Red, there are two items involved with your Meyer lemon. 1) It could well be the loss of leaves. Even though the tree has set new foliage, the new leaves are not yet generating any energy or nutrition, either to develop the fruit or to the benefit of the tree. A citrus leaf does not/cannot send out any energy or nutrition to the tree or fruit until the leaf become fully developed and mature. Therefore, the new foliage probably was of no help to the tree. 2). The tree spent much of its energy last year, by producing a extensive crop of 700 fruit, and was not able to re-supply itsef with enough energy to produce a full crop this year because of the loss of it leaves. - Millet