Wednesday 6 March 2013.

Transcription

1 Wednesday 6 March 213. Today s declaration of drought for the South Auckland, Waikato, Bay of Plenty and Hawkes Bay regions, on top of last week s announcement in Northland recognises the difficult conditions being faced by farmers across much of the North Island. We appreciate that every property is different, and as such, the only across the board advice we can give is to be pro-active in decision making for your property and business. Drought relief is being managed by the Rural Support Trust, and your local representative can be contacted on Other support agencies include Federated Farmers Feed Line on 8 DROUGHT ( ) and is available here. A Ministry for Primary Industries (MPI) advice note on drought is available here while MPI drought publications are available here. Coping with stress and depression is available here. Harvesting drought-stressed maize There is currently huge variation in maize dry matter both within field and between fields. This is influenced by previous rainfall amounts, soil type and compaction, topography, proximity to hedges, trees etc, plant population, and drought tolerance of the hybrid planted. Given this variability, how can you determine whether your drought stressed crop is ready to harvest at the 3 to 4% Dry Matter stage? Expert advice is available from a number of seed and supply company reps and contractors agronomists, so seek their advice and book your contractor well in advance (phoning a couple of days before harvest is not helpful). Remember that drought stressed crops with few kernels or little kernel development can have high nitrate levels. If green chop is required urgently for hungry animals, get a sample to your vet for nitrate testing before feeding. This is usually a same day service. Should you wish to assess the crop yourself, here are a few pointers Stand on a high point and ascertain what percentage of the field is still green (particularly from the cob upwards), what percentage is a lighter green but still has folded leaves (particularly during the heat of the day), and what percentage is completely brown and dead. If the majority of the paddock is completely brown, harvest as soon as possible. If the majority of the paddock is green check the milkline in the kernels, husk cover colour and how many leaves below the cob are totally brown and senesced. As a general guide - if the milkline is starch from the cap to a third, husk cover is turning brown, and the lower leaves are senesced, then contact your contractor. Alternatively, three or four representative plants can be mulched and Dry Matter determined by laboratories or simple microwave testing and weighing. Green leaves above the cob will continue to photosynthesise and produce further Dry Matter and yield in the plant. Apart from peat soils (where plants roots can access moisture) most droughtstressed crops north of Taupo are drying down at up to 1% /day. Currently, Dry Matter in Waikato crops that have lost all green leaf colour below the cob is up to3% higher than you would expect if those leaves were still green. This is because the drought stressed stover is becoming very dry even though kernel milkline development is not well advanced.

2 Many contractors now have NIR Dry Matter determination capability on their choppers, and chop length can be altered to aid stack compaction and the fermentation process of the maize silage. The dry weather means that herbicide residues may remain in the soil after harvest and affect subsequent grass seed germination. You can check this by carefully placing the top 1mm of representative soil in a plant tray, sowing some mustard seed, watering and then checking for normal germination and plant health. FAR s 28 Maize Update Response of Maize to Drought Stress is attached. Upcoming Drought Focused Events 4.pm Tuesday 12 March, Waikato Arable Research Site Managing your droughted maize crops - what can we learn from this experience? An in-field discussion with Mike Parker (FAR) and Dr Paul Johnstone (Plant & Food Research) Weather summary from 16 February to 1 March 213. Some data is unavailable in the Hastings, Wanganui and Rangiora areas. Long term data has been substituted where possible. Radiation data from Rangiora is now available. In areas of severe moisture stress, some of the data may no longer be relevant, however, there are a number of locations where crops are still growing actively and the data continues to be important. Cumulative Radiation (from 1 Sept) - All areas are now recording above their long term average. Cumulative Growing Degree Days (from 1 Sept) - Growing degree days are an average of the daily maximum plus minimum temperatures less a base temperature of 8(NZ) O C. Crop emergence takes about 125GDDs and from emergence to V1 each leaf collar requires 85GDDs. From V1 to tassel each leaf collar requires 5 GDDs. Whangarei, Dargaville, Waikato, Te Puke, Gisborne, New Plymouth and Hawera are still recording below the long term average, ( night temperatures have been cooler), while all other areas are above the long term average. Soil temperature (1cm) averages for the fortnight - Where data is available, all areas are recording at or above the long term average. Palmerston North (now dry) soil temperatures are 1.7 O C above average. Rainfall - Only 6 of the 19 area weather stations have received any rainfall in the last fortnight, and then the maximum was 3.6mm. Evapotranspiration (ET) total for the last fortnight - Whakatane recorded the highest ET (66mm) and Timaru the lowest (43mm). Strong wind runs and warm days have increased ET rates and further dried soils already drier than normal. ET rates are averaging 4-5mm/day across the whole country and moisture stressed crops are now common where irrigation is not practised. Field Report Northland: Crops are variable; those which received greater quantities of rainfall earlier continue to look reasonable, despite the drought. However, many crops are now suffering from the dry weather and harvesting maize silage is well underway. Dairy farmers are now very short of feed, and green chop is being harvested (note comment on nitrate levels above). A few crops are being attacked by armyworm and/or shield beetle but generally damage is not significant. Early planted grain crops are now at blacklayer, and grain harvesting will commence in a fortnight s time Waikato: Southern Waikato crops are looking much more promising (greater earlier rainfall) than the drier mid to Northern Waikato, where many crops now under moderate to severe drought stress. Maize silage

