JOURNAL OF ROOT CROPS

Climate resilient technologies for sustainable production of root and tuber crops

Thu, 09 May 2024 00:00:00 +0000

Root and tuber crops are mostly grown in uplands under rainfed conditions. Uncertain weather is the
major constraint in rainfed farming. Root and tuber crops are propagated vegetatively by using cut
tubers/stems/vines. The cut surface loses moisture quickly and is subjected to drying and decaying.
Being widely spaced long duration crops, weed menace at early stage and moisture stress at later stage
affect growth and development of tubers. Cowdung cap on cassava setts improved the sprouting and
establishes quickly under rainfed conditions. Storing sweet potato vine cuttings with intact leaves in
bundles under shade for two days prior to planting in the main field improved sprouting and establishes
quickly. Ridge height of 45 cm for sweet potato and broad bed and furrow system (20 cm height) for
elephant foot yam resulted in higher yield. Mulching in yams, elephant foot yam and taro conserved soil
moisture, improved sprouting and establishment, suppressed weeds and increased soil fertility apart
from increased tuber yield. Growing maize as intercrop in greater yam served as livestaking and added
organic matter into the soil apart from higher yield and return. Green gram intercropping in elephant
foot yam increased income and improved soil fertility. Grain or vegetable crops intercropping in taro
increased biological efficiency of the cropping system. Drip irrigation and fertigation in greater yam,
elephant foot yam and greater yam+maize intercropping system not only produced higher yield and
income but also saved water and nutrients. Thus, sustainable yield and income can be obtained by
following suitable climate resilient technologies.
Keywords: Cowdung slurry sett treatment, Drip irrigation, Fertigation, Intercropping, Mulching

Integrated nutrient management in tannia (Xanthosoma sagittifolium L. Schott): yield, plant nutrient concentration, plant uptake and soil chemical properties in an ultisol, Kerala

K. Susan John, R.T. Remya Raj — Thu, 09 May 2024 00:00:00 +0000

Tannia (Xanthosoma sagittifolium L. Schott) is an important tropical tuber crop under aroids usually grown
as an intercrop in plantations fetching good income. The leaves, corm and cormels are edible with
good nuetraceutical properties and high content of minerals especially K, Ca and Mg in leaves. An
Integrated Nutrient Management (INM) package was evolved for this crop involving dolomite as soil
amendment (@1 t ha-1) to correct sub soil acidity which usually hinders the growth and yield of the
crop along with FYM @ 25 t ha-1 as organic manure source and NPK @ 80:50:150 kg ha-1. By virtue
of the organic nature of the crop, the N requirement was substituted with green manuring in situ with
cowpea, neem cake and N efficient bio fertilizer to the extent of 75% and the remaining through urea.
The INM strategy developed could rectify the nutrient disorder with increased corm and cormel yields
to 12.821 and 12.863 t ha-1 over the existing adhoc recommendation of taro (FYM @ 12.5 t ha-1+
NPK @80:50:100 kg ha-1) where the cormel and corm yields were 6.37 and 5.86 t ha-1 respectively.
Though the plant dry weight percentages and plant nutrient contents were not affected, the leaf, corm
and cormel dry matter production as well as total plant uptake of nutrients were affected either by
levels of dolomite, levels of K or their interaction effect. However, drastic variation was noticed in the
plant nutrient contents and, in the corm, cormels and leaves, the N content was 1.446, 2.334, 2.40 %,
P content was0.493, 0.333, 0.333 %, K content was 0.226, 0.419, 2.368 %, Ca content was 0.356,
1.141, 1.029 %, Mg content was 0.079, 0.565, 2.492% and Mn content was 31.92, 40.83 and 147.5
ppm respectively. Levels of dolomite significantly affected the post harvest soil pH, soil available Ca and
Mg and levels of K affected soil pH and K and the interaction effect was significant in the case of pH
and K.
Keywords: Tannia, Cormel, Corm, PoP, INM, Nutrients

Phenotypic and biochemical characterisation of land races and variety (Chhattisgarh Tichkur-1) of East Indian arrowroot (Curcuma angustifolia, Roxb.)

