Temperatures of 3-5°C were suitable for the long-term storage of sandersonia tubers. Tubers sprouted during storage at 10°C, but no sprouting occurred with up to 202 days of storage at 3-5°C. Tuber viability and subsequent sprouting were less after storage at 1°C than following 3-5°C storage temperatures. Sprouting temperatures of 20-26°C gave high sprouting percentages following long-term storage. Tubers failed to sprout at 35°C and sprouting percentages were lower at 30°C than 20-25°C following longer storage durations (>60 days). Storage duration, storage temperatures, and sprouting temperatures influenced the time from storage removal to sprouting, storage removal to stem harvest, stem size, and daughter tuber weight. Stem length declined with increasing storage duration of 110-171 days, but was slightly greater after 202 days of storage than after 171 days. Possible reasons for these plant responses are outlined. Daughter tuber weight declined with storage duration and was less following a sprouting temperature of 20°C than 23-26°C.

The effects of five nitrogen (N) application rates-14. 2, 28.4, 56.8, 113.6, and 227.2 g N/ m 2 (equivalent to 37.5, 75, 150, 300, and 600 ppm of N as a daily liquid feed), on greenhouse cut flower production and outdoor tuber production in Sandersonia aurantiaca (Hook.) were compared in two experiments using a peat:pumice medium. Stem length and weight declined with increasing N rate. Tuber weight declined slightly along with tuber quality with increasing N rate. High N rates resulted in an increased incidence of tuber disorders including secondary tuber formation and tuber rots. Leaf N concentration increased with N rate to a maximum of 56.8 g N/m 2 , but tuber N continued to increase (from 0.68 to 2.01% dry weight) with increasing N rate. The effects of the N rates on tuber storage and subsequent cut flower production were assessed at two N rates (28.4 and 113.6 g N/m 2 ) in a third experiment. Leaf nutrient concentrations were not affected when tubers were forced at the two N rates in the third experiment nor was vase-life of stems. This study indicates that sandersonia requires low-medium amounts of nitrogen and that an N rate of Received 12 May 1998; accepted I February 1999 c. 28.4 g/m 2 would optimise both tuber quality and stem production for sandersonia grown in a soil-less medium. Tuber and leaf nutrient concentrations at this N rate could be used for crop cultural guidelines for both flower and tuber production. H98021

The effects of four nitrogen (N) application rates (5, 10, 20, 40 g N/m 2 ) and four potassium (K) soil levels (0.4, 0.8, 1.8, 3.2 me/100 g) on soil-grown Sandersonia aurantiaca (Hook.) stem and tuber production were evaluated. Leaf concentrations of N and K declined with plant age but were greater at the higher N and K levels, respectively. Small increases in some stem production indices (flower number, percentage side laterals) occurred with increasing N but declined with increasing K (stem length). Tuber weights declined with increasing levels of N and K with the largest tubers, 7.9 g produced at 10 g/m 2 N and 1.8 me/100 g K. This study indicates that moderate N and K nutrition rates should be used for soil-grown sandersonia to optimise both stem production and tuber weights.

The effects of three storage temperatures (1,4, and 9.5°C) and six storage durations (0, 30, 60, 90, 120, and 150 days) on tuber sprouting and stem quality of Sandersonia aurantiaca were investigated. Tubers did not sprout at lifting when given inductive conditions, but high percentages sprouted (91.7%) after only 30 days of chilling. Percent sprouting remained high (93.8%) after 90 days of storage, but decreased to 86.5% with 150 days of storage. Sprouting percentages were high for all storage durations at 4°C. Sprouting was significantly less after storage at 9.5°C than at 1 and 4°C at all storage durations. Time to initiation of sprouting and the sprouting period decreased with storage duration up to 90-120 days and were lowest at 4°C. Stem length and flower numbers per stem were significantly higher at storage durations of 90-120 days. Following 90 days of storage, stem length was greater for storage at 9.5°C than at 1 or 4°C. Storage at 4°C for 90-120 days is required to ensure rapid and even sprouting of sandersonia.

Four onion cultivars were grown in sterilised Patumahoe soil and inoculated with 5 different V A mycorrhizal fungi. Three cultivars were then grown in unsterilised Patumahoe and Horotiu soils with 6 different mycorrhizal inoculants. Mycorrhizal fungi greatly stimulated onion growth and P uptake in sterilised soil and there were very significant fungi x cultivar interactions in both unsterilised soils. Glomus spp. and F 20 were the most efficient inoculants over all onion cultivars