STONE FRUIT ROOTSTOCKS

Transcription

1 STONE FRUIT ROOTSTOCKS BACKGROUND AND LATEST INFORMATION Piet Stassen

2 ACKNOWLEDGEMENTS FUNDING ARC Infruitec-Nietvoorbij SASPA CFPA DFTS ASSISTANCE Kobus de Kock, Ria Roode and Johny Daniels Dr Marde Booyse (stats)

3 INTRODUCTION Kakamas seedling and Marianna remains popular/widely use Reasons: Reliable over time, lower costs (royalties), ease of propagation and take for nurseries, less come backs after plant in orchard, information on new rootstocks limited especially for certain soil types, die-back occurrence, compatibility, adaptability and other uncertainties. New clonal hybrids and other rootstocks from different breeding programmes over the world are available. Their ability to optimise scion performance have been widely evaluated for South African situations. Objective: To look at the information available and discuss the bigger picture

4 What do we want from a rootstock? To increase yield and quality above that of the standard rootstocks in each situation or otherwise stick to what we have Give us resistance to abiotic stresses (calcareous soil) Resistance to pest and diseases (plant-parasitic nematodes) Adaptability to our variability in soil textures Adaptability to climatic conditions To tolerate rising water tables during rainy periods Provide the necessary synchronisation between the scion and roots

5 FIELD EVALUATION RESULTS: High ph sites Table 1 Excelsior Worcester: 33% clay and silt, 57% sand. ph (KCl) 7.9. Nematodes low. Artic Star Previous year 2014 before treatment for chlorosis: Flordaguard 80% yellow, Tsukuba, Kakamas, Guardian 40%. Viking, Atlas, Cadaman 20% and Garnem less than 10% Third harvest: Atlas t/ha, Garnem 28.53, Viking 28.31, Guardian and Cadaman No statistically difference. Kakamas, Penta, Flordaguard and Tetra respectively, 25.9, 24.65, 19.8 and Effect of ph having effect, but treatment for lime induced iron chloroses was accidentally done. Fruit weight: Garnem and Viking best but not sig better than Atlas, Monegro, Cadaman, Kakamas and Tetra. Tetra and Flordaguard smallest Strongest growth: Felinem, Garnem and Cadaman

6 Excelsior conclusions Effect of high ph show effect on Kakamas, Penta, Flordaguard and Tetra in terms of production and Tskuba 4 and Flordaguard in terms of fruit weight. After one more season differences between rootstocks clear. High potential soil favours Kakamas. In terms of yield and fruit size: Atlas, Monegro, Garnem, Viking, Cadaman promising. Three more seasons.

7 Table 2 Sonskyn, Robertson. African Delight 10.6 silt and clay, 89.4% sand, ph 7.6, High numbers of ring nematodes After five harvest seasons: GF 677 best average yield, but not sig better than Cadaman. Best fruit weight: Cadaman, Atlas and Chuche Picudo, but not sig better than GF 677 Effect of ring on fruit weight of Marianna, Maridon and Tsukuba 5 evident sig also effect of iron chlorosis on Flordaguard, SAPO 778 and SAPO 778 seedling Cadaman induces strongest growth but not sig better than GF 677, Atlas, Viking, Marianna, Flordaguard and SAPO 778.

8 Conclusions Sonskyn Over five harvest seasons, GF 677 and Cadaman performs the best in terms of yield and fruit weight followed by Atlas under condition of high ph and ring numbers as well as sandy soils. Marianna, Maridon and Tsukuba: reduced fruit weight under these conditions SAPO 778 and Flordaguard not suitable for high ph Ring nematodes have a high reproduction index on Tsukuba, Marianna and Maridon

9 Roodehoogte, Robertson. African Rose 25% silt and clay, 75% sand. ph 7. High spiral and increasing ring. Third harvest. Best performance in terms of yield and fruit weight: Atlas, GF 677, Marianna, Garnem. Lowest yield and fruit weight: Penta and Tetra Higher soil potential, lower ph and lower ring until harvest than Sonskyn. Future results will show effect of increasing ring

10 Middelplaas, Bonnievale. Alpine 17.7% clay and silt, 82.3% sand. ph 7.6. Second harvest. Ring moderate to high, root lesion moderate. Chlorosis: Kakamas 100%, Viking, Atlas about 40% and GF 677, Cadaman and Garnem 20%. Penta and Tetra removed due to very poor growth. In terms of yield and fruit weight no sig difference between Atlas, Viking, Garnem, Cadamen and GF 677. Kakamas sig lower

11 High ph Conclusions Excelsior, low ring, high potential soil: Atlas, Garnem, Viking and Cadaman. GF 677 planted later Sonskyn, high ring, sandy soil: GF 677, Cadaman, Atlas. No Garnem in trial Roodehoogte, high potential soil, increasing ring: Atlas, GF 677, Garnem and Marianna Middelplaas, moderate to high ring (increasing): Atlas, Viking, Garnem, Cadaman and GF 677 It is clear that the rootstocks: Kakamas seedling, Flordaguard, SAPO 778 clone and seedling, Penta and Tetra and Guardian cannot be recommended for high ph soils

