From June 2005 till June 2007 different soil preparation techniques like chiselling and advance sowing of medicinal plants and green manuring were proofed for their influence on reducing plant losses of strawberries caused by root diseases like Phytophthora species and Verticillium dahliae. The variants were combined with potted plants and Frigos. The experiment took place on an organic fruit farm near Stuttgart, Germany, with the strawberry variety ´Elsanta´.

Focused on root diseases, habit and yield chiselling combined with Frigos and green manuring combined with potted plants showed the best results. Generally the marketable yield was often below yields from conventional cultivation.

This project is granted by Bundesprogramm Ökologischer Landbau (BÖL, FKZ 03OE087: 2004-2006, FKZ 06OE221: 2007-2009). It includes also experiments about cutting techniques at raspberries, plant protection at black- and gooseberries and weed control at blueberries and black currants. The part of weed control is carried out by ÖON Jork (Germany)

Eis, Birgit

Leona, Brockamp

English

Organic Eprints

148Influence of different soil preparation techniques on organically grown strawberries Brockamp, Leona1; Eis, Birgit 1AbstractFrom  June  2005  till  June  2007  different  soil  preparation  techniques  like  chiselling  and advance sowing of medicinal plants and green manuring were proofed for their influence on  reducing  plant  losses  of  strawberries  caused  by  root  diseases  like  Phytophthora species  and  Verticillium  dahliae.  The  variants  were  combined  with  potted  plants  and Frigos. The experiment took place on an organic fruit farm near Stuttgart, Germany, with the strawberry variety ´Elsanta´.Focused  on  root  diseases,  habit  and  yield  chiselling  combined  with  Frigos  and  green manuring combined with potted plants showed the best results. Generally the marketable yield was often below yields from conventional cultivation. This project is granted by Bundesprogramm Ökologischer Landbau (BÖL, Nr: 03OE087: 2004-2006,  Nr.  06OE221:  2007-2009).  It  includes  also  experiments  about  cutting techniques at raspberries, plant protection at black- and gooseberries and weed control at blueberries  and  black  currants.  The  part  of  weed  control  is  carried  out  by  ÖON  Jork (Germany).  Keywords:  Strawberry,  organic  orchards,  root  diseases,  soil  preparation  techniques, green manuring IntroductionRoot  diseases  on  strawberry  plants  are  specially  found  in  areas  with  heavy  soil (SCHERER, 1989). Stagnant moisture, soil compaction, nematodes and soil exhaustion support  presence  of  Phytophthora  sp..  Therefore  fruit  growers  have  to  take  care  of  a proper soil preparation to guarantee optimal soil conditions for strawberries.The influence of different green manuring plants on the infestation of root diseases and nematodes  were  described  by  KRÜGER  (1996).  Also  KREBS  and  FORRER  (2001) reduced late blight of potatoes with different medicinal plants like mallow or sage (dried plants as addition to the potting substrate).The experiment also includes a comparison between Frigos and potted plants. Organic fruit  growers  prefer  Frigos  as  planting  stock  although  there  were  considerable  quality problems  in  the  past.  One  great  problem  is  the  special  sensitiveness  towards Phytophthora cactorum. Frigos are more sensitive than potted plants (SCHERER, 1989).The  experiment  should  result  in  new  findings  transfered  into  recommendations  for  the practical use in organic cultivation of strawberries.1 LVWO Weinsberg, Traubenplatz 5, 74189 Weinsberg, Germany, leona.brockamp@lvwo.bwl.deArchived at http://orgprints.org/13662/149Influence of different soil preparation techniques on organically grown strawberries Brockamp, Leona1; Eis, Birgit 1AbstractFrom  June  2005  till  June  2007  different  soil  preparation  techniques  like  chiselling  and advance sowing of medicinal plants and green manuring were proofed for their influence on  reducing  plant  losses  of  strawberries  caused  by  root  diseases  like  Phytophthora species  and  Verticillium  dahliae.  The  variants  were  combined  with  potted  plants  and Frigos. The experiment took place on an organic fruit farm near Stuttgart, Germany, with the strawberry variety ´Elsanta´.Focused  on  root  diseases,  habit  and  yield  chiselling  combined  with  Frigos  and  green manuring combined with potted plants showed the best results. Generally the marketable yield was often below yields from conventional cultivation. This project is granted by Bundesprogramm Ökologischer Landbau (BÖL, Nr: 03OE087: 2004-2006,  Nr.  06OE221:  2007-2009).  