P. Murugesan, Padmakshi Thakur, Deo Shankar, N. Krishna Radhika, A.N. Jyothi — Thu, 09 May 2024 00:00:00 +0000

East Indian arrowroot (Cucuma angustifolia) is widely cultivated in the tribal areas of Chhattisgarh,
Northeast and certain Southern pockets of India, as source of starch. In the present study, selected
eight accessions of land races of C. angustifolia along with its released variety and related species (C.
zedoaria) were characterised for phenotypic and biochemical traits for selecting desirable genetic
stocks. The East Indian arrowroot land races, variety and related species had morphological differences
in plant, leaf and rhizome traits. This study also has helped to distinguish land races from rest of East
Indian arrowroots and wild species. Investigation on quantitative characters and biochemical analysis
unveiled one land race (CTCRI-CA-PM-1) collected from Thiruvananthapuram district of Kerala which
showed superior performance in terms of lengthy primary rhizome (21.25 cm) coupled with highest
starch content (16.8%), rhizome yield per plant (709.8 g) and rhizome dry recovery (19.15%). Other
equally better promising genetic stocks selected from the present study are IGSJT-10-2 (IGKV-Variety
Chhattisgarh Tikhur-1) and IGDMT-10-1(landrace from Dhamtari, Chhattisgarh). Selected genetic
stocks along with other population will be further studied for molecular; biochemical and processing
properties for their effective utilisation. All the germplasm accessions are conserved at ICAR-CTCRI,
Thiruvananthapuram (NAGs centre), Kerala, India.
Keywords: East Indian arrowroot, PPV & FRA, DUS guidelines, starch and genetic stocks

Development and performance evaluation of a tractor operated Chinese potato harvester

T. Krishnakumar, M.S. Sajeev, C. Pradeepika, M. Velmurugan, C. Thangamani — Thu, 09 May 2024 00:00:00 +0000

Manual harvesting of Chinese potato tubers is labour intensive, time consuming and tedious. An average
of 100 female labourers and 20 male labourers are needed to harvest one acre of Chinese potato tubers.
To mitigate labour shortages and to reduce harvesting costs, a tractor operated prototype Chinese potato
harvester has been designed and developed to harvest the tubers grown in ridge and furrow system.
The harvester comprises of a main frame, digging system, discharge system, power transmission system
and transport system. It can cover three ridges with a spacing of 30 cm and a depth of operation of 15
cm. The performance evaluation of the developed unit was conducted, and the operational parameters
were standardized. The digging unit of the harvester was tested with different treatment combinations
of blade geometries viz., inverted V shape, crescent shape and straight type blade at different rake angles
of 15, 20 and 25° and at different forward operating speeds of 1.5, 2.0 and 2.5 km h-1. The effects due
to these parameters were optimized based on performances parameters viz., digging efficiency, per cent
damage and fuel consumption by numerical optimization technique. The maximum digging efficiency
of 97.28 per cent was noticed for inverted V type digging blade, whereas the lowest of 82.37 per cent
was obtained for straight shaped blade. The least percent damage of 3.42 per cent was for the inverted
V shape blade and the highest of 9.91 per cent was recorded for straight blade. Among the different
types of blade geometry, the maximum (6.24 l h-1) and minimum (4.75 l h-1) fuel consumptions were
obtained for straight blade and inverted V shape blade, respectively. The cost per hectare of harvesting
using the developed harvester was determined to be ` 18,400/- per hectare compared to ` 1,12,500/-
for harvesting manually, with a cost savings ` 94,100/- per hectare.
Keywords: Chinese potato, Harvester, Manual harvesting, Labour shortage, Mechanical harvesting

Water productivity and crop water production function of Taro (Colocasia esculenta L. Schott) under different irrigation regimes

