Simulation modeling of damage caused by downy mildew and grapevine rust in Vitis spp. under different training systems

• Grant number: 17/02432-6
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: May 01, 2017
• End date: April 30, 2020
• Field of knowledge: Agronomical Sciences - Agronomy - Plant Health
• Principal Investigator: Lilian Amorim
• Grantee: Antonio Fernandes Nogueira Júnior
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Associated research grant: 13/24003-9 - Grape diseases: epidemiology, damage assessment and control, AP.TEM
• Associated scholarship(s): 19/11590-0 - Histochemical and histopathological analyses of cv. Solaris infected with Plasmopara viticola and expression of pathogenesis-related genes in two temperatures, BE.EP.PD 18/00952-5 - Photosynthesis limitations and monocycle development of downy mildew at different temperatures and Vitis spp., BE.EP.PD

Abstract

Viticulture in Brazil has been expanding in the last ten years. Both the area planted to vines and productivity increased during this period. In most grape regions, high disease severities of downy mildew (Plamospara viticola) and rust (Phakposora euvitis) are observed in vines when climatic conditions are favourable to the development of pathogens. The control of these diseases is basically with fungicide applications and the number of applications reaches 60 per cycle. These were the motivations of the thematic project "Epidemiology, damage assessment and control of diseases of the vine" (Process FAPESP 2013/24003-9) that has been achieved relevant results: the effect of downy mildew and rust on the green tissue surrounding the lesion of the pathogens was quantified with the application of the concept of the virtual lesion (²) proposed by Bastiaans. Rust reduced drastically the photosynthetic efficiency of the leaves, with an estimated value of ² of 5.78, while downy mildew presented a moderate reduction in the photosynthesis of leaves of Vitis labrusca and the estimated ² in this pathosystem was 2.9. Rust reduced the apparent electron transport, the efficiency of photosystem 2 and the activity of Rubisco, while the mildew reduced the activity of Rubisco. ² and photosynthetic limitations were determined under ideal conditions for the development of diseases (Nogueira Júnior, 2016). These effects were not evaluated in V. vinifera or at different leaf temperatures. The evaluation of monocyclic components of rust showed that although spore germination is minimal at 30°C, the disease severity in plants kept at that temperature is high (Alves, 2015). The effect of temperature on pathogenic colonization and photosynthetic metabolism of plants is not clear. The downy mildew severity is practically nil in plants cover by plastic and the occurrence of rust is not altered by plasticulture. However, literature data show that the air temperature in plants under the plastic is 3°C higher than that without plasticulture; In addition, the photosynthetically active radiation is 30% lower than in plasticulture. The growth simulation model of V. labrusca (Genecrop-P) was developed, parameterized and tested. The objective of this project is to advance the understanding of damage mechanisms and to elaborate the disease damage simulation model in grapevine. The effects of the pathogens on the green tissue surrounding the lesion as a function of leaf temperature and in Vitis species (V. vinifera and V. labrusca) under controlled conditions will be determined. Cuttings of cv. Niagara Rosada and cv. Moscato will be inoculated and maintained in Conviron ® chambers at temperatures of 15, 25 and 30°C. The severity of diseases will be related to variables obtained from gas exchange analysis using a portable infrared gas analyzer. Photosynthesis limitations caused by P. viticola and P. euvitis will be determined under controlled conditions in V. vinifera by measurements of gas exchange and photosynthesis response curves to the increase of intercellular CO2 (A/Ci) concentration. The effects of the pathogens on the green tissue surrounding lesions and the photosynthetic limitations will also be determined in field plants conducted in the Y training system with plasticulture and without plastic cover. Measurements of gas exchange, light response curves and A/Ci curves will be performed in healthy and diseased plants, with and without plastic covering, during two crop cycles. Plants with and without plastic cover will also be inoculated with different concentrations of inoculum of P.viticola and P. euvitis and the severity of the diseases will be correlated with the production of grape. The data obtained will be used in the parameterization and validation of the simulation model of damages caused by P. viticola and P. euvitis on grapevine. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

NAVARRO, B. L.; NOGUEIRA JUNIOR, A. F.; RIBEIRO, R. V.; SPOSITO, M. B.. Photosynthetic damage caused by grapevine rust (Phakopsora euvitis) in Vitis vinifera and Vitis labrusca. AUSTRALASIAN PLANT PATHOLOGY, v. 48, n. 5, p. 509-518, SEP 2019. (17/02432-6, 13/24003-9)

NOGUEIRA JUNIOR, ANTONIO F.; TRAENKNER, MERLE; RIBEIRO, V, RAFAEL; VON TIEDEMANN, ANDREAS; AMORIM, LILIAN. Photosynthetic Cost Associated With Induced Defense to Plasmopara viticola in Grapevine. FRONTIERS IN PLANT SCIENCE, v. 11, MAR 19 2020. (18/00952-5, 17/02432-6, 13/24003-9)

NOGUEIRA JUNIOR, ANTONIO F.; RIBEIRO, RAFAEL V.; MARCOS, FERNANDA C. C.; AMORIM, LILIAN. Virtual lesions and photosynthetic damage caused by Plasmopara viticola in Vitis labrusca. European Journal of Plant Pathology, v. 155, n. 2, p. 545-555, OCT 2019. (17/02432-6, 13/24003-9)