This chart shows the industry value (left axis) and volume (right axis) over time

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Joan Robertson
6 years ago
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venue TBC Katikati: 28 July 5-7pm, venue

1 This chart shows the industry value (left axis) and volume (right axis) over time Important notices: Grower export registration is open online Meet the candidates for NZAGA elections Te Puke: 26 July 5-7pm, venue TBC Katikati: 28 July 5-7pm, venue TBC Grower Forum and AGM 1 September, Mount Club, 45 Kawaka Street, Mount Maunganui Anti-theft signage available from NZ Avocado, please midge.munro@nzavocado.co.nz if you would like to order. Up to two signs per PPIN free of charge.

2 Craib Sensor 1 Temperature ( C) Heller Top Temperature ( C) Grayling Sensor 1 Temperature ( C) Understanding temperature variation on your orchard can help with making decisions about frost protection, shelter and tree height. On cold nights, the in a flat sheltered orchard are reasonably constant. On this orchard there was a 1.3 C difference. Grayling Sensor 2 Temperature ( C) On cold nights, in a sloped, sheltered orchard showed some consistency. On this orchard, there was a difference of 4.0 C. Heller Bottom Temperature ( C) On cold nights, in an orchard where one sensor was in a sheltered gully and the other was exposed to winds did not show as much consistency. Craib Sensor 2 Temperature ( C)

Temperature ( C) The information below shows factors at Heller orchard which are related to orchard temperature. Frost Damage Frost damage varies across the Heller property.

In the winter of 2015 there was a visible tide line, below which the trees are damaged in both blocks. Frost Protection There are shelters surrounding the borders of the orchard.

Topography Each block of the orchard slopes down towards the depression between the two blocks. The difference in elevation is approximately 40m between the top and bottom of the slopes.

3 Temperature ( C) The information below shows factors at Heller orchard which are related to orchard temperature. Frost Damage Frost damage varies across the Heller property. The trees lower down the slope are regularly impacted by frost while the trees further up the slope are not. In the winter of 2015 there was a visible tide line, below which the trees are damaged in both blocks. Frost Protection There are shelters surrounding the borders of the orchard. Previously there was a water sprinkler frost-protection system but this was removed in order to try to minimise the effects of tree decline due to waterlogging. Topography Each block of the orchard slopes down towards the depression between the two blocks. The difference in elevation is approximately 40m between the top and bottom of the slopes. There is a small creek running through the depression. 2 C -2 C Temperatures H09 is located at the bottom of the Heller Orchard slope, and H01 and H14 at the top of opposing slopes. There is a wide range of temperatures experienced by sensors down the front slope of Heller Orchard on one cold night. The trend is that as you go down the slope, the temperatures experienced by the sensors are colder. Date

Below shows the effect of cold air drainage on temperature in two different orchards.

point at Coles orchard were similar to those experienced by a sensor elevated approximately 7 m higher at Heller

This may be caused by the fact that at the bottom of Hellers orchard there is a gully which traps cold air, there

4 Below shows the effect of cold air drainage on temperature in two different orchards. Heller and Coles orchards are in close proximity, however the temperatures experienced by the sensor at the lowest point at Coles orchard were similar to those experienced by a sensor elevated approximately 7 m higher at Heller orchard. This results in a large difference in the impacts of cold overnight temperatures between the two orchards. This may be caused by the fact that at the bottom of Hellers orchard there is a gully which traps cold air, there is no clear drainage path for the cold air to flow away, and therefore the cold air builds up to a higher elevation. After the lowest point of Coles orchard, the slope continues downwards until it meets the coast, providing a clear pathway for cold air drainage. This suggests that cold air drainage may be an important on-orchard consideration. Heller orchard Coles orchard

5 % of % healthy of 'healthy' samples Flowers which experienced different temperatures had different percentages of healthy ovaries. When flowers are in later stages of development, they are more sensitive to cold temperatures. It is important to keep them as warm as possible at this time p< degrees C 4 degrees C 8 degrees C 4 degrees C 40 A immature <2.4mm 30 p<0.05 p=0.1 B immature C D E developed, still to Pistillate previously opened 0 A B C D E Stage Stage Stage Stage Stage Flowering stage When compared to control inflorescences at 8 C, flowers chilled to 4 C for four hours had a reduced percentage of healthy ovaries. The effects appeared to be greater on ovules at later stages of development (developed, pistillate or previously opened).

NCEA Level 2 Agricultural and Horticultural Science (91290) 2012 page 1 of 6

Assessment Schedule 2012 NCEA Level 2 Agricultural and Horticultural Science (91290) 2012 page 1 of 6 Agricultural and Horticultural Science: Demonstrate understanding of techniques used to modify physical