Whether grown as a main crop or as a summer catch crop, camelina shows the same behavior in the face of these diseases and parasites.

Camelina can be affected by clubroot, a disease caused by the pathogen Plasmodiophora brassicae. This is a telluric disease with a host range extending to most species of the Brassicaceae family, including crops such as rape, turnip, cabbage and mustard.

Hernia can also infect certain weeds belonging to this family, such as ravenella, shepherd's purse or sanvia, all of which are potential reservoirs for its spread. Contamination occurs via mobile spores in the soil which, thanks to free water, penetrate the absorbent hairs of camelina roots and induce infection.

The main symptoms visible on the aerial parts are a temporary wilting of the foliage, particularly on hot days, and a slowdown in growth.

When affected plants are pulled up, the roots show characteristic deformations and swellings known as galls. These galls are responsible for the aerial symptoms, as they interfere with the absorption of water and nutrients from the soil. Initially firm and white on the inside, they gradually turn brown before cracking.

There are currently no effective chemical control methods. The development of the disease is favored by poor drainage of the plot, as well as by the absence of liming on acid soils. Once established, the disease persists in the soil, with spores remaining viable for up to 15 years. We therefore strongly advise against planting camelina on a plot known to be contaminated by this pathogen. Below is a map showing plots infected by clubroot, as reported online on the Terres Inovia website. https://www.terresinovia.fr/-/enquete-hernie-des-cruciferes

Mainly grown as a summer catch crop, camelina can be affected by mildew at the end of the cycle. This is the foliar disease most frequently observed on this crop, although its severity generally remains low and does not justify fungicide intervention.

Infection can be either localized or systemic. Symptoms observed on camelina include grayish-white mycelial growth on the underside of leaves, stems and siliques. Heavily affected plants may show distorted, twisted or bent growth.
The development of mildew is favored by temperatures between 15 and 23°C, combined with rainy spells generating high humidity, an essential condition for the spread of the disease.

White rust symptoms on camelina are similar to those observed on other crucifers. They take the form of white, powdery pustules, containing sporangia (reproductive structures), on the underside of leaves. At a more advanced stage, hypertrophied siliques or deformed inflorescences can also be observed.

Optimum development of the disease occurs between 10 and 18°C, with relative humidity above 90%.

It can be confused with mildew. However, it is possible to differentiate the two diseases by their symptoms: in the case of white rust, pustules are larger, well-defined and clearly visible, while mildew manifests itself through more diffuse spots and a more "powdery" appearance, linked to the presence of mycelium.

On camelina, mildew is observed more frequently than white rust.

Other diseases have been observed on camelina, but their harmfulness is so low as to warrant no intervention in the crop. These include sclerotinia(Sclerotinia sclerotiorum), botrytis(Botrytis cinerea) and alternaria(Alternaria brassicae).

Orchardgrass is a non-chlorophyllous parasitic plant, present as seeds in the soil. They can only germinate in the presence of molecules emitted by the roots of certain plants, before attaching themselves to the latter.

It is capable of parasitizing many plant species, both winter and spring crops (rapeseed, hemp, tobacco, melon, sunflower, tomato...as well as camelina) and weeds (ammi majus, bedstraw, geraniums, erodium, cauliflower...).

Orchardgrass is highly invasive.

• It is capable of producing thousands of tiny seeds (0.2-0.3 mm) per plant, easily spread by wind, animals, farm machinery and so on.
• Seeds can live up to 10 years in the soil, and are resistant to passage through the digestive tract of animals.
• It has a very broad host spectrum (crops, weeds) and can synchronize its cycle with that of its host.
• It thrives in a wide range of pedoclimatic conditions.

Chemical or biocontrol methods are not currently authorized in France, and/or are ineffective in providing protection against stunted broomrape.

We therefore strongly advise against planting camelina on a plot known to be infested with stalked broomrape. Below, a map showing plots infected by stalked broomrape, identified following declarations made online on the Terres Inovia website. https://www.terresinovia.fr/web/guest/-/enquete-de-surveillance-orobanche-rameuse-participer-et-visualiser-les-zones-a-risque

However, given the limited number of approved chemical solutions for weed control, both against grasses and broadleaf weeds, it is advisable to plant it in a clean, weed-free plot at the time of sowing.

