FRUIT CROP PEST UPDATES. Dr. Elina Coneva ACES, Auburn University

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1 FRUIT CROP PEST UPDATES Dr. Elina Coneva ACES, Auburn University

2 MAJOR PEACH PRODUCTION PROBLEMS Armillaria Root Rot Peach Tree Short Life (PTSL) Replant sites

3 MAJOR PEACH PRODUCTION PROBLEMS Armillaria root rot the number one cause of peach tree decline in the SE US ARR replaced the Peach tree Short Life (PTSL) as the main cause for premature tree decline after the implementation of PTSL resistant Guardian rootstock as a commercial peach rootstock in the Southeast Replant sites with a history of ARR are considered economically useless for peach production the longer peach trees are cultivated at a single location, the more inoculum infested root pieces are building up in the soil Many growers are using ARR infested sites for peach production

4 Armillaria Root Rot Fungal root rot disease Aboveground symptoms: failure to leaf out in the spring, loss of scaffold limbs, followed by tree dead, weaker tree with small leaves Belowground symptoms: White mycelium underneath the bark of the lower trunk and roots Infection of new roots occur through root to root contact via root grafts

5 Peach Tree Short Life (PTSL) PTSL is caused not by a single specific factor, but by a complex of cold damage and bacterial canker Other factors contributing to the PTSL complex: time of pruning, rootstock, fertilization practices, nematodes, orchard floor management, rapid fluctuations in late winter/early spring temperatures, and physical characteristics of the orchard site. Classical symptom sudden spring collapse of peach trees that were apparently healthy the previous fall Internal browning beneath the bark extended to the soil line Secondary infections of Cytospora canker are common

6 Peach Tree Short Life (PTSL)

7 Multistate Coop Project: Improving Economic and Environmental Sustainability in Tree Fruit Production Through Changes in Rootstock Use Redhaven/ 14 peach rootstocks Size control for higher efficiency Armillaria root rot resistance Bacterial canker and PTSL Resistance Site with a history of ARR

8 PEACH ROOTSTOCK TRIAL, 2009 Rootstocks included in the 2009 NC 140 Peach Rootstock Trial planted at the CREC, Clanton, 2009 Vigor (relative to Rootstock Genetics Source Origin Lovell) Lovell Peach CA USA CA 100% Guardian Peach UDSA Clemson USA SC 100% HBOK 10 Peach UC Davis, CA USA CA 65% HBOK 32 Peach UC Davis, CA USA CA 65% KV Peach USDA, Kearneysville USA WV? KV Peach USDA, Kearneysville USA WV? Controller 5 Japanese Plum X Peach UC Davis, CA USA CA 65% Krymsk 86 Myrobolan Plum X Peach Krymsk Res. St. Russia 100% Krymsk 1 Nankin Cherry X Myrobolan Plum Krymsk Res. St. Russia 60% Bright's Hybrid #5 (BH 5) Almond X Peach Bright's Nursery USA CA 100% Mirobac Myrobolan Plum X Almond Agromillora Catalana Spain? Atlas Peach X Almond X Flowering Plum Zaiger's Genetics USA CA 110% Viking Peach X Almond X Flowering Plum Zaiger's Genetics USA CA 110%

9 PEACH TREE GROWTH, 06/17/2011 HBOK 10 65% Viking 110%

10 PEACH ROOTSTOCK SURVIVAL, 2012 One HBOK 32 tree dead in 2009 No additional trees died in 2010 One tree of Krymsk 1 and Empyrean died in 2011 Fourteen dead trees (12.5%) in spring of 2012: 7 trees (88%) Mirobac (Myrobolan Plum X Almond) 5 trees (63%) Krymsk 1 (Nankin Cherry X Myrobolan Plum) 2 trees (25%) Empyrean (P. persica X P. davidiana)

11 Armillaria Root Rot February and March 2012 samples submitted to the AU Plant Diagnostic Lab: Peach trees grafted on Krymsk 1 and Empyrean died in 2011: Both trees had Armillaria root rot growing in the tissue, abundant under the bark and in the roots Phytophthora infection was also evident

12 Armillaria Root Rot Resistant Rootstocks Sharpe and MP 29 (USDA Byron GA) have shown good resistance/tolerance in limited trials in Georgia, US. Both are plum hybrids with plum or peach SAM 1 and SAM 2 (Progressive Genetics Group, CA) both are almond hybrids Densipac Rootpac 20 (Agromillora Iberica, Spain) Zee Stem interstem (Zaiger Genetics) on Myrobolan stock (Dr. Greg Reighard, Clemson University)

