The effects of different applied nitrate concentrations ( 1 to 50 mol m ') on growth of Phaseolus vulgaris cv. Seafarer at temperatures around 15°C was examined. Total plant dry weight and carbon content decreased sharply with increased applied nitrate 1 to 10 mol m -? then decreased slightly with further increases in applied N. Total plant reduced -N content increased sharply with increased applied nitrate concentration from 1 to 5 mol m ', changed little with increased applied nitrate from 5 to 25 mol m -' , then increased when applied nitrate was increased from 25 to 50 mol m-3. Nitrate concentration in all tissues increased sharply with applied nitrate increased from 1 to 10 rnol ni and showed a further increase at 50 mol m applied nitrate.Fresh weight to dry weight ratio for all leaves and specific leaf area for all secondary leaves increased sharply with applied nitrate concentration from 1 to 5 rnol mthen decreased with applied nitrate 25 to 50 rnol m j. Secondary leaf chlorophyll concentration decreased sharply when applied nitrate increased from 1 to 5 rnol m-' but increased with applied nitrate from 25 to 50 mol m -? . Initially, the rate of leaf extension was greater at 20 mol m -j applied nitrate than 1 mol m -:' applied nitrate.It is proposed that decreased growth with increased applied nitrate in the range 1 to 10 rnol m -' is due to increased leaf damage caused by a greater rate of leaf expansion.

A three factor central composite second order design in incomplete blocks was used to quantify the responses of semidwarf 'Karamu' wheat established at five seeding rates (170-580 seeds/m 2 ), and fertilised at five rates of N at the onset of tillering (0-124 kg/hal and during spikelet growth (0-38 kg/ha). N applied at tillering raised grain yields by increasing spike populations and the mean number of spike lets per spike, but generally depressed mean grain dry weights and, at low rates, reduced grain content. Persistence of N in the soil after higher rates of application may have accounted for its linear responses in that it influenced more of the yield components. N fertiliser applied during spikelet growth tended to reduce spike populations, and its effects on other yield components depended on the level of N applied at early tillering. Thus it depressed spikelets per ~.pike and mean grain weight when no N was applied at tillering and increased the values of these components when high rates were applied. Applications of N at tillering generally increased grain N content and grain N yield but had little influence on grain yield. Seeding rate increments modified components of yield but had little effect on grain yield or grain N content. Spike populations increased linearly with seeding rate but mean numbers of spikelets per spike declined especially at lower levels of N nutrition. At low seeding rates N appeared to be limiting grain set whereas at higher seeding rates assimilates appeared to be limiting. Thus the effects of seeding rate and N fertilisers at tillering were related to their common effect on spike populations.

A paddock-scale experiment was conducted over two seasons to determine whether winter barley will fit adequately into a farming system that requires both feed and grain, and to investigatehow grazing affects the grain yieldcomponents. The 6-row 'Illia' and 2-row 'Priver' cultivars produced 1.3-2 tlha of DM by mid August when sown in April. Grazing to ground level in August reduced grain yields by about 10%, by reducing the ear population, despite the fact that mainstem apices were below soil level at thetime of grazing. Combine harvested grain yields ranged from 2.3 to 3.6 tlha in seasons with below average rainfall.

In two growing seasons, navy beans cv. Sanilac were sown at populations ranging from 44 to 120 plants/m 2 with or without irrigation and shelter in Canterbury. In the two seasons, rainfall was 156% and 66% of the long term mean. Irrigation had the largest effect on seed yield. In 1983/84 irrigated plants yielded 319 g/m2 and unirrigated plants only 278 g/m2. In the drier season, irrigated plants yielded 309 g/m2 while the dryland crop yielded only 131 g/m2. Shelter had only a small effect on seed yield, in only one season, despite reducing wind run by about 40%. Generally, higher plant populations resulted in higher seed yields particularly with irrigation. However in 1984/85, unirrigated crop yield with 30 plants/m 2 was 135 g/m 2 and at 120 plants/m 2 only 125 g/m2. The results indicated that navy beans should be grown with irrigation in Canterbury to be a viable farm option. High plant populations may produce higher yields and ease harvesting problems.

Genomic selection has recently become an established part of breeding strategies in cereals. However, a limitation of linear genomic prediction models for complex traits such as yield is that these are unable to accommodate Genotype by Environment effects, which are commonly observed over trials on multiple locations. In this study, we investigated how this environmental variation can be captured by the collection of a large number of phenomic markers using high-throughput field phenotyping and whether it can increase GS prediction accuracy. For this purpose, 44 winter wheat (Triticum aestivum L.) elite populations, comprising 2,994 lines, were grown on two sites over 2 years, to approximate the size of trials in a practical breeding programme. At various growth stages, remote sensing data from multi- and hyperspectral cameras, as well as traditional ground-based visual crop assessment scores, were collected with approximately 100 different data variables collected per plot. The predictive power for grain yield was tested for the various data types, with or without genome-wide marker data sets. Models using phenomic traits alone had a greater predictive value (R2 = 0.39–0.47) than genomic data (approximately R2 = 0.1). The average improvement in predictive power by combining trait and marker data was 6%–12% over the best phenomic-only model, and performed best when data from one full location was used to predict the yield on an entire second location. The results suggest that genetic gain in breeding programmes can be increased by utilisation of large numbers of phenotypic variables using remote sensing in field trials, although at what stage of the breeding cycle phenomic selection could be most profitably applied remains to be answered.