Test PB Collection: FTE

Susan Ustin ShuHua Chen, Quinn Hart, Kyaw Tha Paw U, Matthias Falk, Liyi Xu Evapotranspiration (ET) describes the movement of water into the atmosphere, comprised of water evaporated from surfaces, and water released from vegetation as vapor through leaf openings (stomates).

Current research involves improvements to allow the models to run at higher spatial resolutionthat is, improve clarity, so the model can be accurately applied to smaller physical blocks. The result will be a model to better meet the irrigation scheduling needs of nut tree farmers.

Jan W. Hopmans, Maziar Mollaei Kandelous, Andres Olivos, Patrick Brown, Blaine R. Hanson, David R.

Patrick Brown and Muhammad Ismail Siddiqui The objectives of our work with pistachio are to improve the practice, use and utility of leaf sampling, develop a phenology and yield based nutrient model.

It is important to establish spatial patterns of nitrous oxide (N2O) emissions in orchards, and to assess whether the quantity of these emmissions emitted might be substantially influenced by the microirrigation system used.

Experiments were conducted for both almond and pistachio. Almond leaves were collected on two dates in 2008 and four dates in 2009. Samples were taken from a Kern County orchard where a four-level N fertigation trial was being conducted, thus a wide range of leaf N concentration was expected.

A common question of interest to growers and plant scientists concerned the accuracy of a handheld leaf chlorophyll meter and its ability to predict leaf N content. To address this interest, leaf samples were collected in almond and pistachio in 2009 to test the performance of a chlorophyll meter.

Our research addresses whole plant growth.

Our overall goal is to develop a management model to monitor and predict nutrient demand and nutrient status in pecan trees, along with the interaction of nutrient and water stress on nut yield.

The first two seasons of data collection have been completed. Soil Water Depletion (SWD), a root zone measurement of the amount of water within the soil, is an indicator of water stress within the tree.