S. Sunitha, J. Sreekumar — Thu, 09 May 2024 00:00:00 +0000

Field studies were conducted to assess the performance of upland taro (Colocasia esculenta L. Schott)
to varying levels of drip irrigation, furrow irrigation and rainfed conditions in terms of yield, water
productivity and to work out the crop water production function, during 2016-2019. Pooled analysis of
data collected for three seasons indicated that, drip irrigation at ETc 100% was optimum for achieving
maximum cormel yield (21.08 t ha-1) and was the most viable option compared to other unstressed
conditions for optimum water productivity (3.5 kg m-3). The field experimental data showed a quadratic
relation between crop water requirement and yield (R2 = 0.666). The derived crop water production
function (CWPF), Yield = -2.382 + 0.00652WR - 0.000047WR2 estimated the yield of 20.33 t ha-1 in
taro, corresponding to the simulated gross irrigation requirement of 695 mm under the humid tropical
conditions of Kerala, India. The information will support the farmers to develop irrigation plans in
advance during summer season, and for ensuring effective usage of irrigation water in water scarce areas.
Keywords: Cormel yield, Crop water production function, Drip irrigation, Taro, Water productivity

Synergistic effect of oil cakes and Trichoderma asperellum in the suppression of Sclerotium rolfsii

S.S. Veena, P. Neethu Krishna, S. Karthikeyan — Thu, 09 May 2024 00:00:00 +0000

Root and tuber crops are important as principal staple and nutritive foods for human beings. They are
mainly used as food, animal feed and in industries. The tropical tuber crops are susceptible to many
pathogens in field as well as in storage which lead to significant economic loss. Elephant foot yam (EFY)
(Amorphophallus paeoniifolius) is a highly preferred crop in tropical and sub-tropical regions due to its high
production potential (50–80 t ha-1), market acceptability and lucrative economic returns. In organic
cultivation of EFY, many growers practice incorporation of oil cakes to soil and use bio-agent, Trichoderma
to enhance crop health and to reduce collar rot incidence. Collar rot caused by Sclerotium rolfsii is the most
destructive and predominant disease, which causes significant crop loss. In the present study, oil cakes
of coconut, groundnut, neem, mustard and sesame were evaluated in sterile and unsterile conditions
for their ability to suppress S. rolfsii. The ability of oil cakes to support the growth and sporulation of
Trichoderma asperellum was also studied. All the oil cakes completely inhibited the growth of S. rolfsii.
When the concentration of oil cakes was reduced to 50% by diluting it with soil, sesame and groundnut
oil cakes could not arrest the mycelia growth. Except neem oil cake, pathogen suppression potential
of all other cakes was reduced upon sterilization. It varied from 39.53% (mustard oil cake) to 87.44%
(sesame oil cake). Under unsterile condition, mycelial growth of Trichoderma completely covered the
substrates, neem and groundnut oil cakes, which turned to green due to the sporulation. No growth was
observed in coconut oil cake while scanty growth without sporulation was noticed with mustard and
sesame oil cakes. Upon sterilization, mycelial growth of Trichoderma completely covered all the substrates
except coconut oil cake. Thus, neem oil cake is ideal for the organic cultivation of elephant foot yam
since it suppresses the pathogen as well as promotes growth and proliferation of Trichoderma.
Keywords: Elephant foot yam, Neem oil cake, Trichoderma, Sclerotium rolfsii, Mustard oil cake

