Search Results

You are looking at 1 - 4 of 4 items for

  • Author or Editor: B.E. Clothier x
Clear All Modify Search
Full access

M.B. Kirkham and B.E. Clothier

In 1992, all governmental resourcing and investment in New Zealand, including that for science, underwent dramatic reform. The global philosophy driving the reform was new public management—a method by which nations could be run more economically by emulating the commercial world. Central to the reform was separation of policy, purchasing (investment), and providers (in the case of research scientists). The reform led to a large reduction in the number of governmental scientists. For example, in 1 year alone, 2001–2002, the Horticultural and Food Research Institute, one of the nine governmental branches of science, lost 51 staff members, 10% of its work force. Over a decade later after the establishment of the reform, in July 2003, the New Zealand government's investment agency announced its budget for the next 6 years. The government-funded science sectors considered to do modern research such as computer technology and biotechnology, and halved funding for land-related sciences. The reduced budget dramatically limited New Zealand's capacity for research in soil and land-use science and ended all research positions in this area (38 jobs). Public outcry through newspaper editorials and from leading businessmen, along with effective leadership from the scientific community, led to the reestablishment of funding in the form of a virtual national center called Sustainable Land Use Research Initiative (SLURI). The elimination of funding for soil and land-use science research in New Zealand was an unexpected and potentially disastrous result of new public management. New Zealand's experience has relevance for the United States, because budgets for agricultural research are being severely reduced or converted to competitive funding. The U.S. President's fiscal year 2006 budget proposed to cut formula funding by 50% and to zero it out in fiscal year 2007. The funds would have been put in competitive grants. In New Zealand, the lack of ability to respond to a scientific problem demonstrated that a balance must be maintained in funding decisions so that scientific capability is retained to solve unforeseen future problems.

Free access

S.R. Green, T.M. Mills and B.E. Clothier

We recorded canopy development and stomatal function of a kiwifruit vine for the purpose of calculating the seasonal water use by the crop. Canopy development was described using an empirical “S-shaped” curve fitted to weekly measurements of the vine's leaf area. Stomatal conductance was described using a semi-empirical model based on the incident radiation, and the ambient vapor pressure deficit of the air. These two descriptors, leaf area and stomatal conductance, were combined with meteorological data to calculate vine transpiration via the Penman–Monteith model. Transpiration rates calculated at 30-min intervals were in good agreement with the instantaneous rates of sap flow measured by heat-pulse sensors located in the vine stem. The measured and calculated transpiration remained in concert throughout the experiment, thereby confirming the Penman-Monteith model as a robust and suitable model to describe the seasonal water use by kiwifruit vines. The model validation enables confident predictions of crop water use and thus aids irrigation allocation for kiwifruit crops.

Free access

T.M. Mills, M.H. Behboudian and B.E. Clothier

Three-year-old `Braeburn' apple trees (Malus domestica Borkh.) on MM106 rootstock were studied in a glasshouse to assess the effects of deficit irrigation on fruit growth, water relations, composition, and the vegetative growth of the trees. Trees were assigned to one of three treatments. The control (C) was fully watered. The first deficit treatment (D1) was deficit-irrigated from 55 days after full bloom (DAFB) until final harvest at 183 DAFB. The second deficit treatment (D2) was deficit-irrigated from 105 to 183 DAFB. Compared to C, the D1 and D2 trees developed a lower photosynthetic rate, leaf water potential (Ψl), and stomatal conductance (gs) during the stress period. Trunk-circumference growth was reduced in both D1 and D2 trees, but leaf area and shoot length were reduced in D1 only. Total soluble solids increased in both D1 and D2 fruit. Fructose, sorbitol, and total soluble sugar concentrations were higher in D1 fruit than in C and D2. Titratable acidity and K+ levels were higher in D1 fruit than C and D2. For D1, lowering of fruit water potential (Ψw) was accompanied by a decrease in osmotic potential (Ψs), and therefore turgor potential (Ψp) was maintained throughout the sampling period. Regardless of fruit turgor maintenance, the weight of D1 fruit was reduced from 135 DAFB. Weight, sugar concentration, and water relations of D2 fruit were not affected by deficit irrigation. This indicates that fruit water relations and sugar concentration are modified if water deficit is imposed from early in the season. However, if water deficit is imposed later in the season it has less impact on the composition and water relations of the fruit.

Free access

T.M. Mills, M.H. Behboudian, P.Y. Tan and B.E. Clothier

Five-year-old `Braeburn' apple trees (Malus domestica Borkh.) on MM.106 rootstock were studied to determine plant and fruit quality responses to reduced plant water status late in the season. Trees were irrigated or not irrigated. Those not irrigated developed reduced xylem water potential and stomatal conductance from 110 and 132 days after full bloom (DAFB), respectively. However, they showed no reduction in photosynthetic rates. Fruit were harvested at stage 1 (S1), starting 167 DAFB, or stage 2 (S2), starting 180 DAFB. At S1, fruit had higher soluble solids concentrations, enhanced red skin pigmentation, and a tendency for higher sorbitol concentrations. Total soluble sugar concentrations at final harvest showed no difference between treatments, but fruit from the nonirrigated trees showed earlier sugar accumulation during the season. Such fruit also had reduced Ca+2 concentrations at S1 and S2 relative to those on plants that were irrigated. No incidence of any disorder was found in fruit from either treatment at harvest or after 12 weeks of 0C storage.