A field experiment was conducted during 2012–13 and 2013–14 at Bhubaneswar, Odisha to study the effects of intercrop and drip irrigation on growth, corm yield, water-use efficiency as well as economics of production of elephant foot yam [Amorphophallus paeoniifolius (Dennst.) Nicolson]. The experiment was laid out in split plot design with 5 replications, keeping elephant foot yam + green gram and elephant foot yam sole crop in the main plots and surface irrigation, drip irrigation at 100% cumulative pan evaporation (CPE), drip irrigation at 80% CPE and drip irrigation at 60% CPE in the sub-plots. The results revealed that, drip irrigation at 60–80% CPE resulted in higher green gram seed yield (630 kg/ha). Elephant foot yam + green gram intercropping system recorded better growth, yield attributes and yield than sole elephant foot yam. Drip irrigation at 100% and 80% CPE realized better growth, yield attributes and yield compared to other treatments. Surface irrigation resulted in higher consumptive use of water (204 cm) than drip irrigation (50, 41 and 30 cm at 100, 80 and 60 CPE respectively). The highest water-use efficiency was noticed in elephant foot yam + green gram intercropping with drip irrigation at 60% CPE (1080 kg/ha-cm). The highest net returns was recorded with elephant foot yam + green gram intercropping with drip irrigation at 100% CPE (309 × 103 /ha), which was statistically at par with elephant foot yam + green gram intercropping with drip irrigation at 80% CPE (307 × 103 /ha). Thus, elephant foot yam and green gram can be grown as an intercrop profitably with application of drip irrigation at 80% CPE to harvest greater yield and realize more returns.

Greater yam being a commercial tuber crop in Odisha state occupying a prominent place in food basket, the importance of meeting the planting material demand of the farmers, was realized by the ICAR-Central Tuber Crops Research Institute and initiated mass efforts to multiply the high-yielding and disease-resistant varieties of yam to supply to farmers as quality planting materials.. As the farmers’ willingness to pay for the planting material depends on their assessment of the utility of each attribute of it, a research investigation was carried out in Odisha to estimate the utility value of each yam planting material attribute from the farmers’ perspective. The utility values for each planting material attribute were estimated through a choice-based conjoint analysis. Results indicated that yield had the highest utility level (30 t/ha = 5.20 and 25 t/ha = 2.60), followed by planting material price (Rs. 30/kg = 1.147) and culinary quality (excellent quality = 0.794). The marginal WTP for the yield 30 t/ha versus 25 t/ha was Rs 4.54/kg. It clearly shows that the farmers were willing to pay an additional amount of Rs 4.54/kg for a quality yam planting material that gave a higher yield than their variety.

An experiment was laid out in split-plot design with three replications. Main and sub plots consisted of drip irrigation [I1- at 80% of cumulative pan evaporation (CPE) during 1-270 days after planting (DAP), I2-at 100% of CPE during 1-90 DAP + at 80% of CPE during 91-270 DAP and I3-at 100% of CPE during 1-270 DAP] and fertigation (F1-N-P2O5-K2O 100-90-100 kg/ha, F2-N-P2O5-K2O 120-90-120 kg/ha, F3-N-P2O5-K2O 140-90-140 kg/ha and F4- N-P2O5-K2O 160-90-160 kg/ha) treatments respectively. The drip irrigation treatments I1(F2) and I2(F2) saved 17.3% (690 m3/ha) and 7.8% (310 m3/ha) irrigated water over surface flood irrigation at same level of fertilizer application (N-P2O5-K2O 120-90-120 kg/ha) (check). Electricity consumption saved 104 (17.4%) and 47 (7.9%) kWh/ha by adopting drip irrigation levels I1(F2) and I2(F2), respectively over check. The system productivity with the application of N-P2O5-K2O 100-90-100 kg/ha (F1) along with drip irrigation at I2 was comparable with check which indicated a net saving of N-K2O 20-20 kg/ha. The net income from drip irrigated greater yam (Dioscorea alata L.) + maize (Zea mays L.) under I1(F2) and I2(F2) was about 9 100 and 62 100 ₹/ha higher than the crop cultivated with surface flood irrigation (check), respectively. Greater system productivity in the treatments I2F4 (31.8%) and I2F3 (29.9%) over check indicated fertilizer responsiveness under drip fertigation. Considering environmental and economical impact, the partial deficit drip irrigation and fertigation treatment I2F3 could be the best for greater yam+maize intercropping system.

stripped mealybug (Ferrisia virgata Cockerrel) was first noticed infesting on yam bean (Pachyrrhizus erosus (L) Urban) seed crop at the Regional Centre of Central Tuber Crops Research Institute, Bhubaneswar, Odisha, India.Analyses of weather data revealed that higher maximum and lower minimum temperatures coupled with wide diurnal variation of temperature from October to December during the year 2011 compared to decennial mean was observed.Further, a sharp decline in mean relative humidity and rainfall was observed between October and December during 2011 compared to decennial mean.It was observed 38.3% yam bean seed yield loss due to stripped mealybug infestation.

