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NSWAgricultureQuick questions
Core Part A: Plant Production
Quick questions on Constraints on plant production explained: HSC Agriculture Plant Production
2short Q&A pairs drawn directly from our worked dot-point answer. For full context and worked exam questions, read the parent dot-point page.
What is water as a constraint?Show answer
Across most of dryland Australia, water is the dominant constraint. Yield is closely tied to growing-season rainfall plus stored soil moisture. Producers manage water through fallow practices that store moisture (stubble retention and weed control over the fallow), matching plant population to expected moisture, and choosing crops by stored moisture, as in opportunity cropping on the northern plains. Where irrigation is available, scheduling water to the crop's critical stages maximises water-use efficiency.
What are weeds?Show answer
Weeds compete with crops for water, light and nutrients, harbour pests and diseases, and contaminate grain. They are often the largest yield-robbing constraint in broadacre cropping. Control combines cultural tactics (competitive crops, narrow rows, crop rotation, stubble management), physical tactics (cultivation, harvest weed-seed control such as chaff carts and seed mills), and chemical herbicides. Reliance on a narrow set of herbicides has driven serious resistance, most notably glyphosate-resistant and group-A-resistant annual ryegrass.
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