Table 1. IRegression equations of marketable fruit yield vs electrical conductivities
 (and soluble salts, ppia) of soil solution for various harvest periods and
 soil sampling dates.



 electrical
 Soil conductivities
I"arvest s ling
period saling Cultivar Equationz mnilliros cr ? Significance

April Noveaber Der ver Y=88 + 190S 22S2 4.2 5830 0%

April February Dover Y=319 + 2343S 72032 1.6 2240 1%
Season February Tufts Y=12144 + 19928S 6143S2 1.6 2240 1%
April February Tufts Y=3030 + 8380S 24442 1.7 2380 1%
April Noverber Tufts Y=1788 + 667S 7632 5.0 7000 5%
April Noverber Clandler Y=6102 + 28032 4.0 5600 1%
.arch Novamber Chandler Y=4706 + 1460S 3.6 5040 1%
Season Noveiber Chandler Y=17123 +483S2 4.1 5740 5%
April January Chandler Y=7018 29S + 736S2 2.4 3360 1%


Z7= yield in Ib/ac, and S = electrical conductivities of saturated paste extract.

Electrical conductivities vwhici produced highest yields as determined by the equations and yet were still within
ranges represented by the data.
The optimrmi conductivities are valid only for a cultural system which applies all fertilizer prior to mulching
and a saturated paste extract is used. Also fertilizer nitrogen must be derived one-half each frao slow release
nitrogen fertilizer (sulfur coated urea, IBDU, osmocoate, etc) and one-half from soluble nitrogen sources (irO3,,
urea, S3' 4)2SO, etc).
 403' )2%