FRUIT. NOTES 

 January 27, 1954 



VJHY DO STR/a'JBEP.RY PLMTS FAIL TO M^KE RUNNERS? 



During the past few years strawberry growers have become increasingly aware 

 of the failure of many plants to grovr normally and produce a satisfactory number of 

 runners. This has been especially noticeable in certain parts of the state and with 

 certain varieties. In the Falmouth area there has been a great deal of trouble with 

 Howard 17. Midland has practically gone out of production because of its failure 

 to grow and produce runners. What is the reason for these failures which are becom- 

 ing far too frequent to be passed over lightly? 



Among a number of possible causes for failure to produce runners, two, virus 

 and black root, appear of first importance and should receive prompt and careful 

 attention. The first, virus, is probably the most important. As was pointed out in 

 November Fruit Notes, probably 99% of strawberry plants now in commercial production 

 are virus infected. IJhere virus-free plants have been compared with virus infected 

 plants, the superior runner production of the former has been little short of amazing. 

 The answer is virus-free plants, which are now available. 



The black root trouble is probably second only i^i virus in reducing runner 

 production. This disease may not only reduce growth and runner formation but also ■ 

 cause the death of both the mother and imnner plants. This trouble appears to be 

 associated with certain weather conditions and is, therefore, worse in some years 

 and in some places than in others. The cause of black root is not known, but mry 

 be related to the presence of nematodes in the roots. A discussion of black root 

 appeared in the November Fruit Notes. If nematodes are responsible, then soil fumi- 

 gation and nematode-free plants will be the solution. 



During the past few years dry periods during the summer seem to be increas- 

 ing in frequency. These dry spells certainly reduce the growth of strawberry plants 

 and may in themselves be a cause of reduced runner growth. However, it is strongly 

 suspected that the dry weather effect on the strawberry plant is much wor^e because 

 of the previous destruction of a portion of the root system by black root. In 

 other words, the dry weather gets blamed for what may be partly or even largely the 

 effects of blrck root. 



J 



There are a number of other possible causes for failure to nnke runners: 

 lac): of fertilizer, lack of soil organic matter, nutrient deficiencies, infestations 

 of insects and other diseases. At times one, or a combination of these, is unc.oubt- 

 edly responsible. However, their effects in Massachusetts have not been so wide- 

 spread as the effects of virus or black root. Certainly the effects of other trouble; 

 have been confused by the presence of virus and their remedy hojapered. In many in- 

 stances the some can probably be said of black root. One thing is certain. Until 

 these two troubles are corrected, good runner growth will be uncertain and it will 

 be very difficvilt, if not impossible, to sort out and appraise properly the effects 

 of tliese other causes for failure of strawbej-ry plrnts to make good lunner grouth, 



J, S. Bailey 



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