1. ARE GROWERS SPRAYING COPPER? Copper Analysis: SPRAY DIARY ANALYSIS 2012/13 SEASON September 2013

Transcription

1 SPRAY DIARY ANALYSIS 2012/13 SEASON September 2013 Copper Analysis: Contents 1. Are Growers Spraying Copper? Areas been sprayed How Does Copper Use Vary Between Varieties? Regional copper spray practices Bay of Plenty Copper Use Period of copper use Hayward Copper Use Gold3 Copper Use Organic Hayward Growers Copper Use How soon after fruit-set are growers applying product? Copper Products and their Rates Copper Product Selection Application Rates for Copper Adjuvants used with Copper Use of spreaders in the post fruit set period Total Amount of Copper Applied Note This analysis is of the 2012/12 Zespri spray diary. Its accuracy is reliant on accurate entry of spray lines. Recording of spray applications in the dormant period may well be understated due to applicators not recording these sprays. 1. ARE GROWERS SPRAYING COPPER? Table 1: Season Percentage of KPIN s Spraying Copper Gold3 Hort16A Gold9 Green14 Hayward Total Total KPIN s Auckland 86% 77% 86% 100% 88% 86% 228 Bay of Plenty 92% 91% 92% 91% 90% 91% 3,667 Hawkes Bay 92% 95% 100% 75% 93% 92% 87 Nelson 53% 64% 60% 50% 46% 52% 246 Northland 77% 85% 78% 50% 86% 83% 269 Gisborne 96% 100% 100% 100% 89% 95% 118 Southern North Island 100% NA NA 50% 63% 63% 26 Waikato 91% 100% 100% 89% 93% 94% 203 Total 90% 89% 87% 89% 88% 88% Total KPIN s ,844 Copper is the core product in grower s spray program against Psa. The majority of growers are spraying at least a single spray (Table 1). The Bay of Plenty has less than 10% applying no coppers across all varieties. More concerning is the 9% of Hort16A growers who did not apply copper in the Bay of Plenty. 1 P a g e

2 Table 2: Season Percentage of KPIN's Spraying Copper Gold3 Hort16A Gold9 Green14 Hayward Total KPIN s Auckland 60% 84% 79% 86% 84% 201 Bay of Plenty 88% 94% 90% 88% 87% 3,535 Hawkes Bay 85% 89% 100% 100% 85% 84 Nelson 100% 77% 86% 67% 65% 223 Northland 30% 44% 33% 50% 47% 229 Gisborne 77% 97% 75% 100% 83% 119 Southern North Island NA NA NA Na 44% 26 Waikato 43% 50% 58% 43% 55% 180 Total KPIN s ,597 Table 1&2 allows a comparison of copper use by region over the last two seasons. There is a general trend for Psa infected regions to be using more copper than those uninfected. There was a slight increase in growers applying coppers in Bay of Plenty last season compared to the previous season. The biggest change has been seen in Waikato and Northland where the number of growers spraying, has closed to double. This is more likely to do with the spread of Psa to these regions rather than more effective provision of information by KVH or OPC. Table 3: Percentage of Growers Who Applied Copper Season Gold3 Hort16A Gold9 Green14 Hayward Bay of Plenty 14% 8% 29% 17% 9% Hawkes Bay 17% 41% 0% 0% 16% Nelson 0% 3% 0% 0% 2% Northland 0% 3% 0% 0% 0% When looking back even further to 2010/2011 season, there was minimal spraying of copper in any region. This is likely due to growers believing that Psa will be contained to Te Puke. 1.1 Areas been sprayed Areas sprayed reflect similar trends as seen at a KPIN level. It should be noted that as spraying of non-producing blocks is not mandatory, the hectare percentage may not be as accurate on Gold3. The percentages are based upon a grower spraying a single spray on a block, and then they are counted for recorded sprays. Therefore if a grower reports a spray product then doesn t report a copper it shows that they haven t sprayed. 2 P a g e

