Review of Various Harvesting Options for Cassava

Harvesting plays a critical role in the cassava production value chain. A review of some existing cassava harvesting options is necessary to facilitate the proper adaption and uptake of improved harvesting methods applicable to farmers from different parts of the globe. In terms of capacity, manual, semi-manual and fully mechanised harvesting options respectively require about 22–51 man-hha-1, 16-45 man-hha-1 and 1–4 man-hha-1. An added advantage with mechanised options is that the field is left ploughed after harvesting with savings on fuel, time and cost. Mechanised harvesters work best on ridged fields with minimal trash or weeds and relatively dry soils (12–16% d.b. moisture content). Earlier attempts at mechanised harvesting have been affected by constraints such as soil characteristics, nature and size of tubers, depth and width of cluster and bond between tubers and the soil, leading to high tuber damage. Though less research attention is given to cassava harvesting mechanisation, that aspect of the global cassava transformation agenda has always been the problem. There is still room for improvement in the provision of appropriate harvesting options for cassava worldwide and a more concerted effort from both the government and private sector is vital

Comparative evaluation of manual cassava harvesting techniques in Kerala, India

Abstract: In India, cassava is consumed as a secondary staple along with the main staple, rice, and many rural poor consume it as the staple in different forms of preparations.  Though harvesting is known to be one of the most difficult and cost-intensive field operation in cassava cultivation, mechanisation of cassava harvesting is still very low in most cassava growing areas of India due to topographic constraints, methods and scale of cultivation.  The most viable solution to overcome these constraints is to promote the use of more efficient manual harvesting tools.  Thus, the main objective of this study was to field evaluate the efficiency of four manual cassava harvesting techniques under different land preparation methods in terms of field capacity, level of drudgery and root tuber damage or breakage.  The study also sought to investigate the effect of cassava agronomic parameters on uprooting force requirement.  Field study was carried out at the Central Tuber Crops Research Institute (CTCRI) research field (under upland mound method) and at Chenkal village on farmers’ fields (under lowland flat method); both in the Kerala state of India.  Harvesting was done using the CTCRI lever, prototype harvester, hoe and manual uprooting (control) techniques. Results from the study showed that the use of manual harvesting tools is preferable on relatively dryer soils, whereas manual uprooting technique is best suited for soils with relatively higher moisture contents.  However, best efficiency of manual harvesting is achieved when cassava plants are coppiced before harvesting.  Also, cassava uprooting force requirement, to a greater extent is influenced by root tuber yield, root depth and number of root tubers per plant, especially under upland mound land preparation method.  It is however recommended that a user performance assessment and economic feasibility analysis of the prototype harvester and CTCRI lever be conducted with farmers to facilitate future design modifications, where necessary and to support future adoption.  As a design recommendation, the pressure at the fulcrum for both the CTCRI lever and prototype harvester should be reduced to avoid sinking during harvesting in soils with relatively higher moisture contents.   Keywords: cassava, field capacity, drudgery, coppiced, efficienc

