The experiments reported here investigated the influence of high or low concentrations of nitrogen, phosphorus and potassium on the multiplication of X.campestris pv. malvacearum in cotton leaf tissue.

This 3 year study examined the relationships between catches of Heliothis adults in monitoring traps and the abundance of eggs on cotton crops.

* Testing various versions of SIRATAC on a commercial scale. * Ptoviding a database of the response of cotton to damage. *Comparing the response of the new varieties Siokra and DP90 with DP61.

To determine the various factors affecting the loss of activity of insecticides on cotton over time.

The visits to research institutions proved extremely enlightening and valuable.

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Heliothis spp. have two main attributes which give rise to their pest status and make them difficult to manage (see Fitt this volume).

The development and release of SIOKRA, the new okra-leaf variety, has created considerable interest with respect to pest management.

Early crop protection is a controversial subject in modern pest management. Grower magazines in Australia and the U.S. carry articles expressing firm opinions both for and against.

The scouting of cotton for eggs and larvae of Heliothis spp is a labour intensive and therefore expensive undertaking.

Three species of pest mites are found in cotton in NSW and Qld: the two spotted mite, Tetranychus urticae, the bean mite, T. ludenli, and the strawberry mite, T. lambi. Of these T.

Each furrow irrigation waterlogs most of the root zone of cotton in cracking clay soils. This deprives the roots of oxygen, they take up less water and nutrients. and this reduces growth and yield.

The cotton bollworm, Heliothis armigera Hubner, is the most serious pest of cotton in Thailand.