Browsing by Author "Millner JP"
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- ItemAssessment of manuka provenances for production of high ‘unique manuka factor’ honey(Agronomy Society of New Zealand, 2013) Millner JP; Hamilton G; Robertson A; Stephens J; Hill, GD; McGill, CRManuka (Leptospermum scoparium) honey with high methylglyoxal content, commonly expressed as unique manuka factor (UMF®) content, has strong antibacterial and anti-fungal properties. Consequently, there is a strong demand for high UMF manuka honey in the health food industry both in New Zealand and overseas. Currently manuka honey is produced from natural stands of manuka, but UMF content varies among regions. The active ingredient methylglyoxal is produced by natural chemical transformation of dihydroxyacetone (DHA) present in the nectar. Production of high UMF honey is insufficient to meet market demand; this is due to variation in UMF amongst stands causing unpredictability in quality as well as inaccessibility of many manuka stands. The feasibility of increasing production by establishing manuka plantations using plants known to produce nectar with high DHA content is being investigated. This study compared establishment, growth and nectar DHA content of four manuka provenances; two from Northland, and one each from Waikato and Wairarapa in a replicated, randomised complete block trial (Site A). In addition a manuka plantation of a single provenance was monitored for nectar DHA content (Site B). Both sites are in the Whanganui area. Survival of seedlings in the Site A trial at 12 months was high in all provenances. Nectar DHA content ranged from 3666 to 6902 mg/kg 80° Brix and there were no significant differences amongst the provenances. These DHA levels were considerably higher than levels measured in the local manuka (2565 mg/kg 80° Brix). At Site B nectar DHA content of the plantation manuka (5770 mg/kg 80° Brix) was significantly (P=0.05) higher than the indigenous manuka (2565 mg/kg 80° Brix). Early results suggest that manuka provenances can be utilised on different sites to produce high DHA nectar and ultimately high UMF manuka honey, providing landowners with an additional income and help prevent erosion of marginal hill country.
- ItemEvaluation of sorghum, sudan-grass and pearl millet cultivars in Manawatu(Agronomy Society of New Zealand, 2013-09) Millner JP; Silungwe D; McGill CR; McGill, CR; Hill, GDSorghum, sudan-grass and pearl millet are versatile summer forages able to be grazed or conserved as silage. However, there is little recently published information on the performance these crops in New Zealand. A trial was carried out at Massey University, Palmerston North, to compare forage yields and crop morphology of four sorghum x sudan-grass hybrids (Pac 8421, Pac 8423, Pacific BMR and Bettagraze), two sudan-grass (Superdan 2 and Sprint) and one pearl millet (Nutrifeed) cultivars sown on the 8 and 21 December 2009. At final harvest, 57 and 58 days after sowing for the first and second sowing dates respectively, dry matter yields decreased (P<0.005) with delayed sowing from 12,792 kg ha-1 to 11,356 kg ha-1. There were cultivar differences (P<0.0001) at both sowing dates. Mean yields (across sowing dates) ranged from 9,823 (Nutrifeed) to 13,953 kg DM ha-1 (Pac 8423). There was a significant interaction (P<0.0001) between sowing date and cultivar for yield at the second harvest; cultivar differences for the first sowing date were larger than for the second, which suffered more from cool autumn temperatures. There was a strong, positive, linear relationship between plant height at harvest and DM yield (R2 = 0.69). Mean leaf:stem ratio, for the first sowing (1.9), was significantly (P<0.001) higher than in the second sowing (1.8) and was influenced by cultivar.
- ItemGrazing activity increases decomposition of yak dung and litter in an alpine meadow on the Qinghai-Tibet plateau(Springer Nature Switzerland AG on behalf of the Royal Netherlands Society of Agricultural Science, 2019-11) Millner JP; Yang C; Zhang Y; Hou F; Wang Z; Chang SAims This study investigated the influences of herbivore grazing intensity and grazing season on decomposition and nutrient release of dung and litter, which aimed to improve our understandings of grazing affecting nutrient cycling in alpine meadows on the Qinghai-Tibetan Platean. Methods A factorial design experiment comprising 3 grazing intensities (non-grazing, moderate grazing, and heavy grazing) and 2 grazing seasons (summer and winter), was applied to quantify the decomposition and chemistry of dung and litter in an alpine pasture using the litterbag technique. Litterbags were retrieved for analysis of mass loss and nutrient release with 180, 360, 540, and 720 days after placement. Results Grazing activity accelerated the decomposition of dung and litter and increased nutrient release from dung and litter by increasing soil temperature compared with non-grazing pastures, whereas grazing season had no effect on decomposition. The decomposition time was shorter for dung than that for litter. Conclusions Herbivores grazing benefited dung and litter decomposition and nutrient cycling directly by increasing soil temperature, which is likely to promote soil microbial activity due to low temperatures in alpine meadows, and indirectly through herbage ingestion and dung deposition which increase the organic debris concentration used for microorganisms growth and reproduction. This study provides insights into the mechanisms of grazing regulating nutrient cycling in alpine ecosystems.
- ItemThe growth of Gerhan plantations: A case study of re-greening projects in Karanganyar Regency, Central Java Province, Indonesia.(2013-08-28) Millner JP; Abdiyani S; Nunung P