H.—34.

The results thus indicate that the Sturmer can be maintained in very good condition in gasstorage up till December. The work requires confirmation and is therefore being continued. It is a highly significant fact that superficial scald, severe on the fruit cool-stored in air, was eliminated in storage atmospheres containing more than 3 per cent, of carbon dioxide. Fungous wastage was markedly retarded, and in atmospheres containing 9 per cent, of carbon dioxide was almost entirely suppressed. Effect of Fertilizers on Storage Quality. At the Research Orchard, studies of the effect of the manurial treatments applied to apples on the storage quality of the fruit have been continued, although the light crop in 1939 tended to increase the variability of the fruit available and so decrease the reliability of the results. The following summarizes the observations on the different varieties : — Cox's Orange Pippin.—Owing to the extremely light crop in this variety, it was not possible to obtain a sample of fruit for storage tests. Dunn's Favourite. —With this variety also a light crop interfered with the significance of the results. It was significant, however, that a heavy dressing of 4 lb. ammonium sulphate per tree, additional to a normal dressing of phosphate and potash, had induced a marked increase in susceptibility to breakdown in the fruit. Jonathan. —It was again found that in the " off " year of the variety, nitrogenous dressings increased the amount of breakdown and fungous disease, the increases being roughly proportional to the amount of nitrogen used. Nitrogen and potash both appeared to increase susceptibility to Jonathan-spot, although the degree of damage was very slight. Delicious.—All treatments have again been without effect on the storge quality of this variety. Sturmer.—A feature of the behaviour of the variety this season was the high percentage of wilting that occurred in most samples. As a generalization, it can be said that wilt and breakdown occurred in inverse ratio one to the other, and this fact tended to keep the percentage of sound fruit fairly constant throughout treatments. Fruit from trees receiving nitrogen alone was very subject to breakdown but resistant to wilt. Phosphate treatment induced a large amount of wilt but reduced breakdown as compared with the untreated controls. The skin mottling to which the variety is subject was markedly increased by both nitrogen and potash but was reduced by phosphate. Effect of Boron on Storage Quality of Apples. (a) Soil Dressings.—The adverse effect of rather large applications of hydrated borax on the storage quality of the Jonathan apple was noted, in the last annual report. Observations have been continued by the Cawthron Institute, and fruit from trees treated three years ago with 3 lb. borax per tree is still more subject to breakdown. Chemical analysis suggests that when the boron content of the fruit rises above 30 p.p.m. the storage quality of the fruit suffers. (b) Sprays.- Two applications of both 0-1 per cent, and 0-25 per cent, borax sprays were made on Cox's Orange, Jonathan, and Sturmer varieties. The boron content of the fruit was markedly increased, but the storage quality of the fruit was not significantly affected. Superficial Scald in Granny Smith Apples. The Horticulture Division of the Department of Agriculture made a further test of the influence of pre-storage factors on the development of superficial scald on the Granny Smith variety, but the results were rendered somewhat inconclusive by the relatively low incidence of scald even in the control samples. Fruit of a mid-April picking was almost free from scald, whereas some scald developed in fruit picked at the end of March. Delay between picking and storing did not have any consistent effect on the development of scald. Oiled wraps appeared to give some measure of control, more noticeable after the fruit had been out of store for a period. Deep Scald in Jonathan Apples. Tests at a number of different temperatures, singly and in combination, were made by the Horticulture Division to ascertain if lower temperatures could be used to check ripening of the Jonathan in storage without incurring damage from deep scald. In some sections of the experiment a period of four to eight days at a temperature of 40° F. preceded subsequent storage at lower temperatures, but the period at high temperature proved insufficient to eliminate scald. Further clear evidence was obtained that at the low temperature of 31° F. the Jonathan is extremely susceptible to deep scald. Fruit picked in the first week of March was less susceptible to scald than fruit picked in the last week of March, but early picking is not recommended in preference to a higher storage temperature as a means of controlling deep scald. Pre-cooling of Winter Cole Pears. Temperature measurements made by the Horticulture Division during the cooling of sixteen lots, each of fifty cases, of pears showed that the fall in temperature was more rapid when the fruit was placed loose in open cases than when packed up as for delivery to market. With a final holding temperature of 31° F. the unpacked fruit required approximately 72 hours to fall 36° F., whereas the packed fruit required approximately 108 hours to fall 34° F. The unpacked fruit was

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