ACAI first harvest of the Cassava Intercropped with Sweet potato trials

ACAI first harvest of the Cassava Intercropped with Sweet potato trials

Four months after planting 102 trials for the Cassava intercropped with Sweet Potato (CIS) in the Islands of Unguja and Pemba, Zanzibar in the United republic of Tanzania, ACAI and implementing partners in Zanzibar, ZARI, has begun the harvest of potatoes from the trial fields.

Under the auspices of IITA, ZARI in collaboration with Farm Concern International, (FCI) will carry out the potato harvests from the 22nd of August into the second week of September 2017. The successful harvest will be the first CIS trials harvest in Zanzibar since the project began. The initial 2016 trials harvest was not carried out after bad weather conditions resulted stunted crop growth and hampered root as well as tuber formation.

ZARI’s head of Roots and Tuber research Dr Haji Saleh says the 2017 season has shown robust growth developing under better weather conditions.

“We are expecting to harvest something this season, based on visual evidence as opposed to the previous season.” Says Dr Saleh


when grown alongside sweet potatoes under different plant densities for the two crops in order to establish the optimum density for the intercropping, as well as observe the effect of additional nutrients, and the effect of different planting times in introduction of the sweet potatoes.

The trials were planted in varying the densities of sweet at high to lower density (10,000, 20,000 and 33,000). Planting periods were also spaced between planting the two crops simultaneously and introducing sweet potatoes at two weeks after planting (2WAP) the Cassava. Other treatments include fertiliser application to some plots and none for other plots in the same trials.

ACAI in partnership with ZARI set up 102 CIS trials at ZARI stations in Kizimbani on Unguja Island and Matangatwani on Pemba Island as well as in selected farmers’ field trials in both Islands. Sweet potato is a key cash and food crop for smallholder farmers in Zanzibar.

Dr Veronica NE Uzokwe, ACAI’s agronomist in Tanzania expresses optimism on the trial performance of the 2017 season trials.

“We are noticing that in cases where sweet potatoes were introduced later the plants look more robust and healthy than in cases where they were planted together.” Dr. Uzokwe

In both Unguja and Pemba districts of Zanzibar, sweet potato is the most commonly intercropped with cassava according to the report from the ACAI rapid characterization. Farmers in Zanzibar face scarcity of arable land, unfavorable and unstable weather conditions and pests as factors that compound to result in poor yields.

ACAI is developing a cassava intercropping decision support tool to prescribe the best planting times, period of introducing sweet potatoes in the cassava planted plots, the optimal density of intercropping and the appropriate fertilizer application.