Mealybug management in elephant foot yam corms during storage

Thu, 09 May 2024 00:00:00 +0000

In India, mealybug (Rhizoecus amorphophalli Betrem) is big menace during storage of elephant foot yam
corms and threatening elephant foot yam cultivation. A storage study was conducted to find out the
effects of various treatments on mealybug infestation on elephant foot yam corms during 2022 and
2023 at the Regional Centre of ICAR-Central Tuber Crops Research Institute, Bhubaneswar, Odisha
under AICRPTC. The treatment consists of : Imidacloprid 17.8 SL (0.6 ml l-1) (T1), Thiamethoxam 25
WG (0.6 g l-1) (T2), Salt (NaCl) solution @ 1000 ppm (T3), Neem oil:soap mixture @ (10:4) ml l-1
followed by Neem oil @ 15 ml L-1 after one week (T4), 1:1 combination of neem oil:soap mixture @
(10:4) ml l-1: Imidacloprid 17.8 SL (0.6 ml l-1) (T5), Cowdung slurry (2 kg l-1) (T6) and Control (T7).
The experiment was conducted in a randomized block design with three replications. During the year
2022, mealybug field infested corms were used for the study, whereas, during the year 2023, mealybug
field infestation was not found, hence, uninfested corms were used. The results revealed that during
the year 2022 at 3 months after storage, the treatment cowdung slurry (T6) was found very effective
in minimizing the mealybug numbers on the corms followed by the application of 1:1 combination of
neem oil : soap mixture @ (10:4) ml l-1: Imidacloprid 17.8 SL (0.6 ml l-1) (T5). Maximum number
of mealybug was found in the corms of control treatment (T7). During the year 2023, no mealybug
infestation was found in any of the treatments up to 2 months storage. However, at 3 months ofter
storage, mealybug infestation was noticed in control (T7) and application of salt (NaCl) solution @
1000 ppm (T3) treatments. Sprouting percentage 3 months after storage revealed that during the year
2022, the highest sprouting (96%) was noticed in cowdung slurry (T6) treatment followed by the
application of 1:1 combination of neem oil : soap mixture @ (10:4) ml l-1: Imidacloprid 17.8 SL (0.6
ml l-1) (T5) (92%). In control treatment (T7) only 10% sprouting was observed. During the year 2023,
100% sprouting was registered in all the treatments. Thus, mealybugs appearance and infestation are
depending upon the prevailing climate and its damaging effect is depends on duration of the infestation.
Keywords: Cowdung slurry, Elephant foot yam, Mealybug, Sprouting

Diagnosis and confirmation of subsoil acidity induced multi nutrient disorders in Tannia (Xanthosoma sagittifolium L. Schott) grown in an Ultisol, Kerala, India

K. Susan John, R.T. Remya Raj — Thu, 09 May 2024 00:00:00 +0000

Aroids are a group of tropical tuber crops which includes taro, tannia and elephant foot yam. Tannia
(Xanthosoma sagittifolium L. Schott) belonging to the family Araceae is considered as a remunerative
intercrop in the partial shaded conditions of plantations. The tubers, consisting of corm and cormels
as well as the leaves are edible, and have good nutraceutical properties, but many of them are yet to
unravel. The leaves are rich sources of phytochemicals and minerals like P, Ca and K. Being a shade
tolerant and acid sensitive crop, when it is grown in potentially acidic aluminium (Al) rich laterite soils,
they are prone to the occurrence of some nutritional disorders which was suspected as subsoil acidity
induced Mg, K and Ca deficiency. Experiments conducted in the nutrient omission pot trial gave the
inference of the same which was further confirmed through soil and plant analysis. More confirmation
on the occurrence of the antagonistic effect of excess K on the deficiency of Mg and Ca too was evolved
by conducting experiments in lysimeter tanks followed by the analysis of the soil filled in lysimeter tanks
and the symptomatic leaf samples. Though both experiments were done to confirm the susceptibility
of the crop to potential acidity manifested in the form of interveinal chlorosis, typical of Mg deficiency,
and associated K and Ca disorders. The growth and yield data of the crop recorded indicated the need
to replenish the soil with required quantities of nutrients viz., K, Ca and Mg at an application rate of
K2O @ 100 kg ha-1 along with lime@1 t ha-1 and MgSO4 @100 kg ha-1. Since acidity being the primary
cause and K being the crucial nutrient in affecting the yield, further experiments conducted revealed
dolomite as the best soil ameliorant @ 1 t ha-1 and K2O @ 150 kg ha-1.
Keywords: Tannia, Nutrient disorder, Subsoil acidity, Nutrient deficiency, Lysimeter