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Not AvailableA study was conducted to develop optimal irrigation schedules and crop water production function for cassava in the three major growing areas of India, viz., Salem (Tamil Nadu), Thiruvananthapuram (Kerala), and West Godavari (Andhra Pradesh). The irrigation schedules and water requirements weresimulated using CROPWAT, and the model result was verified with field values in Thiruvananthapuram, one of the study areas. The results indicated the wider applicability of CROPWAT in calculating water requirement as well as developing irrigation schedules for cassava irrespective of the agro-climatic conditions. The optimal gross irrigation requirement simulated by CROPWAT was 362, 610, and 703 mm in Thiruvananthapuram, West Godavari, and Salem, respectively, based on the soil, crop and climatic parameters.The optimal schedules were also developed in the study locations using CROPWAT, and it can be used for further irrigation practices and plans to maximize water productivity. Also, the field experimental data in Thiruvananthapuram showed a quadratic relation between crop water requirement and yield (R = 0.86).The derived crop water production function (CWPF), provided yield of 39 × 10 kg ha of cassava corresponding to the simulated gross irrigation requirement of 362 mm in Thiruvananthapuram. Thus the CWPF together with the optimal schedules is a useful tool for water managers and farmers to develop appropriate irrigation plans in advance to mitigate the water scarcity as the result of climate change 1✉ 1 The results indicated the wider applicability of CROPWAT in calculating water requirement as well as developing irrigation schedules for cassava irrespective of the agro-climatic conditions. The optimal gross irrigation requirement simulated by CROPWAT was 362, 610, and 703 mm in Thiruvananthapuram, West Godavari, and Salem, respectively, based on the soil, crop and climatic parameters. The optimal schedules were also developed in the study locations using CROPWAT, and it can be used for further irrigation practices and plans to maximize water productivity. Also, the field experimental data in Thiruvananthapuram showed a quadratic relation between crop water requirement and yield (R = 0.86). The derived crop water production function (CWPF), provided yield of 39 × 103 kg ha of cassava corresponding to the simulated gross irrigation requirement of 362 mm in Thiruvananthapuram. Thus the CWPF together with the optimal schedules is a useful tool for water managers and farmers to develop appropriate irrigation plans in advance to mitigate the water scarcityas aresult of climate change.Not Availabl

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Not AvailableThere is a preference for organic vegetables, including Chinese potato [Plectranthus rotundifolius (Poir.) Spreng. or Solenostemon rotundifolius (Poir.) J.K. Morton], due to concerns regarding plant health, safe food, and sustainable yields. However, organic technologies in this crop is lacking. Comparison of crop growth, biomass production, yield, quality, soil properties, nutrient uptake, and cost-benefit analysis between organic and conventional systems in Chinese potato has not been thoroughly investigated. Field experiments were done from 2014 to 2016 at the Indian Council of Agricultural Research-Central Tuber Crops Research Institute, Thiruvananthapuram, India, to assess differences due to conventional (I1); integration of animal manure, chemical fertilizers and plant growth-promoting rhizobacteria (I2), and organic treatments, traditional farmer practice comprised animal manure @ 15 t·ha−1 and ash @ 2 t·ha−1 (O1); use of animal manure @ 10 t·ha−1, green manure @ 10–15 t·ha−1, neem cake @ 1 t·ha−1 and ash @ 2 t·ha−1 (O2), and organic + plant growth- promoting rhizobacteria as above, but instead of ash the bacterium Azospirillum, and a P and K solubilizer @ 3 kg∙ha−1 (O3) were examined for effects on productivity, tuber quality, soil productivity,and economics of production of Chinese potato. Organic management improved biomass partitioning to tubers, harvest index, higher pH ( + 1.14, + 0.23 unit), organic C ( + 15%, + 21.33%), available N and P, tuber K, P and Zn uptake over conventional and integrated practices, respectively. Tuber yield, gross income (avg. US$7777.13∙ha−1), and profit (avg. US$5721.80∙ha−1), were unaffected. Organic production may be an alternative for Chinese potato with responses equal to conventional production while possibly delivering improved soil health.Not Availabl

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Not AvailableA study was carried out to test the SIMCAS (growth simulation model for cassava) model over major cassava-growing regions in India with different agro-climatic conditions to understand the wider acceptability of this model. The study locations included the major growing areas of cassava in India, viz. Thiruvananthapuram, Salem, Navsari, Ratnagiri, and West Godavari. Two varieties, H-226 (long-duration) and Sree Vijaya (short-duration), were used to validate this model. The crop growth parameters for calibrating the model were derived by conducting field experiments at the five locations under the All India Coordinated Research Project on Tuber Crops. The model verification score and agreement index during yield simulation in the case of H-226 and Sree Vijaya were ranged from 0.69 to 0.99 and from 0.52 to 0.59, respectively. The values of normalized objective function (0.10–0.26) and normalized root mean square error (excellent to fair simulations) also showed the reliability of the model simulations with the field observations. Based on the model performance, this study recommended the wider applicability of SIMCAS for simulating cassava yield irrespective of the agro-climatic conditions.Not Availabl