12 Sandy soils (more than 90% sand) Bufland, Mookgophong (Naboomspruit), Alpine. Two experimental sites. Results over 5 harvest seasons. 91% sand, ph 5.8. RCU , ICU Moderate ring, high spiral 1) Flordaguard and Cadaman best performance in terms of yield and fruit weight. Kakamas only 50% of yield of Flordaguard and fruit weight 14% less than Flordaguard. Atlas not sig lower than Cadaman. Guardian and Tsukuba sig better than Kakamas in terms of yield but fruit weight same. SAPO 778 seedling, GF 677 and Kakamas performs poorly in under these conditions

13 Sandy soils Bufland 2, 5 harvesting seasons Flordaguard sig higher yield than Atlas, Viking, SAPO 778 clone, Penta and Tetra. Fruit weight of trees on Flordaguard, Atlas and SAPO 778 same. Yield on Penta and Tetra only about 23% than Flordaguard and 9% smaller fruit weight Conclusions Bufland: Flordaguard ideal for sandy soils where ring is moderate, low chill and early cultivar. Cadaman and Atlas as alternatives. Viking if irrigation is good during summer months but risks. Too warm for SAPO 778, Penta and Tetra. Guardian?

14 Sandy soils Riverside, Simondium. Summertime on 9 rootstocks, 95.3% sand, ph 5.8. RCU 470. Short periods of high water tables. Two years harvest data. Area tree die-back (Sundew/Marianna). Moderate ring nematodes Best performance: Mr 2/5, Tetra, Kakamas, Penta and Krymsk 1 Die-back: SAPO 778 seedling 6/10, SAPO 778 clone 6/10, Cadaman 4/10, Viking 4/10. Rest of orchard on Flordaguard, only few trees died in whole orchard. Because of possibility of high water table Flordaguard and GF 776 was not included in trial. Analysis of trees show Leucostoma and Botryosphaeria Conditions at this site and pruning practises put trees under stress and predispose trees to opportunistic latent fungal diseases. Synchronisation of scion and rootstock (SAPO 778) may also play a role.

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16 Sandy soils. Elkana, Simondium. African Delight 93.4% sand, 5 harvest seasons, moderate/high ring, but treated regularly and Telone treatment before plant. High water table but drainage system and ridges. RCU 450. Best cumulative yield over 5 years Maridon but not sig better than Marianna, Flordaguard, SAPO 778 and Viking. No sig difference in fruit weight

17 Conclusions Sandy soils Flordaguard can handle high % sandy soil with moderate ring in low chill areas for early cultivars. Alternatives: Cadaman and Atlas Areas prone to fungal diseases and bacterial canker and where stresses occur use peach rootstock and not rootstocks with almond parent (Flordaguard? Guardian?). Maridon instead of Marianna. SAPO 778 synchronisation and almond? High water table: drainage and ridges. Marianna and Maridon best but need to treat for ring. More aggressive fruit thinning necessary than at Sonskyn. Flordaguard too risky. Viking and SAPO 778 only if no standing water.

18 Soils with between 50 and 70% sand. Normal ph. RCU Wakkerstroom, Bonnievale. Old grape land. High root lesion, low ring, 27% clay and silt, ph 6.4. Two harvest seasons Best performance in terms of yield and fruit weight: Kakamas, Garnem, GF 677. Atlas and Cadaman in between. Viking, Tetra and Penta poor performance Ripening: Kakamas few days ahead of Garnem. Atlas and Viking one week later than Kakamas. GF 677 over irrigated after plant. Many died of Botryosphaeria

19 Higher potential soils Timberlea, Stellenbosch. Summersun. 52% clay and silt, ph 6.5. Second harvest season. Severe brown rot due to rain. Low ring. Best performance in terms of yield and fruit weight: Atlas, Guardian. Followed by Viking, SAPO 778 seedling, SAPO 778 clone and Kakamas. Poor performance Flordaguard.

20 Higher potential soils, Stellenbosch. 58% clay and silt Sensation, Laetitia and Sunbreeze. One harvest season. Viking, Maridon, Marianna, Atlas and SAPO 778 seedling, Guardian good performers. Too early for any conclusions

21 Conclusion Higher potential soil Depending on the situation we have: Kakamas (soils with no limitations), Atlas, Viking, Maridon, Marianna, Garnem, Guardian (not very low chill)

22 Overall Conclusions High ph, High ring, sandy: GF 677, Cadaman, Atlas High ph, high pot soil, low ring: Atlas, Garnem, Viking, Cadaman, GF 677 High sand, god drained low chill, early cultivars, moderate ring: Flordaguard. As second alternatives: Cadaman and Atlas Areas prone to fungal and bacterial problems in sandy soils: Peach rootstocks better than peach/almond. Flordaguard and Guardian if no water risk, Maridon. Not GF 677 and SAPO 778 High water tables in winter/spring: Marianna/Maridon on ridges and soil drained. Treat for ring. Depending on situation: Kakamas, Atlas, Viking, Maridon, Marianna, Garnem, Guardian

23 PARENTAL BACGROUND AND CHARACTERISTS OF COMMERCIAL STONE FRUIT ROOTSTOCKS SEE TABLE 3

24 Things that need attention Propagation innovations to make live easier for nurserymen Nurseries specialising in specific rootstocks ARC rootstocks bred for ring tolerance need to go into the field Detailed integration of all information when more data on new rootstocks are available

25 THANK YOU END