It  includes  also  experiments  about  cutting techniques at raspberries, plant protection at black- and gooseberries and weed control at blueberries  and  black  currants.  The  part  of  weed  control  is  carried  out  by  ÖON  Jork (Germany).  Keywords:  Strawberry,  organic  orchards,  root  diseases,  soil  preparation  techniques, green manuring IntroductionRoot  diseases  on  strawberry  plants  are  specially  found  in  areas  with  heavy  soil (SCHERER, 1989). Stagnant moisture, soil compaction, nematodes and soil exhaustion support  presence  of  Phytophthora  sp..  Therefore  fruit  growers  have  to  take  care  of  a proper soil preparation to guarantee optimal soil conditions for strawberries.The influence of different green manuring plants on the infestation of root diseases and nematodes  were  described  by  KRÜGER  (1996).  Also  KREBS  and  FORRER  (2001) reduced late blight of potatoes with different medicinal plants like mallow or sage (dried plants as addition to the potting substrate).The experiment also includes a comparison between Frigos and potted plants. Organic fruit  growers  prefer  Frigos  as  planting  stock  although  there  were  considerable  quality problems  in  the  past.  One  great  problem  is  the  special  sensitiveness  towards Phytophthora cactorum. Frigos are more sensitive than potted plants (SCHERER, 1989).The  experiment  should  result  in  new  findings  transfered  into  recommendations  for  the practical use in organic cultivation of strawberries.1 LVWO Weinsberg, Traubenplatz 5, 74189 Weinsberg, Germany, leona.brockamp@lvwo.bwl.deMaterial and methods The experiment took place at an organic fruit farm near Stuttgart. Apart from the controls there were the following four variants: “Chiselling + Frigos”, “Chiselling + potted plants”, “Malva sylvestris + potted plants” and “Green manuring + potted plants” (tab. 1). Potted plants control couldn’t be continued in 2007 caused by an apple replanting.    Table 1: Combinations 2005 - 2007 Variant  Soil preparation 2005  Planting stock  Planting date 1  Control  Frigoplants  03.06.05 2  Chiselling  Frigoplants  03.06.05 3  Control   Potted plants  19.08.05 4  Chiselling   Potted plants  19.08.05 5  Sowing of Malva sylvestris  Potted plants  19.08.05 6  Sowing of Green manuring   Potted plants  19.08.05 Four rows with 33 strawberry plants of the variety ´Elsanta´ were planted per variant, with a  distance  of  0,30  m  x  1,00  m.  The  Frigos  and  potted  plants  had  been  propagated organically but not by the same growers. In the year 2006 a number of 25 uniform plants were chosen per variant, without repetition. In the year 2007 three repetitions per variant were set up with 15 equal plants per repetition.The medicinal plant Malva sylvestris (4 kg/ha) and the green manuring (190 kg/ha) were sawn in the middle of April 2005. The green manuring consisted of broads, pease, vetches and cereal. The chiselling with a depth of 0,5 m at the beginning of June 2005 was done shortly  before  the  planting  of  the  Frigos.  After  the  incorporation  of  mallows  and  green manuring the potted plants could be placed in the field by mid of August 2005.  In the harvest years 2006 and 2007 the yield, fruit size and fruit damage like botrytis blight, sunburn, leather rot and deformation were evaluated. Furthermore there was a monitoring of habit, foliage diseases and plant losses. Two times per growing period the habit from each strawberry plant was evaluated with a grade from one to nine. One means “small plant”, nine means “vigorous plant”. The plants were also checked two times per growing period for leaf scorch of strawberry, powdery mildew and strawberry leaf spot. Each parcel was evaluated by grades from one to nine. One means “without infestation”, nine means “strong infestation”. The plant losses caused by V. dahliae and Phytophthora sp. were counted per variant.Results and discussionDuring the years 2006 and 2007 the combination “Chiselling + Frigos” showed the best results. Caused by the early planting date the Frigos had the advantage of being ahead in growing for eleven weeks showing a vigorous habit. In November 2005 for example Frigos had an average grade of 6 while potted plants were valuated with grade 3. This trend continued in 2006 ( Frigos: grade 8, potted plants: grade 4). The plant losses by root diseases were low while small potted plants showed infections with strawberry black root rot. Furthermore this combination reached the highest marketable yield in 2006 and 2007 with 320 g per plant (approx. 