Cassava is a perennial crop that can adapt to periods of drought at different times in a growing season, which permits scheduling planting and harvest to develop production systems supplying roots continuously. However, farmers plant and harvest cassava at the onset of rains which creates glut and results in unattractive root prices. Thus, farmers need to understand how cassava varieties respond to different planting dates and crop ages at harvest to be able to use opportunities in income generation that may arise from flexible planting and harvest dates resulting from price and dry matter (DM) variabilities. Thus, this study was conducted to identify the best time to plant and harvest cassava for different varieties (TME419 and TMS581) and to determine the effect of fertilizer on root DM yields in three locations (Idi-Ose, Moniya and Ido) in Nigeria, over two years. The overall objective was to provide information to guide farmers on how to schedule planting and harvesting in Nigeria. The trials were conducted using a factorial split-split plot design. Effects of early, mid and late planting dates combined with harvest at 9, 11 and 13 months after planting (MAP) were tested. Fertilizer treatments included a control (F0) and applications of 75 kg N ha⁻¹, 20 kg P ha⁻¹ combined with 90 (F1), 135 (F2) and 180 (F3) kg K ha⁻¹. A root DM yield increase of 44.8% was observed when crop age increased from 9 to 11 MAP, and an increase of 13.1% when crop age increased from 11 to 13 MAP, indicating that delaying harvests does increase root DM yield across all planting dates. In contrast, root DM yield differences between planting dates were marginal, an increase of 8.1% was observed from early to mid-planting date and of 9.5% from early to late planting dates. Fertilizer treatments significantly interacted with location and the largest responses were observed at Ido. Fertilizer increased cassava root DM yields when compared with control at Ido by 15.38%, 23.1% and 16.7% in F1, F2 and F3, respectively. Responses were inconsistent at Moniya and Idi-Ose. With information on the effect of crop age and fertilizer, farmers could benefit from targeting seasons with shortage of cassava roots and high cassava prices, which would benefit processing industries securing year-round root supply.

木薯是一种多年生作物，可以适应生长季节不同时期的干旱时期，因此可以安排种植和收获，以发展持续供应根部的生产系统。然而，农民在降雨开始时种植和收获木薯，这会造成供应过剩并导致根茎价格不具吸引力。因此，农民需要了解木薯品种如何对不同的种植日期和收获时的作物年龄做出反应，以便能够利用可能因价格和干物质 (DM) 变化导致的灵活种植和收获日期而产生的创收机会。因此，本研究旨在确定不同品种（TME419 和 TMS581）种植和收获木薯的最佳时间，并确定肥料对三个位置（Idi-Ose、Moniya 和 Ido）在尼日利亚，两年多。总体目标是提供信息以指导农民如何安排尼日利亚的种植和收获。这些试验是使用因子裂区设计进行的。测试了早、中、晚种植日期以及种植后 9、11 和 13 个月 (MAP) 收获的影响。肥料处理包括对照 (F0) 和 75 kg N ha 的施用^-1 , 20 kg P ha ^-1结合 90 (F1), 135 (F2) 和 180 (F3) kg K ha ^-1. 当作物年龄从 9 MAP 增加到 11 MAP 时，观察到根干物质产量增加了 44.8%，当作物年龄从 11 MAP 增加到 13 MAP 时增加了 13.1%，表明延迟收获确实增加了所有种植日期的根干物质产量。相比之下，种植日期之间的根干物质产量差异很小，从种植早期到中期观察到增加了 8.1%，从种植早期到晚期增加了 9.5%。肥料处理与位置显着相互作用，在 Ido 观察到最大的反应。与 Ido 的对照相比，肥料在 F1、F2 和 F3 中分别使木薯根干物质产量增加了 15.38%、23.1% 和 16.7%。Moniya 和 Idi-Ose 的反应不一致。有了关于作物年龄和肥料影响的信息，