3 Table 4: Percentage of Hectares being sprayed with Copper Gold3 HORT16A Gold9 Green14 Hayward Number of hectares Auckland 38% 80% 84% 92% 84% 601 Bay of Plenty 65% 86% 92% 73% 89% 11,106 Hawkes Bay 75% 90% 100% 76% 88% 227 Nelson 6% 54% 59% 54% 55% 601 Northland 46% 90% 76% 11% 70% 524 Gisborne 58% 100% 100% 86% 83% 322 Southern North Island 23% 25% 77% 86.5 Waikato 51% 126% 92% 77% 91% 582 Number of Hectares ,051 Table 5: Percentage of Hectares being Sprayed with Copper Gold3 Hort16A Gold9 Green14 Hayward Total hectares Auckland 51% 58% 54% 50% 45% 493 Bay of Plenty 55% 64% 58% 61% 54% 9,791 Hawkes Bay 50% 55% 63% 71% 62% 189 Nelson 100% 67% 68% 82% 54% 509 Northland 20% 32% 29% 29% 21% 445 Gisborne 51% 61% 52% 57% 45% 264 Southern North Island NA NA NA NA 21% 76 Waikato 25% 30% 34% 6% 29% 497 Number of Hectares ,266 3 P a g e

4 2. HOW DOES COPPER USE VARY BETWEEN VARIETIES? As expected, higher risk varieties appear to be more likely to receive a copper spray (Table 6) Table 6: Number of Coppers applied over the season by variety. Region Gold3 Hort16A Gold9 Green14 Hayward Average Auckland Bay of Plenty Hawkes Bay Nelson Northland Gisborne Southern North Island 2.0 NA NA Waikato Variety Average The average number of copper sprays across all varieties was 6.3. Hayward had the least applications at 5.5. This likely reflects its perceived lower risk and lower profitability. Generally the best regions for applying copper were Waikato, Bay of Plenty and the Hawkes Bay. The two lowest regions for spraying are the Southern North Island and Nelson, indicating that growers in these regions may have believed their remoteness will protect them from Psa. Table 7: Number of coppers applied over the season. Row Labels Gold3 Hort6A Gold9 Green14 Hayward Average Auckland Bay of Plenty Hawkes Bay Nelson Northland Gisborne Southern North Island Waikato Variety Average When compared to the previous season the overall number of sprays applied on a single orchard has increased on all varieties. The two regions not increasing their sprays are Nelson and Southern North Island. This seems to be a trend with growers relying on remoteness to protect them from Psa. 4 P a g e

5 2.1 Regional copper spray practices The number of copper sprays applied by region is shown in Chart1. Most regions have around 10% of growers not spraying. Bay of Plenty, Waikato and Hawkes Bay are the districts applying the most copper sprays. The only region that has growers applying more than 20 sprays is Bay of Plenty. Southern North Island is only a single KPIN.. Regions Bay of Plenty Hawkes Bay Nelson Northland Gisborne Southern North Island Auckland Number of KPIN s Waikato 5 P a g e

6 Region Number of KPIN s Auckland Bay of Plenty Hawkes Bay Nelson Northland Gisborne Southern North Island Waikato 90 2, Interestingly some Hawkes Bay growers are applying more coppers on their Hayward than the Hawkes Bay Gold3 growers. As to be expected the two areas for lowest number of sprays are Nelson and Southern North Island. 6 P a g e

7 2.2 Bay of Plenty Copper Use BOP is the region applying the most copper applications. An analysis of use within its districts is shown in chart below. Katikati Maketu Maniatutu Opotiki Paengaroa Pukehina Tauranga Te Puke High Te Puke Low Te Puke Mid Waihi Whakatane Opotiki, Waihi and Whakatane appear to be the districts applying the most copper sprays on Gold3. This likely reflects the high level of Psa infection seen in Gold3 in these districts last season. Pukehina is an interesting area with high percentage of growers at each end of spectrum. It also has a small group of growers around the 6-8 copper spray per year. The higher than 20 sprays applied primarily come from colder lower elevation areas. 7 P a g e

