ISSN: 0041-3216

ISSN: 0041-3216 (Online), 0041-3216 (Print)
Volume 62 Number 3
Research Papers
The effect of time of planting on yield of six varieties of sweet potato (Ipomoea batatas (L.) Lam.) in the southern coastal lowlands of Papua New Guinea
Graham A. King
Six varieties of sweet potato were planted each month for twelve months in Papua New Guinea. Tuber yields were highest during the dry season and lowest during the wet season. Total tuber yield, tuber number per plant and mean tuber weight were significantly negatively correlated with total rainfall/irrigation (mm/5 months). Percentage marketable yield was positively correlated with total rainfall/irrigation. Tuber initiation and tuber bulking were both equally effected by high rainfall/irrigation. One variety gave significantly higher yields in the wet season than the other varieties. Further work is required to quantify the response of sweet potato to soil moisture and to identify varieties which give high yields in the wet season.
Keywords: Sweet potato; Ipomoea batatas; Planting time; Papua New Guinea