It has certainly been a busy week, let me tell you. As usual we started off Monday heading out to the Redlands site, but this time along with SWP we got to do some berry sampling! For berry sampling depending on the site we usually pick 50-60 berries for a representative of that specific treatment. We then use those berries for a multitude of various results that all provide us with different information. The first thing we do with each bag of berries is collect the weight. The second step is from each set of berries we sub-sample 20 to be used for phenolics later. After that we crush the remaining berries with our hands to get all of the juice out, which we then pour into a 15 mL centrifuge tube. We then put all of those centrifuge tubes into a centrifuge to spin down any solid particulates in the juice. After that we pour the juice into a 50 mL centrifuge tube, and discard the old tubes with the solid matter. After that we begin collecting results.
With this juice we test for many different things. One thing we look at is pH, which is done using pH probe. We also test for brix using a refractometer. Brix are used as an indicator for veraison and when to harvest. With the juice we also take 1 mL of each sample and set it aside for enzymatic analysis. Lastly using a ratio of 5 mL of the juice to 20 mL of DI water we run all the samples through an acid titration. It’s a long process and it takes up almost the whole day but it’s actually kind of fun.
On Tuesday we went out to Grestoni to collect some leaf samples but this time we did things a little differently. We started off by picking a leaf from a preselected fine, somewhere around mid-canopy. We then used a SPAD meter, which gives us a relative SPAD value which is proportional to the amount of chlorophyll in the leaf. We then used the same leaf to take a photosynthesis reading using a Licor Photosynthesis and Gas Exchange Analyzer. After that we bag the leaf for SWP. After SWP we take the leaf back to the lab where we cut out 1 square centimeter for chlorophyll extraction, we weigh the rest and put it in the incubator for NSC.
On Wednesday we went to Belle Fiore to collect some berry samples, as well as leaf samples for NSC (Non-Structural Carbohydrates, which I talked about in an earlier blog) and leaf samples for nutritional analysis which we sent off to OSU.
On Thursday we went back to Grestoni to collect Berry and cluster samples. Cluster samples meaning we take the entire cluster off the vine for analysis. Lastly on Friday we spent the whole day in the lab, partly because it was raining and thundering outside and partly because we needed to run some of the samples through NSC. So as you can now tell it was a very busy week indeed.