8 Katikati Maketu Maniatutu Opotiki Paengaroa Pukehina Tauranga Te Puke High Te Puke Low Te Puke Mid Waihi Whakatane A similar trend is seen with Hayward. The major difference is there is a much lower percentage of Hayward growers spraying a high number of coppers applications. The other major difference is the slight increase in growers in Hayward who are not spraying copper. Hayward is more centred between two and eight applications of copper while Gold3 was more widely spread. 3. PERIOD OF COPPER USE 3.1 Hayward Copper Use Knowledge of when best to spray to prevent infection is still limited. Currently the KVH best practice advice recommends spraying over the entire season, timing sprays to provide protection before wet events especially when there are natural or man-made wounds present. Averages do not include growers who didn t spray in these periods. Table 8: Number of Coppers Applied on Hayward in Specific Periods in Season Row Labels Dormant Pre-flowering Fruit-set to Monitoring Monitoring KPIN s per Area Sprayed Auckland Bay of Plenty ,115 Hawkes Bay Nelson Northland Gisborne Southern North Island Waikato Grand Total ,591 8 P a g e

9 Hayward growers are applying on average one to two sprays in each of the spray diary periods. Given 2012/13 was an exceptionally dry summer the low number of sprays in the post fruit to harvest period is justified. However, the low number of sprays in the other periods is suggesting far from optimal control practices and reflects the general low level of use of protectants seen (Actigard and KeyStrepto use was considered sub-optimal as well refer to separate reports). Apart from the Psa free areas (last season) of Nelson, Northland, Southern North Island, preflowering is the period which had the highest average number of coppers applied. Averages do not include growers who didn t spray in these periods. Table 9: Copper sprays applied to Hayward in selective periods in year Row Labels Dormant Pre-flowering Fruit-set to Monitoring Monitoring KPIN s per Region Sprayed Auckland Bay of Plenty Hawkes Bay Nelson Northland Gisborne Southern North Island Waikato Grand Total An increase in the use of copper in the non-dormant periods in 2012/13 compared to 2011/12 was seen. This likely reflects growers are becoming more comfortable applying copper on green tissue. Most regions generally were down in the dormant period and up in all of the other periods. 9 P a g e

10 3.2 Gold3 Copper Use Table 11: Number of coppers applied on Gold3 in specific periods in season Regions Dormant Pre-flowering Fruit set to Monitoring Monitoring Auckland Bay of Plenty Hawkes Bay Nelson Northland Gisborne Waikato Gold3 blocks, which sprayed copper, had a higher frequency of copper spraying compared to Hayward in each period. Greater applications were most noticeable in the monitoring period. A decrease to no sprays was seen in Nelson from fruit set to harvest. Bay of Plenty and Waikato are the two regions spraying the most copper across all periods. Gisborne seems to have a higher spray use in the fruit set to monitoring period. Generally the pre flowering and monitoring period are the two periods in which the most coppers are applied. The lowest period is fruit-set to monitoring reflecting the perceived risk of fruit damage. Table 12: Number of Copper Applied on Gold3 in Specific Periods in Season Row Labels Dormant Pre-flowering Fruit-set to Monitoring Monitoring Auckland Bay of Plenty Hawkes Bay Nelson Northland Gisborne Waikato No spraying after fruit-set was seen in the Waikato, Hawkes Bay, Nelson, and Northland in 2011/12. These regions didn t have Psa in the 2011/12 season and likely assumed that the risk of fruit damage from copper outweighed the need to apply a copper. Nelson was the only region to have no increase in 2012/13 with the average number of copper sprays in any period compared to 2011/12. In 2011/12 BOP growers applied on average of 1.4 applications of copper in the monitoring period. This increased to / P a g e