It is also advisable to avoid situations of high weed pressure, particularly in the presence of resistant grasses or particularly invasive species such as mugwort(Ambrosia artemisiifolia).

Weed pressure

In 2024, agronomic monitoring was carried out on camelina plots planted as summer catch crops. The graph below shows significant to total weed cover on around a quarter of the areas observed. The main weed species observed were :

• Crop regrowth: barley and peas
• Annual broadleaf weeds: goosefoot, mercurial, bindweed, barnyard grass, ragwort, etc.
• Perennials: thistles

The graph below illustrates the level of weediness observed in camelina plots planted with summer cover crops, according to the type of previous crop. It shows that weed control is more complex after winter peas, notably due to the presence of pea regrowth and broadleaf weeds.

Weed pressure is one of the main limiting factors identified in the 2024 plot monitoring program, and weed management is therefore a key factor in ensuring crop success.

Weed management levers

First and foremost, it's important to choose a plot with a low risk of weed infestation, as control levers are limited during summer intercropping. To limit the risk of weed infestation, it's important to choose suitable crop successions, alternating spring and winter crops.

Beyond the choice of plot, it's important to sow camelina on clean soil. If weeds are present at harvest time, they can be managed by stubble ploughing, or with a total herbicide if camelina is direct-seeded.

Finally, there are a number of registered herbicides available for chemical weed control.

Below is a non-exhaustive list of authorized molecules (source: ephy-Anses and phytosanitary index):

Where winter cereals are grown before camelina, a herbicide treatment is essential in the event of heavy infestation of post-plant regrowth. To ensure optimum selectivity and maximum efficacy, the treatment should be carried out with a specific graminicide based on clethodim or quizalofop-P-ethyl, applied imperatively before the camelina resumes active growth (start of elongation).

If a herbicide is used in vegetation, whatever the product used, it must be applied before stem elongation begins, in order to limit any risk of phytotoxicity.

Mechanical weeding of summer catch crops is not relevant.

The choice of crop succession is an important lever in weed management: alternating winter and spring crops helps maintain low weed pressure on the plot.

As a main spring crop, camelina can be sown late due to its relatively short cycle length. This offers the opportunity to carry out several false sowings in spring, and reduce the weed population. Late sowing of camelina, which can be done as late as May, also makes it possible to avoid a large proportion of the spring weed flora, and create a real break in the rotation. The table below gives a non-exhaustive list of authorized control molecules (source: ephy-Anses and phytosanitary index).

If a herbicide is used in vegetation, whatever the product used, it must be applied before the start of stem elongation, in order to limit any risk of phytotoxicity.

As far as mechanical weed control is concerned, only one blind pass of the currycomb harrow can be used on the main crop. In post-emergence, the use of this tool is not recommended due to the high risk of pulling out plants.

Nitrogen nutrition

Nitrogen dose trials have been carried out. Camelina yield increases with nitrogen fertilization, until it reaches a plateau (see graph below - source: Malhi et al., 2013, Canada). This yield increase is explained by improvements in several components: the number of plants per square meter, the number of branches, the number of siliques per plant, as well as the number of seeds per silique. On the other hand, thousand kernel weight (MGW) does not seem to be affected (source: Agegnehu et al.1996, USA).

The optimum dose of nitrogen to be applied is between 80 and 100 units per hectare, depending on residues, corresponding to the economic optimum. For spring camelina, nitrogen can be applied in a single application just after sowing. However, it is possible to split the application according to the following recommendations: 30% of the dose at sowing, then the remainder at the rosette stage. For winter camelina, the application should be made when vegetation resumes before bolting.

In addition, the use of a sulfur fertilizer is recommended to ensure an application of 12 to 24 units of sulfur per hectare (source: Camelina Company).

Beware of excess nitrogen, which makes the crop more susceptible to disease, particularly albugo, and can accentuate the risk of lodging.
As nitrogen fertilization increases, so does the nitrogen content of the plant and the protein concentration of the seed. On the other hand, oil content and nitrogen use efficiency decrease (source: Malhi et al., 2013, Canada).

