Báo cáo nghiên cứu nông nghiệp " Development and Management of Seed Production Areas " ppt

Development and Management of Seed Production Areas Khongsak Pinyopusarerk CSIRO/Ensis-Genetics Canberra, Australia Why not just collect seed out of plantations? z We may not know the genetic origin of the plantation – it could be inferior, or the genetic base too narrow z No selective thinning to remove inferior trees in the plantation z The inferior trees contribute their pollen to the other, better trees in the plantation, lowering seed quality z Because the trees are growing at close spacing, flowering may be poor, resulting in inbreeding and poor genetic quality of seed Seed Production Area z Seed production area is a stand developed and managed specifically for seed production purpose. z Two ways to develop seed production area: – Develop from existing planted stand – Develop from specially planted new stand Existing stand suitable for conversion to seed production area z Known seed origin z Trees are mature but not too old z Near full stocking and good phenotypes z No pests or diseases z Proven capacity to flower and set seed z Easily accessible z Not subject to commercial harvesting in near future z Conversion to seed production area by selective thinning Stand not suitable for conversion to seed production area Very poor plantations with evidence of disease attack Development of seed production area from specially planted stand z Site should be representative of target planting areas z Evidence of flowering and seed set at the location z Seed from most suitable provenance or several provenances z Start like a new plantation z Initially close spacing (more trees for selective thinning) – 3m x 2m for most eucalypts – 3m x 3m or 4m x 2m for acacias z Fertilizer application to help in successful establishment Establishing new seed production area z A seed production area of E. camaldulensis in Laos, 5 ha z Initial spacing 4m x 2m (1250 stems/ha) z Two selective thinnings reduce to 300 stems/ha 8/1996 2/2002 Size of seed production area z 4-5 ha is appropriate for most species z May be smaller (< 1 ha) for heavy seed producer, e.g. eucalypts z Area should be close to square, not long narrow block to promote more cross pollination Isolation is important to minimise contamination from outside pollen !!! Selection of trees in seed production area z Development of SPA involves 2-3 thinnings to remove undesired trees, retaining good trees to produce seed z Retained trees should have the following characteristics – Fast growth – Straight single stem – Good crown development – Good self pruning – Free from insects and diseases z No trees below standard should be kept, regardless of the gap z For dioecious species (e.g. casuarinas), make sure to have enough male trees (at least 30%) for pollination Thinning seed production area z An essential activity to remove poor-performing trees z Aim to reduce stocking to 150-200 trees/ha z At least 2-3 thinnings each time selectively removes 50% of trees z Thinning in small groups, e.g. 16 (4 x 4) trees, for ease of comparison z Avoid thinning in typhoon season, strong winds can cause wind-throw and crown damage z Avoid damage to adjacent trees [...]... survey of flowering At least do a survey of seed crops - at least 40-50 % of trees should carry seed crops May divide SPA into 3 sections and collect seed in each section in a year Conclusions Seed production areas have three important attributes 1 Seed quality better than seed from commercial collections from routine plantations 2 The origin of seed is known 3 Reliable sources for well-adapted and inexpensive... old enough for conversion to seed production area 1250 stems/ha Seed production area before first thinning Thin in groups: remove poorest 8 out of every 16 trees Selection criteria: - growth - stem straightness - light branching Initial stocking: 1250 trees/ha Seed production area - after first selective thinning Stocking: before : 1250 trees/ha after: 600 trees/ha Seed production area – after second... after mass flowering following thinning Thinning seed production area Seed production area Acacia mangium Sarawak 4 years old, selectively thinned to best 250 trees per ha Acacia mangium SPA, Bansud, Mindoro Oriental Island 3.5 years old, thinned from 1000 to 400 stems/ha Over 50% of retained trees have fruits/flowers Management of seed production area Remove cut material after thinning Control weed growth... Fertilisation Protection Importance of weed control and nutrition – E urophylla SPA, Philippines Year 2004 – with chemical weed control and fertilizer, good flowering and seed production Year 2000 – mechanical weed control ineffective – trees not flowering Potassium deficiency symptoms – year 2000 Poor maintenance 2/2002 3/2005 3/2005 Record keeping Species Seed origin Location Year of establishment Rainfall,... superior, trees after mass flowering following thinning A seed production area after three thinnings 150 trees/ha A specially planted seed production area, before first selective thinning at 2 years old h h h h hh h h h h hh h h h h hh hh hh hh h h h h hh h h h h hh Row 1 Seedlot used to establish SPA: mix of equal weights of 50+ unrelated, superior seed families Initial spacing 3mx3m (1110 stems/ha Row... pods no green pods 47 Scale - 10 metres Example of flowering survey in Acacia mangium seed production area Reproductive status survey: SPA 1, Sim ilajau Date May 1 2003 (example - not real data) 36 35 72 71 38 34 74 33 Survey once per month 75 76 78 79 39 flow ers green pods 44 77 Calculate % of trees in SPA with heavy, medium and light, crops of flowers and no flowers 43 45 42 46 Key heavy flow ering... early-flowering and lateflowering individuals/branches – avoid collecting from them Seed harvesting Survey of flowering - flower crops should be moderate to heavy, not very light If fewer than 40-50% of trees are flowering, don’t collect seed (unless other good seed sources are not available) Identify any tress that are early or late flowering – not in synchrony with other flowering trees Avoid collecting seed. .. Species Seed origin Location Year of establishment Rainfall, temperature Soil Silvicultural operations (time of thinning, weeding, fertilization) Flowering characteristics (flowering time, seed set) Annual seed collection (quantity, number of trees) Example of flowering survey in Acacia mangium seed production area Reproductive status survey: SPA 1 Date May 1 2003 (example - not real data) 36 35 72 71 38... removing 50% of trees Stocking: Initial : 1250 stems/ha After 1st thin : 600 After 2nd thin: 300 Collect seed from remaining, superior, trees after mass flowering following thinning Seed production area – after third selective thinning Three selective thinnings each removing 50% of trees Stocking: Initial : 1250 stems/ha After 1st thin : 600 After 2nd thin 300 After 3rd thin 150 Collect seed from remaining,... Collect seed from remaining, superior, trees after mass flowering following thinning After third selective thinning, age 6 years Row 1 Row 2 Row 3 Two selective thinnings each removing 50% of trees Stocking: Initial : 1100 stems/ha Row 4 After 1st thin: 550 After 2nd thin: 275 Row 5 After 3rd thin: 125-150 Collect seed from remaining, superior, trees after mass flowering following thinning Thinning seed production . Development and Management of Seed Production Areas Khongsak Pinyopusarerk CSIRO/Ensis-Genetics Canberra, Australia Why not just collect seed out of plantations? z We. seed production area Very poor plantations with evidence of disease attack Development of seed production area from specially planted stand z Site should be representative of target planting areas z. lowering seed quality z Because the trees are growing at close spacing, flowering may be poor, resulting in inbreeding and poor genetic quality of seed Seed Production Area z Seed production