-5- 



EFFECT OF lUIJG-ICIDS OK YIELD - (E. J. Rasmussen of the University of 

 Hot/ Hampshire presents the folloy.'in^ data as further evidence that the 

 continued use of lime sulfur reduces the yield of on apple orchard), 



A plot of lO-yiar-old Northern Spy trees at the Grsiiam Station 

 in Michigan ivhich had previously been sprayed for a nuiuber of years ^with 

 lime sulfur and v^hich v/as erratic in bearing, sometimes bearing only once 

 in three years, v;as divided into three plots. One plot was sprayed with 

 lime sulfur, another ^=;ith a wettable sulfur and the third with a proprietary 

 copper compound. These plots received the same treatment for 5 ysars, 

 1939-1944, 



Tho average annual yield for the 5 year period on the limo 

 sulfur plot T;as 442 bushels, on the v/ettable sulfur plot, 568 bush'vls, and 

 on the copper sprayed plot 673 bushels. The yield v-as closely related 

 to the amount of foliage on the tress. About September 1 xh"; lime sulfur 

 sprayed trees avn,raged 474 leaves per 100 spurs, tho v.-ettable sulfur 

 sprayed trees, G05, and the copper sprayed tr'^es, 643 leaves per 100 spurs. 



The increase in yield on tho plots sprayed v,ith a mild sulfur, 

 v;ettable sulfur, v.as 28 to 55^^ more than on the lime sulfur sprayed plot» 

 The copper sprays caused considerable russet on the fruit when used in 

 an all season spray program, and would not be satisfactory v/here fruit 

 v;as grcvvTi f^r the fresh fruit market. The information emphasires the 

 importance of testing pest control materials for purposes other than 

 for disease and insect control. 



Another Spider Invades Massachusetts Orchards . The 

 conimon red spider has recently been found in several 

 Middlesex County orchards. On infested trees, it 

 is usually more abmidant thrji the iCuropean red mite. 

 This pest has frequently been reported on apple 

 trees in Virginia and Nev/ York, but has not been 

 observed in large numbers on apples in Massachusetts 

 before this spring. 



Tho coTimon red spider spends the winter 

 as an adult in mulch or similar protection. 

 During cool spring weather they migrate to the 

 vmrmor, sunny places and may go into tress. They 

 feed on a great varioty of plcuits and durin^^ the 

 sumrAer are more abundant on such plants as clover, 

 alfalfa and chiclcweed, Y.'o do not anticipate any 

 significant daraage from them but suggest sprayi^ijlg 

 v;ith Dil-lll in mid- June, if necessary, 



liV, D, V/hitcomb 



