Whitton, New South Wales

“iMapPESTS is monitoring airborne pests & diseases in the southern cotton-growing region with Sentinel 5” Sentinel 5 has been monitoring […]

“iMapPESTS is monitoring airborne pests & diseases in the southern cotton-growing region with Sentinel 5”

Sentinel 5 has been monitoring the presence of cotton & horticulture pests & pathogens at a commercial cotton grower property at Whitton in Riverina. During this trial, we’ll be sharing our observations with local industry through CottonInfo’s Kieran O’Keeffe.

Insect pests targeted

Green mirid (Creontiades dilutus)

Onion thrips (Thrips tabaci)

Green peach aphid (Myzus persicae)

Green vegetable bug (Nezara viridula)

Fungal pathogens targeted

Sclerotinia white rot (Sclerotinia minor &/ S. sclerotiorum)

Blackleg of canola (Leptosphaeria maculans)

Septoria tritici blotch (STB) (Zymoseptoria tritici)

Yellow leaf spot (Pyrenophora tritici-repentis)

Chocolate spot of fava bean (Botrytis fabae)

Botrytis grey mould (Botryitis cinerea)

Thrips in early season Southern cotton

CottonInfo’s Kieran O’Keeffe has been collecting insect samples from Sentinel 5 since early November.

In summary, thrip numbers are now starting to decline and no mirids have been detected yet.

Initial spray decision strategies in a cool start year are justified but follow-up sprays when numbers are declining and the crop is growing out of damage are not warranted.

Note that thrips populations will naturally crash in the field at about 50 DAS. This is very typical and this natural decline provides the opportunity for plants to recover. Plants will recover from less severe damage often with no yield loss or delay. This has been shown in southern NSW trials over several seasons.

Early season insecticide spray applications may seem a cheap option at the time but it will have consequences and lead to a reduction in beneficial insect populations. Cheap and early can result in expensive sprays later.

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