause the damage rate of grape plants up to 70%[16]. In Taian area， without implementing any prevention and control measures， the damage rate of A. lucorum to grape leaves is as high as 80%. A. lucorum depends on the piercing and sucking mouthparts of adults and nymphs to injure the buds and young leaves of grape， and because the wound is small， they are usually found only after a few days when the damage has already formed， which not only affects the normal growth and development of grapes， but also seriously affects the commercial value of grapes due to the scars on the fruit. The adults of A. lucorum hide in the base of the tip leaves after feeding， and quickly escape after being slightly touched， so it is difficult to control them. The investigation found that the rain shelter cultivation could effectively reduce the occurrence of grape leaf pests， and compared with the open field cultivation， the incidence of leaf pests was reduced by 57%-72%. It might be related to the rain shelters or roof shed films that prevented the jumping and migration of pests. The damage to grape leaves in Taian area was greater than that in Jining area. The reason might be that there were overgrown trees on the slopes around the test site in Taian area， and there were apple， peach and other fruit trees in the orchards， which provided a place for the eggs to live through the winter， so as the temperature rose in spring， the pests migrated to the grape leaves to damage them. Therefore， attention should be paid to site selection when constructing orchards， and we should try to avoid mountainous areas with lush trees and choose plots far away from the woods， and should not interplant host fruit trees and seedlings in orchards.

The investigation results for 2 consecutive years showed that the rain shelter cultivation delayed the phenological period of grape， and the fruit ripening period was 5-8 d later than that of open field cultivation. Although the types and time of occurrence of diseases in grape in the rain shelter cultivation mode were basically the same as those in the open field cultivation， the incidence of leaf diseases could be reduced by up to 60% compared with the open field cultivation.   Leaf diseases mainly occurred in the later stages of growth， especially downy mildew that occurred from August to October. Sour rot was most harmful to grape fruit， followed by white rot， but in many cases the two occur at the same time. The incidence of fruit cluster diseases of grape cultivated in sheltered areas could be reduced by 50%-78%.

In summary， compared with the open field cultivation， the types of pests and diseases that occurred in grape cultivated in the rain shelter mode did not changed much， but the incidence of pests and diseases was significantly reduced， which in turn could reduce the use frequency and quantity of agrochemicals. As a green method of preventing and controlling diseases and pests， rain shelter cultivation not only reduces the production investment， but also helps to improve the safety of products and the environmental friendliness of the production system. Therefore， in Shandong Province， which is wet and rainy in summer， grape cultivation under rain shelters has a good promotion value.

References

[1] LIU TS， LI GF. Advances in research on physiology of grape protected cultivation[J]. Acta Horticulturae Sinica， 200 29（S1）： 24-28. （in Chinese）

[2] LIU HN， ZHU JQ. Feeding effect of buffer in fattening beef cattle diet[J]. Hubei Agricultural Sciences， 2001（4）： 70-72. （in Chinese）

[3] WANG ZH， ZHANG W， GUAN LP， et al. Effect of rain shelter cultivation on microenvironment and fruit quality of Zexiang grape[J]. Sino-Overseas Grapevine & Wine， 2015（3）： 14-17. （in Chinese）

[4] CAO M， GUO JN， GAO DT， et al. Feeding effect of buffer in fattening beef cattle diet[J]. Journal of Henan Agricultural Sciences， 2016， 45（1）： 15-19. （in Chinese）

[5] HAN Z， LI XJ， ZHANG QT， et al. Effects of rain-shelter cultivation on light intensity in canopy， cost and benefit[J]. Shandong Agricultural Sciences， 2018， 50（11）： 52-54. （in Chinese）

[6] HAN Z， LI XJ， ZHANG QT， et al. Effects of rain shelter cultivation on the microclimate and cost[J]. Journal of Anhui Agricultural Sciences， 2018， 46（34）： 184-185， 189. （in Chinese）

[7] LI B， LI XJ， HAN Z， et al. Effects of shading on shoot growth and fruit quality of Summer Black grape[J]. Shandong Agricultural Sciences， 2017， 49（8）： 45-48. （in Chinese）

[8] LI B， ZHAO XQ， LI XJ， et al. Effect of shading on the endogenous hormones in the shoots during the differentiation of grape flower buds[J]. Jiangsu Agricultural Sciences， 2017， 45（13）： 104-107. （in Chinese）

[9] LI B， LI C， LI XJ， et al. Effect of shading on the microenvironment， leaf quality and fruit quality of ‘Xiahei grape[J]. China Fruits， 2017（5）： 45-48. （in Chinese）

[10] GONG HJ， JIANG QS， YE KY， et al. Field investigation of downy mildew （Plasmapara viticola） of the main grape cultivars with rain shelter cultivation in Guangxi[J]. Southern Horticulture， 2016， 27（5）： 17-19. （in Chinese）

[11] YU SY， LIU CY， FU JF， et al. Spatial distribution pattern and sampling technique for grapevine downy mildew in grape seedlings under open and rain-shelter cultivations [J]. Journal of Fruit Science， 2015， 32（4）： 720-726. （in Chinese）

[12] XIA YM. Control effects of different rain shelter cultivation patterns on main grape diseases and their effects on plant canopy temperature and humidity[J]. South China Agriculture， 2014（21）： 25， 27. （in Chinese）

[13] HUANG XD， HU WL， ZHU SS， et al. Research and application of disease control techniques for sheltered grape planting[J]. China Plant Protection， 201 32（10）： 25-27. （in Chinese）

[14] JIA TK， WANG LK. Investigation of effects on fruit quality and controlling main diseases of rainproof cultivation grape[J]. Shanxi Fruits， 2018（5）： 4-5， 9. （in Chinese）

[15] FU F， FAN K， QU JL. Investigation on the main pests and diseases of grape in the mountainous area of central Shandong[J]. Deciduous Fruits， 2019， 51（5）： 40-43. （in Chinese）

[16] ZHAO QF， LI QL， LI J， et al. Grape Apolygus lucorum in China： Occurrence trend and prevention and control strategies[J]. Chinese Agricultural Science Bulletin， 2019， 35 （36）： 138-142. （in Chinese）