-3- 



Although IcGG spcctaculr.r in its cffoct on the tree than 

 fire blight, pear poylla is undoubtedly the most drmaging pest of 

 pear trees in Massachusetts. It has put pear grovrers out of 

 business, and is responsible for much reduction in yield as ^7ell 

 as quality. In the writer's opinion, the situation calls for a 

 tightening up in the spray program. a more thorough application 

 of oil in spring before the eggs arc laid, \7ill help. A better 

 distribution and more gnllons per tree is a real need in many or- 

 chards. When v/c realize the lengthy succession of broods and the 

 importance of a.ctually hitting the insect rith the spray mn.tcrial, 

 we \7ill come nearer making a cleanup of the individuals present 

 each time v/e spray, knywmy, there is some consolation in knowing 

 that persistent efforts vrill greatly delay the "peak" of infesta- 

 tion. And this permits the foliage to function much more effi- 

 ciently with a higher yield, better size of fruit and better qual- 

 ity. 



Effect of Water Shortage on Nutrition of Fruit Trees 



In a paper on the Status of Orchard Soil Moisture Research, 

 J. R. Magness of the U. S. D. A. makes this statement, "The most 

 sensitive criterion of the moisture condition in fruit trees is 

 the number of stomata which open and the length of time they re- 

 main open. As more mA. more of the root zone reaches the v;ilting 

 percentage on lighter type soils or approaches it in heavy soils, 

 the rrte that moisture can bo cupplied to the tree decreases ac- 

 cordingly fjid the daily period during which the foliage and other 

 tree pnrts ore functi-ining also decrea<.ses. V/hen most of the root 

 zone has reached the wilting percentage, tissues of the tree fail 

 to become fully turgid even at night. Under these conditions, 

 stomata may fail to open in the morning, grovfth of fruit ceases, 

 and definite shrinkage of fruit may occur. Fortunately, even under 

 such conditions fruit trees growing in the open soil vrill survive 

 for considerable periods of time. Probably under these conditions 

 a few roots that have i^enctrrted deeply obtain v:ater at lc;\st in 

 sufficient quantities to prevent the death of the tree." 



The above statement comes very near describing a condition 

 in" many Massachusetts orchards. Small size of fruit, internal 

 breakdovrn, biennial bearing of Mcintosh, inferior quality and lo\7 

 yields are often associated v/ith a deficiency of water during the 

 growing season. 



Progress in Orchard Trenching 



Since the September issue of Fruit Notes orchard trenches 

 have been studied in the following orchards: Hampshire County 

 (M. S. C), Hampden County (Rice), Middlesex County (Drew, Saari), 

 Worcester County (Clemens, Davis, Trask, Charlton, Calkins, Lin- 

 coln). Additional work is now under way in the two latter coun- 

 ties, and in two orchards in Franklin County. 



Among the observa.tions of most interest care those relating 

 to subsoil and root distribution beneath trees affected by drought 

 spot as compared vrith normal trees in the same orchard. Four such 

 comparisons have been made and several others are contemplated. 



