Preliminary study on the control of cucumber green mottle mosaic virus in commercial greenhouses using agricultural disinfectants and resistant cucumber varieties

Authors: ELLOUZE, OUALID - Ministry Of Agriculture And Forestry; MISHRA, VACHASPATI - Ministry Of Agriculture And Forestry; HOWARD, RONALD - Rjh Ag Research Solutions Ltd; Ling, Kai-Shu; ZHANG, WEIZHENG - Ministry Of Agriculture And Forestry

Submitted to: Agronomy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/24/2020
Publication Date: 11/27/2020
Citation: Ellouze, O., Mishra, V., Howard, R.J., Ling, K., Zhang, W. 2020. Preliminary study on the control of cucumber green mottle mosaic virus in commercial greenhouses using agricultural disinfectants and resistant cucumber varieties. Agronomy. 10:1879. https://doi.org/10.3390/agronomy10121879.
DOI: https://doi.org/10.3390/agronomy10121879

Interpretive Summary: Cucumber green mottle mosaic virus (CGMMV) is a re-emerging tobamovirus causing serious disease outbreaks on cucumber, melon, and watermelon worldwide, including North America. This seed-borne and mechanical transmitted virus is difficult to manage due to lack of a cultivar with resistance, persistence of virus infectivity in the environment and intensive crop production in a greenhouse. Those horticultural practices with frequent touching to plants by contaminated hands, dirty clothings, cutting tools and moving machineries are especially vulnerable points for virus spread. In collaboration with scientist at the Alberta Agriculture and Forestry, ARS scientist at the U.S. Vegetable Laboratory participated in a collaborative project to evaluate a management program through the use of a rigorous sanitization and tolerant cucumber varieties to manage CGMMV on cucumber in a greenhous. The results demonstrated that although CGMMV can survive better on porous surface, it was still possible to achieve a total cleaning of a CGMMV - contaminated greenhouse with high pressure-wash and multiple applications of an alkaline foam cleanser. In variety trials, although all 15 test commercial cucumber cultivars (including both Mini and Long English fruit types) had no true resistance to CGMMV infection, two Mini and three Long English cultivars were more tolerant than others. It is especially important to point out that some of these cultivars could still maintain a meaningful productivity despite of a virus infection. However, growing grafted plants between two different cucumber cultivars did not improve disease resistance to CGMMV. Although it is difficult to eradicate CGMMV in a contaminated greenhouse, it is still possible to manage the virus infection through high pressure washing to a contaminated greenhouse, using proper disinfectant and planting a tolerant cucumber cultivar to maintain a profitable crop production.

Technical Abstract: Cucumber green mottle mosaic virus (CGMMV) is a re-emerging threat to greenhouse cucumber and other Cucurbitaceae crop productions worldwide. This seed-borne virus can easily spread from a contaminated seed to seedlings and to adjacent plants through mechanical contact of the foliage of diseased and healthy plants causing extensive yield losses. Additionally, infection may not be limited to the current crop but may also affect subsequent crops due to the long-term persistence of the virus on contaminated crop residues, greenhouse hard surfaces and soil or soil-less greenhouse substrates. In the present work, three greenhouse trials were conducted to develop an integrated pest management strategy towards controlling CGMMV in commercial cucumber greenhouses, by implementing an effective sanitization program and using resistant and grafted cucumber varieties. Results of sanitization trial highlighted that pressure washing and cleansing with an alkaline foam cleanser has eliminated CGMMV on some of the most heavily infested areas. However, three successive applications of cleanser and disinfectants were essential to completely eliminate CGMMV on porous and uneven surfaces, such as cement alleyway, tray gutter and floor mats. The varietal trial revealed that out of 15 cucumber varieties evaluated, two Mini (‘Katrina’ and ‘Khassib’) and three Long English (‘Sepire’, ‘Bomber’ and ‘LC13900’) had reduced or delayed CGMMV infection spread in the greenhouse but were intermediate in yield. The varieties ‘Sunniwell’ and ‘Bonbon’ were the most tolerant to CGMMV. They showed a high CGMMV infection level without compromising yield. These results proved the need for new productive cucumber varieties with CGMMV resistance. Grafting experiment showed only yield increase in case of grafted ‘Picowell’ over ‘Bonbon’ and not marked CGMMV resistance, which is a much desirable result when the grafting experiments are evaluated for their economic potential. In all, the current experimental trials unfold unique methodologies on CGMMV management in commercial greenhouses that are recommended to the growers to be followed for reducing crop losses and get benefited on revenue compromise.