3 harvesting is now in full swing due to the rapid dry down caused by high daytime temperatures and lack of rainfall. Yields are extremely variable and to date range between 7 and 28t/ha. Generally however, yields will be down 2 to 3% across the greater Waikato. Growers are again advised to book and talk to their contractor as early as possible because drought-stressed crops are now drying down extremely rapidly. Bay of Plenty: As in the Waikato, drought stress has impacted on yield potential, especially on the lighter soils. Rainfall last week varied across the region but was generally significantly more than that received in the Waikato and therefore crops on the better soils are still looking reasonable. Maize silage harvesting is well underway with contractors experiencing difficulty in steering trucks due to the now powder like nature of some of the soils. Yields are very variable. Gisborne: The higher received rainfall areas of Wairoa and Tolaga Bay north continue to look promising. The Gisborne flats however, are now showing the effects of less rainfall and hot dry conditions. Minor shield beetle damage is showing on a few crops. Hawke s Bay: Unless irrigated, most maize crops are very drought-stressed. No reports of harvesting to date. Green vegetable bug shield beetle numbers have been building so continue to scout for these. Taranaki: Crops are generally looking promising especially in the higher rainfall area around New Plymouth. Maize silage harvesting and green chop have commenced and yield reports are good. The Hawera area earlier received less rainfall and the dry is now starting to impact on crops. Manawatu: Some maize silage harvesting has commenced, but it is too early to report on yields. As in other regions the dry weather is now stressing crops, and yields will be compromised. Wairarapa: Maize crops are holding well despite the dry. Silage harvesting is 1 to 14 days away. Wairarapa has experienced greater rainfall and looks particularly promising. Canterbury: Despite a few cooler days the irrigated maize crops continue to look promising. Harvesting for maize silage has not commenced. Contact Us Mike Parker parkerm@far.org.nz Diana Mathers mathersd@far.org.nz Disclaimer This FAR Maize Action Report was prepared with current information at the time of publication. Neither FAR or its staff may be held liable for any crop damage or loss from interpretation of the information. Information contained in this Maize Action is intended as a guide only. Please note if you no longer wish to receive the FAR INFORMATION electronically through this list, reply to this with REMOVE ME in the subject line. You will still receive hard copy mail if you are a FAR grower. Please advise if you change your address

4 Whangarei: 16 February 1 March 213 For the last fortnight: :.6 ET (mm): 56.4 Soil for the last fortnight: ( o C): X ( o C): X This Year: Last Year: Long term average: Fortnight

5 Dargaville: 16 February 1 March 213 For the last fortnight: : ET (mm): 61.6 Soil for the last fortnight: ( o C): 19.8 ( o C): 19.7 This Year: Last Year: Long term average: Fortnight

