CROP CRACK - 16.06.07
By WENDY FEARON
Clarendon Agricare - Sunshine Brings On Crops

The pleasant weather conditions over the last few weeks have allowed fungicide and growth regulator applications to be sprayed on time. Winter barley is now senescing and early potatoes are being dug in some parts of the province. Many spring barley crops are showing signs of yellowing due to drought stress and in many cases the cause is BYDV. An application of Cereal Plus may be applied to boost crops on. Rhyncosporium is present at moderate levels with mildew remaining a real problem on many varieties and therefore growers need to ensure the crop is adequately covered with a fungicide spray. Mildew and yellow rust are extremely bad on winter wheat especially Robigus. The recent welcome rainfall will please most farmers as many vegetable crops were beginning to suffer from drought stress.

Potatoes
Although it has been very dry, humidity has been high and several Smith periods have been recorded. In late planted crops that are still putting on new growth spray with a blighticide containing a systemic compound such as Infinito, Fubol Gold, Electis or Tattoo. When the period of rapid growth has begun to slow it is advisable to change from systemic to translaminar products such as Curzate M or Invader or alternatively protectant products such as Shirlan, Electis or Dithane DF NT. Curzate M and Invader have kick-back activity, which controls infection at an early stage within the plant.

Spring Barley
The majority of crops are now between 3rd node and awns just appearing. Most crops will benefit from a fungicide treatment at this time. Products such as Midas, Colstar or Opus may be used to control rhyncosporium and if mildew is present add Talius or Corbel. Alternatively a triazole/strob mix such as Mobius or Mantra may be used. It is essential to keep the flag leaf and ear clean as this accounts for 70-80% of the overall yield. An aphicide should also be applied at this time.Cerone should be applied before the first spikelet appears on strong crops. Although crops are not very tall they are extremely lush and a growth regulator should be applied. Cerone should be applied before the first spikelet appears.

Winter Wheat
Most wheat crops are now beyond flowering. Ear wash fungicides are important to keep the heads clean, keeping grain quality high. These can be applied once the head has fully emerged. Prosaro or Mantra has good activity against Fusarium and Chlorothalonil can be added for extra protection. Crops which have had only one strobilurin treatment to date should receive a follow up dose to ensure optimum results. As aphids are evident on most wheat crops at present it is advisable to spray.

Winter Barley
Crops of winter barley are now ripening with the grain in the soft development stage (GS85-91). Crops which received fungicide treatments at the correct time are looking exceptional. If a pre-harvest treatment with Round-up Gold is to be carried out, it is essential to inspect the crop to ensure the timing is correct.

Grassland
There is still time to spray docks in grazing and second cut silage ground.
A wide range of products are available ranging from Compitox plus which gives leaf control only to those containing dicamba giving various degrees of root kill such as Mircam Plus, Dockmaster, Grassland Herbicide, and Foundation. As it is important at this time not to check the growth of grass, products based on fluroxypyr such as Forefront, Doxstar and Pastor are the safest to use. Where clover is important Allistel or Squire can be used.
There is still time to spray soft rush provided they are at the correct stage i.e. soft green and about 12 inches high. Use Agritox 50. If the rushes are very established with a lot of dead leaf material present then the best option would be to top them now and spray them when the soft green regrowth appears, probably next spring.
Gorse should be sprayed now. Use Grazon 90 and ensure good plant coverage using a knapsack or handlance on a tractor mounted sprayer.

Horticulture
Weeds are a major problem in all vegetable crops and should be treated at the appropriate stage as the dry conditions at planting were less than ideal to achieve good residual weed control. The first generation turnip fly will be due to hatch over the next week or two and carrot fly will hatch out earlier this year with recent weather conditions. Aphids and caterpillar are now appearing on many brassica crops and should be treated as soon as possible. It is essential to treat turnip crops with Boron at this time to help prevent brown heart. Many apple growers are pleased with how orchards are looking at present. Fungicide programmes will continue for a while yet, with mildew the more dominant disease at present.Topas 100 gives excellent control of mildew. A second application of phosphorous should be applied now and calcium applied from next week onwards. There is quite a bit of red spider appearing and growers should inspect orchards and spray with Masai if there is a problem.