Growing Varieties Tolerant or Resistant to Pests in Vegetable Crops
1. Presentation
Characterization of the technique
Description of the technique:
Information originally from the Practical guide for designing vegetable cropping systems saving phytosanitary products (2014) / Technical sheet T4 - For more information see link
Principle
This genetic control lever concerns all technical choices related to seeds and seedlings aimed at preventing or hindering the establishment and development of a pest in a crop. Choices concern the use of resistant varieties (total or partial), grafting, use of healthy seeds and seedlings, their preventive treatment...
Regarding the choice of varieties, different resistances exist for all crops of vegetables. The choice of a resistant variety should be reasoned according to potential risks or problems already encountered on the farm.
Grafting consists of using the agronomic potential of a sensitive variety on the root system of a variety resistant to one or more soil-borne pests. This grafting should limit risk, or even improve the agronomic value of the variety.
Finally, the use of healthy seeds and seedlings is an important protection lever for crops. Indeed, pests such as fungi, bacteria, viruses and nematodes
can persist in the embryo or seed coat. For some quarantine organisms, mandatory phytosanitary seed controls exist. It is necessary to verify the specific purity of seed lots to ensure variety homogeneity and limit the presence of weeds. For seedlings, a phytosanitary passport exists which certifies the origin of the seedlings and allows knowing the treatments carried out in the nursery. Before planting, a visual inspection allows early detection of certain pests and removal of suspicious seedlings.
Details on the technique:
Grafting allows cultivation of varieties for which breeding work has not resulted in the introduction of resistances. Today, grafting is commonly practiced on eggplant, tomato, cucumber, melon and more rarely on pepper.
Various seed and seedling treatment methods exist:
- Phytosanitary products: this technique allows obtaining healthy seeds and seedlings and can, in some cases, avoid a treatment during growth or delay the establishment of a pest. However, seed treatment should not be systematic but decided based on the risk of pest presence. These treatments can be carried out using phytosanitary products, plant extracts (studies ongoing), essential oils (studies ongoing), microorganisms...
-Thermotherapy: technique allowing disinfection of seeds or seedlings by immersion in hot water at a constant temperature for a short duration. When poorly performed, this technique can reduce seed germination capacity. Thermotherapy can for example be used on shallot bulbs against Botrytis, Sclerotinia, downy mildew... The soaking is then 2 hours in water at 43 °C.
- Macro-organisms: releases of Macrolophus pygmaeus in nurseries facilitate early establishment of predators and can improve control of aerial pests upon their arrival (whiteflies, Tuta absoluta...).
Implementation period
Spatial scale of implementation Plot
Application of the technique to...
All crops: Sometimes difficult to generalize
Sometimes difficult to generalize
Not all vegetable species have resistances to pests. However, many species grown in greenhouses, under cover and in open fields are concerned.
Regulation
All varieties used must be registered in the official catalog.
No specific regulation for the presented techniques, except when seed treatments are carried out with phytosanitary products; in this case, marketing authorizations must be verified.
2. Services provided by the technique
3. Effects on the sustainability of the cropping system
"Environmental" criteria
Effect on air quality: Increasing
phytosanitary emissions: DECREASE
GHG emissions: DECREASE
Effect on water quality: Increasing
pesticides: DECREASE
Effect on fossil resource consumption: Decreasing
fossil energy consumption: DECREASE
Other: No effect (neutral)
Comments
Reduction of transfers of phytosanitary products to water, air and reduction of GHG emissions.
Reduction of fossil energy consumption when treatments are avoided.
"Agronomic" criteria
Productivity: Variable
Variable
Risk of resistance breakdowns more or less rapid.
Production quality: Increasing
Increasing
Better product quality if damage is reduced.
Functional Biodiversity: Increasing
Increasing
Increase in functional biodiversity if treatments are avoided.
"Economic" criteria
Operational costs: Increasing
Increasing
Higher costs of seeds (purity, treatments, resistances) or seedlings (grafting).
"Social" criteria
Peak period: Variable
Variable
Overall working time can decrease if the technique used reduces the number of treatments during the crop.
Impact on work organization if seed or seedling treatments, or grafting are done on the farm.
4. Favored or disadvantaged organisms
Favored pests
| Organism | Impact of the technique | Type | Details |
|---|
Disadvantaged pests
| Organism | Impact of the technique | Type | Details |
|---|
Favored Auxiliaries
| Organism | Impact of the technique | Type | Details |
|---|
Disadvantaged Auxiliaries
| Organism | Impact of the technique | Type | Details |
|---|
Favored climatic and physiological accidents
| Organism | Impact of the technique | Details |
|---|
Disadvantaged climatic and physiological accidents
| Organism | Impact of the technique | Details |
|---|
5. For more information
- Protection of vegetable crops under cover and in open field, Prophylaxis and indirect control methods, Case of tomato and carrot
- -Trottin-Caudal Y. et al.
CTIFL, Technical brochure, 2006
Infos-CTIFL n° 224, 36-42.
To access the brochure see link
- Biological seed treatments, Focus on thermotherapy
- -Itab
ITAB, Multimedia, 2008
Technical day, Paris. To access the information see link
6. Keywords
Pest control method: Genetic control
Mode of action: Action on the initial stock
Type of strategy regarding pesticide use: Substitution Redesign
