Heavy stripe rust found in Brock

Press, 6 October 1989, Page 18

Heavy stripe rust found in Brock

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Some young crops of Brock wheat have been found to be heavily infected with stripe rust. The rust is being characterised by Dr Matthew Cromey, of the D.5.1.R., Lincoln, and appears to be a race previously unidentified in New Zealand.

All crops of Brock should be carefully monitored for stripe rust infection and sprayed if any is found.

Powdery mildew is showing in some Kotare crops. Monitor these crops for powdery mildew and spray where necessary.

Leaf rust and scald has been identified in barley. If conditions favour disease (overcaste and humid) then growers should consider a fungicide application. Check the resistance status of the cultivar you are growing first. Growers who have yet to drill spring cereals should remember to sample paddocks for the presence of actively feeding grass grubs. Young seedlings are vulnerable to damage from actively feeding grubs and if necessary a soil insecticide should be applied at drilling. Plant Health Clinics Today, from 10 a.m. until 3 p.m. at the M.A.F. office in Ashburton, the Lincoln Plant Protection centre is holding the first of six free Plant Health Clinics for the season.

problems diagnosed free of charge.

The clinics, sponsored by Ciba-Geigy, will be held fortnightly and provide an opportunity for growers to have crop

STONE FRUIT Peaches and nectarines are now approaching shuck fall. Protectant sprays should be maintained for brown rot control. Baycor, Bravo, Saprol, Benlate, Bavistan FL or Topsin M4A can be applied up to shuck fall. If any overcast, damp weather occurs then the time between sprays should be reduced. For the control of thrips and aphids on export summerfruit, apply Mavrik if the trees are still flowering and chlorpyrifos if the trees are at shuckfall.

MAFQuaI is conducting a national summerfruit pest and disease survey this season as part of its national surveillance responsibilities. Orchardists noting particular problems 'in stonefruit crops should draw them to the attention of their MAFQuaI consultant for possible inclusion in the survey. BLACKCURRANTS If big bud mite is a problem, apply endosulfan at first flower. Spray only under warm calm conditions (above 15 deg.C). The swollen buds caused by big bud mite are readily identified in the autumn. Infested buds fail to break in the spring or produce only weak shoots. PIPFRUIT

A booklet on manage-

ment of pipfruit pests and diseases has been produced by the Lincoln Plant Protection Centre for free distribution to orchardists. The booklet will be available at CibaGeigy Plant Health Clinics or on request from M.A.F. office. Protectant sprays against black spot and powdery mildew should be applied at fortnightly intervals over the flowering period, tight cluster to petal fall. If wet conditions favour disease infection, growers will need to consider the application of curative fungicides to control black spot. For apples now at open cluster, apply an ovicide (Apollo or Nissorun) for mite control if necessary. Ovicides can be used only up to pre-flowering. Tokuthion can be applied up to tight cluster for control of mealybugs, scale and wooly apple aphid. Porina

Early reports of porina flights have been received, but the peak flights are unlikely to occur until the end of October in most of Canterburty.

It is important to note the timing of peak porina flights in your area as this influences the timing of caterpillar control measures to be taken later in the season.