9 t/ha) each year.Archived at http://orgprints.org/13662/150The best potted plant variant was “green manuring”. Infection with strawberry black root rot was  very  low  and  the  plants  showed  a  good  habit.  Potted  plants  had  also  a  lower infestation with strawberry leaf spot than the Frigos. The early planting date of the Frigos forced the infection with foliage diseases.  Powdery mildew and leaf scorch of strawberry couldn´t be observed. The marketable yield from the green manuring was given with 200 g per plant in 2006 and 160 g per plant in 2007.Figure 1 and 2 show the total yield of ´Elsanta´ in the year 2006 and 2007 divided into marketable yield and fruit losses.Yield data 'Elsanta' 20060100200300400500600700ControlFrigoplantsChisellingFrigoplantsChiselling pottedplantsGreen manuringpotted plantsMalva sylvestrispotted plantsgram/plantfruit lossesmarketable yieldFigure 1: Total yield of ´Elsanta´ influenced by soil preparation technique and type of planting stock      in 2006 Yield data 'Elsanta' 20070100200300400500600700ControlFrigoplantsChisellingFrigoplantsChiselling pottedplantsGreen manuringpotted plantsMalva sylvestrispotted plantsgram/plantfruit lossesmarketable yieldbaaabab abbbbFigure 2: Total yield of ´Elsanta´ influenced by soil preparation technique and type of planting stock      in 2007 (Tukey Test for fruit losses and marketable yield, � = 0,05)Archived at http://orgprints.org/13662/151The  marketable  yield  includes fruit  sizes  >  30  mm  and  >  25  mm.  Fruit  damages  like botrytis blight, sunburn, leather rot or deformation and small fruits (< 25 mm, < 22 mm) were  counted  as  fruit  losses.  In  the  year  2006  the  fruit  loss  mainly  consisted  of deformation (11%) and feeding damages (14%). The infestation with Botrytis cinerea was very low (1%). The year 2007 instead showed a higher percentage of fruit losses. On the one hand there was  an  increase  of  small  not  marketable  fruits  (20  %)  which  is  typical  for  the  second harvest year. On the other hand supported warm and humid weather in the middle and at the end of harvest the presence of B. cinerea (4 %). Snails caused an additional damage of 20%.The  combinations  “Chiselling  +  potted  plants”  and  “Malva  sylvestris  +  potted  plants” couldn’t satisfy because of low marketable yield, weakly habit and many plant losses.  An examination of plants showed that the most losses weren’t caused by Phytophthora sp. as initially expected but by Verticillium dahliae initiated by arid weather in spring and at the beginning of harvest. This result allows new ways of controlling, for example inoculation of plants with a mixture of Verticillium genotypes (Leibniz-Zentrum for Agrarian Landscape Research) and Biofumigation.  Looking  at  the  described  results  an  optimal  combination  could  be  “Green  manuring  + Frigos”. But before this can be given as recommendation for the practical use it first should be tested in additional experiments. At least one soil preparation technique should become a  standard  in  every  organic  fruit  farm.  Application  of  tillage  implements  against  soil compaction or advance sowing of green manuring have a fundamental positive influence on the soil structure. This results finally into positive effects for habit, disease susceptibility and yield of strawberry plants.If the fruit grower choose an advance sowing he had to consider that plants like clover, lucern,  phacelia  and  potatoes  support  the  presence  of  nematodes  (MICHEL,  2007). Instead Cereals and Tagetes erecta / patula for example can be used against nematodes reducing potential infestation with V. dahliae (KRÜGER, 1996). Acknowledgements This project is granted by Budesprogramm Ökologischer Landbau (BÖL, Nr. 06OE221). References Krebs, H. and Forrer, H.R. (2001): Wirkung von Medizinalpflanzen im Kartoffelbau.    AGRARForschung 8 (11-12): 470-475 Krüger, E. (1996): Geeignete Anbaumaßnahmen und Vorfrüchte können Wachstum und     Ertrag der Erdbeere fördern. Öko-Obstbau 1/96: 17-24 Michel, V. (2007): Handbuch Beeren. Schweizer Obstverband in Zusammenarbeit mit     ACW, FiBL und Agridea Scherer, W. (1989): Schäden an Erdbeeren. Scherer-Verlag Augsburg Archived at http://orgprints.org/13662/

Influence of different soil preparation techniques on organically grown strawberries

Abstract

Similar works

Full text

Available Versions

Organic Eprints