A field experiment was conducted during 2013 and 2014 at the Regional Centre of ICAR-Central Tuber Crops Research Institute, Dumuduma, Bhubaneswar, Odisha to study the drip fertigation effects on quality characters of elephant foot yam [Amorphophallus paeoniifolius (Dennst.) Nicolson] and water use efficiency of elephant foot yam+green gram (Vigna radiata L.) intercropping system. The experiment was laid out in randomized block design with four replications. The experiment consisted of six treatments i.e. T1-Soil application of fertilizers N-K2O @ 100-100 kg ha-1, T2-Fertigation of N-K2O @ 60-60 kg ha-1, T3-Fertigation of N-K2O @ 80-80 kg ha-1, T4-Fertigation of N-K2O @ 100-100 kg ha-1, T5-Fertigation of N-K2O @ 120-120 kg ha-1 and T6-Fertigation of N-K2O @ 140-140 kg ha-1. During the final land preparation FYM @ 10 t ha-1 was applied along with P2O5 @ 80 kg ha-1 as single super phosphate (SSP), borax @ 10 kg ha-1 and zinc sulphate @ 10 kg ha-1 in all the treatments. The result revealed that increasing fertigation level increased nutritional status. Greater amount of protein, sugar, starch and mineral nutrient yields were noticed in the treatment T6 followed by T5 during both the years of study. The system productivity and water use efficiency were also greater in treatment T6. However the difference between T6 and T5 was negligible during both the years of study. Thus, the treatment fertigation of N-K2O @ 120-120 kg ha-1 (T5) was found optimum for elephant foot yam+green gram intercropping system.

An investigation was carried out during 2013–14 at the research farm of ICAR-Central Tuber Crops Research Institute, Dumuduma, Bhubaneswar, Odisha to study the effects of fertigation on elephant foot yam [Amorphophallus paeoniifolius (Dennst.) Nicolson]+greengram (Vigna radiata L.) intercropping system. The result revealed that the number of pods/plant, seed and haulm yield of greengram were greater in fertigation treatments than soil application. However, greengram responded to fertigation up to N-K2O @80–80 kg/ha. The elephant foot yam corm yield increased with fertigation up to N-K2O @140–140 kg/ha. The corm yield of elephant foot yam and corm equivalent yield of elephant foot yam+greengram intercropping system with fertigation of N-K2O @100–100 kg/ha was comparable with N-K2O @140–140 kg/ha. The fertigation of N-K2O @100–100 kg/ha resulted in increase of 20.1–22.4% corm yield, 19.8–22.3% corm equivalent yield and 19.9–24.4% nutrient use efficiency over soil application of the same quantity of nutrients. The fertigation of elephant foot yam+greengram intercropping system with N-K2O @100–100 kg/ha also resulted in 26.7–28.7% greater net return and higher benefit: cost ratio over soil application of the same quantity of nutrients. The study indicated that fertigation of N-K2O @100–100 kg/ha was sufficient for obtaining optimum yield, returns and nutrient use efficiency in elephant foot yam+greengram intercropping system.

Root and tuber crops are important food crops that are climate resilient. Crop interventions involving tuber crops aimed at improving the livelihood security were demonstrated in the disadvantaged districts (Kandhamal, Kalahandi and Dhenkanal) of Odisha. Greater yam (var. Orissa Elite) produced average tuber yield of 24.3 t ha-1 with a net income of ` 5698 per household (200 m2 demonstration). Elephant foot yam (var. Gajendra) yielded 35.0 t ha-1 with a net income of ` 4600 per household (100 m2 demonstration). Orange-fleshed sweet potato variety ST-14 that contained 14 mg of βcarotene per 100 g fresh weight of tubers performed well in both the years in all the three districts. The average productivity of ST-14 was 10.5 t ha-1, which was lesser than white-fleshed sweet potato variety Kishan. Cassava performed well in all the demonstrations during both the years. But lack of awareness about the food value and utilization of cassava tubers were observed to be the major hindrance in its popularization. Greater yam + maize intercropping produced 24.0 tonnes of tubers + 22500 cobs ha-1. The average net income of this system was ` 4691 per household. Maize in this system not only provided additional yield but also acted as a live stake. Proximate composition of greater yam, elephant foot yam and sweet potato tubers were analyzed in terms of protein, fat, minerals, fibre and carbohydrates and are discussed in this paper. Improved varieties and production techniques offered good scope in improving the livelihood and nutritional security of rainfed farmers in the disadvantaged districts of Odisha.