11 3.3 Organic Hayward Growers Copper Use Organic growers applied less copper applications than conventional growers. While there are 10% of BOP conventional growers not applying copper, 15% of organic growers did not. Organic growers applied 4.7 copper sprays compared to conventional applying 5.5. This fact is worrying as organic growers have no other proven agrichemicals that can be used for Psa control while the conventional growers have Key Strepto and Actigard. 3.4 How soon after fruit-set are growers applying product? There is a perceived risk of fruit damage of spraying copper post fruit-set, this section looks at the spraying practices within a month of fruit set, it should be noted that approximately 20% of kpins applied a copper in the fruit set period. 11 P a g e

12 Determination of fruit set date is an arbitrary calculation and should be treated with caution in the context of spray diary analysis. That said it appears some growers were comfortable spraying fruitlets in the immediate fruit set period. OPC is not aware of any reported instances of fruit damage in the 2012/13 season. Of those that sprayed within the first week, 75% occurred within 3 days of the reported fruit set date. Much less spraying occurred between 2 and 3 weeks, perhaps reflecting the concerns of spraying in oil sensitive periods. 12 P a g e

13 4. COPPER PRODUCTS AND THEIR RATES. 4.1 Copper Product Selection This section outlines what coppers were sprayed, and if spray patterns between products changed over time. The two main products, Nordox 75 WG and Kocide Opti, make up over 90% of the copper sprayed. Champ DP and Liquicop were the only other two copper products listed in the KVH Seasonal Management Guide. The most noticeable trend was the switch from Nordox 75 WG to Kocide Opti after flowering despite Nordox being the only copper spray with a post bud-break claim. This reflects perceived risk of phytotoxicity differences between the two products. (This perception has not been validated with any trials undertaken). 13 P a g e

14 4.2 Application Rates for Copper This section will look at the rates of Nordox 75 WG and Kocide Opti, as these make up the majority of copper sprayed for Psa. Because some applicators use concentrate spraying, rates have been converted to rates/ha to simplify comparison. The g per hectare rate and rates above this, reflect application at or above summer label rates. The g/ha rate for Kocide Opti and higher reflects the rates advocated last season. It appears around half of the Nordox applications made post flowering were made at or above the summer label rate. The number of Kocide Opti applications made at or above label rates was higher than that of Nordox. (e.g. nearly 80% of applications on Gold3 in the monitoring period). A proportion of growers appeared to be applying less than the Nordox label winter rate (assuming 700g/ha minimum). 14 P a g e

15 4.3 Adjuvants used with Copper. Spreaders are being used predominately in the pre flowering period or the dormant period. The rates of adjuvant usage do seem to be lower than expected especially in the dormant period. Table 13: Comparing Spreader use with Copper 2013 and / /2012 Row Labels No Spreader Spreader No Spreader Spreader Dormant 85.1% 14.9% 82.2% 17.8% Pre-flowering 65.4% 34.6% 88.9% 11.1% Fruit-set to Monitoring 96.3% 3.7% 89.6% 10.4% Monitoring 96.8% 3.2% 97.5% 2.5% When comparing this to the 2011/2012 season for adjuvant use, the only significant change was the increase in spreader use in the pre-flowering period in 2012/ Use of spreaders in the post fruit set period. Use of superspreaders can improve coverage and thus potentially control. Research has indicated no increased phytotoxicity risk from their use, especially if used in conjunction concentrate spraying. Approximately 20% of Hayward and Gold3 growers utilised adjuvants with coppers. No problems for adjuvant were reported to OPC. However, only 3% of applications occurred in the post flowering periods.. 15 P a g e

16 5. TOTAL AMOUNT OF COPPER APPLIED. The maximum application of elemental copper allowed is 8kg over a five year average. This is based on what is considered a sustainable copper input. Most growers applied less than 2kg last season. This suggests that improved copper usage is unlikely to result in unsustainable practices. (Although many of the leaf dropping sprays may not be recorded in the spray diary. One 12kg/ha application of copper sulphate applies ~6 kg of copper per hectare). Thirteen KPIN s applied over 8kg. Considerations should be given to notifying those growers so they are aware of options to manage their copper inputs as alternatives to leaf dropping copper sprays area available. 16 P a g e