6 Pukekohe: 16 February 1 March 213 For the last fortnight: : ET (mm): 52.5 Soil for the last fortnight: ( o C): 2 ( o C): 19.3 This Year: Last Year: Long term average: Fortnight

7 Hamilton: 16 February 1 March 213 For the last fortnight: : ET (mm): 53.8 Soil for the last fortnight: ( o C): 19.5 ( o C): 19.3 This Year: Last Year: Long term average: Fortnight

8 Morrinsville: 16 February 1 March 213 For the last fortnight: : ET (mm): 56.9 Soil for the last fortnight: ( o C): 18.4 ( o C): 18.3 This Year: Last Year: Long term average: Fortnight

9 Matamata: 16 February 1 March 213 For the last fortnight: : X ET (mm): X Soil for the last fortnight: ( o C): 18.3 ( o C): 17.8 This Year: X Last Year: X Long term average: X Fortnight

10 Te Puke: 16 February 1 March 213 For the last fortnight: : ET (mm): 63.5 Soil for the last fortnight: ( o C): 19. ( o C): 19.1 This Year: Last Year: Long term average: Fortnight

11 Whakatane: 16 February 1 March 213 For the last fortnight: : ET (mm): 65.8 Soil for the last fortnight: ( o C): X ( o C): X This Year: Last Year: Long term average: Fortnight

12 Gisborne: 16 February 1 March 213 For the last fortnight: : 3.2 ET (mm): 52.4 Soil for the last fortnight: ( o C): X ( o C): X This Year: Last Year: Long term average: Fortnight

13 Hastings: 16 February 1 March 213 For the last fortnight: : ET (mm): 47.6 Soil for the last fortnight: ( o C): 2.3 ( o C): 19. This Year: Last Year: Long term average: Fortnight

14 New-Plymouth: 16 February 1 March 213 For the last fortnight: : ET (mm): 63.3 Soil for the last fortnight: ( o C): X ( o C): X This Year: Last Year: Long term average: Fortnight

15 Hawera: 16 February 1 March 213 For the last fortnight: : ET (mm): 64.2 Soil for the last fortnight: ( o C): 17.7 ( o C): 17. This Year: Last Year: Long term average: Fortnight

16 Wanganui: 16 February 1 March 213 For the last fortnight: : ET (mm): 6.3 Soil for the last fortnight: ( o C): 19.8 ( o C): 18.7 This Year: Last Year: Long term average: Fortnight

17 Palmerston North: 16 February 1 March 213 For the last fortnight: : ET (mm): 58.4 Soil for the last fortnight: ( o C): 19.4 ( o C): 17.7 This Year: Last Year: Long term average: Fortnight

18 Masterton: 16 February 1 March 213 For the last fortnight: : ET (mm): 58.5 Soil for the last fortnight: ( o C): X ( o C): X This Year: Last Year: Long term average: Fortnight

19 Takaka: 16 February 1 March 213 For the last fortnight: : ET (mm): 54.4 Soil for the last fortnight: ( o C): 17.8 ( o C): 17. This Year: Last Year: Long term average: Fortnight ) 1 m (m 125 l fa 1 a in R 25

20 Rangiora: 16 February 1 March 213 For the last fortnight: : ET (mm): 5 Soil for the last fortnight: ( o C): 17.1 ( o C): 15.6 Cumulative radiation MJ/m 2 from 9 th Nov Cumulative GDDs from 1 Sept This Year: Last Year: X Long term average: Fortnight

21 Ashburton: 16 February 1 March 213 For the last fortnight: : 3.2 ET (mm): 44 Soil for the last fortnight: ( o C): 16.1 ( o C): 15.3 This Year: Last Year: Long term average: Fortnight

22 Timaru: 16 February 1 March 213 For the last fortnight: : 3.6 ET (mm): 42.9 Soil for the last fortnight: ( o C): X ( o C): X This Year: Last Year: Long term average: Fortnight