Concerning fatty acid composition, oleic and linoleic acid percentages increase with nitrogen dose, while linolenic acid percentage decreases. The concentration of iron (Fe) and zinc (Zn) in the seeds also decreases (source: Magdalena Czarnik et al., 2027, University of Rzeszów, Poland).

Phosphorus and potash

Camelina has moderate phosphorus and potassium requirements. Inputs should be rationed throughout the rotation, based on soil analysis results. In a well-supplied soil, we recommend applying 40 units per hectare of phosphorus and 40 units per hectare of potash. These fertilizations can be carried out at any time during the intercropping period preceding camelina planting, or directly at sowing time.

Camelina is a cruciferous plant. It needs nitrogen from the start of its cycle to express its full potential right up to harvest.

Managing nitrogen fertilization depends on the previous crop. In the case of cereals, 40 units of nitrogen per hectare must be applied at sowing. It is strongly recommended to apply this fertilizer locally. No additional nitrogen should be applied during vegetation. Excessive nitrogen applications could lengthen the vegetative phase of camelina, delaying maturity.

Where peas are grown before camelina, the nitrogen residue is generally sufficient to ensure good camelina development. Therefore, nitrogen is not essential. However, an optional fertilization of 10 units of nitrogen per hectare at sowing can be considered.

No background fertilization is required.

It is often combined, especially with lentils, to act as a support and help manage weeds. In this case, camelina is sown at a fairly low density, so its yield is lower than pure yield.

It can also be grown as a pure crop, in autumn or spring, and is an interesting option for integrating a cruciferous crop into organic rotations. It is particularly useful for weed management: with its short cycle, it can be sown very late in the spring, thus breaking the weed cycle and allowing several false sowings in the spring.

If planting conditions are favorable, camelina develops rapidly and is highly competitive with weeds. If not, however, camelina becomes a very messy crop, as it is difficult to use mechanical tools (risk of stubble formation, particularly with the harrow).

Farmers' testimonials also reveal a potential allelopathic effect of camelina, which to our knowledge has not yet been demonstrated in the field.

The camelina produced organically is mainly used as edible oil, or in the cosmetics sector, while the oilcake is used in animal feed.

A particularity of camelina is its very short cycle length, which also makes it suitable for intercropping.

Pure cultivation

Camelina can be grown pure as a main crop, with winter and spring varieties. In areas with mild climates (winter temperatures not exceeding -10°C), spring varieties can also be planted in autumn.
As a main crop, the proportion of organically-produced camelina is particularly high, thanks to its hardiness and resistance to pests and diseases, and to the opportunities for using the oil for human consumption.

In some countries of the southern Mediterranean basin, camelina is grown on so-called "marginal" land with low potential, which it valorizes well.

In combination

Camelina lends itself well to crop combinations, particularly in organic farming. The lentil-camel association is widely practiced, with camelina acting as a staking plant, thus limiting the risk of lentil lodging.

What's more, if planting conditions are favorable, camelina develops rapidly and is highly competitive with weeds at the rosette stage, in contrast to the generally slow initial development of legumes, which contributes to better weed control. Other camelina-legume combinations mentioned in the literature are camelina combined with pea, lupin or chickpea.

There are also references to camelina combined with barley or wheat, but these refer to competition between the two species and associated yield losses (M. Leclère's thesis on camelina insertion in Picardie).

The length of camelina's cycle, around 3 months for short-cycle varieties, means that it can be grown as a catch crop. Recent changes in the regulatory framework open up major market opportunities for intercropped camelina, such as sustainable fuel for aviation.

Summer intercropping

While camelina adapts well to a wide range of soil and climate conditions, a number of conditions must be met to maximize its chances of success in summer intercropping: sufficient rainfall during the planting period (late June - early July), few days of high temperature (35°C - 40°C) during flowering, and a sufficient temperature sum (1700°J base 0) to reach maturity before mid-October. These criteria exclude areas very far north and south of France.
To maximize chances of success, camelina in summer intercropping should be planted after an early-harvested preceding crop, such as barley or winter peas.

Winter intercropping

Camelina can also be intercropped in winter, before a late-sown spring crop such as sunflower or sorghum. The challenge for this type of succession is to harvest the camelina early enough, so as not to delay the sowing of the following crop too much and impact its yield potential.