Hybrid rye has come a long way in a relatively short space of time and it is now time to consider the crop as a real option for Irish farms. Commercial hybrid rye breeding began in the 1980s and has, so far, delivered yield increases of over 45% when compared to conventional rye varieties. As breeding programmes continue to churn out shorter, higher-yielding varieties, this crop could have a bright future in the country.

The crop now warrants serious consideration when deciding on which fodder crops to grow. While there are no spring hybrid rye varieties commercially available, there are several winter varieties available which can be sown as early as September. This can be an attraction to tillage farmers in order to spread the workload throughout the year.

Its high yields and feeding value could make this crop an attractive alternative to triticale or maize for livestock farmers.

The crop is still relatively new to Ireland. It is currently grown for malting and distilling markets, wholecropped for feed and anaerobic digestion or for the commercial foods sector. Knowledge of the crop’s performance in Irish conditions is still somewhat limited.

A field of hybrid rye in Waterford. The crop has came through the winter in good condition. The picture was taken last week.

However, many who have grown the crop here have subsequently increased their area, owing to its success. This article draws from the knowledge of experts, growers’ experiences and literature to bring you some of the main points about the crop from an agronomy and feeding point of view.

We caught up with Tim O’Donovan, technical director with Seedtech, to ask him about the crop. Seedtech distributes KWS hybrid rye varieties and also undertakes field trials.

An ear of hybrid rye showing some of the grains inside in the glumes.

Why hybrid rye

Just like wheat and barley, rye is a cereal. However, rye is a cross-pollinator, while wheat and barley are self-pollinators. Cross-pollination traditionally meant that conventional rye varieties were susceptible to ergot infection during flowering. However, through the development of hybrid varieties, the time required for fertilisation was reduced, reducing the risk of ergot infection.

Sowing rates and dates

Hybrid rye has a strong resilience to take-all disease, meaning it fits into rotational slots where wheat and barley wouldn’t. It acts as a break crop, similar to oats. However, it is not recommended to plant rye on rye within a rotation as this increases the risk of ergot infection.

Breeders in the UK have found that the crop has a strong tolerance to BYDV, which permits September drilling. This has yet to be put to the test in Irish trial sites, however.

Drilling 2cm to 4cm deep, the crop is fast-establishing and has a wide drilling window (see Table 1). The crop grows well in a wide range of soil types (light to heavy) but needs to be well established before winter dormancy. This is especially the case on heavier soils. Seed is generally more expensive than conventional winter cereal crops.

Weed and pest control

Hybrid rye generally requires less inputs compared to winter wheat or barley. Irish growers report that the crop is €50/ac to €100/ac cheaper to grow compared with winter wheat.

Hybrid rye moves through stem elongation faster than most cereals and has good competitive properties.

However, Tim explains that it doesn’t compete well against wild oats, in particular.

Moreover, Axial Pro isn’t cleared for use on the crop. The crop generally requires an autumn herbicide and a spring follow-up, if needed.

Most broadleaved herbicides are cleared for use, as are a number of grassweed herbicides including Broadway Star.

Hybrid rye is generally 30cm to 40cm taller than winter wheat. While this gives greater bulk, it requires increased lodging management through a robust PGR programme.

Watch for slugs after drilling as the crop is susceptible to slug grazing. The main leaf diseases that affect hybrid rye are brown rust and powdery mildew. However, these are easily controlled by foliar fungicides as part of a fungicide programme.

Tim explains that, based on Seedtech trial observations, the crop has better sprouting resistance and fusarium resistance than winter wheat.

The risk of ergot has been reduced substantially through modern plant breeding.

Nutrition

Hybrid rye is a scavenger for nutrients and this is why it can out-yield winter wheat or barley in low fertility sites. However, subsequent nutrient removal can also be high. Fertiliser demand is highest in early spring due to its early growth and hybrid vigour. See Table 2 for suggested nutrient requirements.

Harvest yields

Grain yields of 10t/ha to 12t/ha are achievable in Ireland with straw yields around 25% to 30% higher than wheat or barley. The crop is generally harvested between winter barley and wheat.

However, hybrid rye has the potential to become a serious source of animal feedstock. Wholecropping modern hybrid rye varieties for inclusion in ruminant rations has the potential to yield 35t/ha to 50t/ha fresh weight with average dry matter yields of between 13t/ha and 16t/ha. Literature suggests the crop contains a crude protein content of 10% with a digestibility value of 65%.

Just like barley, triticale or wheat, rye can also be crimped and stored for a later date. Crimping allows cereals to be harvested from 25% to 45% moisture content. Once crimped and treated with a preservative, the crop can be ensiled in indoor or outdoor clamps.