Assessment of species composition of hay, pasture, and range samples is an important but laborious factor in forage quality evaluation. Near‐infrared reflectance spectroscopy (NIRS) was evaluated as a rapid technique for prediction of the species composition of hay and pasture forages and weeds. In Exp. 1, 97 mixtures were formed using eight species. Each species varied from 0 to 100% in each mixture. Each mixture of dried, ground material was scanned with monochromatic light from 1100 to 2500 nm at 2‐nm intervals, and the reflected energy was recorded. Percentage of each species was then regressed on the spectra using a modified stepwise regression procedure. Calibration equations with coefficients of determination (R2) from 0.94 to 0.99 and standard errors of difference (SED) from 1.9 to 6.8% were obtained using five to seven equation terms. Johnsongrass [Sorghum halepense (L.) Pers.] could not be predicted (SED = 6.8%) as precisely as the others, whereas blue panicgrass (Panicum antidotale Retz.) and sunflower (Helianthus annuus L.) were precisely predicted (SED < 2%). One to three harvest dates of seven species of hay were used in a second experiment to determine if variability within a species resulted in additional imprecision. In general, SED were higher; however, all but ‘Midland’ bermudagrass [Cynodon dactylon (L.) Pers.] gave SED of 10 or less, and the R2 of the calibration data set ranged from 0.84 to 0.98. Bermudagrass predictions were more precise if samples containing eastern gamagrass [Tripsacum dactyloides (L.) L.] cut at boot were removed from the data set. With proper calibration, NIRS could save much time normally used to separate species in hand‐clipped samples. The number of samples that can be analyzed in an experiment could be increased, and hence the accuracy of determination of species composition in a given pasture should be improved.

Lucerne (Medicago sativa L.) has a large taproot to store and release starch, carbohydrates and nutrients during the plant's growth. Recommended management of the lucerne crop aims to keep the taproot stable subject to the demands for feed provision and stand longevity. Field experiments were conducted in Victoria, Australia, to examine the effects of recovery period on taproot mass and nutritive status. Both experiments used established SARDI Seven lucerne crops and were either cut every 21 days (short recovery SR) or every 42 days (long recovery LR). At each defoliation, taproots were extracted for determination of DM yield and starch, water‐soluble carbohydrate (WSC) and nitrogen (N) concentration and DM yield. At both sites, WSC and N DM yields along with total taproot DM yield did not change greatly as the experiment progressed. Starch was responsive to herbage accumulation with both concentration and DM yield, increasing when herbage accumulation rates were high and decreasing when herbage accumulation rates were low. At both sites, LR taproots had starch levels equal to or higher than those of SR taproots. We conclude that short intervals between defoliations disrupt the energy cycling between shoots and roots. This is likely to reduce lucerne productivity, particularly during periods of rapid growth.

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Macadamia (Macadamia integrifolia) is a recurrent flushing tree, with buds alternating between growth and quiescence. Here we report on factors governing bud release. We used staggered tip-pruning (equivalent to branch decapitation) to generate a range of trees with different flush maturities, but uniform maturity within any given canopy. We then tip-pruned the trees again to remove the most recent flush, and monitored the time taken for visible axillary bud emergence. New flushes appeared 9–16 days after tip-pruning. The slowest bud emergence was associated with flushes of intermediate maturity, approximately 7 weeks old. Overall, the variation in bud emergence was most closely related to the growth rate of the most recent flush at the time of pruning, and not related to the levels of stored carbohydrates.

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