The timing of flowering in canola (Brassica napus) is an important determinant of adaptation to its environment. Cultivars of canola varying in maturity are grown over a wide range of photoperiod and temperature conditions in Australia. A quantitative understanding of the genotypic and environmental control of time to flowering can be used to improve breeding programs and crop management strategies. Controlled environment and field studies were used to determine the responses of 21 cultivars of canola and breeding lines of Indian mustard to vernalisation, temperature, and photoperiod. The number of days to flowering in all genotypes was reduced in response to vernalisation and long days, due to a reduced duration between sowing and buds visible. The vernalisation response was saturated with c. 25 days at 3°C. Base and optimum temperatures for development were confirmed at 0 and 20°C, respectively. The photoperiod response occurred between 10.8 and 16.3 h, and plants responded to photoperiod from emergence. A simulation model incorporating these effects was developed, which predicted days to flowering with a mean deviation of c. 5 days. Later flowering genotypes had model parameters that indicated greater responses to vernalisation and photoperiod than early-flowering genotypes.

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Maximum light‐saturated photosynthetic rate (Pmax) and stomatal conductance (gs) of field‐grown cocksfoot (Dactylis glomerata L.) leaves in a silvopastoral system were measured at different times under moderate (850–950 µmol m−2 s−1 photosynthetic photon flux density, PPFD) and severe shade (85–95 µmol m−2 s−1 PPFD). Also Pmax and gs were measured after 30, 60 and 180 min of severe shade to determine the lag in the rise of photosynthesis rate from low to high irradiance levels (induction state). The highest Pmax and gs values obtained were 26·5 µmol CO2 m−2 s−1 and 0·41 mol H2O m−2 s−1 in non‐limiting conditions with full sunlight (1900 µmol m−2 s−1 PPFD). These values were defined as standardized dimensionless Pmaxs=1 and gss=1 for comparison of treatment effects. The Pmaxs under severe shade decreased by 0·004 units per minute from 1 to 180 min and reached a steady‐state of 0·37 units after 140 min. Under moderate shade, Pmaxs decreased by 0·002 units per minute from 1 to 120 min and reached a steady‐state of 0·76 units. The time required to reach full induction on return to full sun (Pmaxs=1) was 15 min after 30 min of severe shade and 37 min after 180 min of shade. Mathematical equations were derived to describe the changes in Pmaxs and gss under severe and moderate shade and during induction. The rate of change of gss was slower than for Pmaxs on entering shade and also slower during the subsequent induction process. This indicated other factors in addition to gs were operating in the reduction and increment of Pmax and a two‐step model to explain this is proposed. The defined photosynthetic responses of cocksfoot leaves to fluctuating light regimes could be used to develop quantitative predictions of Pmax for inclusion in a canopy photosynthesis model of silvopastoral systems.

Trichoderma isolates were evaluated for growth promotion effects on cabbage seedlings (Brassica oleracea L.) in glasshouse trials. Dipping transplants in spore suspensions (10 7 conidia/ml) of T. longipile (6Sr4 and 3Sr4-2) and T. tomentosum (5Sr2-2) increased (P<0.05) leaf area (58-71%), shoot dry weight (91-102%) and root dry weight (100-158%) compared with the untreated control in one trial but not in a second. In a field trial, yield of lettuce (Lactuca sativa L.) treated with T. longipile 6Sr4 was also increased.

Maximum light-saturated photosynthetic rate (P max ) of field-grown cocksfoot (Dactylis glomerata L.) leaves was measured in a temperate, sub-humid environment (Canterbury, New Zealand). The aim was to derive an individual function for P max of newly expanded leaves against regrowth duration when other environmental factors were nonlimiting. The decrease in P max with regrowth duration was described by a quadratic function. From 20 to 25 days regrowth, P max per unit of leaf was constant and maximal (27.4 µmol CO 2 m -2 s -1 ). It then decreased by 0.42 µmol CO 2 m -2 s -1 per day of regrowth. The decline in P max was attributed to (i) differences in chronological age of the youngest expanded leaf as shown by changes in tiller morphology over time, and (ii) shading within the canopy during leaf expansion. These factors affected P max by decreasing the leaf nitrogen and chlorophyll content, and stomatal conductance. The function for regrowth duration was an additional factor included in a multiplicative model to predict P max with different levels of temperature, nitrogen, and water status, expressed as pre-dawn leaf water potential (Ψ lp ). The only interaction detected was when water stress increased (Ψ lp < -1.2 bar) and leaves had grown for 40-60 days. In this limited situation, stomatal closure at 40-60 days was greater than expected from the non-limiting condition. The inclusion of this function into a simple multiplicative model enabled 80% of the variation in P max for individual cocksfoot leaves to be explained by their temperature, nitrogen, water, and regrowth status. These functions could then be used to develop a canopy photosynthesis model for the prediction of cocksfoot pasture production.