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Crop Crack 11.09.10
By Wendy Fearon
Due to the very unsettled weather this week the remainder of cereal harvesting has come to a stand still. Yields have been extremely good and price is also at a premium but the bad news at the other end is meal has got another ten pounds a tonne increase at the beginning of this week. Most of the vegetable crop is now being harvested but ground conditions are making it very difficult. Some winter barley has been drilled and the fruit growers will hope to be in full swing over the next week. There has been a fair acreage reseeded over the last 3-4 weeks and drilling will continue well into September.
PREPARATION FOR RE-SEEDING
The average grazing ley in Northern Ireland is kept down for 10 years. By this time the sward will contain approximately 50% of weed grasses which are lower yielding, of inferior quality, and will be significantly less responsive to fertilizer. Reseeding creates the best opportunity to introduce clover into the sward. The best start to any reseed is good destruction of the existing sward. This Provides good control of deep-rooted perennial weeds and grasses allowing easier ploughing.Burning off will provide a clean start for new seed whilst making weed control in the new ley easier. Choose a glyphosate based weed killer for best results, as only glyphosate will completely kill deep-rooted grasses and perennial weeds.
Round-up Biactive/Round-up Energy will give good destruction of perennial grass and broad-leaved weeds in swards if used correctly. A period of at least three weeks regrowth after cutting should be left before spraying the sward. Weeds must be actively growing and the correct water volume must be used. To increase utilization of the old pasture plan to graze or cut 1 week after spraying.
GRASSLAND WEED CONTROL
A large percentage of Northern Irelands grass acreage has been treated for weeds this season. In situations where it was not possible earlier in the season the opportunity may still come. It is important to note that ragwort, thistles, docks and wild oats are all classed as noxious weeds.
Ragwort is appearing in many grass situations at present and is becoming a greater problem especially in lower fertility situations; it is an ‘injurious weed’ and is not permitted to grow unchecked. Ragwort is a biennial plant i.e. it grows from seed the first season to produce a rosette plant and then the following season it will produce a flowering stem, produce seed then die. Ragwort contains alkaloids which are poisonous to all livestock. Each plant can produce up to 150,000 seed with a 70% germination rate and seeds can remain dormant in the soil for up to 20 years. Treatment of plants, which are at the rosette stage now, can be very effective and an autumn application allows a check on the efficacy of the treatment to be made in early spring before allocating fields for silage or hay. Autumn is a good time to spray as the grass growth slows down and grass utilization and withdrawal periods are not as critical as they can be in the spring time when stock are turned out. Whilst ragwort is unpalatable when it is green it becomes extremely palatable once sprayed. It is important to remove as much of the root as possible; ragwort can regenerate like docks from its root fragments. A single application of weed killer is unlikely to completely eliminate a ragwort infestation due to overlapping generations of the weed. A follow up treatment should be made in the spring.
Docks are a particular problem in intensively managed grassland, especially where seeds are spread through slurry applications or poaching has occurred. Docks look unsightly, but more importantly, can reduce the grass yield and productivity. Early autumn is often overlooked as a potential time to achieve effective dock control. At this time the dock plant will revert back to vegetative growth. During vegetative growth the plant food being produced in the leaf is moved into the root for storage. Translocated herbicides are moved through the plant along with the food, hence if they are applied at this stage more product will end up in the root giving better root control.
Where clover is not considered important sprays based on the chemicals Fluroxypyr, triclopyr or dicamba/mecoprop mixtures should be used. If clovers are an important component of the sward Squire may be used .Remember in most circumstances treatment is most effective where a second application takes place within a 12 month period.
Chickweed is an annual weed and seeds will germinate at any time of year but particularly in autumn when growing without competition from other plants. Common chickweed can produce approximately 800 seeds and it takes 7 to 8 years for the seed bank (supply of viable seeds in soil) to be 95% depleted, insuring an infestation for many years. Because of its ability to produce large numbers of seeds under cool temperatures, common chickweed rapidly colonizes any cool, moist area before winter or spring crops can become competitive.
POTATOES
Reglone is now approved for a total dose of up to 5 litres per hectare and Syngenta advise a water volume of 400 litres per hectare for initial application where crop haulms are dense, and reducing to 200l/ha for subsequent applications targeting stems.
Growers should continue to maintain fungicide protection of the haulm until the crop is harvested or the haulm is 100% desiccated. Timely desiccation is an essential part of good seed and ware production.Diquat is the most widely used farmer applied chemical desiccant especially with recent weather conditions .The rate of haulm desiccation is slow and therefore fungicide protection should continue after application.
PROPIONIC ACID
Propionic when applied to moist grain prevents moulds and bacterial activity.Propionic is an active liquid preservative based on feed grade Propionic acid and prevents deterioration, loss of dry matter, nutrition loss and removes the associated health hazard to grain handlers, livestock and the end user.
The addition of Propionic adds to the energy value of the grain. One tonne of Propionic acid on 100 tonnes of grain gives an additional energy value equivalent to 1.5 tonnes of barley.
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