ANSWERS TO INQUIRIES.

New Zealand Journal of Agriculture, Volume XXXVI, Issue 1, 20 January 1928, Page 71

ANSWERS TO INQUIRIES.

IN order to ensure reply to questions, correspondents must give their name and address, not necessarily for publication, but as a guarantee of good faith. Letters should be addressed to the Editor.

SPARTINA GRASS.

C. J. Claasen, Rawene : —•

I enclose cutting from an English paper regarding rice-grass {Spartina Townsendii) and would be glad of an opinion on same. Is the grass on the market anywhere in New Zealand, and has it been tried out anywhere here ? Do you know if it would be of any use trying to grow it on the heavy mangrove flats of Hokianga Harbour ? Has it any feeding-value for stock, and would it be inclined to spread too much ?

The Fields Division :• —•

Spartina Townsendii, also known as rice-grass, has been grown in a few places in New Zealand, but we are not certain whether you can buy roots of the grass on the market. It would be a useful experiment for you to try it on the heavy mangrove flats of Hokianga Harbour. ' You should' sow it on the upper tidal zone ; it grows best in the soft mud of the flats. Some roots were distributed from Auckland in 1925. A settler, Mr. A. Glyn Fell, of Waihutu, Opononi, who tried some, reported that , the roots spread and were quite vigorous-looking, appearing in little clumps, and he saved some seed. Some roots were also tried at Onerahi, Whangarei Harbour. Mr. K. W. Dalrymple, Bull’s (Lower Rangitikei), introduced some plants in 1913, and reported in 1925 that the plants were spreading fairly rapidly, but were slow at first. The grass had collected the mud about itself where it was first planted about twelve years ago. He further remarked that the level was some 2 ft. higher and almost above ordinary tidal level. The evidence we have in New Zealand is too slender yet for any definite opinion to be passed on this grass ; experiment will have to be carried further. In England, where they have had over fifty years’ experience with Spartina, they do not appear to have decided its value as a forage, but suggest that it may be profitably used for grazing stock, for litter, hay-making, or for the manufacture of paper. One report from Poole Harbour shows that cattle go down to the marshes and eat the plant. It spreads fairly slowly,' judging by the experience we have had in New Zealand,' and it does not appear that it would become a nuisance, except where it might detrimentally affect navigation in tidal rivers. Spartina Townsendii may be (and has already been) confused with Canadian wild rice or rice-grass {Zizania aquatica Linn.) found on the Northern Wairoa River. ' This resembles raupo, and is regarded by settlers fronting the river as a pest. For further information you are referred to the N.Z. Journal of Science and Technology, Vol. 7, No. 4 (1924), “ Spartina Grass and its Introduction into New Zealand,” by H. H. Allan.

DISEASED LEMON-TREES.

W. 8., Pukekohe :—■

I have two lemon-trees that lost their leaves, with dropping of the fruit. The fruit showed a soft spot on the side, and turned bad if not destroyed by burning or otherwise. Could you advise me what to do under the circumstances ?

The Horticulture Division -

The description given of the condition of the lemon-trees is not sufficient to definitely determine the cause of the trouble. It is very possibly caused by lemon brown-rot fungus {Pythiacy stis. citrophthora},__yvhich browns the leaves and causes them to fall, and gradually turns the fruit into a soft spongy condition with a light buff colour. Thia disease is best dealt with by collecting affected fruit at short intervals and destroying it, pruning • the trees so that the bottom branches are 2 ft. to 3 ft. up off the ground, and cutting out all dead and affected wood and burning it. As the greatest danger exists in wet weather, when spores

are produced on infected fragments lying on the ground, it is desirable at such seasons to grow a cover-crop to prevent the distribution of spores by rain-splashes. One or two bordeaux sprays, 4—4-40, when the blossoms fall in spring and autumn, will also assist in a large measure to keep the trees in good health.