POTATO PRODUCTION BY ORGANIC FARMING 3 - EFFECT OF ORGANIC FERTILIZER AND WHEY ON PLANT GROWTH, YIELD AND TUBERS QUALITY CHARACTERISTICS

An experiment was carried out at the Vegetable Field of the College Agric, Abu - Ghraib, to study the effect of application of organic residues to the soil (poultry residues 0 , 10% of 20% , or cows residues) (WAV) and whey at concentrations 0 , 10% or 20% of irrigation water on growth , yield and tubers quality during the spring and autumn seasons (2006) . The design adopted was RCBD with three replicates. Results showed that application of organic residues 20% and 20% whey increased the number of stems, and the highest number of stems was 10.67 and 9.33, Plant when 20% of Poultry residues with 20% whey were used for both seasons, respectively. However, the best tuber's quality was found when 20% of cow or poultry residues with 10% of whey were used highest. The percentage of starch was 27.9% and 28.6% in spring season, while in fall season it was 30.8% and 31.7% for 20% of either residue source with 20% whey. Thus last treatment produced highest total yield (58.7and 66.0 ton. ka(-1)) and marketable yield (56.6 and 64.1 ton.ha(-1)) for spring season. Some treatments give highest yield (52.6 and 57.9 ton.ha(-1)) and marketable yield (51.5 and 55.8 ton.ha(-1)) for fall season as compared with the treatment yield ( 29.4 and 22.1 ton.ha(-1) ) and marketable yield ( 26.4 and 20.7 ton.ha(-1) ) for both control seasons, respectively. Significant increases occurred in fertilizer use efficiency and reached 123.9 and 161.0% in treatment 20% poultry residues with 20% Whey for both seasons, respectively. Tuber's Contents of amino acids was increased with increasing levels of either residue and the highest was in treatments of 20% (W/W) of both residue source and whey.