Abstract
An experiment was conducted at the Teaching and Research farm of the Department of Crop Science, Faculty of Agriculture, University of Nigeria, Nsukka in the 2006 cropping season, to assess the effects of planting distance and organic manure rates on yield and nutrient composition of waterleaf at Nsukka. in Southeastern Nigeria. Treatments comprised five planting spacings and four manure rates. The planting spacings were 25cm x 10cm, 25cm x 15cm, 25cm x 20cm, 25cm x 25cm and 25cm x 30cm corresponding to 1,000,000; 444,444; 250,000; 160,000 and 111,111 plants per hectare, respectively. The manure rates were 0,10,20 and 30t/ha, and the nutrients were nitrogen (N), calcium (Ca), phosphorus (P), potassium (K), magnesium (Mg) and iron (Fe). Also vitamins A, B and C were investigated. All possible combinations of spacing and manure rates were laid out in a factorial arrangement using randomize complete block design in twenty treatment combinations per block, and there were three replications. The closest spacing of 25cm x 10cm gave the highest waterleaf vegetable yield, and yields generally decreased with progressive harvests. Yields tended to decrease with wider spacings. Vegetable yield was significantly lowest with where no manure was applied. Application of manure at 30t/ha significantly Yield higher than application of either 10t/ha or 20t/ha. Combination of organic manure at 30t/ha with 25cm x 10cm spacing gave the highest yield while combining manure at 30t/ha with the spacing of 25cm x 20cm followed in yield improvement. Marketable vegetable yield was significantly increased with successive increment in the manure rate. Where no manure was applied, yield was greatly depressed by over 58%. The dry matter yield of waterleaf decreased as the spacing increased with 25cm x 30cm spacing giving the lowest dry matter yield and the closest spacing of 25cm x 10cm giving the highest dry matter yield. The moisture content of the leaf was high all through the harvest periods being as high as 89% on the average. The ash content and fibre were low while fat was in trace quantity in the stem and in the inflorescence. Studies on the elemental content of the vegetable indicated that there are no significant effects of manuring on the Mg, Ca Fe and on the N, P and K contents of the leaf. There were no clear effects of manuring on the vitamins A, B and C in the leaf or in the stem or in the inflorescence fractions of the waterleaf vegetable.