H—29

Disease Control. —One of the main problems of disease control in Kerikeri orchards is the limited number of efficient spray outfits used by growers. The position is being improved as growers buy new equipment. At Kerikeri a severe outbreak of red mite was caused in citrus orchards by the application of D.D.T. sprays for the control of dicky rice weevil. The D.D.T. sprays had reduced the number of insects that prey on red mite. The Division now recommends that only the lower foliage of the trees should be sprayed with D.D.T. for the control of dicky rice weevil. The damage caused to citrus trees by citrus borer is still a serious problem to growers, as much time is used in finding and eradicating this infection. Older citrus trees are more liable to infection with citrus borer than young trees. Soft- and hard-wax scales are infecting many orchards at Kerikeri and are a problem to growers because sprays must be applied later than the optimum period for the control of other scales. No outbreak of citrus canker occurred in the main commercial citrus orchards in 1949. Steps have been taken to eradicate citrus canker infection found in a domestic garden on Great Barrier Island. Sour sap induced by poor soil drainage continues to take its toll of citrus trees near Auckland. Economic. —The production of citrus fruit in bushel cases in 1949 is estimated at: —

At Kerikeri a small factory has begun the manufacture of candied fruits, including citrus and sub-tropical fruits. Of the many problems in the citrus industry, the market prospects for New Zealand grapefruit in the future are causing most serious concern to growers because of the steadily increasing production of this fruit. Sub-tropical Fruits The growing of tree tomatoes, passion-fruit, feijoas, and Chinese gooseberries has proved commercially possible in North Auckland, near Auckland City, and in the Bay of Plenty district. There is no accurate information about the areas planted with these fruits, but the area in tree tomatoes and Chinese gooseberries has extended considerably since 1939. Feijoas are grown on a small scale in Auckland. Nearly all orchards at Kerikeri are planted with a mixture of citrus and sub-tropical fruits. Production in bushels of sub-tropical fruits in 1949 is estimated at: —

A factor limiting the production of passion-fruit has been lack of effective control of disease. It has been proved that disease can be controlled only by pruning and regular spraying at two-weekly intervals during the growing season. The two fungous diseases that seriously restrict production are passion-fruit grease-spot and passion-fruit leaf-spot.

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Kind of Fruit. Kaikohe. Auckland. Tauranga. Gisborne. Total. Meyer lemon Standard lemon New Zealand grapefruit Sweet orange 6,000 9,000 11,000 13,000 1,400 35,000 75,000 1,500 2,000 75,000 34,000 2,200 400 4,500 500 2,750 9,800 123,500 120,500 19,450

Kind of Fruit. Kaikohe. Auckland. Tauranga. Total. Passion-fruit Chinese gooseberries Tree tomatoes 2,500 350 4,000 1,600 400 5,000 4,000 3,500 2,000 8,100 4,250 11,000