13 Aboveground Root Collar Excavation for ARR Management Root collar excavation for ARR control in citrus and grape Above ground root collar excavation is effective for managing ARR in peach orchards Proof of concept that the system may be useful in commercial peach orchards infested with ARR Eliminating the difficulty of excavating root collars below ground level Eliminating the need for repeated soil removal The AG RCE treatment showed dramatic reduction in ARR related peach tree decline Schnabel, G., Agudelo, P., Henderson, G. W., and Rollins, P. A Aboveground root collar excavation of peach trees for Armillaria root rot management. Plant Dis. 96:

14 Peach Tree Short Life (PTSL) March 2012: Microbac peach tree suddenly collapsed: sample showing large cankers on the scaffold limbs Leucostoma canker (Cytospora canker), associated with Peach Tree Short Life (PTSL) The trees seemed dead when they were brought in, but shortly thereafter they sprouted back out from the base a typical PTSL symptom Botryosphaeria was also isolated from these cankers; Botryosphaeria is associated with weak tissue as usually enters through wounds The root and crown tissue tested negative for Phytophthora and there was no evidence of Armillaria beneath the bark

15 Ring Nematode Soil samples from declining peach tree grafted on Mirobac rootstock showed very high ring nematode populations

16 Peach Tree Short Life (PTSL) Tolerance Guardian excellent Viking excellent MP-29 excellent Sharpe - moderate

17 Ring Nematode Resistant Rootstocks Guardian and Viking good tolerance HBOK 50 (Controller 9.5) tolerance in early trials Sharpe & MP 29 likely tolerant P. pumila (Pumiselect ) and P. besseyi are poor nematode hosts

18 Blueberry Pests Mummy berry fungus Monilinia vacciniicorymbosi Can infect flowers, and fruit and shoots/leaves Early detection and control is necessary to reduce the impact The earliest symptoms: drooping of developing leaves followed by browning of the upper side of bent shoots, midribs and lateral veins of leaves As normal berries ripen, the infected berries begin to shrivel and turn a pinkish color

19 Blueberry Pests Mummy Berry Control : An IPM program: cultural and chemical control strategies for best results For new orchards, select resistant varieties or late blooming cultivars Avoid wet sites to reduce conditions that favor mummy berry development Remove or destroy infected fruit at the end of the harvest season; covering mummies with at least 2 of soil or mulch Limit or delay overhead irrigation until petal fall during the growing season Follow a fungicide spray program from green tip until petal fall Southeast Regional Blueberry Integrated Management Guide: rrysprayguide.pdf

20 Blueberry Pests Blueberry stem blight Botryosphaeria dothidea The primary disease limiting establishment of blueberry plantings Enters the plant through wounds and causes rapid death of individual canes and entire bushes Especially severe on 1 and 2 yr old plantings of susceptible cultivars The most obvious symptom is called 'flagging A stem blight infected stem will have a light brown discoloration in the wood extending down the infected side of the stem

21 Management Cultural methods: Fungicidal chemicals do not provide adequate protection Pruning to remove infected stems Pruning can be done anytime infected stems are observed Cut well below the infected area Site selection directly related to the disease severity Extremely sandy soils poor growth Heavy pruning to promote rapid growth should be avoided in 1 to 2 yr old plantings

22 Grape Pests Botrytis Bunch Rot fungus Botrytis cinerea Infects grape shoots, flowers, leaves and fruit Early season shoot blight occurs following frequent spring rains Botrytis causes premature cluster drop

23 Management During the growing season: Avoid overhead irrigation Canopy management: shoot thinning and leaf removal will reduce botrytis bunch rot In warm AL climate, avoid removing excessive numbers of leaves: sunburned fruit During the dormant season: Remove mummified fruit and infected prunings and cover with soil (or burn) Chemical control: Southern Region Small Fruit Consortium IPM Guide:

24 Grape Pests Anthracnose fungus Elsinoe ampelina Most common on young shoots and fruit Lesions on shoots and leaves are sunken with a reddish appearance On leaves, the centers of the lesions can fall out, producing a "shot hole" appearance On fruit, lesions may be sunken and reddish black

25 Management Cultural Management Options: Sanitation is extremely important Remove old and infected plant material Dormant pruning and destruction of old canes and clusters Canopy management during the season to increase airflow Chemical Management Options: Apply lime sulfur sprays during the dormant season Fungicide sprays every 10 to 14 days from bud break until veraison

26 SWD IDENTIFICATION Male Female Black spot on wings 2 black combs on front legs She inserts saw like Device (ovipositor) into fruits and lays eggs

27 Integrated Management of SWD Monitor orchard and surrounding area with traps Sample fruit for infestation Consider post harvest clean up spray to reduce population Stay informed

28 THANK YOU!