Tropical tuber crops play a significant role in the food and nutritional security to the human being. Tuber crops are classified as the third most important food crop for man after cereals and grain legumes. The major tropical tuber crops include cassava, elephant foot yam, sweet potato, yams and aroids. Sound water management has the potential to improve fertilizer/nutrient use efficiency. The introduction of well-tested, efficient fertilizer application through irrigation water or “fertigation” techniques could help turn vast areas of arid and semi-arid land in many parts of the world into farmland, as well as preventing water from being wasted in conventional irrigation systems. Drip irrigation has the greatest potential for the efficient use of water and fertilizers. The limited area of wetting under trickle· irrigation reduces the active root zone and also the foraging area of plants to draw water and nutrients from the soil. For minimizing the cost of irrigation and fertilizers, adoption of drip irrigation with fertigation is essential which will maximize the nutrient uptake, while using minimum amount of water and fertilizer. Fertigation gives advantages such as higher use efficiency of water and fertilizer, minimum losses of N due to leaching, supplying nutrients directly to root zone in available forms, control of nutrient concentration in soil solution and saving in application cost. Thus, fertigation becomes prerogative for increasing the yield of most of the crops under drip irrigation. In this paper, the literatures pertaining to the different aspects of fertigation are reviewed. Fertigation in High Value Tuber Crops A Review S. K. Jata, M. Nedunchezhiyan, Tapas Ranjan Sahoo and Viswanath Sahoo

Elephant foot yam (  Amorphophallus paeoniifolius (Dennst.) Nicolson) is a popular tropical tuber crop grown for its starchy corms. It is propagated through both corms and cormels. A field experiment followed by post-harvest study was conducted during 2008-2010 at Regional Centre of Central Tuber Crops Research Institute, Dumuduma, Bhubaneswar, India, to find out the effect of growth regulators on cormel production, dormancy breaking and sprout growth. The results revealed that pre-harvest foliar spraying (at 5 and 6 MAP) followed by post-harvest application (soaking the corms for 30 min) of thiourea 200 ppm reduced corm dormancy by 21 days and increased the sprout growth. Pre-harvest application of potassium nitrate 200 ppm was found to be effective in inducing cormels. This growth regulator can be tried in cormel producing varieties for better cormel production.

Sweet potato is a staple food in several tropical countries. It is one of the world’s highest yielding crops with the total food production per unit area exceeding that of rice and having greater food value. It is an important food crop in tropical and sub-tropical countries and grown in large scale in Mexico, Central America, South America, Mediterranean regions of Europe, Africa, India, China, Japan, South East Asia, East Indies and the Pacific Islands. It is a major source of carbohydrate for millions of people, especially in developing countries. The plant is grown for its edible tuberous roots that contain about 27% carbohydrate and high concentrations of Vitamin A Vitamin C, Calcium and Iron. Fresh sweet potatoes provide about 50% more calories than Irish potatoes. The leaves is used as leaf vegetable as well as good fodder value and much more industrial value. Sweet potatoes are packed with nutrition. They are a great source of minerals such as manganese, folate, copper, and iron. The darker-coloured variety is a great source of The Triple ‘f’ (food, fodder and fuel) Crop Sweet Potato [Ipomoea batatas (L.) Lam.]

A pot culture experiment on vermicomposting of cassava and sweet potato wastes/byproducts was conducted for March–May (season I) and June–August (season II) during 2010 at the Regional Centre of Central Tuber Crops Research Institute, Bhubaneswar, Orissa. The study revealed that the vermicompost prepared from biomass and byproducts of tuber crops had fairly higher levels of nitrogen (1.12–2.23%), phosphorus (0.26–0.88%), and potassium (0.33–1.29%) compared to initial status. The vermicompost prepared from sweet potato dry leaves had the highest nitrogen (2.23% and 2.03%), phosphorus (0.88% and 0.69%), and potassium (1.29% and 0.84%) content during both the years of study. Cassava thippi (tuber residue) required 40–43 days for the complete conversion into vermicompost, whereas all other biomass and byproducts needed more time (43–65 days). The rate of increase of earthworm weight and population was higher in vermicompost made from cassava and sweet potato thippi. Microbial counts indicated that populations of bacteria and fungi were higher in season I, whereas actinomycetes were higher in season II. The study indicated that all the biomass and byproducts of tuber crops can be effectively converted into high-value vermicompost.

SUMMARY Amorphophallus paeoniifolius, popularly known as elephant foot yam, is an important tropical tuber crop in India. Its modified stem (corm) is consumed as a vegetable after boiling, baking or frying. Mealybug (Rhizoecus amorphophalli), a soft-bodied insect, infests the corms both in storage and in the field. Though pesticides are effective in controlling mealybugs, they can be hazardous to human health and the environment. Two experiments, one in storage followed by one in the field, were conducted during 2009 and 2010 at the Regional Centre of Central Tuber Crops Research Institute, Dumuduma, Bhubaneswar, India, to determine the effect of six low cost and environmentally safe management practices on mealybug. In the absence of mealybug control measures, mealybug numbers increased by 4–5 times during the storage period. The pest affected the quality of the corms and reduced subsequent field establishment and crop growth. Salt (NaCl) solution (1000 ppm), cow urine, cow dung slurry (2 kg of cow dung in 1 litre of water) and clay slurry (1 kg of clay in 1 litre of water) treatments were effective in reducing mealybug numbers and the associated corm damage. However, availability of cow urine, cow dung and clay slurry limit their usage. Common salt is cheap, widely available and easy to use in treating the corms prior to storage. Relative to untreated corms, those treated with salt solution recorded greater emergence when field planted as well as producing plants with more vigorous growth.