Factors which influence the efficacy of an NPV application These include: (i) the initial actjvity of the virus preparation, distribution (.i.i) lts rate or application and distribution on the crop, (Jji) Its persiste

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

Egg parasites of the genus Trichogramma arH used to control lepidopterous pests throughout the world (Stinner, 1977). These small parasitic wasps are released in large numbers (e.g.

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

Several factors influence the nitrogen demands of a cotton crop and the ability of the soil and fertiliser to satisfy these demands. Some of these factors (eg weather) are beyond the control of a cotton grower.

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.

Drip irrigation has been of interest in regions where water is scarce or expensive (e.g. Israel and Arizona).

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.

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

Bacterial blight of cotton is a major disease in most cotton growing countries of the world.

A review of overseas literature shows that several approaches have been recommended for the control of bacterial blight of cotton .

Questions are often raised about whether trace elements are required on cotton.

As a result of a major fall in world cotton prices, the Namoi Cotton Co-operative has been actively looking at ways of reducing costs on cotton farms.

Techniques to Improve Profitability of Growing Cotton

firstly canvassed growers on their experiences with Siokra. Most said that weeds were no more difficult to control in Siokra than in Deltapine 90.

I have been asked to discuss two features of the CSIRO cotton breeding work at Narrabri. The first concerns the quality. criteria we use, the second the role that biotechnology will play in varietal improvement.

In 1985 one of the main questions asked by growers was "How does Deltapine 90 and Siokra compare with Deltapine 61?". Now in 1986, the questions is "How does Deltapine 90 compare with Siokra?".

The short season cotton breeding program at Narrabri is continuing to make good progress in developing early maturing cultivars adapted to Australian conditions.

The renewed interest in non-irrigated cotton production in recent years led us to undertake co-operative cultivar trials, commencing in 1981/82.