Potato (Solanum Tuberosum) Variety and Cost Production Trial at Mount Wilton, Barbados A. Maynard MAFCA, Barbados V. Ojeda IICA, Barbados B. Clarke MAFCA, Barbados The potato originated in Peru and was used by the Incas. It was taken by Spanish explorers to Europe about 1540, where it became the major food in Ireland from 1600 to 1845. The potato is the only vegetable among the five principal world food crops (Splittstoesser, 1982). Most commercial potato crops belong to the species Solanum tuberosum. The tuber can be considered as part of the stem adapted to food storage and reproduction. The potato is not commonly cultivated in mid-elevation and lowland tropics, two regions where approximately one-third of the world's population is concentrated. Experimental crops grown in these regions have yielded up to 30 t/ha in 90 days (Midmore, 1983). The range of maturity for genotypes that initiate tubers under hot tropical conditions varies between 60 and 110 days (Midmore, CIP). In Barbados, work in potato research and production began in the late 1960's and was scattered through 1977. It was limited to variety screening trials, employing tuber seeds rather than botanical seeds as planting materials. As a result of the variety trials, 'Patronnes,' because of its good quality size tuber and high yielding potential, has been recommended to farmers for com- mercial production. Yields as high as 12 t/ha have been obtained by farmers. Francis Chandler, in 1978, obtained 15 t/ha under experimental conditions with the seeding rate of 2.5 t/ha. However, in warm tropical lowland areas such as in Peru, where research in all possible areas has been advanced and where highly developed agronomic techniques have been employed, yields averaging 24 t/ha, planted from botanical seed, have been obtained commercially. Also at La Romana and San Rafael del Yuma in the Dominican Republic (50m) potatoes are grown com- mercially. They are usually planted in November and December. This could be considered to be a major breakthrough, and offers much encouragement to countries like Barbados which have similar climatic conditions. Low yields and the high cost of production, seed cost being the major factor, have halted potato production in Barbados. There TABLE 1. Potato imports classified by percent of total imports of fruits and vegetables Barbados. FRUIT AND YEAR POTATO IMPORTS $ VEGETABLE IMPORTS $ % 1980 5,074.550 26,074.882 19.46 1981 5,200.166 28,546.715 18.22 1982 5,323.777 25,285.186 21.05 1983 5,627.900 22,971.479 23.31 1984 5,529.555 24,148.098 22.90 P= Projected 208 are at present no commercial plantings. This could also have been due to the lack of a more adaptable cultivar. The importation of potatoes into Barbados has increased over the past five years. Table 1 shows the comparative import figures of potato, fruits and vegetables between 1980 and 1983, and the projected figure for 1984. In December 1983, a variety trial involving ten varieties was conducted at Mount Wilton, Barbados. The main objectives of this trial were: 1. To evaluate the performance of these varieties under local climatic conditions; and 2. To carry out a cost analysis of potato production in order to support the government's efforts in promoting non-sugar, agricultural diversification in Barbados. MATERIALS AND METHODS The trial was located at Mount Wilton, St. Thomas, Barbados, with an elevation of approximately 300 m. This area is considered to be in the high rainfall area of Barbados, with an average around 1500mm/yr. The trial was planted December 28, 1983, and harvested 100 days later on April 6, 1984. Rainfall during that period amounted to 227mm. The land classified as "Red Soils of Barbados," on which the trial was carried out, was owned by Mr. Vernon Nicholls. The varieties planted from tuber seed screened were: 'Maris Piper,' 'Desiree,' 'Kerrs Pink,' 'Pentland Crown,' 'Pentland Hawk,' 'Maris Peer,' 'Arran Banner,' 'Arran Consul,' 'Home Guard,' and 'King Edward.' This material was generously sup- plied by Wallace Potato (UK) Ltd., imported from Northern Ireland, and was in satisfactory condition when planted. The experimental design was a completely randomised block with three replications. The size of each plot was 7.5m x 4.5m. The potatoes were planted by hand, on ridges, with a spacing of 75cm between rows and 45cm within the row, at a depth of 7cm. The land was disced, harrowed and the fertilizer 12:12:17-2 was applied at the rate of 1250 kg/ha and incorporated by fur- rowing. A top dressing of urea at 125 kg/ha was broadcast in two doses at around four and seven weeks after planting. The potato tuber seed was planted in two rows per bed on the furrow. Weed Control Gramoxone and Dacthal were applied at the rate of 2.35 kg/ha and 11.2 kg/ha respectively, preemergence. Two hand weedings and moldings (hillings) were carried out simultaneously at week four and eight. Pest and Disease Control Captan was used as a seed dip before planting. Rogor, Benlate and Kocide 605 were applied every 10-15 days up to three weeks before harvesting. In Table 6 are the rates and unit costs/ha. PROCEEDINGS of the CARIBBEAN FOOD CROPS SOCIETY-VOL. XX