OIL-SPRAY TESTS AT ARATAKI

Bay of Plenty Times, Volume XLVI, Issue 7039, 15 July 1918, Page 4

OIL-SPRAY TESTS AT ARATAKI

An interesting set of expeiiments with oil sprays was carried out at the Arataki Horticultural Station during the past season. The objects in view were:—

(1) To ascertain the value of two applications of oil at a reduced strength, ono applied early and the other late in the dormant sea son, for the control of red mite and woolly aphis, as compared wiih the usual single dressing. (2) To ascertain, the strength of oil in either case most effective in the control of the infects mentioned : (3) To afcertain the value of oil sprays at a reduced strength applied at the cluster-bud and colour, bud stages, as compared with (1) and (2) for the same purpose : (4) To ascertain how late the spray could be applied without damage to fruit or foliage.

A detailed report of these experi ments has been furnished by the Manager of the station (Mr T. B. Rodda), but it is not intended to pub lieh the full results-until the tests have been extended over acother season. A few of the leading features, however, may be referred to provisionally.

In the case of the single oil application the experiment supported the recently accepted opinion that oil applied at a-lesser strength than 1 12 cannot be relied upon to destroy mussel scale or the eggs of red mite. The two weaker applications, although possibly of value in the case of woolly aphis, are of little value against red mite.

The application of 6 4-40 btrdeaux followed by oil 1 -25 and 1-30 at the cluster-bud and colour-bud stages resulted very satisfactorily for the control of black-spot and red mite, but when applied at the pink stage con eiderablo rasseting and loss of fruit resulted.

As the close-cluster, open-cluster, colour-bud and pink stages—terms used to mark different periods of spraying—are apt to be confused, the following definition of the terms by Mr Rodda may be of use to orchardists not fully conversant with cluster-bed spraying :- The fruit-bud, as the orehardist terms it, consist of an envelope or aae containing a number of diminutive buds which eventually give rise to a cluster of blossom 3 that later on de velop into fruit. When the sap starts to operate in spring the envelopes burst aDd expose the internal arrangement of tiny buds nestling closely together. That stage is known as the " close cluster," When ths buds have reached the stage when it is possible to see the upper portion of the stem of each bud-stalk the period is termed " open cluster." The third stage is "expanded cluster " —when the whole of the bud-stalks have drawn so far apart that every stalk can be traced to the base. The next stage is known as the " pink stage " —when each bud begins to burst and shows a faitt tinge of pink at the apex. The fifth stage is termed the "advanced pink"— when the buds are showing up like miniature pink balloons buc not actually opened out into flowers.— Journal of Agriculture.